2022-08-20 13:33:14

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 00/33] dmaengine: at_hdmac: Fix concurrency bugs and then convert to virt-dma

Peter Rosin reported a memory corryption bug on Atmel SAMA5D31 that
happened under high CPU load and low memory resources. See:
https://lore.kernel.org/lkml/[email protected]/

The problem was two fold:
1/ The atmel nand driver uses dma_map_single() but failed to call its
dma_unmap_single() counterpart. As the DMA address space is a shared
resource, one could render the machine unusable by consuming all DMA
addresses. Also, failing to call dma_unmap_single translated to failing
to invalidate the data cache withing that specific region. Since SAMA5D3
uses VIPT (Virtually Indexed Physically Tagged) cache model, cache aliases
occured. The issue occurs when a physical memory page is mapped twice (or
more) in the virtual memory space. With VIPT models, the choice of the
cache line depends on the virtual address so even if two different virtual
addresses are mapped to point to the very same physical address, they may
use two different cache lines. Then dma_map_single() or dma_map_sg()
functions, only cleans / invalidates the data cache lines associated to
their virtual address argument. The cache lines used by the second virtual
memory address won't be cleaned / invalidated hence cache coherency issues
may occur. This was fixed at:
https://lore.kernel.org/linux-mtd/[email protected]/

2/ at_hdmac driver had poor list handling and concurrency bugs. We
experienced calling of the completion call twice for the same descriptor.

Fix all the concurrency bugs in at_hdmac driver and then convert the driver
to use virt-dma.

The series was tested with NAND (prep_dma_memcpy), MMC (prep_dma_slave_sg),
usart (cyclic mode), dmatest (memcpy, memset). All went fine. With the
conversion to virt-dma I replaced the election of a new transfer in the
tasklet with the election of the new transfer in the interrupt handler. We
should have a shorter idle window as we remove the scheduling latency of
the tasklet. Using mtd_speedtest showed similar performances when using
NAND with DMA.

There are other some cosmetic patches that could facelift this 13 years old
driver, but I'll let those for another series.

Tudor Ambarus (33):
dmaengine: at_hdmac: Keep register definitions and structures private
to at_hdmac.c
dmaengine: at_hdmac: Use bitfield access macros
dmaengine: at_hdmac: Rename "dma_common" to "dma_device"
dmaengine: at_hdmac: Rename "chan_common" to "dma_chan"
dmaengine: at_hdmac: Remove unused member of at_dma_chan
dmaengine: at_hdmac: Return dma_cookie_status()'s ret code when
txstate is NULL
dmaengine: at_hdmac: Fix at_lli struct definition
dmaengine: at_hdmac: Don't start transactions at tx_submit level
dmaengine: at_hdmac: Start transfer for cyclic channels in
issue_pending
dmaengine: at_hdmac: Fix premature completion of desc in issue_pending
dmaengine: at_hdmac: Do not call the complete callback on
device_terminate_all
dmaengine: at_hdmac: Protect atchan->status with the channel lock
dmaengine: at_hdmac: Fix concurrency problems by removing
atc_complete_all()
dmaengine: at_hdmac: Fix concurrency over descriptor
dmaengine: at_hdmac: Free the memset buf without holding the chan lock
dmaengine: at_hdmac: Fix concurrency over the active list
dmaengine: at_hdmac: Fix descriptor handling when issuing it to
hardware
dmaengine: at_hdmac: Fix completion of unissued descriptor in case of
errors
dmaengine: at_hdmac: Don't allow CPU to reorder channel enable
dmaengine: at_hdmac: Do not print messages on console while holding
the lock
dmaengine: at_hdmac: Fix impossible condition
dmaengine: at_hdmac: Pass residue by address to avoid unneccessary
implicit casts
dmaengine: at_hdmac: s/atc_get_bytes_left/atc_get_residue
dmaengine: at_hdmac: Introduce atc_get_llis_residue()
dmaengine: at_hdmac: Remove superfluous cast
dmaengine: at_hdmac: Use devm_kzalloc() and struct_size()
dmaengine: at_hdmac: Use devm_platform_ioremap_resource
dmaengine: at_hdmac: Use devm_request_irq()
dmaengine: at_hdmac: Use devm_clk_get()
dmaengine: at_hdmac: Check return code of dma_async_device_register
dmaengine: at_hdmac: Use pm_ptr()
dmaengine: at_hdmac: Set include entries in alphabetic order
dmaengine: at_hdmac: Convert driver to use virt-dma

MAINTAINERS | 1 -
drivers/dma/Kconfig | 1 +
drivers/dma/at_hdmac.c | 1901 ++++++++++++++++++-----------------
drivers/dma/at_hdmac_regs.h | 478 ---------
4 files changed, 985 insertions(+), 1396 deletions(-)
delete mode 100644 drivers/dma/at_hdmac_regs.h

--
2.25.1


2022-08-20 13:34:14

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 16/33] dmaengine: at_hdmac: Fix concurrency over the active list

The tasklet did not held the channel lock when retrieving the first active
descriptor, causing concurrency problems if issue_pending() was called in
between. If issue_pending() was called exactly after the lock was released
in the tasklet, atc_chain_complete() could complete a descriptor for which
the controller has not yet raised an interrupt.

Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <[email protected]>
Cc: [email protected]
Signed-off-by: Tudor Ambarus <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
---
drivers/dma/at_hdmac.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index c2b3d7b63920..635c3be74399 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -897,8 +897,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
if (!atc_chan_is_cyclic(atchan))
dma_cookie_complete(txd);

- /* Remove transfer node from the active list. */
- list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);

dma_descriptor_unmap(txd);
@@ -930,6 +928,7 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
*/
static void atc_advance_work(struct at_dma_chan *atchan)
{
+ struct at_desc *desc;
unsigned long flags;

dev_vdbg(chan2dev(&atchan->dma_chan), "advance_work\n");
@@ -937,9 +936,12 @@ static void atc_advance_work(struct at_dma_chan *atchan)
spin_lock_irqsave(&atchan->lock, flags);
if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
return spin_unlock_irqrestore(&atchan->lock, flags);
- spin_unlock_irqrestore(&atchan->lock, flags);

- atc_chain_complete(atchan, atc_first_active(atchan));
+ desc = atc_first_active(atchan);
+ /* Remove the transfer node from the active list. */
+ list_del_init(&desc->desc_node);
+ spin_unlock_irqrestore(&atchan->lock, flags);
+ atc_chain_complete(atchan, desc);

/* advance work */
spin_lock_irqsave(&atchan->lock, flags);
--
2.25.1

2022-08-20 13:34:31

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 10/33] dmaengine: at_hdmac: Fix premature completion of desc in issue_pending

Multiple calls to atc_issue_pending() could result in a premature
completion of a descriptor from the atchan->active list, as the method
always completed the first active descriptor from the list. Instead,
issue_pending() should just take the first transaction descriptor from the
pending queue, move it to active_list and start the transfer.

Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/lkml/[email protected]/
---
drivers/dma/at_hdmac.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index d9f492081e76..c445575f8646 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1963,16 +1963,26 @@ atc_tx_status(struct dma_chan *chan,
}

/**
- * atc_issue_pending - try to finish work
+ * atc_issue_pending - takes the first transaction descriptor in the pending
+ * queue and starts the transfer.
* @chan: target DMA channel
*/
static void atc_issue_pending(struct dma_chan *chan)
{
- struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_desc *desc;
+ unsigned long flags;

dev_vdbg(chan2dev(chan), "issue_pending\n");

- atc_advance_work(atchan);
+ spin_lock_irqsave(&atchan->lock, flags);
+ if (atc_chan_is_enabled(atchan) || list_empty(&atchan->queue))
+ return spin_unlock_irqrestore(&atchan->lock, flags);
+
+ desc = atc_first_queued(atchan);
+ list_move_tail(&desc->desc_node, &atchan->active_list);
+ atc_dostart(atchan, desc);
+ spin_unlock_irqrestore(&atchan->lock, flags);
}

/**
--
2.25.1

2022-08-20 13:35:54

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 01/33] dmaengine: at_hdmac: Keep register definitions and structures private to at_hdmac.c

Do not expose register definitions, structures and helpers via a .h file
because there are used only by at_hdmac.c. Since there are no other users,
remove the ambiguity and move all the .h contents to the .c file.

One may notice some checkpatch warnings and errors with this move. The move
was done "as it was", checkpatch complaints can be fixed in a further
patch.

Signed-off-by: Tudor Ambarus <[email protected]>
---
MAINTAINERS | 1 -
drivers/dma/at_hdmac.c | 457 +++++++++++++++++++++++++++++++++-
drivers/dma/at_hdmac_regs.h | 478 ------------------------------------
3 files changed, 456 insertions(+), 480 deletions(-)
delete mode 100644 drivers/dma/at_hdmac_regs.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 7f21b890187a..17765d5c04ca 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13092,7 +13092,6 @@ L: [email protected]
S: Supported
F: Documentation/devicetree/bindings/dma/atmel-dma.txt
F: drivers/dma/at_hdmac.c
-F: drivers/dma/at_hdmac_regs.h
F: drivers/dma/at_xdmac.c
F: include/dt-bindings/dma/at91.h

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 5a50423b7378..bcd67e12ca31 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -22,7 +22,6 @@
#include <linux/of_device.h>
#include <linux/of_dma.h>

-#include "at_hdmac_regs.h"
#include "dmaengine.h"

/*
@@ -34,6 +33,462 @@
* atc_ / atchan : ATmel DMA Channel entity related
*/

+#define AT_DMA_MAX_NR_CHANNELS 8
+
+#define AT_DMA_GCFG 0x00 /* Global Configuration Register */
+#define AT_DMA_IF_BIGEND(i) (0x1 << (i)) /* AHB-Lite Interface i in Big-endian mode */
+#define AT_DMA_ARB_CFG (0x1 << 4) /* Arbiter mode. */
+#define AT_DMA_ARB_CFG_FIXED (0x0 << 4)
+#define AT_DMA_ARB_CFG_ROUND_ROBIN (0x1 << 4)
+
+#define AT_DMA_EN 0x04 /* Controller Enable Register */
+#define AT_DMA_ENABLE (0x1 << 0)
+
+#define AT_DMA_SREQ 0x08 /* Software Single Request Register */
+#define AT_DMA_SSREQ(x) (0x1 << ((x) << 1)) /* Request a source single transfer on channel x */
+#define AT_DMA_DSREQ(x) (0x1 << (1 + ((x) << 1))) /* Request a destination single transfer on channel x */
+
+#define AT_DMA_CREQ 0x0C /* Software Chunk Transfer Request Register */
+#define AT_DMA_SCREQ(x) (0x1 << ((x) << 1)) /* Request a source chunk transfer on channel x */
+#define AT_DMA_DCREQ(x) (0x1 << (1 + ((x) << 1))) /* Request a destination chunk transfer on channel x */
+
+#define AT_DMA_LAST 0x10 /* Software Last Transfer Flag Register */
+#define AT_DMA_SLAST(x) (0x1 << ((x) << 1)) /* This src rq is last tx of buffer on channel x */
+#define AT_DMA_DLAST(x) (0x1 << (1 + ((x) << 1))) /* This dst rq is last tx of buffer on channel x */
+
+#define AT_DMA_SYNC 0x14 /* Request Synchronization Register */
+#define AT_DMA_SYR(h) (0x1 << (h)) /* Synchronize handshake line h */
+
+/* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */
+#define AT_DMA_EBCIER 0x18 /* Enable register */
+#define AT_DMA_EBCIDR 0x1C /* Disable register */
+#define AT_DMA_EBCIMR 0x20 /* Mask Register */
+#define AT_DMA_EBCISR 0x24 /* Status Register */
+#define AT_DMA_CBTC_OFFSET 8
+#define AT_DMA_ERR_OFFSET 16
+#define AT_DMA_BTC(x) (0x1 << (x))
+#define AT_DMA_CBTC(x) (0x1 << (AT_DMA_CBTC_OFFSET + (x)))
+#define AT_DMA_ERR(x) (0x1 << (AT_DMA_ERR_OFFSET + (x)))
+
+#define AT_DMA_CHER 0x28 /* Channel Handler Enable Register */
+#define AT_DMA_ENA(x) (0x1 << (x))
+#define AT_DMA_SUSP(x) (0x1 << ( 8 + (x)))
+#define AT_DMA_KEEP(x) (0x1 << (24 + (x)))
+
+#define AT_DMA_CHDR 0x2C /* Channel Handler Disable Register */
+#define AT_DMA_DIS(x) (0x1 << (x))
+#define AT_DMA_RES(x) (0x1 << ( 8 + (x)))
+
+#define AT_DMA_CHSR 0x30 /* Channel Handler Status Register */
+#define AT_DMA_EMPT(x) (0x1 << (16 + (x)))
+#define AT_DMA_STAL(x) (0x1 << (24 + (x)))
+
+#define AT_DMA_CH_REGS_BASE 0x3C /* Channel registers base address */
+#define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */
+
+/* Hardware register offset for each channel */
+#define ATC_SADDR_OFFSET 0x00 /* Source Address Register */
+#define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */
+#define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */
+#define ATC_CTRLA_OFFSET 0x0C /* Control A Register */
+#define ATC_CTRLB_OFFSET 0x10 /* Control B Register */
+#define ATC_CFG_OFFSET 0x14 /* Configuration Register */
+#define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */
+#define ATC_DPIP_OFFSET 0x1C /* Dst PIP Configuration Register */
+
+/* Bitfield definitions */
+/* Bitfields in DSCR */
+#define ATC_DSCR_IF(i) (0x3 & (i)) /* Dsc feched via AHB-Lite Interface i */
+
+/* Bitfields in CTRLA */
+#define ATC_BTSIZE_MAX 0xFFFFUL /* Maximum Buffer Transfer Size */
+#define ATC_BTSIZE(x) (ATC_BTSIZE_MAX & (x)) /* Buffer Transfer Size */
+#define ATC_SCSIZE_MASK (0x7 << 16) /* Source Chunk Transfer Size */
+#define ATC_SCSIZE(x) (ATC_SCSIZE_MASK & ((x) << 16))
+#define ATC_SCSIZE_1 (0x0 << 16)
+#define ATC_SCSIZE_4 (0x1 << 16)
+#define ATC_SCSIZE_8 (0x2 << 16)
+#define ATC_SCSIZE_16 (0x3 << 16)
+#define ATC_SCSIZE_32 (0x4 << 16)
+#define ATC_SCSIZE_64 (0x5 << 16)
+#define ATC_SCSIZE_128 (0x6 << 16)
+#define ATC_SCSIZE_256 (0x7 << 16)
+#define ATC_DCSIZE_MASK (0x7 << 20) /* Destination Chunk Transfer Size */
+#define ATC_DCSIZE(x) (ATC_DCSIZE_MASK & ((x) << 20))
+#define ATC_DCSIZE_1 (0x0 << 20)
+#define ATC_DCSIZE_4 (0x1 << 20)
+#define ATC_DCSIZE_8 (0x2 << 20)
+#define ATC_DCSIZE_16 (0x3 << 20)
+#define ATC_DCSIZE_32 (0x4 << 20)
+#define ATC_DCSIZE_64 (0x5 << 20)
+#define ATC_DCSIZE_128 (0x6 << 20)
+#define ATC_DCSIZE_256 (0x7 << 20)
+#define ATC_SRC_WIDTH_MASK (0x3 << 24) /* Source Single Transfer Size */
+#define ATC_SRC_WIDTH(x) ((x) << 24)
+#define ATC_SRC_WIDTH_BYTE (0x0 << 24)
+#define ATC_SRC_WIDTH_HALFWORD (0x1 << 24)
+#define ATC_SRC_WIDTH_WORD (0x2 << 24)
+#define ATC_REG_TO_SRC_WIDTH(r) (((r) >> 24) & 0x3)
+#define ATC_DST_WIDTH_MASK (0x3 << 28) /* Destination Single Transfer Size */
+#define ATC_DST_WIDTH(x) ((x) << 28)
+#define ATC_DST_WIDTH_BYTE (0x0 << 28)
+#define ATC_DST_WIDTH_HALFWORD (0x1 << 28)
+#define ATC_DST_WIDTH_WORD (0x2 << 28)
+#define ATC_DONE (0x1 << 31) /* Tx Done (only written back in descriptor) */
+
+/* Bitfields in CTRLB */
+#define ATC_SIF(i) (0x3 & (i)) /* Src tx done via AHB-Lite Interface i */
+#define ATC_DIF(i) ((0x3 & (i)) << 4) /* Dst tx done via AHB-Lite Interface i */
+ /* Specify AHB interfaces */
+#define AT_DMA_MEM_IF 0 /* interface 0 as memory interface */
+#define AT_DMA_PER_IF 1 /* interface 1 as peripheral interface */
+
+#define ATC_SRC_PIP (0x1 << 8) /* Source Picture-in-Picture enabled */
+#define ATC_DST_PIP (0x1 << 12) /* Destination Picture-in-Picture enabled */
+#define ATC_SRC_DSCR_DIS (0x1 << 16) /* Src Descriptor fetch disable */
+#define ATC_DST_DSCR_DIS (0x1 << 20) /* Dst Descriptor fetch disable */
+#define ATC_FC_MASK (0x7 << 21) /* Choose Flow Controller */
+#define ATC_FC_MEM2MEM (0x0 << 21) /* Mem-to-Mem (DMA) */
+#define ATC_FC_MEM2PER (0x1 << 21) /* Mem-to-Periph (DMA) */
+#define ATC_FC_PER2MEM (0x2 << 21) /* Periph-to-Mem (DMA) */
+#define ATC_FC_PER2PER (0x3 << 21) /* Periph-to-Periph (DMA) */
+#define ATC_FC_PER2MEM_PER (0x4 << 21) /* Periph-to-Mem (Peripheral) */
+#define ATC_FC_MEM2PER_PER (0x5 << 21) /* Mem-to-Periph (Peripheral) */
+#define ATC_FC_PER2PER_SRCPER (0x6 << 21) /* Periph-to-Periph (Src Peripheral) */
+#define ATC_FC_PER2PER_DSTPER (0x7 << 21) /* Periph-to-Periph (Dst Peripheral) */
+#define ATC_SRC_ADDR_MODE_MASK (0x3 << 24)
+#define ATC_SRC_ADDR_MODE_INCR (0x0 << 24) /* Incrementing Mode */
+#define ATC_SRC_ADDR_MODE_DECR (0x1 << 24) /* Decrementing Mode */
+#define ATC_SRC_ADDR_MODE_FIXED (0x2 << 24) /* Fixed Mode */
+#define ATC_DST_ADDR_MODE_MASK (0x3 << 28)
+#define ATC_DST_ADDR_MODE_INCR (0x0 << 28) /* Incrementing Mode */
+#define ATC_DST_ADDR_MODE_DECR (0x1 << 28) /* Decrementing Mode */
+#define ATC_DST_ADDR_MODE_FIXED (0x2 << 28) /* Fixed Mode */
+#define ATC_IEN (0x1 << 30) /* BTC interrupt enable (active low) */
+#define ATC_AUTO (0x1 << 31) /* Auto multiple buffer tx enable */
+
+/* Bitfields in CFG */
+#define ATC_PER_MSB(h) ((0x30U & (h)) >> 4) /* Extract most significant bits of a handshaking identifier */
+
+#define ATC_SRC_PER(h) (0xFU & (h)) /* Channel src rq associated with periph handshaking ifc h */
+#define ATC_DST_PER(h) ((0xFU & (h)) << 4) /* Channel dst rq associated with periph handshaking ifc h */
+#define ATC_SRC_REP (0x1 << 8) /* Source Replay Mod */
+#define ATC_SRC_H2SEL (0x1 << 9) /* Source Handshaking Mod */
+#define ATC_SRC_H2SEL_SW (0x0 << 9)
+#define ATC_SRC_H2SEL_HW (0x1 << 9)
+#define ATC_SRC_PER_MSB(h) (ATC_PER_MSB(h) << 10) /* Channel src rq (most significant bits) */
+#define ATC_DST_REP (0x1 << 12) /* Destination Replay Mod */
+#define ATC_DST_H2SEL (0x1 << 13) /* Destination Handshaking Mod */
+#define ATC_DST_H2SEL_SW (0x0 << 13)
+#define ATC_DST_H2SEL_HW (0x1 << 13)
+#define ATC_DST_PER_MSB(h) (ATC_PER_MSB(h) << 14) /* Channel dst rq (most significant bits) */
+#define ATC_SOD (0x1 << 16) /* Stop On Done */
+#define ATC_LOCK_IF (0x1 << 20) /* Interface Lock */
+#define ATC_LOCK_B (0x1 << 21) /* AHB Bus Lock */
+#define ATC_LOCK_IF_L (0x1 << 22) /* Master Interface Arbiter Lock */
+#define ATC_LOCK_IF_L_CHUNK (0x0 << 22)
+#define ATC_LOCK_IF_L_BUFFER (0x1 << 22)
+#define ATC_AHB_PROT_MASK (0x7 << 24) /* AHB Protection */
+#define ATC_FIFOCFG_MASK (0x3 << 28) /* FIFO Request Configuration */
+#define ATC_FIFOCFG_LARGESTBURST (0x0 << 28)
+#define ATC_FIFOCFG_HALFFIFO (0x1 << 28)
+#define ATC_FIFOCFG_ENOUGHSPACE (0x2 << 28)
+
+/* Bitfields in SPIP */
+#define ATC_SPIP_HOLE(x) (0xFFFFU & (x))
+#define ATC_SPIP_BOUNDARY(x) ((0x3FF & (x)) << 16)
+
+/* Bitfields in DPIP */
+#define ATC_DPIP_HOLE(x) (0xFFFFU & (x))
+#define ATC_DPIP_BOUNDARY(x) ((0x3FF & (x)) << 16)
+
+/*-- descriptors -----------------------------------------------------*/
+
+/* LLI == Linked List Item; aka DMA buffer descriptor */
+struct at_lli {
+ /* values that are not changed by hardware */
+ dma_addr_t saddr;
+ dma_addr_t daddr;
+ /* value that may get written back: */
+ u32 ctrla;
+ /* more values that are not changed by hardware */
+ u32 ctrlb;
+ dma_addr_t dscr; /* chain to next lli */
+};
+
+/**
+ * struct at_desc - software descriptor
+ * @at_lli: hardware lli structure
+ * @txd: support for the async_tx api
+ * @desc_node: node on the channed descriptors list
+ * @len: descriptor byte count
+ * @total_len: total transaction byte count
+ */
+struct at_desc {
+ /* FIRST values the hardware uses */
+ struct at_lli lli;
+
+ /* THEN values for driver housekeeping */
+ struct list_head tx_list;
+ struct dma_async_tx_descriptor txd;
+ struct list_head desc_node;
+ size_t len;
+ size_t total_len;
+
+ /* Interleaved data */
+ size_t boundary;
+ size_t dst_hole;
+ size_t src_hole;
+
+ /* Memset temporary buffer */
+ bool memset_buffer;
+ dma_addr_t memset_paddr;
+ int *memset_vaddr;
+};
+
+static inline struct at_desc *
+txd_to_at_desc(struct dma_async_tx_descriptor *txd)
+{
+ return container_of(txd, struct at_desc, txd);
+}
+
+/*-- Channels --------------------------------------------------------*/
+/**
+ * atc_status - information bits stored in channel status flag
+ *
+ * Manipulated with atomic operations.
+ */
+enum atc_status {
+ ATC_IS_ERROR = 0,
+ ATC_IS_PAUSED = 1,
+ ATC_IS_CYCLIC = 24,
+};
+
+/**
+ * struct at_dma_chan - internal representation of an Atmel HDMAC channel
+ * @chan_common: common dmaengine channel object members
+ * @device: parent device
+ * @ch_regs: memory mapped register base
+ * @mask: channel index in a mask
+ * @per_if: peripheral interface
+ * @mem_if: memory interface
+ * @status: transmit status information from irq/prep* functions
+ * to tasklet (use atomic operations)
+ * @tasklet: bottom half to finish transaction work
+ * @save_cfg: configuration register that is saved on suspend/resume cycle
+ * @save_dscr: for cyclic operations, preserve next descriptor address in
+ * the cyclic list on suspend/resume cycle
+ * @dma_sconfig: configuration for slave transfers, passed via
+ * .device_config
+ * @lock: serializes enqueue/dequeue operations to descriptors lists
+ * @active_list: list of descriptors dmaengine is being running on
+ * @queue: list of descriptors ready to be submitted to engine
+ * @free_list: list of descriptors usable by the channel
+ */
+struct at_dma_chan {
+ struct dma_chan chan_common;
+ struct at_dma *device;
+ void __iomem *ch_regs;
+ u8 mask;
+ u8 per_if;
+ u8 mem_if;
+ unsigned long status;
+ struct tasklet_struct tasklet;
+ u32 save_cfg;
+ u32 save_dscr;
+ struct dma_slave_config dma_sconfig;
+
+ spinlock_t lock;
+
+ /* these other elements are all protected by lock */
+ struct list_head active_list;
+ struct list_head queue;
+ struct list_head free_list;
+};
+
+#define channel_readl(atchan, name) \
+ __raw_readl((atchan)->ch_regs + ATC_##name##_OFFSET)
+
+#define channel_writel(atchan, name, val) \
+ __raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET)
+
+static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
+{
+ return container_of(dchan, struct at_dma_chan, chan_common);
+}
+
+/*
+ * Fix sconfig's burst size according to at_hdmac. We need to convert them as:
+ * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7.
+ *
+ * This can be done by finding most significant bit set.
+ */
+static inline void convert_burst(u32 *maxburst)
+{
+ if (*maxburst > 1)
+ *maxburst = fls(*maxburst) - 2;
+ else
+ *maxburst = 0;
+}
+
+/*
+ * Fix sconfig's bus width according to at_hdmac.
+ * 1 byte -> 0, 2 bytes -> 1, 4 bytes -> 2.
+ */
+static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
+{
+ switch (addr_width) {
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ return 1;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ return 2;
+ default:
+ /* For 1 byte width or fallback */
+ return 0;
+ }
+}
+
+/*-- Controller ------------------------------------------------------*/
+/**
+ * struct at_dma - internal representation of an Atmel HDMA Controller
+ * @chan_common: common dmaengine dma_device object members
+ * @atdma_devtype: identifier of DMA controller compatibility
+ * @ch_regs: memory mapped register base
+ * @clk: dma controller clock
+ * @save_imr: interrupt mask register that is saved on suspend/resume cycle
+ * @all_chan_mask: all channels availlable in a mask
+ * @dma_desc_pool: base of DMA descriptor region (DMA address)
+ * @chan: channels table to store at_dma_chan structures
+ */
+struct at_dma {
+ struct dma_device dma_common;
+ void __iomem *regs;
+ struct clk *clk;
+ u32 save_imr;
+
+ u8 all_chan_mask;
+
+ struct dma_pool *dma_desc_pool;
+ struct dma_pool *memset_pool;
+ /* AT THE END channels table */
+ struct at_dma_chan chan[];
+};
+
+#define dma_readl(atdma, name) \
+ __raw_readl((atdma)->regs + AT_DMA_##name)
+#define dma_writel(atdma, name, val) \
+ __raw_writel((val), (atdma)->regs + AT_DMA_##name)
+
+static inline struct at_dma *to_at_dma(struct dma_device *ddev)
+{
+ return container_of(ddev, struct at_dma, dma_common);
+}
+
+/*-- Helper functions ------------------------------------------------*/
+static struct device *chan2dev(struct dma_chan *chan)
+{
+ return &chan->dev->device;
+}
+
+#if defined(VERBOSE_DEBUG)
+static void vdbg_dump_regs(struct at_dma_chan *atchan)
+{
+ struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
+
+ dev_err(chan2dev(&atchan->chan_common),
+ " channel %d : imr = 0x%x, chsr = 0x%x\n",
+ atchan->chan_common.chan_id,
+ dma_readl(atdma, EBCIMR),
+ dma_readl(atdma, CHSR));
+
+ dev_err(chan2dev(&atchan->chan_common),
+ " channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n",
+ channel_readl(atchan, SADDR),
+ channel_readl(atchan, DADDR),
+ channel_readl(atchan, CTRLA),
+ channel_readl(atchan, CTRLB),
+ channel_readl(atchan, CFG),
+ channel_readl(atchan, DSCR));
+}
+#else
+static void vdbg_dump_regs(struct at_dma_chan *atchan) {}
+#endif
+
+static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli)
+{
+ dev_crit(chan2dev(&atchan->chan_common),
+ "desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n",
+ &lli->saddr, &lli->daddr,
+ lli->ctrla, lli->ctrlb, &lli->dscr);
+}
+
+static void atc_setup_irq(struct at_dma *atdma, int chan_id, int on)
+{
+ u32 ebci;
+
+ /* enable interrupts on buffer transfer completion & error */
+ ebci = AT_DMA_BTC(chan_id)
+ | AT_DMA_ERR(chan_id);
+ if (on)
+ dma_writel(atdma, EBCIER, ebci);
+ else
+ dma_writel(atdma, EBCIDR, ebci);
+}
+
+static void atc_enable_chan_irq(struct at_dma *atdma, int chan_id)
+{
+ atc_setup_irq(atdma, chan_id, 1);
+}
+
+static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id)
+{
+ atc_setup_irq(atdma, chan_id, 0);
+}
+
+/**
+ * atc_chan_is_enabled - test if given channel is enabled
+ * @atchan: channel we want to test status
+ */
+static inline int atc_chan_is_enabled(struct at_dma_chan *atchan)
+{
+ struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
+
+ return !!(dma_readl(atdma, CHSR) & atchan->mask);
+}
+
+/**
+ * atc_chan_is_paused - test channel pause/resume status
+ * @atchan: channel we want to test status
+ */
+static inline int atc_chan_is_paused(struct at_dma_chan *atchan)
+{
+ return test_bit(ATC_IS_PAUSED, &atchan->status);
+}
+
+/**
+ * atc_chan_is_cyclic - test if given channel has cyclic property set
+ * @atchan: channel we want to test status
+ */
+static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan)
+{
+ return test_bit(ATC_IS_CYCLIC, &atchan->status);
+}
+
+/**
+ * set_desc_eol - set end-of-link to descriptor so it will end transfer
+ * @desc: descriptor, signle or at the end of a chain, to end chain on
+ */
+static void set_desc_eol(struct at_desc *desc)
+{
+ u32 ctrlb = desc->lli.ctrlb;
+
+ ctrlb &= ~ATC_IEN;
+ ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS;
+
+ desc->lli.ctrlb = ctrlb;
+ desc->lli.dscr = 0;
+}
+
#define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO)
#define ATC_DEFAULT_CTRLB (ATC_SIF(AT_DMA_MEM_IF) \
|ATC_DIF(AT_DMA_MEM_IF))
diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
deleted file mode 100644
index 4d1ebc040031..000000000000
--- a/drivers/dma/at_hdmac_regs.h
+++ /dev/null
@@ -1,478 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Header file for the Atmel AHB DMA Controller driver
- *
- * Copyright (C) 2008 Atmel Corporation
- */
-#ifndef AT_HDMAC_REGS_H
-#define AT_HDMAC_REGS_H
-
-#define AT_DMA_MAX_NR_CHANNELS 8
-
-
-#define AT_DMA_GCFG 0x00 /* Global Configuration Register */
-#define AT_DMA_IF_BIGEND(i) (0x1 << (i)) /* AHB-Lite Interface i in Big-endian mode */
-#define AT_DMA_ARB_CFG (0x1 << 4) /* Arbiter mode. */
-#define AT_DMA_ARB_CFG_FIXED (0x0 << 4)
-#define AT_DMA_ARB_CFG_ROUND_ROBIN (0x1 << 4)
-
-#define AT_DMA_EN 0x04 /* Controller Enable Register */
-#define AT_DMA_ENABLE (0x1 << 0)
-
-#define AT_DMA_SREQ 0x08 /* Software Single Request Register */
-#define AT_DMA_SSREQ(x) (0x1 << ((x) << 1)) /* Request a source single transfer on channel x */
-#define AT_DMA_DSREQ(x) (0x1 << (1 + ((x) << 1))) /* Request a destination single transfer on channel x */
-
-#define AT_DMA_CREQ 0x0C /* Software Chunk Transfer Request Register */
-#define AT_DMA_SCREQ(x) (0x1 << ((x) << 1)) /* Request a source chunk transfer on channel x */
-#define AT_DMA_DCREQ(x) (0x1 << (1 + ((x) << 1))) /* Request a destination chunk transfer on channel x */
-
-#define AT_DMA_LAST 0x10 /* Software Last Transfer Flag Register */
-#define AT_DMA_SLAST(x) (0x1 << ((x) << 1)) /* This src rq is last tx of buffer on channel x */
-#define AT_DMA_DLAST(x) (0x1 << (1 + ((x) << 1))) /* This dst rq is last tx of buffer on channel x */
-
-#define AT_DMA_SYNC 0x14 /* Request Synchronization Register */
-#define AT_DMA_SYR(h) (0x1 << (h)) /* Synchronize handshake line h */
-
-/* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */
-#define AT_DMA_EBCIER 0x18 /* Enable register */
-#define AT_DMA_EBCIDR 0x1C /* Disable register */
-#define AT_DMA_EBCIMR 0x20 /* Mask Register */
-#define AT_DMA_EBCISR 0x24 /* Status Register */
-#define AT_DMA_CBTC_OFFSET 8
-#define AT_DMA_ERR_OFFSET 16
-#define AT_DMA_BTC(x) (0x1 << (x))
-#define AT_DMA_CBTC(x) (0x1 << (AT_DMA_CBTC_OFFSET + (x)))
-#define AT_DMA_ERR(x) (0x1 << (AT_DMA_ERR_OFFSET + (x)))
-
-#define AT_DMA_CHER 0x28 /* Channel Handler Enable Register */
-#define AT_DMA_ENA(x) (0x1 << (x))
-#define AT_DMA_SUSP(x) (0x1 << ( 8 + (x)))
-#define AT_DMA_KEEP(x) (0x1 << (24 + (x)))
-
-#define AT_DMA_CHDR 0x2C /* Channel Handler Disable Register */
-#define AT_DMA_DIS(x) (0x1 << (x))
-#define AT_DMA_RES(x) (0x1 << ( 8 + (x)))
-
-#define AT_DMA_CHSR 0x30 /* Channel Handler Status Register */
-#define AT_DMA_EMPT(x) (0x1 << (16 + (x)))
-#define AT_DMA_STAL(x) (0x1 << (24 + (x)))
-
-
-#define AT_DMA_CH_REGS_BASE 0x3C /* Channel registers base address */
-#define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */
-
-/* Hardware register offset for each channel */
-#define ATC_SADDR_OFFSET 0x00 /* Source Address Register */
-#define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */
-#define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */
-#define ATC_CTRLA_OFFSET 0x0C /* Control A Register */
-#define ATC_CTRLB_OFFSET 0x10 /* Control B Register */
-#define ATC_CFG_OFFSET 0x14 /* Configuration Register */
-#define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */
-#define ATC_DPIP_OFFSET 0x1C /* Dst PIP Configuration Register */
-
-
-/* Bitfield definitions */
-
-/* Bitfields in DSCR */
-#define ATC_DSCR_IF(i) (0x3 & (i)) /* Dsc feched via AHB-Lite Interface i */
-
-/* Bitfields in CTRLA */
-#define ATC_BTSIZE_MAX 0xFFFFUL /* Maximum Buffer Transfer Size */
-#define ATC_BTSIZE(x) (ATC_BTSIZE_MAX & (x)) /* Buffer Transfer Size */
-#define ATC_SCSIZE_MASK (0x7 << 16) /* Source Chunk Transfer Size */
-#define ATC_SCSIZE(x) (ATC_SCSIZE_MASK & ((x) << 16))
-#define ATC_SCSIZE_1 (0x0 << 16)
-#define ATC_SCSIZE_4 (0x1 << 16)
-#define ATC_SCSIZE_8 (0x2 << 16)
-#define ATC_SCSIZE_16 (0x3 << 16)
-#define ATC_SCSIZE_32 (0x4 << 16)
-#define ATC_SCSIZE_64 (0x5 << 16)
-#define ATC_SCSIZE_128 (0x6 << 16)
-#define ATC_SCSIZE_256 (0x7 << 16)
-#define ATC_DCSIZE_MASK (0x7 << 20) /* Destination Chunk Transfer Size */
-#define ATC_DCSIZE(x) (ATC_DCSIZE_MASK & ((x) << 20))
-#define ATC_DCSIZE_1 (0x0 << 20)
-#define ATC_DCSIZE_4 (0x1 << 20)
-#define ATC_DCSIZE_8 (0x2 << 20)
-#define ATC_DCSIZE_16 (0x3 << 20)
-#define ATC_DCSIZE_32 (0x4 << 20)
-#define ATC_DCSIZE_64 (0x5 << 20)
-#define ATC_DCSIZE_128 (0x6 << 20)
-#define ATC_DCSIZE_256 (0x7 << 20)
-#define ATC_SRC_WIDTH_MASK (0x3 << 24) /* Source Single Transfer Size */
-#define ATC_SRC_WIDTH(x) ((x) << 24)
-#define ATC_SRC_WIDTH_BYTE (0x0 << 24)
-#define ATC_SRC_WIDTH_HALFWORD (0x1 << 24)
-#define ATC_SRC_WIDTH_WORD (0x2 << 24)
-#define ATC_REG_TO_SRC_WIDTH(r) (((r) >> 24) & 0x3)
-#define ATC_DST_WIDTH_MASK (0x3 << 28) /* Destination Single Transfer Size */
-#define ATC_DST_WIDTH(x) ((x) << 28)
-#define ATC_DST_WIDTH_BYTE (0x0 << 28)
-#define ATC_DST_WIDTH_HALFWORD (0x1 << 28)
-#define ATC_DST_WIDTH_WORD (0x2 << 28)
-#define ATC_DONE (0x1 << 31) /* Tx Done (only written back in descriptor) */
-
-/* Bitfields in CTRLB */
-#define ATC_SIF(i) (0x3 & (i)) /* Src tx done via AHB-Lite Interface i */
-#define ATC_DIF(i) ((0x3 & (i)) << 4) /* Dst tx done via AHB-Lite Interface i */
- /* Specify AHB interfaces */
-#define AT_DMA_MEM_IF 0 /* interface 0 as memory interface */
-#define AT_DMA_PER_IF 1 /* interface 1 as peripheral interface */
-
-#define ATC_SRC_PIP (0x1 << 8) /* Source Picture-in-Picture enabled */
-#define ATC_DST_PIP (0x1 << 12) /* Destination Picture-in-Picture enabled */
-#define ATC_SRC_DSCR_DIS (0x1 << 16) /* Src Descriptor fetch disable */
-#define ATC_DST_DSCR_DIS (0x1 << 20) /* Dst Descriptor fetch disable */
-#define ATC_FC_MASK (0x7 << 21) /* Choose Flow Controller */
-#define ATC_FC_MEM2MEM (0x0 << 21) /* Mem-to-Mem (DMA) */
-#define ATC_FC_MEM2PER (0x1 << 21) /* Mem-to-Periph (DMA) */
-#define ATC_FC_PER2MEM (0x2 << 21) /* Periph-to-Mem (DMA) */
-#define ATC_FC_PER2PER (0x3 << 21) /* Periph-to-Periph (DMA) */
-#define ATC_FC_PER2MEM_PER (0x4 << 21) /* Periph-to-Mem (Peripheral) */
-#define ATC_FC_MEM2PER_PER (0x5 << 21) /* Mem-to-Periph (Peripheral) */
-#define ATC_FC_PER2PER_SRCPER (0x6 << 21) /* Periph-to-Periph (Src Peripheral) */
-#define ATC_FC_PER2PER_DSTPER (0x7 << 21) /* Periph-to-Periph (Dst Peripheral) */
-#define ATC_SRC_ADDR_MODE_MASK (0x3 << 24)
-#define ATC_SRC_ADDR_MODE_INCR (0x0 << 24) /* Incrementing Mode */
-#define ATC_SRC_ADDR_MODE_DECR (0x1 << 24) /* Decrementing Mode */
-#define ATC_SRC_ADDR_MODE_FIXED (0x2 << 24) /* Fixed Mode */
-#define ATC_DST_ADDR_MODE_MASK (0x3 << 28)
-#define ATC_DST_ADDR_MODE_INCR (0x0 << 28) /* Incrementing Mode */
-#define ATC_DST_ADDR_MODE_DECR (0x1 << 28) /* Decrementing Mode */
-#define ATC_DST_ADDR_MODE_FIXED (0x2 << 28) /* Fixed Mode */
-#define ATC_IEN (0x1 << 30) /* BTC interrupt enable (active low) */
-#define ATC_AUTO (0x1 << 31) /* Auto multiple buffer tx enable */
-
-/* Bitfields in CFG */
-#define ATC_PER_MSB(h) ((0x30U & (h)) >> 4) /* Extract most significant bits of a handshaking identifier */
-
-#define ATC_SRC_PER(h) (0xFU & (h)) /* Channel src rq associated with periph handshaking ifc h */
-#define ATC_DST_PER(h) ((0xFU & (h)) << 4) /* Channel dst rq associated with periph handshaking ifc h */
-#define ATC_SRC_REP (0x1 << 8) /* Source Replay Mod */
-#define ATC_SRC_H2SEL (0x1 << 9) /* Source Handshaking Mod */
-#define ATC_SRC_H2SEL_SW (0x0 << 9)
-#define ATC_SRC_H2SEL_HW (0x1 << 9)
-#define ATC_SRC_PER_MSB(h) (ATC_PER_MSB(h) << 10) /* Channel src rq (most significant bits) */
-#define ATC_DST_REP (0x1 << 12) /* Destination Replay Mod */
-#define ATC_DST_H2SEL (0x1 << 13) /* Destination Handshaking Mod */
-#define ATC_DST_H2SEL_SW (0x0 << 13)
-#define ATC_DST_H2SEL_HW (0x1 << 13)
-#define ATC_DST_PER_MSB(h) (ATC_PER_MSB(h) << 14) /* Channel dst rq (most significant bits) */
-#define ATC_SOD (0x1 << 16) /* Stop On Done */
-#define ATC_LOCK_IF (0x1 << 20) /* Interface Lock */
-#define ATC_LOCK_B (0x1 << 21) /* AHB Bus Lock */
-#define ATC_LOCK_IF_L (0x1 << 22) /* Master Interface Arbiter Lock */
-#define ATC_LOCK_IF_L_CHUNK (0x0 << 22)
-#define ATC_LOCK_IF_L_BUFFER (0x1 << 22)
-#define ATC_AHB_PROT_MASK (0x7 << 24) /* AHB Protection */
-#define ATC_FIFOCFG_MASK (0x3 << 28) /* FIFO Request Configuration */
-#define ATC_FIFOCFG_LARGESTBURST (0x0 << 28)
-#define ATC_FIFOCFG_HALFFIFO (0x1 << 28)
-#define ATC_FIFOCFG_ENOUGHSPACE (0x2 << 28)
-
-/* Bitfields in SPIP */
-#define ATC_SPIP_HOLE(x) (0xFFFFU & (x))
-#define ATC_SPIP_BOUNDARY(x) ((0x3FF & (x)) << 16)
-
-/* Bitfields in DPIP */
-#define ATC_DPIP_HOLE(x) (0xFFFFU & (x))
-#define ATC_DPIP_BOUNDARY(x) ((0x3FF & (x)) << 16)
-
-
-/*-- descriptors -----------------------------------------------------*/
-
-/* LLI == Linked List Item; aka DMA buffer descriptor */
-struct at_lli {
- /* values that are not changed by hardware */
- dma_addr_t saddr;
- dma_addr_t daddr;
- /* value that may get written back: */
- u32 ctrla;
- /* more values that are not changed by hardware */
- u32 ctrlb;
- dma_addr_t dscr; /* chain to next lli */
-};
-
-/**
- * struct at_desc - software descriptor
- * @at_lli: hardware lli structure
- * @txd: support for the async_tx api
- * @desc_node: node on the channed descriptors list
- * @len: descriptor byte count
- * @total_len: total transaction byte count
- */
-struct at_desc {
- /* FIRST values the hardware uses */
- struct at_lli lli;
-
- /* THEN values for driver housekeeping */
- struct list_head tx_list;
- struct dma_async_tx_descriptor txd;
- struct list_head desc_node;
- size_t len;
- size_t total_len;
-
- /* Interleaved data */
- size_t boundary;
- size_t dst_hole;
- size_t src_hole;
-
- /* Memset temporary buffer */
- bool memset_buffer;
- dma_addr_t memset_paddr;
- int *memset_vaddr;
-};
-
-static inline struct at_desc *
-txd_to_at_desc(struct dma_async_tx_descriptor *txd)
-{
- return container_of(txd, struct at_desc, txd);
-}
-
-
-/*-- Channels --------------------------------------------------------*/
-
-/**
- * atc_status - information bits stored in channel status flag
- *
- * Manipulated with atomic operations.
- */
-enum atc_status {
- ATC_IS_ERROR = 0,
- ATC_IS_PAUSED = 1,
- ATC_IS_CYCLIC = 24,
-};
-
-/**
- * struct at_dma_chan - internal representation of an Atmel HDMAC channel
- * @chan_common: common dmaengine channel object members
- * @device: parent device
- * @ch_regs: memory mapped register base
- * @mask: channel index in a mask
- * @per_if: peripheral interface
- * @mem_if: memory interface
- * @status: transmit status information from irq/prep* functions
- * to tasklet (use atomic operations)
- * @tasklet: bottom half to finish transaction work
- * @save_cfg: configuration register that is saved on suspend/resume cycle
- * @save_dscr: for cyclic operations, preserve next descriptor address in
- * the cyclic list on suspend/resume cycle
- * @dma_sconfig: configuration for slave transfers, passed via
- * .device_config
- * @lock: serializes enqueue/dequeue operations to descriptors lists
- * @active_list: list of descriptors dmaengine is being running on
- * @queue: list of descriptors ready to be submitted to engine
- * @free_list: list of descriptors usable by the channel
- */
-struct at_dma_chan {
- struct dma_chan chan_common;
- struct at_dma *device;
- void __iomem *ch_regs;
- u8 mask;
- u8 per_if;
- u8 mem_if;
- unsigned long status;
- struct tasklet_struct tasklet;
- u32 save_cfg;
- u32 save_dscr;
- struct dma_slave_config dma_sconfig;
-
- spinlock_t lock;
-
- /* these other elements are all protected by lock */
- struct list_head active_list;
- struct list_head queue;
- struct list_head free_list;
-};
-
-#define channel_readl(atchan, name) \
- __raw_readl((atchan)->ch_regs + ATC_##name##_OFFSET)
-
-#define channel_writel(atchan, name, val) \
- __raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET)
-
-static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
-{
- return container_of(dchan, struct at_dma_chan, chan_common);
-}
-
-/*
- * Fix sconfig's burst size according to at_hdmac. We need to convert them as:
- * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7.
- *
- * This can be done by finding most significant bit set.
- */
-static inline void convert_burst(u32 *maxburst)
-{
- if (*maxburst > 1)
- *maxburst = fls(*maxburst) - 2;
- else
- *maxburst = 0;
-}
-
-/*
- * Fix sconfig's bus width according to at_hdmac.
- * 1 byte -> 0, 2 bytes -> 1, 4 bytes -> 2.
- */
-static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
-{
- switch (addr_width) {
- case DMA_SLAVE_BUSWIDTH_2_BYTES:
- return 1;
- case DMA_SLAVE_BUSWIDTH_4_BYTES:
- return 2;
- default:
- /* For 1 byte width or fallback */
- return 0;
- }
-}
-
-/*-- Controller ------------------------------------------------------*/
-
-/**
- * struct at_dma - internal representation of an Atmel HDMA Controller
- * @chan_common: common dmaengine dma_device object members
- * @atdma_devtype: identifier of DMA controller compatibility
- * @ch_regs: memory mapped register base
- * @clk: dma controller clock
- * @save_imr: interrupt mask register that is saved on suspend/resume cycle
- * @all_chan_mask: all channels availlable in a mask
- * @dma_desc_pool: base of DMA descriptor region (DMA address)
- * @chan: channels table to store at_dma_chan structures
- */
-struct at_dma {
- struct dma_device dma_common;
- void __iomem *regs;
- struct clk *clk;
- u32 save_imr;
-
- u8 all_chan_mask;
-
- struct dma_pool *dma_desc_pool;
- struct dma_pool *memset_pool;
- /* AT THE END channels table */
- struct at_dma_chan chan[];
-};
-
-#define dma_readl(atdma, name) \
- __raw_readl((atdma)->regs + AT_DMA_##name)
-#define dma_writel(atdma, name, val) \
- __raw_writel((val), (atdma)->regs + AT_DMA_##name)
-
-static inline struct at_dma *to_at_dma(struct dma_device *ddev)
-{
- return container_of(ddev, struct at_dma, dma_common);
-}
-
-
-/*-- Helper functions ------------------------------------------------*/
-
-static struct device *chan2dev(struct dma_chan *chan)
-{
- return &chan->dev->device;
-}
-
-#if defined(VERBOSE_DEBUG)
-static void vdbg_dump_regs(struct at_dma_chan *atchan)
-{
- struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
-
- dev_err(chan2dev(&atchan->chan_common),
- " channel %d : imr = 0x%x, chsr = 0x%x\n",
- atchan->chan_common.chan_id,
- dma_readl(atdma, EBCIMR),
- dma_readl(atdma, CHSR));
-
- dev_err(chan2dev(&atchan->chan_common),
- " channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n",
- channel_readl(atchan, SADDR),
- channel_readl(atchan, DADDR),
- channel_readl(atchan, CTRLA),
- channel_readl(atchan, CTRLB),
- channel_readl(atchan, CFG),
- channel_readl(atchan, DSCR));
-}
-#else
-static void vdbg_dump_regs(struct at_dma_chan *atchan) {}
-#endif
-
-static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli)
-{
- dev_crit(chan2dev(&atchan->chan_common),
- "desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n",
- &lli->saddr, &lli->daddr,
- lli->ctrla, lli->ctrlb, &lli->dscr);
-}
-
-
-static void atc_setup_irq(struct at_dma *atdma, int chan_id, int on)
-{
- u32 ebci;
-
- /* enable interrupts on buffer transfer completion & error */
- ebci = AT_DMA_BTC(chan_id)
- | AT_DMA_ERR(chan_id);
- if (on)
- dma_writel(atdma, EBCIER, ebci);
- else
- dma_writel(atdma, EBCIDR, ebci);
-}
-
-static void atc_enable_chan_irq(struct at_dma *atdma, int chan_id)
-{
- atc_setup_irq(atdma, chan_id, 1);
-}
-
-static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id)
-{
- atc_setup_irq(atdma, chan_id, 0);
-}
-
-
-/**
- * atc_chan_is_enabled - test if given channel is enabled
- * @atchan: channel we want to test status
- */
-static inline int atc_chan_is_enabled(struct at_dma_chan *atchan)
-{
- struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
-
- return !!(dma_readl(atdma, CHSR) & atchan->mask);
-}
-
-/**
- * atc_chan_is_paused - test channel pause/resume status
- * @atchan: channel we want to test status
- */
-static inline int atc_chan_is_paused(struct at_dma_chan *atchan)
-{
- return test_bit(ATC_IS_PAUSED, &atchan->status);
-}
-
-/**
- * atc_chan_is_cyclic - test if given channel has cyclic property set
- * @atchan: channel we want to test status
- */
-static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan)
-{
- return test_bit(ATC_IS_CYCLIC, &atchan->status);
-}
-
-/**
- * set_desc_eol - set end-of-link to descriptor so it will end transfer
- * @desc: descriptor, signle or at the end of a chain, to end chain on
- */
-static void set_desc_eol(struct at_desc *desc)
-{
- u32 ctrlb = desc->lli.ctrlb;
-
- ctrlb &= ~ATC_IEN;
- ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS;
-
- desc->lli.ctrlb = ctrlb;
- desc->lli.dscr = 0;
-}
-
-#endif /* AT_HDMAC_REGS_H */
--
2.25.1

2022-08-20 13:38:52

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 33/33] dmaengine: at_hdmac: Convert driver to use virt-dma

Convert the driver to use the core virt-dma. The driver will be easier to
maintain as it uses the list handling and the tasklet from virt-dma.

With the conversion replace the election of a new transfer in the tasklet
with the election of the new transfer in the interrupt handler. With this
we have a shorter idle window as we remove the scheduling latency of the
tasklet. I chose to do this while doing the conversion to virt-dma,
because if I made a prerequisite patch with the new transfer election in
the irq handler, I would have to duplicate some virt-dma code in the
at_hdmac driver that would end up being removed at the virt-dma conversion
anyway. So do this in a single step.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/Kconfig | 1 +
drivers/dma/at_hdmac.c | 1107 +++++++++++++++-------------------------
2 files changed, 403 insertions(+), 705 deletions(-)

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index a06d2a7627aa..dfec6a5842c8 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -97,6 +97,7 @@ config AT_HDMAC
tristate "Atmel AHB DMA support"
depends on ARCH_AT91
select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
help
Support the Atmel AHB DMA controller.

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index a2b24b9e85ce..5ab54f174e87 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -3,6 +3,7 @@
* Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems)
*
* Copyright (C) 2008 Atmel Corporation
+ * Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries
*
* This supports the Atmel AHB DMA Controller found in several Atmel SoCs.
* The only Atmel DMA Controller that is not covered by this driver is the one
@@ -25,6 +26,7 @@
#include <linux/slab.h>

#include "dmaengine.h"
+#include "virt-dma.h"

/*
* Glossary
@@ -197,25 +199,31 @@ struct at_lli {
u32 dscr; /* chain to next lli */
};

+/**
+ * struct atdma_sg - atdma scatter gather entry
+ * @len: length of the current Linked List Item.
+ * @lli: linked list item that is passed to the DMA controller
+ * @lli_phys: physical address of the LLI.
+ */
+struct atdma_sg {
+ unsigned int len;
+ struct at_lli *lli;
+ dma_addr_t lli_phys;
+};
+
/**
* struct at_desc - software descriptor
- * @at_lli: hardware lli structure
- * @txd: support for the async_tx api
- * @desc_node: node on the channed descriptors list
- * @len: descriptor byte count
+ * @vd: pointer to the virtual dma descriptor.
+ * @atchan: pointer to the atmel dma channel.
* @total_len: total transaction byte count
+ * @sg_len: number of sg entries.
+ * @sg: array of sgs.
*/
struct at_desc {
- /* FIRST values the hardware uses */
- struct at_lli lli;
-
- /* THEN values for driver housekeeping */
- struct list_head tx_list;
- struct dma_async_tx_descriptor txd;
- struct list_head desc_node;
- size_t len;
+ struct virt_dma_desc vd;
+ struct at_dma_chan *atchan;
size_t total_len;
-
+ unsigned int sglen;
/* Interleaved data */
size_t boundary;
size_t dst_hole;
@@ -225,14 +233,9 @@ struct at_desc {
bool memset_buffer;
dma_addr_t memset_paddr;
int *memset_vaddr;
+ struct atdma_sg sg[];
};

-static inline struct at_desc *
-txd_to_at_desc(struct dma_async_tx_descriptor *txd)
-{
- return container_of(txd, struct at_desc, txd);
-}
-
/*-- Channels --------------------------------------------------------*/
/**
* atc_status - information bits stored in channel status flag
@@ -240,49 +243,40 @@ txd_to_at_desc(struct dma_async_tx_descriptor *txd)
* Manipulated with atomic operations.
*/
enum atc_status {
- ATC_IS_ERROR = 0,
ATC_IS_PAUSED = 1,
ATC_IS_CYCLIC = 24,
};

/**
* struct at_dma_chan - internal representation of an Atmel HDMAC channel
- * @dma_chan: common dmaengine channel object members
+ * @vc: virtual dma channel entry.
+ * @atdma: pointer to the driver data.
* @ch_regs: memory mapped register base
* @mask: channel index in a mask
* @per_if: peripheral interface
* @mem_if: memory interface
* @status: transmit status information from irq/prep* functions
* to tasklet (use atomic operations)
- * @tasklet: bottom half to finish transaction work
* @save_cfg: configuration register that is saved on suspend/resume cycle
* @save_dscr: for cyclic operations, preserve next descriptor address in
* the cyclic list on suspend/resume cycle
* @dma_sconfig: configuration for slave transfers, passed via
* .device_config
- * @lock: serializes enqueue/dequeue operations to descriptors lists
- * @active_list: list of descriptors dmaengine is being running on
- * @queue: list of descriptors ready to be submitted to engine
- * @free_list: list of descriptors usable by the channel
+ * @desc: pointer to the atmel dma descriptor.
*/
struct at_dma_chan {
- struct dma_chan dma_chan;
+ struct virt_dma_chan vc;
+ struct at_dma *atdma;
void __iomem *ch_regs;
u8 mask;
u8 per_if;
u8 mem_if;
unsigned long status;
- struct tasklet_struct tasklet;
u32 save_cfg;
u32 save_dscr;
- struct dma_slave_config dma_sconfig;
-
- spinlock_t lock;
-
- /* these other elements are all protected by lock */
- struct list_head active_list;
- struct list_head queue;
- struct list_head free_list;
+ struct dma_slave_config dma_sconfig;
+ bool cyclic;
+ struct at_desc *desc;
};

#define channel_readl(atchan, name) \
@@ -291,11 +285,6 @@ struct at_dma_chan {
#define channel_writel(atchan, name, val) \
__raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET)

-static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
-{
- return container_of(dchan, struct at_dma_chan, dma_chan);
-}
-
/*
* Fix sconfig's burst size according to at_hdmac. We need to convert them as:
* 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7.
@@ -336,7 +325,7 @@ static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
* @clk: dma controller clock
* @save_imr: interrupt mask register that is saved on suspend/resume cycle
* @all_chan_mask: all channels availlable in a mask
- * @dma_desc_pool: base of DMA descriptor region (DMA address)
+ * @lli_pool: hw lli table
* @chan: channels table to store at_dma_chan structures
*/
struct at_dma {
@@ -347,7 +336,7 @@ struct at_dma {

u8 all_chan_mask;

- struct dma_pool *dma_desc_pool;
+ struct dma_pool *lli_pool;
struct dma_pool *memset_pool;
/* AT THE END channels table */
struct at_dma_chan chan[];
@@ -358,6 +347,16 @@ struct at_dma {
#define dma_writel(atdma, name, val) \
__raw_writel((val), (atdma)->regs + AT_DMA_##name)

+static inline struct at_desc *to_atdma_desc(struct dma_async_tx_descriptor *t)
+{
+ return container_of(t, struct at_desc, vd.tx);
+}
+
+static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *chan)
+{
+ return container_of(chan, struct at_dma_chan, vc.chan);
+}
+
static inline struct at_dma *to_at_dma(struct dma_device *ddev)
{
return container_of(ddev, struct at_dma, dma_device);
@@ -372,15 +371,15 @@ static struct device *chan2dev(struct dma_chan *chan)
#if defined(VERBOSE_DEBUG)
static void vdbg_dump_regs(struct at_dma_chan *atchan)
{
- struct at_dma *atdma = to_at_dma(atchan->dma_chan.device);
+ struct at_dma *atdma = to_at_dma(atchan->vc.chan.device);

- dev_err(chan2dev(&atchan->dma_chan),
+ dev_err(chan2dev(&atchan->vc.chan),
" channel %d : imr = 0x%x, chsr = 0x%x\n",
- atchan->dma_chan.chan_id,
+ atchan->vc.chan.chan_id,
dma_readl(atdma, EBCIMR),
dma_readl(atdma, CHSR));

- dev_err(chan2dev(&atchan->dma_chan),
+ dev_err(chan2dev(&atchan->vc.chan),
" channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n",
channel_readl(atchan, SADDR),
channel_readl(atchan, DADDR),
@@ -395,7 +394,7 @@ static void vdbg_dump_regs(struct at_dma_chan *atchan) {}

static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli)
{
- dev_crit(chan2dev(&atchan->dma_chan),
+ dev_crit(chan2dev(&atchan->vc.chan),
"desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n",
&lli->saddr, &lli->daddr,
lli->ctrla, lli->ctrlb, &lli->dscr);
@@ -430,7 +429,7 @@ static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id)
*/
static inline int atc_chan_is_enabled(struct at_dma_chan *atchan)
{
- struct at_dma *atdma = to_at_dma(atchan->dma_chan.device);
+ struct at_dma *atdma = to_at_dma(atchan->vc.chan.device);

return !!(dma_readl(atdma, CHSR) & atchan->mask);
}
@@ -454,18 +453,19 @@ static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan)
}

/**
- * set_desc_eol - set end-of-link to descriptor so it will end transfer
+ * set_lli_eol - set end-of-link to descriptor so it will end transfer
* @desc: descriptor, signle or at the end of a chain, to end chain on
+ * @i: index of the atmel scatter gather entry that is at the end of the chain.
*/
-static void set_desc_eol(struct at_desc *desc)
+static void set_lli_eol(struct at_desc *desc, unsigned int i)
{
- u32 ctrlb = desc->lli.ctrlb;
+ u32 ctrlb = desc->sg[i].lli->ctrlb;

ctrlb &= ~ATC_IEN;
ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS;

- desc->lli.ctrlb = ctrlb;
- desc->lli.dscr = 0;
+ desc->sg[i].lli->ctrlb = ctrlb;
+ desc->sg[i].lli->dscr = 0;
}

#define ATC_DEFAULT_CFG FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO)
@@ -508,13 +508,6 @@ struct at_dma_slave {
u32 cfg;
};

-/* prototypes */
-static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx);
-static void atc_issue_pending(struct dma_chan *chan);
-
-
-/*----------------------------------------------------------------------*/
-
static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst,
size_t len)
{
@@ -530,196 +523,72 @@ static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst,
return width;
}

-static struct at_desc *atc_first_active(struct at_dma_chan *atchan)
+static void atdma_lli_chain(struct at_desc *desc, unsigned int i)
{
- return list_first_entry(&atchan->active_list,
- struct at_desc, desc_node);
-}
-
-static struct at_desc *atc_first_queued(struct at_dma_chan *atchan)
-{
- return list_first_entry(&atchan->queue,
- struct at_desc, desc_node);
-}
+ struct atdma_sg *atdma_sg = &desc->sg[i];

-/**
- * atc_alloc_descriptor - allocate and return an initialized descriptor
- * @chan: the channel to allocate descriptors for
- * @gfp_flags: GFP allocation flags
- *
- * Note: The ack-bit is positioned in the descriptor flag at creation time
- * to make initial allocation more convenient. This bit will be cleared
- * and control will be given to client at usage time (during
- * preparation functions).
- */
-static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan,
- gfp_t gfp_flags)
-{
- struct at_desc *desc = NULL;
- struct at_dma *atdma = to_at_dma(chan->device);
- dma_addr_t phys;
-
- desc = dma_pool_zalloc(atdma->dma_desc_pool, gfp_flags, &phys);
- if (desc) {
- INIT_LIST_HEAD(&desc->tx_list);
- dma_async_tx_descriptor_init(&desc->txd, chan);
- /* txd.flags will be overwritten in prep functions */
- desc->txd.flags = DMA_CTRL_ACK;
- desc->txd.tx_submit = atc_tx_submit;
- desc->txd.phys = phys;
- }
-
- return desc;
-}
-
-/**
- * atc_desc_get - get an unused descriptor from free_list
- * @atchan: channel we want a new descriptor for
- */
-static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
-{
- struct at_desc *desc, *_desc;
- struct at_desc *ret = NULL;
- unsigned long flags;
- unsigned int i = 0;
-
- spin_lock_irqsave(&atchan->lock, flags);
- list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
- i++;
- if (async_tx_test_ack(&desc->txd)) {
- list_del(&desc->desc_node);
- ret = desc;
- break;
- }
- dev_dbg(chan2dev(&atchan->dma_chan),
- "desc %p not ACKed\n", desc);
- }
- spin_unlock_irqrestore(&atchan->lock, flags);
- dev_vdbg(chan2dev(&atchan->dma_chan),
- "scanned %u descriptors on freelist\n", i);
-
- /* no more descriptor available in initial pool: create one more */
- if (!ret)
- ret = atc_alloc_descriptor(&atchan->dma_chan, GFP_NOWAIT);
-
- return ret;
-}
-
-/**
- * atc_desc_put - move a descriptor, including any children, to the free list
- * @atchan: channel we work on
- * @desc: descriptor, at the head of a chain, to move to free list
- */
-static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc)
-{
- if (desc) {
- struct at_desc *child;
- unsigned long flags;
-
- spin_lock_irqsave(&atchan->lock, flags);
- list_for_each_entry(child, &desc->tx_list, desc_node)
- dev_vdbg(chan2dev(&atchan->dma_chan),
- "moving child desc %p to freelist\n",
- child);
- list_splice_init(&desc->tx_list, &atchan->free_list);
- dev_vdbg(chan2dev(&atchan->dma_chan),
- "moving desc %p to freelist\n", desc);
- list_add(&desc->desc_node, &atchan->free_list);
- spin_unlock_irqrestore(&atchan->lock, flags);
- }
-}
-
-/**
- * atc_desc_chain - build chain adding a descriptor
- * @first: address of first descriptor of the chain
- * @prev: address of previous descriptor of the chain
- * @desc: descriptor to queue
- *
- * Called from prep_* functions
- */
-static void atc_desc_chain(struct at_desc **first, struct at_desc **prev,
- struct at_desc *desc)
-{
- if (!(*first)) {
- *first = desc;
- } else {
- /* inform the HW lli about chaining */
- (*prev)->lli.dscr = desc->txd.phys;
- /* insert the link descriptor to the LD ring */
- list_add_tail(&desc->desc_node,
- &(*first)->tx_list);
- }
- *prev = desc;
+ if (i)
+ desc->sg[i - 1].lli->dscr = atdma_sg->lli_phys;
}

/**
* atc_dostart - starts the DMA engine for real
* @atchan: the channel we want to start
- * @first: first descriptor in the list we want to begin with
- *
- * Called with atchan->lock held and bh disabled
*/
-static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
+static void atc_dostart(struct at_dma_chan *atchan)
{
- struct at_dma *atdma = to_at_dma(atchan->dma_chan.device);
+ struct virt_dma_desc *vd = vchan_next_desc(&atchan->vc);
+ struct at_desc *desc;

- /* ASSERT: channel is idle */
- if (atc_chan_is_enabled(atchan)) {
- dev_err(chan2dev(&atchan->dma_chan),
- "BUG: Attempted to start non-idle channel\n");
- dev_err(chan2dev(&atchan->dma_chan),
- " channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
- channel_readl(atchan, SADDR),
- channel_readl(atchan, DADDR),
- channel_readl(atchan, CTRLA),
- channel_readl(atchan, CTRLB),
- channel_readl(atchan, DSCR));
-
- /* The tasklet will hopefully advance the queue... */
+ if (!vd) {
+ atchan->desc = NULL;
return;
}

vdbg_dump_regs(atchan);

+ list_del(&vd->node);
+ atchan->desc = desc = to_atdma_desc(&vd->tx);
+
channel_writel(atchan, SADDR, 0);
channel_writel(atchan, DADDR, 0);
channel_writel(atchan, CTRLA, 0);
channel_writel(atchan, CTRLB, 0);
- channel_writel(atchan, DSCR, first->txd.phys);
- channel_writel(atchan, SPIP, FIELD_PREP(ATC_SPIP_HOLE,
- first->src_hole) |
- FIELD_PREP(ATC_SPIP_BOUNDARY, first->boundary));
- channel_writel(atchan, DPIP, FIELD_PREP(ATC_DPIP_HOLE,
- first->dst_hole) |
- FIELD_PREP(ATC_DPIP_BOUNDARY, first->boundary));
+ channel_writel(atchan, DSCR, desc->sg[0].lli_phys);
+ channel_writel(atchan, SPIP,
+ FIELD_PREP(ATC_SPIP_HOLE, desc->src_hole) |
+ FIELD_PREP(ATC_SPIP_BOUNDARY, desc->boundary));
+ channel_writel(atchan, DPIP,
+ FIELD_PREP(ATC_DPIP_HOLE, desc->dst_hole) |
+ FIELD_PREP(ATC_DPIP_BOUNDARY, desc->boundary));
+
/* Don't allow CPU to reorder channel enable. */
wmb();
- dma_writel(atdma, CHER, atchan->mask);
+ dma_writel(atchan->atdma, CHER, atchan->mask);

vdbg_dump_regs(atchan);
}

-/*
- * atc_get_desc_by_cookie - get the descriptor of a cookie
- * @atchan: the DMA channel
- * @cookie: the cookie to get the descriptor for
- */
-static struct at_desc *atc_get_desc_by_cookie(struct at_dma_chan *atchan,
- dma_cookie_t cookie)
+static void atdma_desc_free(struct virt_dma_desc *vd)
{
- struct at_desc *desc, *_desc;
+ struct at_dma *atdma = to_at_dma(vd->tx.chan->device);
+ struct at_desc *desc = to_atdma_desc(&vd->tx);
+ unsigned int i;

- list_for_each_entry_safe(desc, _desc, &atchan->queue, desc_node) {
- if (desc->txd.cookie == cookie)
- return desc;
+ for (i = 0; i < desc->sglen; i++) {
+ if (desc->sg[i].lli)
+ dma_pool_free(atdma->lli_pool, desc->sg[i].lli,
+ desc->sg[i].lli_phys);
}

- list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
- if (desc->txd.cookie == cookie)
- return desc;
+ /* If the transfer was a memset, free our temporary buffer */
+ if (desc->memset_buffer) {
+ dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
+ desc->memset_paddr);
+ desc->memset_buffer = false;
}

- return NULL;
+ kfree(desc);
}

/**
@@ -746,20 +615,19 @@ static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
/**
* atc_get_llis_residue - Get residue for a hardware linked list transfer
*
- * Calculate the residue by removing the length of the child descriptors already
- * transferred from the total length. To get the current child descriptor we can
- * use the value of the channel's DSCR register and compare it against the value
- * of the hardware linked list structure of each child descriptor.
+ * Calculate the residue by removing the length of the Linked List Item (LLI)
+ * already transferred from the total length. To get the current LLI we can use
+ * the value of the channel's DSCR register and compare it against the DSCR
+ * value of each LLI.
*
* The CTRLA register provides us with the amount of data already read from the
- * source for the current child descriptor. So we can compute a more accurate
- * residue by also removing the number of bytes corresponding to this amount of
- * data.
+ * source for the LLI. So we can compute a more accurate residue by also
+ * removing the number of bytes corresponding to this amount of data.
*
* However, the DSCR and CTRLA registers cannot be read both atomically. Hence a
- * race condition may occur: the first read register may refer to one child
- * descriptor whereas the second read may refer to a later child descriptor in
- * the list because of the DMA transfer progression inbetween the two reads.
+ * race condition may occur: the first read register may refer to one LLI
+ * whereas the second read may refer to a later LLI in the list because of the
+ * DMA transfer progression inbetween the two reads.
*
* One solution could have been to pause the DMA transfer, read the DSCR and
* CTRLA then resume the DMA transfer. Nonetheless, this approach presents some
@@ -776,12 +644,11 @@ static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
* Then we'd rather use another solution: the DSCR is read a first time, the
* CTRLA is read in turn, next the DSCR is read a second time. If the two
* consecutive read values of the DSCR are the same then we assume both refers
- * to the very same child descriptor as well as the CTRLA value read inbetween
- * does. For cyclic tranfers, the assumption is that a full loop is "not so
- * fast". If the two DSCR values are different, we read again the CTRLA then the
- * DSCR till two consecutive read values from DSCR are equal or till the
- * maximum trials is reach. This algorithm is very unlikely not to find a stable
- * value for DSCR.
+ * to the very same LLI as well as the CTRLA value read inbetween does. For
+ * cyclic tranfers, the assumption is that a full loop is "not so fast". If the
+ * two DSCR values are different, we read again the CTRLA then the DSCR till two
+ * consecutive read values from DSCR are equal or till the maximum trials is
+ * reach. This algorithm is very unlikely not to find a stable value for DSCR.
* @atchan: pointer to an atmel hdmac channel.
* @desc: pointer to the descriptor for which the residue is calculated.
* @residue: residue to be set to dma_tx_state.
@@ -790,7 +657,6 @@ static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
static int atc_get_llis_residue(struct at_dma_chan *atchan,
struct at_desc *desc, u32 *residue)
{
- struct at_desc *child;
u32 len, ctrla, dscr;
unsigned int i;

@@ -826,24 +692,25 @@ static int atc_get_llis_residue(struct at_dma_chan *atchan,
return -ETIMEDOUT;

/* For the first descriptor we can be more accurate. */
- if (desc->lli.dscr == dscr) {
+ if (desc->sg[0].lli->dscr == dscr) {
*residue = atc_calc_bytes_left(len, ctrla);
return 0;
}
+ len -= desc->sg[0].len;

- len -= desc->len;
- list_for_each_entry(child, &desc->tx_list, desc_node) {
- if (child->lli.dscr == dscr)
+ for (i = 1; i < desc->sglen; i++) {
+ if (desc->sg[i].lli && desc->sg[i].lli->dscr == dscr)
break;
- len -= child->len;
+ len -= desc->sg[i].len;
}

/*
- * For the current descriptor in the chain we can calculate the
- * remaining bytes using the channel's register.
+ * For the current LLI in the chain we can calculate the remaining bytes
+ * using the channel's CTRLA register.
*/
*residue = atc_calc_bytes_left(len, ctrla);
return 0;
+
}

/**
@@ -857,139 +724,42 @@ static int atc_get_llis_residue(struct at_dma_chan *atchan,
static int atc_get_residue(struct dma_chan *chan, dma_cookie_t cookie,
u32 *residue)
{
- struct at_dma_chan *atchan = to_at_dma_chan(chan);
- struct at_desc *desc_first = atc_first_active(atchan);
- struct at_desc *desc;
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct virt_dma_desc *vd;
+ struct at_desc *desc = NULL;
u32 len, ctrla;

- /*
- * If the cookie doesn't match to the currently running transfer then
- * we can return the total length of the associated DMA transfer,
- * because it is still queued.
- */
- desc = atc_get_desc_by_cookie(atchan, cookie);
- if (desc == NULL)
+ vd = vchan_find_desc(&atchan->vc, cookie);
+ if (vd)
+ desc = to_atdma_desc(&vd->tx);
+ else if (atchan->desc && atchan->desc->vd.tx.cookie == cookie)
+ desc = atchan->desc;
+
+ if (!desc)
return -EINVAL;
- else if (desc != desc_first)
- return desc->total_len;

- if (desc_first->lli.dscr)
+ if (desc->sg[0].lli->dscr)
/* hardware linked list transfer */
- return atc_get_llis_residue(atchan, desc_first, residue);
+ return atc_get_llis_residue(atchan, desc, residue);

/* single transfer */
- len = desc_first->total_len;
+ len = desc->total_len;
ctrla = channel_readl(atchan, CTRLA);
*residue = atc_calc_bytes_left(len, ctrla);
return 0;
}

-/**
- * atc_chain_complete - finish work for one transaction chain
- * @atchan: channel we work on
- * @desc: descriptor at the head of the chain we want do complete
- */
-static void
-atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
-{
- struct dma_async_tx_descriptor *txd = &desc->txd;
- struct at_dma *atdma = to_at_dma(atchan->dma_chan.device);
- unsigned long flags;
-
- dev_vdbg(chan2dev(&atchan->dma_chan),
- "descriptor %u complete\n", txd->cookie);
-
- spin_lock_irqsave(&atchan->lock, flags);
-
- /* mark the descriptor as complete for non cyclic cases only */
- if (!atc_chan_is_cyclic(atchan))
- dma_cookie_complete(txd);
-
- spin_unlock_irqrestore(&atchan->lock, flags);
-
- dma_descriptor_unmap(txd);
- /* for cyclic transfers,
- * no need to replay callback function while stopping */
- if (!atc_chan_is_cyclic(atchan))
- dmaengine_desc_get_callback_invoke(txd, NULL);
-
- dma_run_dependencies(txd);
-
- spin_lock_irqsave(&atchan->lock, flags);
- /* move children to free_list */
- list_splice_init(&desc->tx_list, &atchan->free_list);
- /* add myself to free_list */
- list_add(&desc->desc_node, &atchan->free_list);
- spin_unlock_irqrestore(&atchan->lock, flags);
-
- /* If the transfer was a memset, free our temporary buffer */
- if (desc->memset_buffer) {
- dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
- desc->memset_paddr);
- desc->memset_buffer = false;
- }
-}
-
-/**
- * atc_advance_work - at the end of a transaction, move forward
- * @atchan: channel where the transaction ended
- */
-static void atc_advance_work(struct at_dma_chan *atchan)
-{
- struct at_desc *desc;
- unsigned long flags;
-
- dev_vdbg(chan2dev(&atchan->dma_chan), "advance_work\n");
-
- spin_lock_irqsave(&atchan->lock, flags);
- if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
- return spin_unlock_irqrestore(&atchan->lock, flags);
-
- desc = atc_first_active(atchan);
- /* Remove the transfer node from the active list. */
- list_del_init(&desc->desc_node);
- spin_unlock_irqrestore(&atchan->lock, flags);
- atc_chain_complete(atchan, desc);
-
- /* advance work */
- spin_lock_irqsave(&atchan->lock, flags);
- if (!list_empty(&atchan->active_list)) {
- desc = atc_first_queued(atchan);
- list_move_tail(&desc->desc_node, &atchan->active_list);
- atc_dostart(atchan, desc);
- }
- spin_unlock_irqrestore(&atchan->lock, flags);
-}
-
-
/**
* atc_handle_error - handle errors reported by DMA controller
- * @atchan: channel where error occurs
+ * @atchan: channel where error occurs.
+ * @i: channel index
*/
-static void atc_handle_error(struct at_dma_chan *atchan)
+static void atc_handle_error(struct at_dma_chan *atchan, unsigned int i)
{
- struct at_desc *bad_desc;
- struct at_desc *desc;
- struct at_desc *child;
- unsigned long flags;
-
- spin_lock_irqsave(&atchan->lock, flags);
- /*
- * The descriptor currently at the head of the active list is
- * broked. Since we don't have any way to report errors, we'll
- * just have to scream loudly and try to carry on.
- */
- bad_desc = atc_first_active(atchan);
- list_del_init(&bad_desc->desc_node);
-
- /* Try to restart the controller */
- if (!list_empty(&atchan->active_list)) {
- desc = atc_first_queued(atchan);
- list_move_tail(&desc->desc_node, &atchan->active_list);
- atc_dostart(atchan, desc);
- }
+ struct at_desc *desc = atchan->desc;

- spin_unlock_irqrestore(&atchan->lock, flags);
+ /* Disable channel on AHB error */
+ dma_writel(atchan->atdma, CHDR, AT_DMA_RES(i) | atchan->mask);

/*
* KERN_CRITICAL may seem harsh, but since this only happens
@@ -998,47 +768,37 @@ static void atc_handle_error(struct at_dma_chan *atchan)
* controller flagged an error instead of scribbling over
* random memory locations.
*/
- dev_crit(chan2dev(&atchan->dma_chan),
- "Bad descriptor submitted for DMA!\n");
- dev_crit(chan2dev(&atchan->dma_chan),
- " cookie: %d\n", bad_desc->txd.cookie);
- atc_dump_lli(atchan, &bad_desc->lli);
- list_for_each_entry(child, &bad_desc->tx_list, desc_node)
- atc_dump_lli(atchan, &child->lli);
-
- /* Pretend the descriptor completed successfully */
- atc_chain_complete(atchan, bad_desc);
+ dev_crit(chan2dev(&atchan->vc.chan), "Bad descriptor submitted for DMA!\n");
+ dev_crit(chan2dev(&atchan->vc.chan), "cookie: %d\n",
+ desc->vd.tx.cookie);
+ for (i = 0; i < desc->sglen; i++)
+ atc_dump_lli(atchan, desc->sg[i].lli);
}

-/**
- * atc_handle_cyclic - at the end of a period, run callback function
- * @atchan: channel used for cyclic operations
- */
-static void atc_handle_cyclic(struct at_dma_chan *atchan)
-{
- struct at_desc *first = atc_first_active(atchan);
- struct dma_async_tx_descriptor *txd = &first->txd;
-
- dev_vdbg(chan2dev(&atchan->dma_chan),
- "new cyclic period llp 0x%08x\n",
- channel_readl(atchan, DSCR));
-
- dmaengine_desc_get_callback_invoke(txd, NULL);
-}
-
-/*-- IRQ & Tasklet ---------------------------------------------------*/
-
-static void atc_tasklet(struct tasklet_struct *t)
+static void atdma_handle_chan_done(struct at_dma_chan *atchan, u32 pending,
+ unsigned int i)
{
- struct at_dma_chan *atchan = from_tasklet(atchan, t, tasklet);
+ struct at_desc *desc;

- if (test_and_clear_bit(ATC_IS_ERROR, &atchan->status))
- return atc_handle_error(atchan);
+ spin_lock(&atchan->vc.lock);
+ desc = atchan->desc;

- if (atc_chan_is_cyclic(atchan))
- return atc_handle_cyclic(atchan);
+ if (desc) {
+ if (pending & AT_DMA_ERR(i)) {
+ atc_handle_error(atchan, i);
+ /* Pretend the descriptor completed successfully */
+ }

- atc_advance_work(atchan);
+ if (atc_chan_is_cyclic(atchan)) {
+ vchan_cyclic_callback(&desc->vd);
+ } else {
+ vchan_cookie_complete(&desc->vd);
+ atchan->desc = NULL;
+ if (!(atc_chan_is_enabled(atchan)))
+ atc_dostart(atchan);
+ }
+ }
+ spin_unlock(&atchan->vc.lock);
}

static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
@@ -1063,17 +823,10 @@ static irqreturn_t at_dma_interrupt(int irq, void *dev_id)

for (i = 0; i < atdma->dma_device.chancnt; i++) {
atchan = &atdma->chan[i];
- if (pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))) {
- if (pending & AT_DMA_ERR(i)) {
- /* Disable channel on AHB error */
- dma_writel(atdma, CHDR,
- AT_DMA_RES(i) | atchan->mask);
- /* Give information to tasklet */
- set_bit(ATC_IS_ERROR, &atchan->status);
- }
- tasklet_schedule(&atchan->tasklet);
- ret = IRQ_HANDLED;
- }
+ if (!(pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))))
+ continue;
+ atdma_handle_chan_done(atchan, pending, i);
+ ret = IRQ_HANDLED;
}

} while (pending);
@@ -1081,35 +834,7 @@ static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
return ret;
}

-
/*-- DMA Engine API --------------------------------------------------*/
-
-/**
- * atc_tx_submit - set the prepared descriptor(s) to be executed by the engine
- * @tx: descriptor at the head of the transaction chain
- *
- * Queue chain if DMA engine is working already
- *
- * Cookie increment and adding to active_list or queue must be atomic
- */
-static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx)
-{
- struct at_desc *desc = txd_to_at_desc(tx);
- struct at_dma_chan *atchan = to_at_dma_chan(tx->chan);
- dma_cookie_t cookie;
- unsigned long flags;
-
- spin_lock_irqsave(&atchan->lock, flags);
- cookie = dma_cookie_assign(tx);
-
- list_add_tail(&desc->desc_node, &atchan->queue);
- spin_unlock_irqrestore(&atchan->lock, flags);
-
- dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
- desc->txd.cookie);
- return cookie;
-}
-
/**
* atc_prep_dma_interleaved - prepare memory to memory interleaved operation
* @chan: the channel to prepare operation on
@@ -1121,9 +846,12 @@ atc_prep_dma_interleaved(struct dma_chan *chan,
struct dma_interleaved_template *xt,
unsigned long flags)
{
+ struct at_dma *atdma = to_at_dma(chan->device);
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct data_chunk *first;
- struct at_desc *desc = NULL;
+ struct atdma_sg *atdma_sg;
+ struct at_desc *desc;
+ struct at_lli *lli;
size_t xfer_count;
unsigned int dwidth;
u32 ctrla;
@@ -1162,8 +890,7 @@ atc_prep_dma_interleaved(struct dma_chan *chan,
len += chunk->size;
}

- dwidth = atc_get_xfer_width(xt->src_start,
- xt->dst_start, len);
+ dwidth = atc_get_xfer_width(xt->src_start, xt->dst_start, len);

xfer_count = len >> dwidth;
if (xfer_count > ATC_BTSIZE_MAX) {
@@ -1180,32 +907,34 @@ atc_prep_dma_interleaved(struct dma_chan *chan,
ATC_SRC_PIP | ATC_DST_PIP |
FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM);

- /* create the transfer */
- desc = atc_desc_get(atchan);
- if (!desc) {
- dev_err(chan2dev(chan),
- "%s: couldn't allocate our descriptor\n", __func__);
+ desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC);
+ if (!desc)
+ return NULL;
+ desc->sglen = 1;
+
+ atdma_sg = desc->sg;
+ atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
+ &atdma_sg->lli_phys);
+ if (!atdma_sg->lli) {
+ kfree(desc);
return NULL;
}
+ lli = atdma_sg->lli;

- desc->lli.saddr = xt->src_start;
- desc->lli.daddr = xt->dst_start;
- desc->lli.ctrla = ctrla | xfer_count;
- desc->lli.ctrlb = ctrlb;
+ lli->saddr = xt->src_start;
+ lli->daddr = xt->dst_start;
+ lli->ctrla = ctrla | xfer_count;
+ lli->ctrlb = ctrlb;

desc->boundary = first->size >> dwidth;
desc->dst_hole = (dmaengine_get_dst_icg(xt, first) >> dwidth) + 1;
desc->src_hole = (dmaengine_get_src_icg(xt, first) >> dwidth) + 1;

- desc->txd.cookie = -EBUSY;
- desc->total_len = desc->len = len;
-
- /* set end-of-link to the last link descriptor of list*/
- set_desc_eol(desc);
-
- desc->txd.flags = flags; /* client is in control of this ack */
+ atdma_sg->len = len;
+ desc->total_len = len;

- return &desc->txd;
+ set_lli_eol(desc, 0);
+ return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
}

/**
@@ -1220,25 +949,32 @@ static struct dma_async_tx_descriptor *
atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
size_t len, unsigned long flags)
{
+ struct at_dma *atdma = to_at_dma(chan->device);
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_desc *desc = NULL;
- struct at_desc *first = NULL;
- struct at_desc *prev = NULL;
size_t xfer_count;
size_t offset;
+ size_t sg_len;
unsigned int src_width;
unsigned int dst_width;
+ unsigned int i;
u32 ctrla;
u32 ctrlb;

- dev_vdbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n",
- &dest, &src, len, flags);
+ dev_dbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n",
+ &dest, &src, len, flags);

if (unlikely(!len)) {
- dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
+ dev_err(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
return NULL;
}

+ sg_len = DIV_ROUND_UP(len, ATC_BTSIZE_MAX);
+ desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
+ if (!desc)
+ return NULL;
+ desc->sglen = sg_len;
+
ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) |
FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
@@ -1253,50 +989,49 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
ctrla = FIELD_PREP(ATC_SRC_WIDTH, src_width) |
FIELD_PREP(ATC_DST_WIDTH, dst_width);

- for (offset = 0; offset < len; offset += xfer_count << src_width) {
- xfer_count = min_t(size_t, (len - offset) >> src_width,
- ATC_BTSIZE_MAX);
+ for (offset = 0, i = 0; offset < len;
+ offset += xfer_count << src_width, i++) {
+ struct atdma_sg *atdma_sg = &desc->sg[i];
+ struct at_lli *lli;

- desc = atc_desc_get(atchan);
- if (!desc)
+ atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
+ &atdma_sg->lli_phys);
+ if (!atdma_sg->lli)
goto err_desc_get;
+ lli = atdma_sg->lli;
+
+ xfer_count = min_t(size_t, (len - offset) >> src_width,
+ ATC_BTSIZE_MAX);

- desc->lli.saddr = src + offset;
- desc->lli.daddr = dest + offset;
- desc->lli.ctrla = ctrla | xfer_count;
- desc->lli.ctrlb = ctrlb;
+ lli->saddr = src + offset;
+ lli->daddr = dest + offset;
+ lli->ctrla = ctrla | xfer_count;
+ lli->ctrlb = ctrlb;

- desc->txd.cookie = 0;
- desc->len = xfer_count << src_width;
+ desc->sg[i].len = xfer_count << src_width;

- atc_desc_chain(&first, &prev, desc);
+ atdma_lli_chain(desc, i);
}

- /* First descriptor of the chain embedds additional information */
- first->txd.cookie = -EBUSY;
- first->total_len = len;
+ desc->total_len = len;

/* set end-of-link to the last link descriptor of list*/
- set_desc_eol(desc);
-
- first->txd.flags = flags; /* client is in control of this ack */
+ set_lli_eol(desc, i - 1);

- return &first->txd;
+ return vchan_tx_prep(&atchan->vc, &desc->vd, flags);

err_desc_get:
- atc_desc_put(atchan, first);
+ atdma_desc_free(&desc->vd);
return NULL;
}

-static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
- dma_addr_t psrc,
- dma_addr_t pdst,
- size_t len)
+static int atdma_create_memset_lli(struct dma_chan *chan,
+ struct atdma_sg *atdma_sg,
+ dma_addr_t psrc, dma_addr_t pdst, size_t len)
{
- struct at_dma_chan *atchan = to_at_dma_chan(chan);
- struct at_desc *desc;
+ struct at_dma *atdma = to_at_dma(chan->device);
+ struct at_lli *lli;
size_t xfer_count;
-
u32 ctrla = FIELD_PREP(ATC_SRC_WIDTH, 2) | FIELD_PREP(ATC_DST_WIDTH, 2);
u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) |
@@ -1305,27 +1040,24 @@ static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,

xfer_count = len >> 2;
if (xfer_count > ATC_BTSIZE_MAX) {
- dev_err(chan2dev(chan), "%s: buffer is too big\n",
- __func__);
- return NULL;
+ dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__);
+ return -EINVAL;
}

- desc = atc_desc_get(atchan);
- if (!desc) {
- dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
- __func__);
- return NULL;
- }
+ atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
+ &atdma_sg->lli_phys);
+ if (!atdma_sg->lli)
+ return -ENOMEM;
+ lli = atdma_sg->lli;

- desc->lli.saddr = psrc;
- desc->lli.daddr = pdst;
- desc->lli.ctrla = ctrla | xfer_count;
- desc->lli.ctrlb = ctrlb;
+ lli->saddr = psrc;
+ lli->daddr = pdst;
+ lli->ctrla = ctrla | xfer_count;
+ lli->ctrlb = ctrlb;

- desc->txd.cookie = 0;
- desc->len = len;
+ atdma_sg->len = len;

- return desc;
+ return 0;
}

/**
@@ -1340,11 +1072,13 @@ static struct dma_async_tx_descriptor *
atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
size_t len, unsigned long flags)
{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
struct at_desc *desc;
void __iomem *vaddr;
dma_addr_t paddr;
char fill_pattern;
+ int ret;

dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__,
&dest, value, len, flags);
@@ -1375,27 +1109,28 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
(fill_pattern << 8) |
fill_pattern;

- desc = atc_create_memset_desc(chan, paddr, dest, len);
- if (!desc) {
- dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n",
- __func__);
+ desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC);
+ if (!desc)
goto err_free_buffer;
- }
+ desc->sglen = 1;
+
+ ret = atdma_create_memset_lli(chan, desc->sg, paddr, dest, len);
+ if (ret)
+ goto err_free_desc;

desc->memset_paddr = paddr;
desc->memset_vaddr = vaddr;
desc->memset_buffer = true;

- desc->txd.cookie = -EBUSY;
desc->total_len = len;

/* set end-of-link on the descriptor */
- set_desc_eol(desc);
-
- desc->txd.flags = flags;
+ set_lli_eol(desc, 0);

- return &desc->txd;
+ return vchan_tx_prep(&atchan->vc, &desc->vd, flags);

+err_free_desc:
+ kfree(desc);
err_free_buffer:
dma_pool_free(atdma->memset_pool, vaddr, paddr);
return NULL;
@@ -1409,12 +1144,13 @@ atc_prep_dma_memset_sg(struct dma_chan *chan,
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
- struct at_desc *desc = NULL, *first = NULL, *prev = NULL;
+ struct at_desc *desc;
struct scatterlist *sg;
void __iomem *vaddr;
dma_addr_t paddr;
size_t total_len = 0;
int i;
+ int ret;

dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
value, sg_len, flags);
@@ -1433,6 +1169,11 @@ atc_prep_dma_memset_sg(struct dma_chan *chan,
}
*(u32*)vaddr = value;

+ desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
+ if (!desc)
+ goto err_free_dma_buf;
+ desc->sglen = sg_len;
+
for_each_sg(sgl, sg, sg_len, i) {
dma_addr_t dest = sg_dma_address(sg);
size_t len = sg_dma_len(sg);
@@ -1443,38 +1184,33 @@ atc_prep_dma_memset_sg(struct dma_chan *chan,
if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
__func__);
- goto err_put_desc;
+ goto err_free_desc;
}

- desc = atc_create_memset_desc(chan, paddr, dest, len);
- if (!desc)
- goto err_put_desc;
-
- atc_desc_chain(&first, &prev, desc);
+ ret = atdma_create_memset_lli(chan, &desc->sg[i], paddr, dest,
+ len);
+ if (ret)
+ goto err_free_desc;

+ atdma_lli_chain(desc, i);
total_len += len;
}

- /*
- * Only set the buffer pointers on the last descriptor to
- * avoid free'ing while we have our transfer still going
- */
desc->memset_paddr = paddr;
desc->memset_vaddr = vaddr;
desc->memset_buffer = true;

- first->txd.cookie = -EBUSY;
- first->total_len = total_len;
+ desc->total_len = total_len;

/* set end-of-link on the descriptor */
- set_desc_eol(desc);
-
- first->txd.flags = flags;
+ set_lli_eol(desc, i - 1);

- return &first->txd;
+ return vchan_tx_prep(&atchan->vc, &desc->vd, flags);

-err_put_desc:
- atc_desc_put(atchan, first);
+err_free_desc:
+ atdma_desc_free(&desc->vd);
+err_free_dma_buf:
+ dma_pool_free(atdma->memset_pool, vaddr, paddr);
return NULL;
}

@@ -1492,11 +1228,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
+ struct at_dma *atdma = to_at_dma(chan->device);
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma_slave *atslave = chan->private;
struct dma_slave_config *sconfig = &atchan->dma_sconfig;
- struct at_desc *first = NULL;
- struct at_desc *prev = NULL;
+ struct at_desc *desc;
u32 ctrla;
u32 ctrlb;
dma_addr_t reg;
@@ -1516,6 +1252,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
return NULL;
}

+ desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
+ if (!desc)
+ return NULL;
+ desc->sglen = sg_len;
+
ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst);
ctrlb = ATC_IEN;
@@ -1532,13 +1273,17 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
FIELD_PREP(ATC_DIF, atchan->per_if);
reg = sconfig->dst_addr;
for_each_sg(sgl, sg, sg_len, i) {
- struct at_desc *desc;
+ struct atdma_sg *atdma_sg = &desc->sg[i];
+ struct at_lli *lli;
u32 len;
u32 mem;

- desc = atc_desc_get(atchan);
- if (!desc)
+ atdma_sg->lli = dma_pool_alloc(atdma->lli_pool,
+ GFP_NOWAIT,
+ &atdma_sg->lli_phys);
+ if (!atdma_sg->lli)
goto err_desc_get;
+ lli = atdma_sg->lli;

mem = sg_dma_address(sg);
len = sg_dma_len(sg);
@@ -1551,16 +1296,18 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
if (unlikely(mem & 3 || len & 3))
mem_width = 0;

- desc->lli.saddr = mem;
- desc->lli.daddr = reg;
- desc->lli.ctrla = ctrla |
- FIELD_PREP(ATC_SRC_WIDTH, mem_width) |
- len >> mem_width;
- desc->lli.ctrlb = ctrlb;
- desc->len = len;
+ lli->saddr = mem;
+ lli->daddr = reg;
+ lli->ctrla = ctrla |
+ FIELD_PREP(ATC_SRC_WIDTH, mem_width) |
+ len >> mem_width;
+ lli->ctrlb = ctrlb;

- atc_desc_chain(&first, &prev, desc);
+ atdma_sg->len = len;
total_len += len;
+
+ desc->sg[i].len = len;
+ atdma_lli_chain(desc, i);
}
break;
case DMA_DEV_TO_MEM:
@@ -1575,13 +1322,17 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,

reg = sconfig->src_addr;
for_each_sg(sgl, sg, sg_len, i) {
- struct at_desc *desc;
+ struct atdma_sg *atdma_sg = &desc->sg[i];
+ struct at_lli *lli;
u32 len;
u32 mem;

- desc = atc_desc_get(atchan);
- if (!desc)
+ atdma_sg->lli = dma_pool_alloc(atdma->lli_pool,
+ GFP_NOWAIT,
+ &atdma_sg->lli_phys);
+ if (!atdma_sg->lli)
goto err_desc_get;
+ lli = atdma_sg->lli;

mem = sg_dma_address(sg);
len = sg_dma_len(sg);
@@ -1594,16 +1345,17 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
if (unlikely(mem & 3 || len & 3))
mem_width = 0;

- desc->lli.saddr = reg;
- desc->lli.daddr = mem;
- desc->lli.ctrla = ctrla |
- FIELD_PREP(ATC_DST_WIDTH, mem_width) |
- len >> reg_width;
- desc->lli.ctrlb = ctrlb;
- desc->len = len;
+ lli->saddr = reg;
+ lli->daddr = mem;
+ lli->ctrla = ctrla |
+ FIELD_PREP(ATC_DST_WIDTH, mem_width) |
+ len >> reg_width;
+ lli->ctrlb = ctrlb;

- atc_desc_chain(&first, &prev, desc);
+ desc->sg[i].len = len;
total_len += len;
+
+ atdma_lli_chain(desc, i);
}
break;
default:
@@ -1611,21 +1363,16 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
}

/* set end-of-link to the last link descriptor of list*/
- set_desc_eol(prev);
-
- /* First descriptor of the chain embedds additional information */
- first->txd.cookie = -EBUSY;
- first->total_len = total_len;
+ set_lli_eol(desc, i - 1);

- /* first link descriptor of list is responsible of flags */
- first->txd.flags = flags; /* client is in control of this ack */
+ desc->total_len = total_len;

- return &first->txd;
+ return vchan_tx_prep(&atchan->vc, &desc->vd, flags);

err_desc_get:
dev_err(chan2dev(chan), "not enough descriptors available\n");
err:
- atc_desc_put(atchan, first);
+ atdma_desc_free(&desc->vd);
return NULL;
}

@@ -1655,54 +1402,59 @@ atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
*/
static int
atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
- unsigned int period_index, dma_addr_t buf_addr,
+ unsigned int i, dma_addr_t buf_addr,
unsigned int reg_width, size_t period_len,
enum dma_transfer_direction direction)
{
+ struct at_dma *atdma = to_at_dma(chan->device);
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct dma_slave_config *sconfig = &atchan->dma_sconfig;
- u32 ctrla;
+ struct atdma_sg *atdma_sg = &desc->sg[i];
+ struct at_lli *lli;

- /* prepare common CRTLA value */
- ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
- FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) |
- FIELD_PREP(ATC_DST_WIDTH, reg_width) |
- FIELD_PREP(ATC_SRC_WIDTH, reg_width) |
- period_len >> reg_width;
+ atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_ATOMIC,
+ &atdma_sg->lli_phys);
+ if (!atdma_sg->lli)
+ return -ENOMEM;
+ lli = atdma_sg->lli;

switch (direction) {
case DMA_MEM_TO_DEV:
- desc->lli.saddr = buf_addr + (period_len * period_index);
- desc->lli.daddr = sconfig->dst_addr;
- desc->lli.ctrla = ctrla;
- desc->lli.ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
- ATC_DST_ADDR_MODE_FIXED) |
- FIELD_PREP(ATC_SRC_ADDR_MODE,
- ATC_SRC_ADDR_MODE_INCR) |
- FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) |
- FIELD_PREP(ATC_SIF, atchan->mem_if) |
- FIELD_PREP(ATC_DIF, atchan->per_if);
- desc->len = period_len;
+ lli->saddr = buf_addr + (period_len * i);
+ lli->daddr = sconfig->dst_addr;
+ lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
+ ATC_DST_ADDR_MODE_FIXED) |
+ FIELD_PREP(ATC_SRC_ADDR_MODE,
+ ATC_SRC_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) |
+ FIELD_PREP(ATC_SIF, atchan->mem_if) |
+ FIELD_PREP(ATC_DIF, atchan->per_if);
+
break;

case DMA_DEV_TO_MEM:
- desc->lli.saddr = sconfig->src_addr;
- desc->lli.daddr = buf_addr + (period_len * period_index);
- desc->lli.ctrla = ctrla;
- desc->lli.ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
- ATC_DST_ADDR_MODE_INCR) |
- FIELD_PREP(ATC_SRC_ADDR_MODE,
- ATC_SRC_ADDR_MODE_FIXED) |
- FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) |
- FIELD_PREP(ATC_SIF, atchan->per_if) |
- FIELD_PREP(ATC_DIF, atchan->mem_if);
- desc->len = period_len;
+ lli->saddr = sconfig->src_addr;
+ lli->daddr = buf_addr + (period_len * i);
+ lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
+ ATC_DST_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_SRC_ADDR_MODE,
+ ATC_SRC_ADDR_MODE_FIXED) |
+ FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) |
+ FIELD_PREP(ATC_SIF, atchan->per_if) |
+ FIELD_PREP(ATC_DIF, atchan->mem_if);
break;

default:
return -EINVAL;
}

+ lli->ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
+ FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) |
+ FIELD_PREP(ATC_DST_WIDTH, reg_width) |
+ FIELD_PREP(ATC_SRC_WIDTH, reg_width) |
+ period_len >> reg_width;
+ desc->sg[i].len = period_len;
+
return 0;
}

@@ -1723,8 +1475,7 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma_slave *atslave = chan->private;
struct dma_slave_config *sconfig = &atchan->dma_sconfig;
- struct at_desc *first = NULL;
- struct at_desc *prev = NULL;
+ struct at_desc *desc;
unsigned long was_cyclic;
unsigned int reg_width;
unsigned int periods = buf_len / period_len;
@@ -1758,33 +1509,26 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len))
goto err_out;

+ desc = kzalloc(struct_size(desc, sg, periods), GFP_ATOMIC);
+ if (!desc)
+ goto err_out;
+ desc->sglen = periods;
+
/* build cyclic linked list */
for (i = 0; i < periods; i++) {
- struct at_desc *desc;
-
- desc = atc_desc_get(atchan);
- if (!desc)
- goto err_desc_get;
-
if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr,
reg_width, period_len, direction))
- goto err_desc_get;
-
- atc_desc_chain(&first, &prev, desc);
+ goto err_fill_desc;
+ atdma_lli_chain(desc, i);
}
-
+ desc->total_len = buf_len;
/* lets make a cyclic list */
- prev->lli.dscr = first->txd.phys;
-
- /* First descriptor of the chain embedds additional information */
- first->txd.cookie = -EBUSY;
- first->total_len = buf_len;
+ desc->sg[i - 1].lli->dscr = desc->sg[0].lli_phys;

- return &first->txd;
+ return vchan_tx_prep(&atchan->vc, &desc->vd, flags);

-err_desc_get:
- dev_err(chan2dev(chan), "not enough descriptors available\n");
- atc_desc_put(atchan, first);
+err_fill_desc:
+ atdma_desc_free(&desc->vd);
err_out:
clear_bit(ATC_IS_CYCLIC, &atchan->status);
return NULL;
@@ -1813,17 +1557,17 @@ static int atc_pause(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
- int chan_id = atchan->dma_chan.chan_id;
+ int chan_id = atchan->vc.chan.chan_id;
unsigned long flags;

dev_vdbg(chan2dev(chan), "%s\n", __func__);

- spin_lock_irqsave(&atchan->lock, flags);
+ spin_lock_irqsave(&atchan->vc.lock, flags);

dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
set_bit(ATC_IS_PAUSED, &atchan->status);

- spin_unlock_irqrestore(&atchan->lock, flags);
+ spin_unlock_irqrestore(&atchan->vc.lock, flags);

return 0;
}
@@ -1832,7 +1576,7 @@ static int atc_resume(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
- int chan_id = atchan->dma_chan.chan_id;
+ int chan_id = atchan->vc.chan.chan_id;
unsigned long flags;

dev_vdbg(chan2dev(chan), "%s\n", __func__);
@@ -1840,12 +1584,12 @@ static int atc_resume(struct dma_chan *chan)
if (!atc_chan_is_paused(atchan))
return 0;

- spin_lock_irqsave(&atchan->lock, flags);
+ spin_lock_irqsave(&atchan->vc.lock, flags);

dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
clear_bit(ATC_IS_PAUSED, &atchan->status);

- spin_unlock_irqrestore(&atchan->lock, flags);
+ spin_unlock_irqrestore(&atchan->vc.lock, flags);

return 0;
}
@@ -1854,9 +1598,11 @@ static int atc_terminate_all(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
- int chan_id = atchan->dma_chan.chan_id;
+ int chan_id = atchan->vc.chan.chan_id;
unsigned long flags;

+ LIST_HEAD(list);
+
dev_vdbg(chan2dev(chan), "%s\n", __func__);

/*
@@ -1865,7 +1611,7 @@ static int atc_terminate_all(struct dma_chan *chan)
* channel. We still have to poll the channel enable bit due
* to AHB/HSB limitations.
*/
- spin_lock_irqsave(&atchan->lock, flags);
+ spin_lock_irqsave(&atchan->vc.lock, flags);

/* disabling channel: must also remove suspend state */
dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask);
@@ -1874,15 +1620,20 @@ static int atc_terminate_all(struct dma_chan *chan)
while (dma_readl(atdma, CHSR) & atchan->mask)
cpu_relax();

- /* active_list entries will end up before queued entries */
- list_splice_tail_init(&atchan->queue, &atchan->free_list);
- list_splice_tail_init(&atchan->active_list, &atchan->free_list);
+ if (atchan->desc) {
+ vchan_terminate_vdesc(&atchan->desc->vd);
+ atchan->desc = NULL;
+ }
+
+ vchan_get_all_descriptors(&atchan->vc, &list);

clear_bit(ATC_IS_PAUSED, &atchan->status);
/* if channel dedicated to cyclic operations, free it */
clear_bit(ATC_IS_CYCLIC, &atchan->status);

- spin_unlock_irqrestore(&atchan->lock, flags);
+ spin_unlock_irqrestore(&atchan->vc.lock, flags);
+
+ vchan_dma_desc_free_list(&atchan->vc, &list);

return 0;
}
@@ -1912,9 +1663,10 @@ atc_tx_status(struct dma_chan *chan,
if (dma_status == DMA_COMPLETE || !txstate)
return dma_status;

- spin_lock_irqsave(&atchan->lock, flags);
+ spin_lock_irqsave(&atchan->vc.lock, flags);
+ /* Get number of bytes left in the active transactions */
ret = atc_get_residue(chan, cookie, &residue);
- spin_unlock_irqrestore(&atchan->lock, flags);
+ spin_unlock_irqrestore(&atchan->vc.lock, flags);

if (unlikely(ret < 0)) {
dev_vdbg(chan2dev(chan), "get residual bytes error\n");
@@ -1929,27 +1681,17 @@ atc_tx_status(struct dma_chan *chan,
return dma_status;
}

-/**
- * atc_issue_pending - takes the first transaction descriptor in the pending
- * queue and starts the transfer.
- * @chan: target DMA channel
- */
static void atc_issue_pending(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
- struct at_desc *desc;
unsigned long flags;

- dev_vdbg(chan2dev(chan), "issue_pending\n");
-
- spin_lock_irqsave(&atchan->lock, flags);
- if (atc_chan_is_enabled(atchan) || list_empty(&atchan->queue))
- return spin_unlock_irqrestore(&atchan->lock, flags);
-
- desc = atc_first_queued(atchan);
- list_move_tail(&desc->desc_node, &atchan->active_list);
- atc_dostart(atchan, desc);
- spin_unlock_irqrestore(&atchan->lock, flags);
+ spin_lock_irqsave(&atchan->vc.lock, flags);
+ if (vchan_issue_pending(&atchan->vc) && !atchan->desc) {
+ if (!(atc_chan_is_enabled(atchan)))
+ atc_dostart(atchan);
+ }
+ spin_unlock_irqrestore(&atchan->vc.lock, flags);
}

/**
@@ -1962,9 +1704,7 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
- struct at_desc *desc;
struct at_dma_slave *atslave;
- int i;
u32 cfg;

dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
@@ -1975,11 +1715,6 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
return -EIO;
}

- if (!list_empty(&atchan->free_list)) {
- dev_dbg(chan2dev(chan), "can't allocate channel resources (channel not freed from a previous use)\n");
- return -EIO;
- }
-
cfg = ATC_DEFAULT_CFG;

atslave = chan->private;
@@ -1995,26 +1730,10 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
cfg = atslave->cfg;
}

- /* Allocate initial pool of descriptors */
- for (i = 0; i < init_nr_desc_per_channel; i++) {
- desc = atc_alloc_descriptor(chan, GFP_KERNEL);
- if (!desc) {
- dev_err(atdma->dma_device.dev,
- "Only %d initial descriptors\n", i);
- break;
- }
- list_add_tail(&desc->desc_node, &atchan->free_list);
- }
-
- dma_cookie_init(chan);
-
/* channel parameters */
channel_writel(atchan, CFG, cfg);

- dev_dbg(chan2dev(chan),
- "alloc_chan_resources: allocated %d descriptors\n", i);
-
- return i;
+ return 0;
}

/**
@@ -2024,22 +1743,10 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
static void atc_free_chan_resources(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
- struct at_dma *atdma = to_at_dma(chan->device);
- struct at_desc *desc, *_desc;
- LIST_HEAD(list);

- /* ASSERT: channel is idle */
- BUG_ON(!list_empty(&atchan->active_list));
- BUG_ON(!list_empty(&atchan->queue));
BUG_ON(atc_chan_is_enabled(atchan));

- list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
- dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
- list_del(&desc->desc_node);
- /* free link descriptor */
- dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys);
- }
- list_splice_init(&atchan->free_list, &list);
+ vchan_free_chan_resources(to_virt_chan(chan));
atchan->status = 0;

/*
@@ -2264,11 +1971,11 @@ static int __init at_dma_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, atdma);

/* create a pool of consistent memory blocks for hardware descriptors */
- atdma->dma_desc_pool = dma_pool_create("at_hdmac_desc_pool",
- &pdev->dev, sizeof(struct at_desc),
- 4 /* word alignment */, 0);
- if (!atdma->dma_desc_pool) {
- dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
+ atdma->lli_pool = dma_pool_create("at_hdmac_lli_pool",
+ &pdev->dev, sizeof(struct at_lli),
+ 4 /* word alignment */, 0);
+ if (!atdma->lli_pool) {
+ dev_err(&pdev->dev, "Unable to allocate DMA LLI descriptor pool\n");
err = -ENOMEM;
goto err_desc_pool_create;
}
@@ -2293,20 +2000,13 @@ static int __init at_dma_probe(struct platform_device *pdev)

atchan->mem_if = AT_DMA_MEM_IF;
atchan->per_if = AT_DMA_PER_IF;
- atchan->dma_chan.device = &atdma->dma_device;
- dma_cookie_init(&atchan->dma_chan);
- list_add_tail(&atchan->dma_chan.device_node,
- &atdma->dma_device.channels);

atchan->ch_regs = atdma->regs + ch_regs(i);
- spin_lock_init(&atchan->lock);
atchan->mask = 1 << i;

- INIT_LIST_HEAD(&atchan->active_list);
- INIT_LIST_HEAD(&atchan->queue);
- INIT_LIST_HEAD(&atchan->free_list);
-
- tasklet_setup(&atchan->tasklet, atc_tasklet);
+ atchan->atdma = atdma;
+ atchan->vc.desc_free = atdma_desc_free;
+ vchan_init(&atchan->vc, &atdma->dma_device);
atc_enable_chan_irq(atdma, i);
}

@@ -2380,7 +2080,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
err_dma_async_device_register:
dma_pool_destroy(atdma->memset_pool);
err_memset_pool_create:
- dma_pool_destroy(atdma->dma_desc_pool);
+ dma_pool_destroy(atdma->lli_pool);
err_desc_pool_create:
clk_disable_unprepare(atdma->clk);
return err;
@@ -2397,16 +2097,12 @@ static int at_dma_remove(struct platform_device *pdev)
dma_async_device_unregister(&atdma->dma_device);

dma_pool_destroy(atdma->memset_pool);
- dma_pool_destroy(atdma->dma_desc_pool);
+ dma_pool_destroy(atdma->lli_pool);

list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
- struct at_dma_chan *atchan = to_at_dma_chan(chan);
-
/* Disable interrupts */
atc_disable_chan_irq(atdma, chan->chan_id);
-
- tasklet_kill(&atchan->tasklet);
list_del(&chan->device_node);
}

@@ -2440,7 +2136,7 @@ static int at_dma_prepare(struct device *dev)

static void atc_suspend_cyclic(struct at_dma_chan *atchan)
{
- struct dma_chan *chan = &atchan->dma_chan;
+ struct dma_chan *chan = &atchan->vc.chan;

/* Channel should be paused by user
* do it anyway even if it is not done already */
@@ -2481,7 +2177,7 @@ static int at_dma_suspend_noirq(struct device *dev)

static void atc_resume_cyclic(struct at_dma_chan *atchan)
{
- struct at_dma *atdma = to_at_dma(atchan->dma_chan.device);
+ struct at_dma *atdma = to_at_dma(atchan->vc.chan.device);

/* restore channel status for cyclic descriptors list:
* next descriptor in the cyclic list at the time of suspend */
@@ -2555,5 +2251,6 @@ module_exit(at_dma_exit);

MODULE_DESCRIPTION("Atmel AHB DMA Controller driver");
MODULE_AUTHOR("Nicolas Ferre <[email protected]>");
+MODULE_AUTHOR("Tudor Ambarus <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:at_hdmac");
--
2.25.1

2022-08-20 13:39:49

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 19/33] dmaengine: at_hdmac: Don't allow CPU to reorder channel enable

at_hdmac uses __raw_writel for register writes. In the absence of a
barrier, the CPU may reorder the register operations.
Introduce a write memory barrier so that the CPU does not reorder the
channel enable, thus the start of the transfer, without making sure that
all the pre-required register fields are already written.

Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <[email protected]>
Cc: [email protected]
Signed-off-by: Tudor Ambarus <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
---
drivers/dma/at_hdmac.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 825a29ede35e..1cb0d26d30ed 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -691,6 +691,8 @@ static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
channel_writel(atchan, DPIP, FIELD_PREP(ATC_DPIP_HOLE,
first->dst_hole) |
FIELD_PREP(ATC_DPIP_BOUNDARY, first->boundary));
+ /* Don't allow CPU to reorder channel enable. */
+ wmb();
dma_writel(atdma, CHER, atchan->mask);

vdbg_dump_regs(atchan);
--
2.25.1

2022-08-20 13:39:51

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 23/33] dmaengine: at_hdmac: s/atc_get_bytes_left/atc_get_residue

Use dmaengine terminology and rename the method to better indicate what it
does: it gets the residue value which will be later on set with
dma_set_residue().

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index abb884a08bd4..daf2a3af25d4 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -743,15 +743,15 @@ static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
}

/**
- * atc_get_bytes_left - get the number of bytes residue for a cookie.
+ * atc_get_residue - get the number of bytes residue for a cookie.
* The residue is passed by address and updated on success.
* @chan: DMA channel
* @cookie: transaction identifier to check status of
* @residue: residue to be updated.
* Return 0 on success, -errono otherwise.
*/
-static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie,
- u32 *residue)
+static int atc_get_residue(struct dma_chan *chan, dma_cookie_t cookie,
+ u32 *residue)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_desc *desc_first = atc_first_active(atchan);
@@ -1913,10 +1913,7 @@ atc_tx_status(struct dma_chan *chan,
return dma_status;

spin_lock_irqsave(&atchan->lock, flags);
-
- /* Get number of bytes left in the active transactions */
- ret = atc_get_bytes_left(chan, cookie, &residue);
-
+ ret = atc_get_residue(chan, cookie, &residue);
spin_unlock_irqrestore(&atchan->lock, flags);

if (unlikely(ret < 0)) {
--
2.25.1

2022-08-20 13:39:59

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 03/33] dmaengine: at_hdmac: Rename "dma_common" to "dma_device"

"dma_common" name was misleading and did not suggest that's actually
a struct dma_device underneath. Rename it so that readers can follow the
code easier. One may see some checks and a warning when running
checkpatch. Those have nothing to do with the rename and will be addressed
in a further patch.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 92 +++++++++++++++++++++---------------------
1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index d798e3443298..997d20c319e8 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -331,7 +331,7 @@ static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
/*-- Controller ------------------------------------------------------*/
/**
* struct at_dma - internal representation of an Atmel HDMA Controller
- * @chan_common: common dmaengine dma_device object members
+ * @dma_device: dmaengine dma_device object members
* @atdma_devtype: identifier of DMA controller compatibility
* @ch_regs: memory mapped register base
* @clk: dma controller clock
@@ -341,7 +341,7 @@ static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
* @chan: channels table to store at_dma_chan structures
*/
struct at_dma {
- struct dma_device dma_common;
+ struct dma_device dma_device;
void __iomem *regs;
struct clk *clk;
u32 save_imr;
@@ -361,7 +361,7 @@ struct at_dma {

static inline struct at_dma *to_at_dma(struct dma_device *ddev)
{
- return container_of(ddev, struct at_dma, dma_common);
+ return container_of(ddev, struct at_dma, dma_device);
}

/*-- Helper functions ------------------------------------------------*/
@@ -1083,11 +1083,11 @@ static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
if (!pending)
break;

- dev_vdbg(atdma->dma_common.dev,
+ dev_vdbg(atdma->dma_device.dev,
"interrupt: status = 0x%08x, 0x%08x, 0x%08x\n",
status, imr, pending);

- for (i = 0; i < atdma->dma_common.chancnt; i++) {
+ for (i = 0; i < atdma->dma_device.chancnt; i++) {
atchan = &atdma->chan[i];
if (pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))) {
if (pending & AT_DMA_ERR(i)) {
@@ -2031,7 +2031,7 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
* We need controller-specific data to set up slave
* transfers.
*/
- BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_common.dev);
+ BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_device.dev);

/* if cfg configuration specified take it instead of default */
if (atslave->cfg)
@@ -2042,7 +2042,7 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
for (i = 0; i < init_nr_desc_per_channel; i++) {
desc = atc_alloc_descriptor(chan, GFP_KERNEL);
if (!desc) {
- dev_err(atdma->dma_common.dev,
+ dev_err(atdma->dma_device.dev,
"Only %d initial descriptors\n", i);
break;
}
@@ -2288,7 +2288,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
return -ENOMEM;

/* discover transaction capabilities */
- atdma->dma_common.cap_mask = plat_dat->cap_mask;
+ atdma->dma_device.cap_mask = plat_dat->cap_mask;
atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1;

size = resource_size(io);
@@ -2345,16 +2345,16 @@ static int __init at_dma_probe(struct platform_device *pdev)
cpu_relax();

/* initialize channels related values */
- INIT_LIST_HEAD(&atdma->dma_common.channels);
+ INIT_LIST_HEAD(&atdma->dma_device.channels);
for (i = 0; i < plat_dat->nr_channels; i++) {
struct at_dma_chan *atchan = &atdma->chan[i];

atchan->mem_if = AT_DMA_MEM_IF;
atchan->per_if = AT_DMA_PER_IF;
- atchan->chan_common.device = &atdma->dma_common;
+ atchan->chan_common.device = &atdma->dma_device;
dma_cookie_init(&atchan->chan_common);
list_add_tail(&atchan->chan_common.device_node,
- &atdma->dma_common.channels);
+ &atdma->dma_device.channels);

atchan->ch_regs = atdma->regs + ch_regs(i);
spin_lock_init(&atchan->lock);
@@ -2369,49 +2369,49 @@ static int __init at_dma_probe(struct platform_device *pdev)
}

/* set base routines */
- atdma->dma_common.device_alloc_chan_resources = atc_alloc_chan_resources;
- atdma->dma_common.device_free_chan_resources = atc_free_chan_resources;
- atdma->dma_common.device_tx_status = atc_tx_status;
- atdma->dma_common.device_issue_pending = atc_issue_pending;
- atdma->dma_common.dev = &pdev->dev;
+ atdma->dma_device.device_alloc_chan_resources = atc_alloc_chan_resources;
+ atdma->dma_device.device_free_chan_resources = atc_free_chan_resources;
+ atdma->dma_device.device_tx_status = atc_tx_status;
+ atdma->dma_device.device_issue_pending = atc_issue_pending;
+ atdma->dma_device.dev = &pdev->dev;

/* set prep routines based on capability */
- if (dma_has_cap(DMA_INTERLEAVE, atdma->dma_common.cap_mask))
- atdma->dma_common.device_prep_interleaved_dma = atc_prep_dma_interleaved;
+ if (dma_has_cap(DMA_INTERLEAVE, atdma->dma_device.cap_mask))
+ atdma->dma_device.device_prep_interleaved_dma = atc_prep_dma_interleaved;

- if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask))
- atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy;
+ if (dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask))
+ atdma->dma_device.device_prep_dma_memcpy = atc_prep_dma_memcpy;

- if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) {
- atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset;
- atdma->dma_common.device_prep_dma_memset_sg = atc_prep_dma_memset_sg;
- atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES;
+ if (dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask)) {
+ atdma->dma_device.device_prep_dma_memset = atc_prep_dma_memset;
+ atdma->dma_device.device_prep_dma_memset_sg = atc_prep_dma_memset_sg;
+ atdma->dma_device.fill_align = DMAENGINE_ALIGN_4_BYTES;
}

- if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) {
- atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg;
+ if (dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask)) {
+ atdma->dma_device.device_prep_slave_sg = atc_prep_slave_sg;
/* controller can do slave DMA: can trigger cyclic transfers */
- dma_cap_set(DMA_CYCLIC, atdma->dma_common.cap_mask);
- atdma->dma_common.device_prep_dma_cyclic = atc_prep_dma_cyclic;
- atdma->dma_common.device_config = atc_config;
- atdma->dma_common.device_pause = atc_pause;
- atdma->dma_common.device_resume = atc_resume;
- atdma->dma_common.device_terminate_all = atc_terminate_all;
- atdma->dma_common.src_addr_widths = ATC_DMA_BUSWIDTHS;
- atdma->dma_common.dst_addr_widths = ATC_DMA_BUSWIDTHS;
- atdma->dma_common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
- atdma->dma_common.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+ dma_cap_set(DMA_CYCLIC, atdma->dma_device.cap_mask);
+ atdma->dma_device.device_prep_dma_cyclic = atc_prep_dma_cyclic;
+ atdma->dma_device.device_config = atc_config;
+ atdma->dma_device.device_pause = atc_pause;
+ atdma->dma_device.device_resume = atc_resume;
+ atdma->dma_device.device_terminate_all = atc_terminate_all;
+ atdma->dma_device.src_addr_widths = ATC_DMA_BUSWIDTHS;
+ atdma->dma_device.dst_addr_widths = ATC_DMA_BUSWIDTHS;
+ atdma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ atdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
}

dma_writel(atdma, EN, AT_DMA_ENABLE);

dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n",
- dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
- dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask) ? "set " : "",
- dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask) ? "slave " : "",
+ dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask) ? "cpy " : "",
+ dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask) ? "set " : "",
+ dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask) ? "slave " : "",
plat_dat->nr_channels);

- dma_async_device_register(&atdma->dma_common);
+ dma_async_device_register(&atdma->dma_device);

/*
* Do not return an error if the dmac node is not present in order to
@@ -2430,7 +2430,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
return 0;

err_of_dma_controller_register:
- dma_async_device_unregister(&atdma->dma_common);
+ dma_async_device_unregister(&atdma->dma_device);
dma_pool_destroy(atdma->memset_pool);
err_memset_pool_create:
dma_pool_destroy(atdma->dma_desc_pool);
@@ -2459,13 +2459,13 @@ static int at_dma_remove(struct platform_device *pdev)
at_dma_off(atdma);
if (pdev->dev.of_node)
of_dma_controller_free(pdev->dev.of_node);
- dma_async_device_unregister(&atdma->dma_common);
+ dma_async_device_unregister(&atdma->dma_device);

dma_pool_destroy(atdma->memset_pool);
dma_pool_destroy(atdma->dma_desc_pool);
free_irq(platform_get_irq(pdev, 0), atdma);

- list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
+ list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
struct at_dma_chan *atchan = to_at_dma_chan(chan);

@@ -2503,7 +2503,7 @@ static int at_dma_prepare(struct device *dev)
struct at_dma *atdma = dev_get_drvdata(dev);
struct dma_chan *chan, *_chan;

- list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
+ list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
struct at_dma_chan *atchan = to_at_dma_chan(chan);
/* wait for transaction completion (except in cyclic case) */
@@ -2538,7 +2538,7 @@ static int at_dma_suspend_noirq(struct device *dev)
struct dma_chan *chan, *_chan;

/* preserve data */
- list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
+ list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
struct at_dma_chan *atchan = to_at_dma_chan(chan);

@@ -2588,7 +2588,7 @@ static int at_dma_resume_noirq(struct device *dev)

/* restore saved data */
dma_writel(atdma, EBCIER, atdma->save_imr);
- list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
+ list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
struct at_dma_chan *atchan = to_at_dma_chan(chan);

--
2.25.1

2022-08-20 13:40:22

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 07/33] dmaengine: at_hdmac: Fix at_lli struct definition

From: Tudor Ambarus <[email protected]>

Those hardware registers are all of 32 bits, while dma_addr_t ca be of
type u64 or u32 depending on CONFIG_ARCH_DMA_ADDR_T_64BIT. Force u32 to
comply with what the hardware expects.

Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Signed-off-by: Tudor Ambarus <[email protected]>
Cc: [email protected]
---
drivers/dma/at_hdmac.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 91e53a590d5f..e89facf14fab 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -187,13 +187,13 @@
/* LLI == Linked List Item; aka DMA buffer descriptor */
struct at_lli {
/* values that are not changed by hardware */
- dma_addr_t saddr;
- dma_addr_t daddr;
+ u32 saddr;
+ u32 daddr;
/* value that may get written back: */
- u32 ctrla;
+ u32 ctrla;
/* more values that are not changed by hardware */
- u32 ctrlb;
- dma_addr_t dscr; /* chain to next lli */
+ u32 ctrlb;
+ u32 dscr; /* chain to next lli */
};

/**
--
2.25.1

2022-08-20 13:41:44

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 18/33] dmaengine: at_hdmac: Fix completion of unissued descriptor in case of errors

In case the controller detected an error, the code took the chance to move
all the queued (submitted) descriptors to the active (issued) list. This
was wrong as if there were any descriptors in the submitted list they were
moved to the issued list without actually issuing them to the controller,
thus a completion could be raised without even fireing the descriptor.

Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <[email protected]>
Cc: [email protected]
Signed-off-by: Tudor Ambarus <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
---
drivers/dma/at_hdmac.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index e5ac73768d13..825a29ede35e 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -974,10 +974,6 @@ static void atc_handle_error(struct at_dma_chan *atchan)
bad_desc = atc_first_active(atchan);
list_del_init(&bad_desc->desc_node);

- /* As we are stopped, take advantage to push queued descriptors
- * in active_list */
- list_splice_init(&atchan->queue, atchan->active_list.prev);
-
/* Try to restart the controller */
if (!list_empty(&atchan->active_list)) {
desc = atc_first_queued(atchan);
--
2.25.1

2022-08-20 13:44:12

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 32/33] dmaengine: at_hdmac: Set include entries in alphabetic order

It's a good practice to set the include entries in alphabetic order. It
helps humans to read the code easier. Alphabetic order should also prove
that each header is self-contained, i.e. can be included without
prerequisites.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index e35b4b325452..a2b24b9e85ce 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -13,16 +13,16 @@
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
-#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
+#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
#include <linux/of.h>
#include <linux/overflow.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>

#include "dmaengine.h"

--
2.25.1

2022-08-20 13:44:34

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 25/33] dmaengine: at_hdmac: Remove superfluous cast

Conversions of void * are applied automatically when other pointer types
are assigned to and from void *. Remove the superfluous cast.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 4cd3293887f2..f2c645e60619 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1042,7 +1042,7 @@ static void atc_tasklet(struct tasklet_struct *t)

static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
{
- struct at_dma *atdma = (struct at_dma *)dev_id;
+ struct at_dma *atdma = dev_id;
struct at_dma_chan *atchan;
int i;
u32 status, pending, imr;
--
2.25.1

2022-08-20 13:44:36

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 09/33] dmaengine: at_hdmac: Start transfer for cyclic channels in issue_pending

Cyclic channels must too call issue_pending in order to start a transfer.
Start the transfer in issue_pending regardless of the type of channel.
This wrongly worked before, because in the past the transfer was started
at tx_submit level when only a desc in the transfer list.

Fixes: 53830cc75974 ("dmaengine: at_hdmac: add cyclic DMA operation support")
Reported-by: Peter Rosin <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/lkml/[email protected]/
---
drivers/dma/at_hdmac.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index b6b1d2dcfc4c..d9f492081e76 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1972,10 +1972,6 @@ static void atc_issue_pending(struct dma_chan *chan)

dev_vdbg(chan2dev(chan), "issue_pending\n");

- /* Not needed for cyclic transfers */
- if (atc_chan_is_cyclic(atchan))
- return;
-
atc_advance_work(atchan);
}

--
2.25.1

2022-08-20 13:44:55

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 02/33] dmaengine: at_hdmac: Use bitfield access macros

Use the bitfield access macros in order to clean and to make the driver
easier to read. One will see some "line length exceeds 100 columns"
checkpatch warnings. I chose to not introduce new lines for regs
descriptions in order to preserve the style of the comments throughout
the definitions. Style can be fixed in a further patch.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 406 ++++++++++++++++++++---------------------
1 file changed, 198 insertions(+), 208 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index bcd67e12ca31..d798e3443298 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -10,6 +10,7 @@
*/

#include <dt-bindings/dma/at91.h>
+#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
@@ -35,172 +36,151 @@

#define AT_DMA_MAX_NR_CHANNELS 8

-#define AT_DMA_GCFG 0x00 /* Global Configuration Register */
-#define AT_DMA_IF_BIGEND(i) (0x1 << (i)) /* AHB-Lite Interface i in Big-endian mode */
-#define AT_DMA_ARB_CFG (0x1 << 4) /* Arbiter mode. */
-#define AT_DMA_ARB_CFG_FIXED (0x0 << 4)
-#define AT_DMA_ARB_CFG_ROUND_ROBIN (0x1 << 4)
+/* Global Configuration Register */
+#define AT_DMA_GCFG 0x00
+#define AT_DMA_IF_BIGEND(i) BIT((i)) /* AHB-Lite Interface i in Big-endian mode */
+#define AT_DMA_ARB_CFG BIT(4) /* Arbiter mode. */

-#define AT_DMA_EN 0x04 /* Controller Enable Register */
-#define AT_DMA_ENABLE (0x1 << 0)
+/* Controller Enable Register */
+#define AT_DMA_EN 0x04
+#define AT_DMA_ENABLE BIT(0)

-#define AT_DMA_SREQ 0x08 /* Software Single Request Register */
-#define AT_DMA_SSREQ(x) (0x1 << ((x) << 1)) /* Request a source single transfer on channel x */
-#define AT_DMA_DSREQ(x) (0x1 << (1 + ((x) << 1))) /* Request a destination single transfer on channel x */
+/* Software Single Request Register */
+#define AT_DMA_SREQ 0x08
+#define AT_DMA_SSREQ(x) BIT((x) << 1) /* Request a source single transfer on channel x */
+#define AT_DMA_DSREQ(x) BIT(1 + ((x) << 1)) /* Request a destination single transfer on channel x */

-#define AT_DMA_CREQ 0x0C /* Software Chunk Transfer Request Register */
-#define AT_DMA_SCREQ(x) (0x1 << ((x) << 1)) /* Request a source chunk transfer on channel x */
-#define AT_DMA_DCREQ(x) (0x1 << (1 + ((x) << 1))) /* Request a destination chunk transfer on channel x */
+/* Software Chunk Transfer Request Register */
+#define AT_DMA_CREQ 0x0c
+#define AT_DMA_SCREQ(x) BIT((x) << 1) /* Request a source chunk transfer on channel x */
+#define AT_DMA_DCREQ(x) BIT(1 + ((x) << 1)) /* Request a destination chunk transfer on channel x */

-#define AT_DMA_LAST 0x10 /* Software Last Transfer Flag Register */
-#define AT_DMA_SLAST(x) (0x1 << ((x) << 1)) /* This src rq is last tx of buffer on channel x */
-#define AT_DMA_DLAST(x) (0x1 << (1 + ((x) << 1))) /* This dst rq is last tx of buffer on channel x */
+/* Software Last Transfer Flag Register */
+#define AT_DMA_LAST 0x10
+#define AT_DMA_SLAST(x) BIT((x) << 1) /* This src rq is last tx of buffer on channel x */
+#define AT_DMA_DLAST(x) BIT(1 + ((x) << 1)) /* This dst rq is last tx of buffer on channel x */

-#define AT_DMA_SYNC 0x14 /* Request Synchronization Register */
-#define AT_DMA_SYR(h) (0x1 << (h)) /* Synchronize handshake line h */
+/* Request Synchronization Register */
+#define AT_DMA_SYNC 0x14
+#define AT_DMA_SYR(h) BIT((h)) /* Synchronize handshake line h */

/* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */
-#define AT_DMA_EBCIER 0x18 /* Enable register */
-#define AT_DMA_EBCIDR 0x1C /* Disable register */
-#define AT_DMA_EBCIMR 0x20 /* Mask Register */
-#define AT_DMA_EBCISR 0x24 /* Status Register */
-#define AT_DMA_CBTC_OFFSET 8
-#define AT_DMA_ERR_OFFSET 16
-#define AT_DMA_BTC(x) (0x1 << (x))
-#define AT_DMA_CBTC(x) (0x1 << (AT_DMA_CBTC_OFFSET + (x)))
-#define AT_DMA_ERR(x) (0x1 << (AT_DMA_ERR_OFFSET + (x)))
-
-#define AT_DMA_CHER 0x28 /* Channel Handler Enable Register */
-#define AT_DMA_ENA(x) (0x1 << (x))
-#define AT_DMA_SUSP(x) (0x1 << ( 8 + (x)))
-#define AT_DMA_KEEP(x) (0x1 << (24 + (x)))
-
-#define AT_DMA_CHDR 0x2C /* Channel Handler Disable Register */
-#define AT_DMA_DIS(x) (0x1 << (x))
-#define AT_DMA_RES(x) (0x1 << ( 8 + (x)))
-
-#define AT_DMA_CHSR 0x30 /* Channel Handler Status Register */
-#define AT_DMA_EMPT(x) (0x1 << (16 + (x)))
-#define AT_DMA_STAL(x) (0x1 << (24 + (x)))
-
-#define AT_DMA_CH_REGS_BASE 0x3C /* Channel registers base address */
-#define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */
+#define AT_DMA_EBCIER 0x18 /* Enable register */
+#define AT_DMA_EBCIDR 0x1c /* Disable register */
+#define AT_DMA_EBCIMR 0x20 /* Mask Register */
+#define AT_DMA_EBCISR 0x24 /* Status Register */
+#define AT_DMA_CBTC_OFFSET 8
+#define AT_DMA_ERR_OFFSET 16
+#define AT_DMA_BTC(x) BIT((x))
+#define AT_DMA_CBTC(x) BIT(AT_DMA_CBTC_OFFSET + (x))
+#define AT_DMA_ERR(x) BIT(AT_DMA_ERR_OFFSET + (x))
+
+/* Channel Handler Enable Register */
+#define AT_DMA_CHER 0x28
+#define AT_DMA_ENA(x) BIT((x))
+#define AT_DMA_SUSP(x) BIT(8 + (x))
+#define AT_DMA_KEEP(x) BIT(24 + (x))
+
+/* Channel Handler Disable Register */
+#define AT_DMA_CHDR 0x2c
+#define AT_DMA_DIS(x) BIT(x)
+#define AT_DMA_RES(x) BIT(8 + (x))
+
+/* Channel Handler Status Register */
+#define AT_DMA_CHSR 0x30
+#define AT_DMA_EMPT(x) BIT(16 + (x))
+#define AT_DMA_STAL(x) BIT(24 + (x))
+
+/* Channel registers base address */
+#define AT_DMA_CH_REGS_BASE 0x3c
+#define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */

/* Hardware register offset for each channel */
-#define ATC_SADDR_OFFSET 0x00 /* Source Address Register */
-#define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */
-#define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */
-#define ATC_CTRLA_OFFSET 0x0C /* Control A Register */
-#define ATC_CTRLB_OFFSET 0x10 /* Control B Register */
-#define ATC_CFG_OFFSET 0x14 /* Configuration Register */
-#define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */
-#define ATC_DPIP_OFFSET 0x1C /* Dst PIP Configuration Register */
+#define ATC_SADDR_OFFSET 0x00 /* Source Address Register */
+#define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */
+#define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */
+#define ATC_CTRLA_OFFSET 0x0c /* Control A Register */
+#define ATC_CTRLB_OFFSET 0x10 /* Control B Register */
+#define ATC_CFG_OFFSET 0x14 /* Configuration Register */
+#define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */
+#define ATC_DPIP_OFFSET 0x1c /* Dst PIP Configuration Register */

/* Bitfield definitions */
/* Bitfields in DSCR */
-#define ATC_DSCR_IF(i) (0x3 & (i)) /* Dsc feched via AHB-Lite Interface i */
+#define ATC_DSCR_IF GENMASK(1, 0) /* Dsc feched via AHB-Lite Interface */

/* Bitfields in CTRLA */
-#define ATC_BTSIZE_MAX 0xFFFFUL /* Maximum Buffer Transfer Size */
-#define ATC_BTSIZE(x) (ATC_BTSIZE_MAX & (x)) /* Buffer Transfer Size */
-#define ATC_SCSIZE_MASK (0x7 << 16) /* Source Chunk Transfer Size */
-#define ATC_SCSIZE(x) (ATC_SCSIZE_MASK & ((x) << 16))
-#define ATC_SCSIZE_1 (0x0 << 16)
-#define ATC_SCSIZE_4 (0x1 << 16)
-#define ATC_SCSIZE_8 (0x2 << 16)
-#define ATC_SCSIZE_16 (0x3 << 16)
-#define ATC_SCSIZE_32 (0x4 << 16)
-#define ATC_SCSIZE_64 (0x5 << 16)
-#define ATC_SCSIZE_128 (0x6 << 16)
-#define ATC_SCSIZE_256 (0x7 << 16)
-#define ATC_DCSIZE_MASK (0x7 << 20) /* Destination Chunk Transfer Size */
-#define ATC_DCSIZE(x) (ATC_DCSIZE_MASK & ((x) << 20))
-#define ATC_DCSIZE_1 (0x0 << 20)
-#define ATC_DCSIZE_4 (0x1 << 20)
-#define ATC_DCSIZE_8 (0x2 << 20)
-#define ATC_DCSIZE_16 (0x3 << 20)
-#define ATC_DCSIZE_32 (0x4 << 20)
-#define ATC_DCSIZE_64 (0x5 << 20)
-#define ATC_DCSIZE_128 (0x6 << 20)
-#define ATC_DCSIZE_256 (0x7 << 20)
-#define ATC_SRC_WIDTH_MASK (0x3 << 24) /* Source Single Transfer Size */
-#define ATC_SRC_WIDTH(x) ((x) << 24)
-#define ATC_SRC_WIDTH_BYTE (0x0 << 24)
-#define ATC_SRC_WIDTH_HALFWORD (0x1 << 24)
-#define ATC_SRC_WIDTH_WORD (0x2 << 24)
-#define ATC_REG_TO_SRC_WIDTH(r) (((r) >> 24) & 0x3)
-#define ATC_DST_WIDTH_MASK (0x3 << 28) /* Destination Single Transfer Size */
-#define ATC_DST_WIDTH(x) ((x) << 28)
-#define ATC_DST_WIDTH_BYTE (0x0 << 28)
-#define ATC_DST_WIDTH_HALFWORD (0x1 << 28)
-#define ATC_DST_WIDTH_WORD (0x2 << 28)
-#define ATC_DONE (0x1 << 31) /* Tx Done (only written back in descriptor) */
+#define ATC_BTSIZE_MAX GENMASK(15, 0) /* Maximum Buffer Transfer Size */
+#define ATC_BTSIZE GENMASK(15, 0) /* Buffer Transfer Size */
+#define ATC_SCSIZE GENMASK(18, 16) /* Source Chunk Transfer Size */
+#define ATC_DCSIZE GENMASK(22, 20) /* Destination Chunk Transfer Size */
+#define ATC_SRC_WIDTH GENMASK(25, 24) /* Source Single Transfer Size */
+#define ATC_DST_WIDTH GENMASK(29, 28) /* Destination Single Transfer Size */
+#define ATC_DONE BIT(31) /* Tx Done (only written back in descriptor) */

/* Bitfields in CTRLB */
-#define ATC_SIF(i) (0x3 & (i)) /* Src tx done via AHB-Lite Interface i */
-#define ATC_DIF(i) ((0x3 & (i)) << 4) /* Dst tx done via AHB-Lite Interface i */
- /* Specify AHB interfaces */
-#define AT_DMA_MEM_IF 0 /* interface 0 as memory interface */
-#define AT_DMA_PER_IF 1 /* interface 1 as peripheral interface */
-
-#define ATC_SRC_PIP (0x1 << 8) /* Source Picture-in-Picture enabled */
-#define ATC_DST_PIP (0x1 << 12) /* Destination Picture-in-Picture enabled */
-#define ATC_SRC_DSCR_DIS (0x1 << 16) /* Src Descriptor fetch disable */
-#define ATC_DST_DSCR_DIS (0x1 << 20) /* Dst Descriptor fetch disable */
-#define ATC_FC_MASK (0x7 << 21) /* Choose Flow Controller */
-#define ATC_FC_MEM2MEM (0x0 << 21) /* Mem-to-Mem (DMA) */
-#define ATC_FC_MEM2PER (0x1 << 21) /* Mem-to-Periph (DMA) */
-#define ATC_FC_PER2MEM (0x2 << 21) /* Periph-to-Mem (DMA) */
-#define ATC_FC_PER2PER (0x3 << 21) /* Periph-to-Periph (DMA) */
-#define ATC_FC_PER2MEM_PER (0x4 << 21) /* Periph-to-Mem (Peripheral) */
-#define ATC_FC_MEM2PER_PER (0x5 << 21) /* Mem-to-Periph (Peripheral) */
-#define ATC_FC_PER2PER_SRCPER (0x6 << 21) /* Periph-to-Periph (Src Peripheral) */
-#define ATC_FC_PER2PER_DSTPER (0x7 << 21) /* Periph-to-Periph (Dst Peripheral) */
-#define ATC_SRC_ADDR_MODE_MASK (0x3 << 24)
-#define ATC_SRC_ADDR_MODE_INCR (0x0 << 24) /* Incrementing Mode */
-#define ATC_SRC_ADDR_MODE_DECR (0x1 << 24) /* Decrementing Mode */
-#define ATC_SRC_ADDR_MODE_FIXED (0x2 << 24) /* Fixed Mode */
-#define ATC_DST_ADDR_MODE_MASK (0x3 << 28)
-#define ATC_DST_ADDR_MODE_INCR (0x0 << 28) /* Incrementing Mode */
-#define ATC_DST_ADDR_MODE_DECR (0x1 << 28) /* Decrementing Mode */
-#define ATC_DST_ADDR_MODE_FIXED (0x2 << 28) /* Fixed Mode */
-#define ATC_IEN (0x1 << 30) /* BTC interrupt enable (active low) */
-#define ATC_AUTO (0x1 << 31) /* Auto multiple buffer tx enable */
+#define ATC_SIF GENMASK(1, 0) /* Src tx done via AHB-Lite Interface i */
+#define ATC_DIF GENMASK(5, 4) /* Dst tx done via AHB-Lite Interface i */
+#define AT_DMA_MEM_IF 0x0 /* interface 0 as memory interface */
+#define AT_DMA_PER_IF 0x1 /* interface 1 as peripheral interface */
+#define ATC_SRC_PIP BIT(8) /* Source Picture-in-Picture enabled */
+#define ATC_DST_PIP BIT(12) /* Destination Picture-in-Picture enabled */
+#define ATC_SRC_DSCR_DIS BIT(16) /* Src Descriptor fetch disable */
+#define ATC_DST_DSCR_DIS BIT(20) /* Dst Descriptor fetch disable */
+#define ATC_FC GENMASK(22, 21) /* Choose Flow Controller */
+#define ATC_FC_MEM2MEM 0x0 /* Mem-to-Mem (DMA) */
+#define ATC_FC_MEM2PER 0x1 /* Mem-to-Periph (DMA) */
+#define ATC_FC_PER2MEM 0x2 /* Periph-to-Mem (DMA) */
+#define ATC_FC_PER2PER 0x3 /* Periph-to-Periph (DMA) */
+#define ATC_FC_PER2MEM_PER 0x4 /* Periph-to-Mem (Peripheral) */
+#define ATC_FC_MEM2PER_PER 0x5 /* Mem-to-Periph (Peripheral) */
+#define ATC_FC_PER2PER_SRCPER 0x6 /* Periph-to-Periph (Src Peripheral) */
+#define ATC_FC_PER2PER_DSTPER 0x7 /* Periph-to-Periph (Dst Peripheral) */
+#define ATC_SRC_ADDR_MODE GENMASK(25, 24)
+#define ATC_SRC_ADDR_MODE_INCR 0x0 /* Incrementing Mode */
+#define ATC_SRC_ADDR_MODE_DECR 0x1 /* Decrementing Mode */
+#define ATC_SRC_ADDR_MODE_FIXED 0x2 /* Fixed Mode */
+#define ATC_DST_ADDR_MODE GENMASK(29, 28)
+#define ATC_DST_ADDR_MODE_INCR 0x0 /* Incrementing Mode */
+#define ATC_DST_ADDR_MODE_DECR 0x1 /* Decrementing Mode */
+#define ATC_DST_ADDR_MODE_FIXED 0x2 /* Fixed Mode */
+#define ATC_IEN BIT(30) /* BTC interrupt enable (active low) */
+#define ATC_AUTO BIT(31) /* Auto multiple buffer tx enable */

/* Bitfields in CFG */
#define ATC_PER_MSB(h) ((0x30U & (h)) >> 4) /* Extract most significant bits of a handshaking identifier */

-#define ATC_SRC_PER(h) (0xFU & (h)) /* Channel src rq associated with periph handshaking ifc h */
-#define ATC_DST_PER(h) ((0xFU & (h)) << 4) /* Channel dst rq associated with periph handshaking ifc h */
-#define ATC_SRC_REP (0x1 << 8) /* Source Replay Mod */
-#define ATC_SRC_H2SEL (0x1 << 9) /* Source Handshaking Mod */
-#define ATC_SRC_H2SEL_SW (0x0 << 9)
-#define ATC_SRC_H2SEL_HW (0x1 << 9)
-#define ATC_SRC_PER_MSB(h) (ATC_PER_MSB(h) << 10) /* Channel src rq (most significant bits) */
-#define ATC_DST_REP (0x1 << 12) /* Destination Replay Mod */
-#define ATC_DST_H2SEL (0x1 << 13) /* Destination Handshaking Mod */
-#define ATC_DST_H2SEL_SW (0x0 << 13)
-#define ATC_DST_H2SEL_HW (0x1 << 13)
-#define ATC_DST_PER_MSB(h) (ATC_PER_MSB(h) << 14) /* Channel dst rq (most significant bits) */
-#define ATC_SOD (0x1 << 16) /* Stop On Done */
-#define ATC_LOCK_IF (0x1 << 20) /* Interface Lock */
-#define ATC_LOCK_B (0x1 << 21) /* AHB Bus Lock */
-#define ATC_LOCK_IF_L (0x1 << 22) /* Master Interface Arbiter Lock */
-#define ATC_LOCK_IF_L_CHUNK (0x0 << 22)
-#define ATC_LOCK_IF_L_BUFFER (0x1 << 22)
-#define ATC_AHB_PROT_MASK (0x7 << 24) /* AHB Protection */
-#define ATC_FIFOCFG_MASK (0x3 << 28) /* FIFO Request Configuration */
-#define ATC_FIFOCFG_LARGESTBURST (0x0 << 28)
-#define ATC_FIFOCFG_HALFFIFO (0x1 << 28)
-#define ATC_FIFOCFG_ENOUGHSPACE (0x2 << 28)
+#define ATC_SRC_PER GENMASK(3, 0) /* Channel src rq associated with periph handshaking ifc h */
+#define ATC_DST_PER GENMASK(7, 4) /* Channel dst rq associated with periph handshaking ifc h */
+#define ATC_SRC_REP BIT(8) /* Source Replay Mod */
+#define ATC_SRC_H2SEL BIT(9) /* Source Handshaking Mod */
+#define ATC_SRC_PER_MSB GENMASK(11, 10) /* Channel src rq (most significant bits) */
+#define ATC_DST_REP BIT(12) /* Destination Replay Mod */
+#define ATC_DST_H2SEL BIT(13) /* Destination Handshaking Mod */
+#define ATC_DST_PER_MSB GENMASK(15, 14) /* Channel dst rq (most significant bits) */
+#define ATC_SOD BIT(16) /* Stop On Done */
+#define ATC_LOCK_IF BIT(20) /* Interface Lock */
+#define ATC_LOCK_B BIT(21) /* AHB Bus Lock */
+#define ATC_LOCK_IF_L BIT(22) /* Master Interface Arbiter Lock */
+#define ATC_AHB_PROT GENMASK(26, 24) /* AHB Protection */
+#define ATC_FIFOCFG GENMASK(29, 28) /* FIFO Request Configuration */
+#define ATC_FIFOCFG_LARGESTBURST 0x0
+#define ATC_FIFOCFG_HALFFIFO 0x1
+#define ATC_FIFOCFG_ENOUGHSPACE 0x2

/* Bitfields in SPIP */
-#define ATC_SPIP_HOLE(x) (0xFFFFU & (x))
-#define ATC_SPIP_BOUNDARY(x) ((0x3FF & (x)) << 16)
+#define ATC_SPIP_HOLE GENMASK(15, 0)
+#define ATC_SPIP_BOUNDARY GENMASK(25, 16)

/* Bitfields in DPIP */
-#define ATC_DPIP_HOLE(x) (0xFFFFU & (x))
-#define ATC_DPIP_BOUNDARY(x) ((0x3FF & (x)) << 16)
+#define ATC_DPIP_HOLE GENMASK(15, 0)
+#define ATC_DPIP_BOUNDARY GENMASK(25, 16)
+
+#define ATC_SRC_PER_ID(id) (FIELD_PREP(ATC_SRC_PER_MSB, (id)) | \
+ FIELD_PREP(ATC_SRC_PER, (id)))
+#define ATC_DST_PER_ID(id) (FIELD_PREP(ATC_DST_PER_MSB, (id)) | \
+ FIELD_PREP(ATC_DST_PER, (id)))
+

/*-- descriptors -----------------------------------------------------*/

@@ -489,9 +469,9 @@ static void set_desc_eol(struct at_desc *desc)
desc->lli.dscr = 0;
}

-#define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO)
-#define ATC_DEFAULT_CTRLB (ATC_SIF(AT_DMA_MEM_IF) \
- |ATC_DIF(AT_DMA_MEM_IF))
+#define ATC_DEFAULT_CFG FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO)
+#define ATC_DEFAULT_CTRLB (FIELD_PREP(ATC_SIF, AT_DMA_MEM_IF) | \
+ FIELD_PREP(ATC_DIF, AT_DMA_MEM_IF))
#define ATC_DMA_BUSWIDTHS\
(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\
BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |\
@@ -707,10 +687,12 @@ static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
channel_writel(atchan, CTRLA, 0);
channel_writel(atchan, CTRLB, 0);
channel_writel(atchan, DSCR, first->txd.phys);
- channel_writel(atchan, SPIP, ATC_SPIP_HOLE(first->src_hole) |
- ATC_SPIP_BOUNDARY(first->boundary));
- channel_writel(atchan, DPIP, ATC_DPIP_HOLE(first->dst_hole) |
- ATC_DPIP_BOUNDARY(first->boundary));
+ channel_writel(atchan, SPIP, FIELD_PREP(ATC_SPIP_HOLE,
+ first->src_hole) |
+ FIELD_PREP(ATC_SPIP_BOUNDARY, first->boundary));
+ channel_writel(atchan, DPIP, FIELD_PREP(ATC_DPIP_HOLE,
+ first->dst_hole) |
+ FIELD_PREP(ATC_DPIP_BOUNDARY, first->boundary));
dma_writel(atdma, CHER, atchan->mask);

vdbg_dump_regs(atchan);
@@ -748,8 +730,8 @@ static struct at_desc *atc_get_desc_by_cookie(struct at_dma_chan *atchan,
*/
static inline int atc_calc_bytes_left(int current_len, u32 ctrla)
{
- u32 btsize = (ctrla & ATC_BTSIZE_MAX);
- u32 src_width = ATC_REG_TO_SRC_WIDTH(ctrla);
+ u32 btsize = FIELD_GET(ATC_BTSIZE, ctrla);
+ u32 src_width = FIELD_GET(ATC_SRC_WIDTH, ctrla);

/*
* According to the datasheet, when reading the Control A Register
@@ -1223,15 +1205,14 @@ atc_prep_dma_interleaved(struct dma_chan *chan,
return NULL;
}

- ctrla = ATC_SRC_WIDTH(dwidth) |
- ATC_DST_WIDTH(dwidth);
+ ctrla = FIELD_PREP(ATC_SRC_WIDTH, dwidth) |
+ FIELD_PREP(ATC_DST_WIDTH, dwidth);

- ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN
- | ATC_SRC_ADDR_MODE_INCR
- | ATC_DST_ADDR_MODE_INCR
- | ATC_SRC_PIP
- | ATC_DST_PIP
- | ATC_FC_MEM2MEM;
+ ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
+ FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
+ ATC_SRC_PIP | ATC_DST_PIP |
+ FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM);

/* create the transfer */
desc = atc_desc_get(atchan);
@@ -1292,10 +1273,10 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
return NULL;
}

- ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN
- | ATC_SRC_ADDR_MODE_INCR
- | ATC_DST_ADDR_MODE_INCR
- | ATC_FC_MEM2MEM;
+ ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
+ FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM);

/*
* We can be a lot more clever here, but this should take care
@@ -1303,8 +1284,8 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
*/
src_width = dst_width = atc_get_xfer_width(src, dest, len);

- ctrla = ATC_SRC_WIDTH(src_width) |
- ATC_DST_WIDTH(dst_width);
+ ctrla = FIELD_PREP(ATC_SRC_WIDTH, src_width) |
+ FIELD_PREP(ATC_DST_WIDTH, dst_width);

for (offset = 0; offset < len; offset += xfer_count << src_width) {
xfer_count = min_t(size_t, (len - offset) >> src_width,
@@ -1350,11 +1331,11 @@ static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
struct at_desc *desc;
size_t xfer_count;

- u32 ctrla = ATC_SRC_WIDTH(2) | ATC_DST_WIDTH(2);
+ u32 ctrla = FIELD_PREP(ATC_SRC_WIDTH, 2) | FIELD_PREP(ATC_DST_WIDTH, 2);
u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
- ATC_SRC_ADDR_MODE_FIXED |
- ATC_DST_ADDR_MODE_INCR |
- ATC_FC_MEM2MEM;
+ FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) |
+ FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM);

xfer_count = len >> 2;
if (xfer_count > ATC_BTSIZE_MAX) {
@@ -1569,18 +1550,20 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
return NULL;
}

- ctrla = ATC_SCSIZE(sconfig->src_maxburst)
- | ATC_DCSIZE(sconfig->dst_maxburst);
+ ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
+ FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst);
ctrlb = ATC_IEN;

switch (direction) {
case DMA_MEM_TO_DEV:
reg_width = convert_buswidth(sconfig->dst_addr_width);
- ctrla |= ATC_DST_WIDTH(reg_width);
- ctrlb |= ATC_DST_ADDR_MODE_FIXED
- | ATC_SRC_ADDR_MODE_INCR
- | ATC_FC_MEM2PER
- | ATC_SIF(atchan->mem_if) | ATC_DIF(atchan->per_if);
+ ctrla |= FIELD_PREP(ATC_DST_WIDTH, reg_width);
+ ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE,
+ ATC_DST_ADDR_MODE_FIXED) |
+ FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) |
+ FIELD_PREP(ATC_SIF, atchan->mem_if) |
+ FIELD_PREP(ATC_DIF, atchan->per_if);
reg = sconfig->dst_addr;
for_each_sg(sgl, sg, sg_len, i) {
struct at_desc *desc;
@@ -1604,9 +1587,9 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,

desc->lli.saddr = mem;
desc->lli.daddr = reg;
- desc->lli.ctrla = ctrla
- | ATC_SRC_WIDTH(mem_width)
- | len >> mem_width;
+ desc->lli.ctrla = ctrla |
+ FIELD_PREP(ATC_SRC_WIDTH, mem_width) |
+ len >> mem_width;
desc->lli.ctrlb = ctrlb;
desc->len = len;

@@ -1616,11 +1599,13 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
break;
case DMA_DEV_TO_MEM:
reg_width = convert_buswidth(sconfig->src_addr_width);
- ctrla |= ATC_SRC_WIDTH(reg_width);
- ctrlb |= ATC_DST_ADDR_MODE_INCR
- | ATC_SRC_ADDR_MODE_FIXED
- | ATC_FC_PER2MEM
- | ATC_SIF(atchan->per_if) | ATC_DIF(atchan->mem_if);
+ ctrla |= FIELD_PREP(ATC_SRC_WIDTH, reg_width);
+ ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_SRC_ADDR_MODE,
+ ATC_SRC_ADDR_MODE_FIXED) |
+ FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) |
+ FIELD_PREP(ATC_SIF, atchan->per_if) |
+ FIELD_PREP(ATC_DIF, atchan->mem_if);

reg = sconfig->src_addr;
for_each_sg(sgl, sg, sg_len, i) {
@@ -1645,9 +1630,9 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,

desc->lli.saddr = reg;
desc->lli.daddr = mem;
- desc->lli.ctrla = ctrla
- | ATC_DST_WIDTH(mem_width)
- | len >> reg_width;
+ desc->lli.ctrla = ctrla |
+ FIELD_PREP(ATC_DST_WIDTH, mem_width) |
+ len >> reg_width;
desc->lli.ctrlb = ctrlb;
desc->len = len;

@@ -1713,22 +1698,24 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
u32 ctrla;

/* prepare common CRTLA value */
- ctrla = ATC_SCSIZE(sconfig->src_maxburst)
- | ATC_DCSIZE(sconfig->dst_maxburst)
- | ATC_DST_WIDTH(reg_width)
- | ATC_SRC_WIDTH(reg_width)
- | period_len >> reg_width;
+ ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
+ FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) |
+ FIELD_PREP(ATC_DST_WIDTH, reg_width) |
+ FIELD_PREP(ATC_SRC_WIDTH, reg_width) |
+ period_len >> reg_width;

switch (direction) {
case DMA_MEM_TO_DEV:
desc->lli.saddr = buf_addr + (period_len * period_index);
desc->lli.daddr = sconfig->dst_addr;
desc->lli.ctrla = ctrla;
- desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED
- | ATC_SRC_ADDR_MODE_INCR
- | ATC_FC_MEM2PER
- | ATC_SIF(atchan->mem_if)
- | ATC_DIF(atchan->per_if);
+ desc->lli.ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
+ ATC_DST_ADDR_MODE_FIXED) |
+ FIELD_PREP(ATC_SRC_ADDR_MODE,
+ ATC_SRC_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) |
+ FIELD_PREP(ATC_SIF, atchan->mem_if) |
+ FIELD_PREP(ATC_DIF, atchan->per_if);
desc->len = period_len;
break;

@@ -1736,11 +1723,13 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
desc->lli.saddr = sconfig->src_addr;
desc->lli.daddr = buf_addr + (period_len * period_index);
desc->lli.ctrla = ctrla;
- desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR
- | ATC_SRC_ADDR_MODE_FIXED
- | ATC_FC_PER2MEM
- | ATC_SIF(atchan->per_if)
- | ATC_DIF(atchan->mem_if);
+ desc->lli.ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
+ ATC_DST_ADDR_MODE_INCR) |
+ FIELD_PREP(ATC_SRC_ADDR_MODE,
+ ATC_SRC_ADDR_MODE_FIXED) |
+ FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) |
+ FIELD_PREP(ATC_SIF, atchan->per_if) |
+ FIELD_PREP(ATC_DIF, atchan->mem_if);
desc->len = period_len;
break;

@@ -2144,14 +2133,13 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
return NULL;
}

- atslave->cfg = ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW;
+ atslave->cfg = ATC_DST_H2SEL | ATC_SRC_H2SEL;
/*
* We can fill both SRC_PER and DST_PER, one of these fields will be
* ignored depending on DMA transfer direction.
*/
per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK;
- atslave->cfg |= ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id)
- | ATC_SRC_PER_MSB(per_id) | ATC_SRC_PER(per_id);
+ atslave->cfg |= ATC_DST_PER_ID(per_id) | ATC_SRC_PER_ID(per_id);
/*
* We have to translate the value we get from the device tree since
* the half FIFO configuration value had to be 0 to keep backward
@@ -2159,14 +2147,16 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
*/
switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) {
case AT91_DMA_CFG_FIFOCFG_ALAP:
- atslave->cfg |= ATC_FIFOCFG_LARGESTBURST;
+ atslave->cfg |= FIELD_PREP(ATC_FIFOCFG,
+ ATC_FIFOCFG_LARGESTBURST);
break;
case AT91_DMA_CFG_FIFOCFG_ASAP:
- atslave->cfg |= ATC_FIFOCFG_ENOUGHSPACE;
+ atslave->cfg |= FIELD_PREP(ATC_FIFOCFG,
+ ATC_FIFOCFG_ENOUGHSPACE);
break;
case AT91_DMA_CFG_FIFOCFG_HALF:
default:
- atslave->cfg |= ATC_FIFOCFG_HALFFIFO;
+ atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO);
}
atslave->dma_dev = &dmac_pdev->dev;

--
2.25.1

2022-08-20 13:45:08

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 08/33] dmaengine: at_hdmac: Don't start transactions at tx_submit level

tx_submit is supposed to push the current transaction descriptor to a
pending queue, waiting for issue_pending() to be called. issue_pending()
must start the transfer, not tx_submit(), thus remove atc_dostart() from
atc_tx_submit(). Clients of at_xdmac that assume that tx_submit() starts
the transfer must be updated and call dma_async_issue_pending() if they
miss to call it.
The vdbg print was moved to after the lock is released. It is desirable to
do the prints without the lock held if possible, and because the if
statement disappears there's no reason why to do the print while holding
the lock.

Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/lkml/[email protected]/
---
drivers/dma/at_hdmac.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index e89facf14fab..b6b1d2dcfc4c 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1126,19 +1126,11 @@ static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx)
spin_lock_irqsave(&atchan->lock, flags);
cookie = dma_cookie_assign(tx);

- if (list_empty(&atchan->active_list)) {
- dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
- desc->txd.cookie);
- atc_dostart(atchan, desc);
- list_add_tail(&desc->desc_node, &atchan->active_list);
- } else {
- dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
- desc->txd.cookie);
- list_add_tail(&desc->desc_node, &atchan->queue);
- }
-
+ list_add_tail(&desc->desc_node, &atchan->queue);
spin_unlock_irqrestore(&atchan->lock, flags);

+ dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
+ desc->txd.cookie);
return cookie;
}

--
2.25.1

2022-08-20 13:45:11

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 31/33] dmaengine: at_hdmac: Use pm_ptr()

From: Tudor Ambarus <[email protected]>

Use pm_ptr() macro to fill at_xdmac_driver.driver.pm. In case CONFIG_PM is
not enabled, the macro will return NULL.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 0b473e6d161d..e35b4b325452 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -2524,7 +2524,7 @@ static int at_dma_resume_noirq(struct device *dev)
return 0;
}

-static const struct dev_pm_ops at_dma_dev_pm_ops = {
+static const struct dev_pm_ops __maybe_unused at_dma_dev_pm_ops = {
.prepare = at_dma_prepare,
.suspend_noirq = at_dma_suspend_noirq,
.resume_noirq = at_dma_resume_noirq,
@@ -2536,7 +2536,7 @@ static struct platform_driver at_dma_driver = {
.id_table = atdma_devtypes,
.driver = {
.name = "at_hdmac",
- .pm = &at_dma_dev_pm_ops,
+ .pm = pm_ptr(&at_dma_dev_pm_ops),
.of_match_table = of_match_ptr(atmel_dma_dt_ids),
},
};
--
2.25.1

2022-08-20 13:45:12

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 12/33] dmaengine: at_hdmac: Protect atchan->status with the channel lock

Now that the complete callback call was removed from
device_terminate_all(), we can protect the atchan->status with the channel
lock. The atomic bitops on atchan->status do not substitute proper locking
on the status, as one could still modify the status after the lock was
dropped in atc_terminate_all() but before the atomic bitops were executed.

Fixes: 078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
Reported-by: Peter Rosin <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/lkml/[email protected]/
---
drivers/dma/at_hdmac.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index b3895e5d2ae9..aeb241832c52 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1902,12 +1902,12 @@ static int atc_terminate_all(struct dma_chan *chan)
list_splice_tail_init(&atchan->queue, &atchan->free_list);
list_splice_tail_init(&atchan->active_list, &atchan->free_list);

- spin_unlock_irqrestore(&atchan->lock, flags);
-
clear_bit(ATC_IS_PAUSED, &atchan->status);
/* if channel dedicated to cyclic operations, free it */
clear_bit(ATC_IS_CYCLIC, &atchan->status);

+ spin_unlock_irqrestore(&atchan->lock, flags);
+
return 0;
}

--
2.25.1

2022-08-20 13:45:21

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 21/33] dmaengine: at_hdmac: Fix impossible condition

The iterator can not be greater than ATC_MAX_DSCR_TRIALS, as the for loop
will stop when i == ATC_MAX_DSCR_TRIALS. While here, use the common "i"
name for the iterator.

Fixes: 93dce3a6434f ("dmaengine: at_hdmac: fix residue computation")
Signed-off-by: Tudor Ambarus <[email protected]>
Cc: [email protected]
---
drivers/dma/at_hdmac.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 16cea65a708d..c72c796d58bc 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -753,7 +753,8 @@ static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
struct at_desc *desc_first = atc_first_active(atchan);
struct at_desc *desc;
int ret;
- u32 ctrla, dscr, trials;
+ u32 ctrla, dscr;
+ unsigned int i;

/*
* If the cookie doesn't match to the currently running transfer then
@@ -823,7 +824,7 @@ static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
dscr = channel_readl(atchan, DSCR);
rmb(); /* ensure DSCR is read before CTRLA */
ctrla = channel_readl(atchan, CTRLA);
- for (trials = 0; trials < ATC_MAX_DSCR_TRIALS; ++trials) {
+ for (i = 0; i < ATC_MAX_DSCR_TRIALS; ++i) {
u32 new_dscr;

rmb(); /* ensure DSCR is read after CTRLA */
@@ -849,7 +850,7 @@ static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
rmb(); /* ensure DSCR is read before CTRLA */
ctrla = channel_readl(atchan, CTRLA);
}
- if (unlikely(trials >= ATC_MAX_DSCR_TRIALS))
+ if (unlikely(i == ATC_MAX_DSCR_TRIALS))
return -ETIMEDOUT;

/* for the first descriptor we can be more accurate */
--
2.25.1

2022-08-20 13:45:22

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 22/33] dmaengine: at_hdmac: Pass residue by address to avoid unneccessary implicit casts

struct dma_tx_state defines residue as u32. atc_get_bytes_left() returned
an int which could be either an error or the value of the residue. This
could cause problems if the controller supported a u32 buffer transfer size
and the u32 value was past the max int can hold. Our controller does not
support u32 buffer transfer size, but even so, improve the code and pass
the residue by address to avoid unnecessary implicit casts and make
atc_get_bytes_left() return 0 on success or -errno on errors.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 54 +++++++++++++++++++++++-------------------
1 file changed, 30 insertions(+), 24 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index c72c796d58bc..abb884a08bd4 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -728,7 +728,7 @@ static struct at_desc *atc_get_desc_by_cookie(struct at_dma_chan *atchan,
* @current_len: the number of bytes left before reading CTRLA
* @ctrla: the value of CTRLA
*/
-static inline int atc_calc_bytes_left(int current_len, u32 ctrla)
+static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
{
u32 btsize = FIELD_GET(ATC_BTSIZE, ctrla);
u32 src_width = FIELD_GET(ATC_SRC_WIDTH, ctrla);
@@ -743,17 +743,20 @@ static inline int atc_calc_bytes_left(int current_len, u32 ctrla)
}

/**
- * atc_get_bytes_left - get the number of bytes residue for a cookie
+ * atc_get_bytes_left - get the number of bytes residue for a cookie.
+ * The residue is passed by address and updated on success.
* @chan: DMA channel
* @cookie: transaction identifier to check status of
+ * @residue: residue to be updated.
+ * Return 0 on success, -errono otherwise.
*/
-static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
+static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie,
+ u32 *residue)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_desc *desc_first = atc_first_active(atchan);
struct at_desc *desc;
- int ret;
- u32 ctrla, dscr;
+ u32 len, ctrla, dscr;
unsigned int i;

/*
@@ -768,7 +771,7 @@ static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
return desc->total_len;

/* cookie matches to the currently running transfer */
- ret = desc_first->total_len;
+ len = desc_first->total_len;

if (desc_first->lli.dscr) {
/* hardware linked list transfer */
@@ -854,29 +857,31 @@ static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
return -ETIMEDOUT;

/* for the first descriptor we can be more accurate */
- if (desc_first->lli.dscr == dscr)
- return atc_calc_bytes_left(ret, ctrla);
+ if (desc_first->lli.dscr == dscr) {
+ *residue = atc_calc_bytes_left(len, ctrla);
+ return 0;
+ }

- ret -= desc_first->len;
+ len -= desc_first->len;
list_for_each_entry(desc, &desc_first->tx_list, desc_node) {
if (desc->lli.dscr == dscr)
break;

- ret -= desc->len;
+ len -= desc->len;
}

/*
* For the current descriptor in the chain we can calculate
* the remaining bytes using the channel's register.
*/
- ret = atc_calc_bytes_left(ret, ctrla);
+ *residue = atc_calc_bytes_left(len, ctrla);
} else {
/* single transfer */
ctrla = channel_readl(atchan, CTRLA);
- ret = atc_calc_bytes_left(ret, ctrla);
+ *residue = atc_calc_bytes_left(len, ctrla);
}

- return ret;
+ return 0;
}

/**
@@ -1899,31 +1904,32 @@ atc_tx_status(struct dma_chan *chan,
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
unsigned long flags;
- enum dma_status ret;
- int bytes = 0;
+ enum dma_status dma_status;
+ u32 residue;
+ int ret;

- ret = dma_cookie_status(chan, cookie, txstate);
- if (ret == DMA_COMPLETE || !txstate)
- return ret;
+ dma_status = dma_cookie_status(chan, cookie, txstate);
+ if (dma_status == DMA_COMPLETE || !txstate)
+ return dma_status;

spin_lock_irqsave(&atchan->lock, flags);

/* Get number of bytes left in the active transactions */
- bytes = atc_get_bytes_left(chan, cookie);
+ ret = atc_get_bytes_left(chan, cookie, &residue);

spin_unlock_irqrestore(&atchan->lock, flags);

- if (unlikely(bytes < 0)) {
+ if (unlikely(ret < 0)) {
dev_vdbg(chan2dev(chan), "get residual bytes error\n");
return DMA_ERROR;
} else {
- dma_set_residue(txstate, bytes);
+ dma_set_residue(txstate, residue);
}

- dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %d\n",
- ret, cookie, bytes);
+ dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %u\n",
+ dma_status, cookie, residue);

- return ret;
+ return dma_status;
}

/**
--
2.25.1

2022-08-20 13:45:38

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 11/33] dmaengine: at_hdmac: Do not call the complete callback on device_terminate_all

The method was wrong because it violated the dmaengine API. For aborted
transfers the complete callback should not be called. Fix the behavior and
do not call the complete callback on device_terminate_all.

Fixes: 808347f6a317 ("dmaengine: at_hdmac: add DMA slave transfers")
Reported-by: Peter Rosin <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/lkml/[email protected]/
---
drivers/dma/at_hdmac.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index c445575f8646..b3895e5d2ae9 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1879,11 +1879,8 @@ static int atc_terminate_all(struct dma_chan *chan)
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
int chan_id = atchan->dma_chan.chan_id;
- struct at_desc *desc, *_desc;
unsigned long flags;

- LIST_HEAD(list);
-
dev_vdbg(chan2dev(chan), "%s\n", __func__);

/*
@@ -1902,15 +1899,11 @@ static int atc_terminate_all(struct dma_chan *chan)
cpu_relax();

/* active_list entries will end up before queued entries */
- list_splice_init(&atchan->queue, &list);
- list_splice_init(&atchan->active_list, &list);
+ list_splice_tail_init(&atchan->queue, &atchan->free_list);
+ list_splice_tail_init(&atchan->active_list, &atchan->free_list);

spin_unlock_irqrestore(&atchan->lock, flags);

- /* Flush all pending and queued descriptors */
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-
clear_bit(ATC_IS_PAUSED, &atchan->status);
/* if channel dedicated to cyclic operations, free it */
clear_bit(ATC_IS_CYCLIC, &atchan->status);
--
2.25.1

2022-08-20 13:45:52

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 26/33] dmaengine: at_hdmac: Use devm_kzalloc() and struct_size()

Use the resource-managed kzalloc to simplify error logic. Memory allocated
with this function is automatically freed on driver detach. Use
struct_size() helper to calculate the size of the atdma structure with its
trailing flexible array. While here, move the mem allocation higher in the
probe method, as failing to allocate memory indicates a serious system
issue, and everything else does not matter anyway. All these help the code
look a bit cleaner.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index f2c645e60619..85808cfda3cc 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -20,6 +20,7 @@
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/of.h>
+#include <linux/overflow.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>

@@ -2229,6 +2230,12 @@ static int __init at_dma_probe(struct platform_device *pdev)
if (!plat_dat)
return -ENODEV;

+ atdma = devm_kzalloc(&pdev->dev,
+ struct_size(atdma, chan, plat_dat->nr_channels),
+ GFP_KERNEL);
+ if (!atdma)
+ return -ENOMEM;
+
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!io)
return -EINVAL;
@@ -2237,21 +2244,13 @@ static int __init at_dma_probe(struct platform_device *pdev)
if (irq < 0)
return irq;

- size = sizeof(struct at_dma);
- size += plat_dat->nr_channels * sizeof(struct at_dma_chan);
- atdma = kzalloc(size, GFP_KERNEL);
- if (!atdma)
- return -ENOMEM;
-
/* discover transaction capabilities */
atdma->dma_device.cap_mask = plat_dat->cap_mask;
atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1;

size = resource_size(io);
- if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
- err = -EBUSY;
- goto err_kfree;
- }
+ if (!request_mem_region(io->start, size, pdev->dev.driver->name))
+ return -EBUSY;

atdma->regs = ioremap(io->start, size);
if (!atdma->regs) {
@@ -2401,8 +2400,6 @@ static int __init at_dma_probe(struct platform_device *pdev)
atdma->regs = NULL;
err_release_r:
release_mem_region(io->start, size);
-err_kfree:
- kfree(atdma);
return err;
}

@@ -2441,8 +2438,6 @@ static int at_dma_remove(struct platform_device *pdev)
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(io->start, resource_size(io));

- kfree(atdma);
-
return 0;
}

--
2.25.1

2022-08-20 13:53:03

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 27/33] dmaengine: at_hdmac: Use devm_platform_ioremap_resource

Use devm_platform_ioremap_resource() helper for cleanner code and easier
resource management.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma/at_hdmac.c | 37 ++++++-------------------------------
1 file changed, 6 insertions(+), 31 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 85808cfda3cc..9c414f167b62 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -2208,9 +2208,7 @@ static void at_dma_off(struct at_dma *atdma)

static int __init at_dma_probe(struct platform_device *pdev)
{
- struct resource *io;
struct at_dma *atdma;
- size_t size;
int irq;
int err;
int i;
@@ -2236,9 +2234,9 @@ static int __init at_dma_probe(struct platform_device *pdev)
if (!atdma)
return -ENOMEM;

- io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!io)
- return -EINVAL;
+ atdma->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(atdma->regs))
+ return PTR_ERR(atdma->regs);

irq = platform_get_irq(pdev, 0);
if (irq < 0)
@@ -2248,21 +2246,10 @@ static int __init at_dma_probe(struct platform_device *pdev)
atdma->dma_device.cap_mask = plat_dat->cap_mask;
atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1;

- size = resource_size(io);
- if (!request_mem_region(io->start, size, pdev->dev.driver->name))
- return -EBUSY;
-
- atdma->regs = ioremap(io->start, size);
- if (!atdma->regs) {
- err = -ENOMEM;
- goto err_release_r;
- }
-
atdma->clk = clk_get(&pdev->dev, "dma_clk");
- if (IS_ERR(atdma->clk)) {
- err = PTR_ERR(atdma->clk);
- goto err_clk;
- }
+ if (IS_ERR(atdma->clk))
+ return PTR_ERR(atdma->clk);
+
err = clk_prepare_enable(atdma->clk);
if (err)
goto err_clk_prepare;
@@ -2395,11 +2382,6 @@ static int __init at_dma_probe(struct platform_device *pdev)
clk_disable_unprepare(atdma->clk);
err_clk_prepare:
clk_put(atdma->clk);
-err_clk:
- iounmap(atdma->regs);
- atdma->regs = NULL;
-err_release_r:
- release_mem_region(io->start, size);
return err;
}

@@ -2407,7 +2389,6 @@ static int at_dma_remove(struct platform_device *pdev)
{
struct at_dma *atdma = platform_get_drvdata(pdev);
struct dma_chan *chan, *_chan;
- struct resource *io;

at_dma_off(atdma);
if (pdev->dev.of_node)
@@ -2432,12 +2413,6 @@ static int at_dma_remove(struct platform_device *pdev)
clk_disable_unprepare(atdma->clk);
clk_put(atdma->clk);

- iounmap(atdma->regs);
- atdma->regs = NULL;
-
- io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- release_mem_region(io->start, resource_size(io));
-
return 0;
}

--
2.25.1

2022-10-19 17:09:24

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH 07/33] dmaengine: at_hdmac: Fix at_lli struct definition

On 20-08-22, 15:56, Tudor Ambarus wrote:
> From: Tudor Ambarus <[email protected]>
>
> Those hardware registers are all of 32 bits, while dma_addr_t ca be of
> type u64 or u32 depending on CONFIG_ARCH_DMA_ADDR_T_64BIT. Force u32 to
> comply with what the hardware expects.
>
> Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
> Signed-off-by: Tudor Ambarus <[email protected]>
> Cc: [email protected]

Okay

> ---
> drivers/dma/at_hdmac.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 91e53a590d5f..e89facf14fab 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -187,13 +187,13 @@
> /* LLI == Linked List Item; aka DMA buffer descriptor */
> struct at_lli {
> /* values that are not changed by hardware */
> - dma_addr_t saddr;
> - dma_addr_t daddr;
> + u32 saddr;
> + u32 daddr;

I think you should add fixes first in the series and then do header
move, that way we can backport this and other fixes to stable kernels...

> /* value that may get written back: */
> - u32 ctrla;
> + u32 ctrla;
> /* more values that are not changed by hardware */
> - u32 ctrlb;
> - dma_addr_t dscr; /* chain to next lli */
> + u32 ctrlb;
> + u32 dscr; /* chain to next lli */
> };
>
> /**
> --
> 2.25.1

--
~Vinod

2022-10-19 17:11:06

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH 31/33] dmaengine: at_hdmac: Use pm_ptr()

On 20-08-22, 15:57, Tudor Ambarus wrote:
> From: Tudor Ambarus <[email protected]>
>
> Use pm_ptr() macro to fill at_xdmac_driver.driver.pm. In case CONFIG_PM is
> not enabled, the macro will return NULL.

You annotated at_dma_dev_pm_ops with __maybe_unused which is a correct
thing to do, but should be explained here

>
> Signed-off-by: Tudor Ambarus <[email protected]>
> ---
> drivers/dma/at_hdmac.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 0b473e6d161d..e35b4b325452 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -2524,7 +2524,7 @@ static int at_dma_resume_noirq(struct device *dev)
> return 0;
> }
>
> -static const struct dev_pm_ops at_dma_dev_pm_ops = {
> +static const struct dev_pm_ops __maybe_unused at_dma_dev_pm_ops = {
> .prepare = at_dma_prepare,
> .suspend_noirq = at_dma_suspend_noirq,
> .resume_noirq = at_dma_resume_noirq,
> @@ -2536,7 +2536,7 @@ static struct platform_driver at_dma_driver = {
> .id_table = atdma_devtypes,
> .driver = {
> .name = "at_hdmac",
> - .pm = &at_dma_dev_pm_ops,
> + .pm = pm_ptr(&at_dma_dev_pm_ops),
> .of_match_table = of_match_ptr(atmel_dma_dt_ids),
> },
> };
> --
> 2.25.1

--
~Vinod

2022-10-20 08:01:03

by Tudor Ambarus

[permalink] [raw]
Subject: Re: [PATCH 07/33] dmaengine: at_hdmac: Fix at_lli struct definition

On 10/19/22 19:38, Vinod Koul wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> On 20-08-22, 15:56, Tudor Ambarus wrote:
>> From: Tudor Ambarus <[email protected]>
>>
>> Those hardware registers are all of 32 bits, while dma_addr_t ca be of
>> type u64 or u32 depending on CONFIG_ARCH_DMA_ADDR_T_64BIT. Force u32 to
>> comply with what the hardware expects.
>>
>> Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
>> Signed-off-by: Tudor Ambarus <[email protected]>
>> Cc: [email protected]
>
> Okay
>
>> ---
>> drivers/dma/at_hdmac.c | 10 +++++-----
>> 1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
>> index 91e53a590d5f..e89facf14fab 100644
>> --- a/drivers/dma/at_hdmac.c
>> +++ b/drivers/dma/at_hdmac.c
>> @@ -187,13 +187,13 @@
>> /* LLI == Linked List Item; aka DMA buffer descriptor */
>> struct at_lli {
>> /* values that are not changed by hardware */
>> - dma_addr_t saddr;
>> - dma_addr_t daddr;
>> + u32 saddr;
>> + u32 daddr;
>
> I think you should add fixes first in the series and then do header
> move, that way we can backport this and other fixes to stable kernels...

Right, would be easier indeed. Will do, thanks.

Cheers,
ta
>
>> /* value that may get written back: */
>> - u32 ctrla;
>> + u32 ctrla;
>> /* more values that are not changed by hardware */
>> - u32 ctrlb;
>> - dma_addr_t dscr; /* chain to next lli */
>> + u32 ctrlb;
>> + u32 dscr; /* chain to next lli */
>> };
>>
>> /**
>> --
>> 2.25.1
>
> --
> ~Vinod

--
Cheers,
ta

2022-10-20 08:05:17

by Tudor Ambarus

[permalink] [raw]
Subject: Re: [PATCH 31/33] dmaengine: at_hdmac: Use pm_ptr()

On 10/19/22 19:50, Vinod Koul wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> On 20-08-22, 15:57, Tudor Ambarus wrote:
>> From: Tudor Ambarus <[email protected]>
>>
>> Use pm_ptr() macro to fill at_xdmac_driver.driver.pm. In case CONFIG_PM is
>> not enabled, the macro will return NULL.
>
> You annotated at_dma_dev_pm_ops with __maybe_unused which is a correct
> thing to do, but should be explained here

okay, will refine the commit message.

>
>>
>> Signed-off-by: Tudor Ambarus <[email protected]>
>> ---
>> drivers/dma/at_hdmac.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
>> index 0b473e6d161d..e35b4b325452 100644
>> --- a/drivers/dma/at_hdmac.c
>> +++ b/drivers/dma/at_hdmac.c
>> @@ -2524,7 +2524,7 @@ static int at_dma_resume_noirq(struct device *dev)
>> return 0;
>> }
>>
>> -static const struct dev_pm_ops at_dma_dev_pm_ops = {
>> +static const struct dev_pm_ops __maybe_unused at_dma_dev_pm_ops = {
>> .prepare = at_dma_prepare,
>> .suspend_noirq = at_dma_suspend_noirq,
>> .resume_noirq = at_dma_resume_noirq,
>> @@ -2536,7 +2536,7 @@ static struct platform_driver at_dma_driver = {
>> .id_table = atdma_devtypes,
>> .driver = {
>> .name = "at_hdmac",
>> - .pm = &at_dma_dev_pm_ops,
>> + .pm = pm_ptr(&at_dma_dev_pm_ops),
>> .of_match_table = of_match_ptr(atmel_dma_dt_ids),
>> },
>> };
>> --
>> 2.25.1
>
> --
> ~Vinod

--
Cheers,
ta