Hi Arnd,
Am 21.04.2022 um 20:20 schrieb Arnd Bergmann:
> From: Arnd Bergmann <[email protected]>
>
> After a build regression report, I took a look at possible users of
> CONFIG_ISA_DMA_API on m68k and found none, which Greg confirmed. The
> CONFIG_GENERIC_ISA_DMA option in turn is only needed to implement
> ISA_DMA_API, and is clearly not used on the platforms with ISA support.
>
> The CONFIG_ISA support for AMIGA_PCMCIA is probably also unneeded,
> but this is less clear. Unlike other PCMCIA implementations, this one
> does not use the drivers/pcmcia subsystem at all and just supports
> the "apne" network driver. When it was first added, one could use
> ISA drivers on it as well, but this probably broke at some point.
Hoping to clarify some of this:
For the Amiga PCMCIA "apne" driver, both the definitions of
isa_type/isa_sex and the definitions of the low-level accessor and
address translation functions are protected by CONFIG_ISA (see
arch/m68k/kernel/setup_mm.c and arch/m68k/include/asm/io_mm.h for details).
This could conceivably be changed (only AMIGA_PCMCIA and Q40 do use
these definitions, aside from ATARI_ROM_ISA), but as things are right
now, neither Q40 ISA nor Amiga PCMCIA will work without CONFIG_ISA defined.
Regarding the Amiga PCMCIA driver's use of the drivers/pcmcia subsystem,
I have a patch in limbo at netdev that makes use of the cftable parser
code from drivers/pcmcia, but as far as I can recall, none of this
depends on CONFIG_ISA.
None of this is related to ISA_DMA_API, so please don't take this to
mean there's anything wrong with your patch. Just saying removing
CONFIG_ISA support from m68k will have a few ramifications.
Cheers,
Michael
>
> With no reason to keep this, let's just drop the corresponding files
> and prevent the remaining ISA drivers that use this from getting built.
>
> The remaining definitions in asm/dma.h are used for PCI support.
>
> Link: https://lore.kernel.org/lkml/[email protected]/
> Acked-by: Geert Uytterhoeven <[email protected]>
> Acked-by: Ulf Hansson <[email protected]> # For MMC
> Acked-by: Greg Ungerer <[email protected]>
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> v4: actually fix the build regression
> v3: fix build regression
> v2: drop GENERIC_ISA_DMA as well, add some background on CONFIG_ISA.
> ---
> arch/m68k/Kconfig.bus | 10 -
> arch/m68k/coldfire/Makefile | 2 +-
> arch/m68k/coldfire/dma.c | 43 ----
> arch/m68k/include/asm/dma.h | 483 ------------------------------------
> arch/m68k/mm/motorola.c | 1 -
> drivers/mmc/host/Kconfig | 2 +-
> sound/core/Makefile | 2 -
> sound/isa/Kconfig | 2 +-
> 8 files changed, 3 insertions(+), 542 deletions(-)
> delete mode 100644 arch/m68k/coldfire/dma.c
>
> diff --git a/arch/m68k/Kconfig.bus b/arch/m68k/Kconfig.bus
> index d1e93a39cd3b..d5c0b2990ee1 100644
> --- a/arch/m68k/Kconfig.bus
> +++ b/arch/m68k/Kconfig.bus
> @@ -56,16 +56,6 @@ config ATARI_ROM_ISA
> The only driver currently using this adapter is the EtherNEC
> driver for RTL8019AS based NE2000 compatible network cards.
>
> -config GENERIC_ISA_DMA
> - def_bool ISA
> -
> source "drivers/zorro/Kconfig"
>
> endif
> -
> -if COLDFIRE
> -
> -config ISA_DMA_API
> - def_bool !M5272
> -
> -endif
> diff --git a/arch/m68k/coldfire/Makefile b/arch/m68k/coldfire/Makefile
> index a3e18d73d8b8..9419a6c1f036 100644
> --- a/arch/m68k/coldfire/Makefile
> +++ b/arch/m68k/coldfire/Makefile
> @@ -15,7 +15,7 @@
>
> asflags-$(CONFIG_FULLDEBUG) := -DDEBUGGER_COMPATIBLE_CACHE=1
>
> -obj-$(CONFIG_COLDFIRE) += cache.o clk.o device.o dma.o entry.o vectors.o
> +obj-$(CONFIG_COLDFIRE) += cache.o clk.o device.o entry.o vectors.o
> obj-$(CONFIG_M5206) += m5206.o intc.o reset.o
> obj-$(CONFIG_M5206e) += m5206.o intc.o reset.o
> obj-$(CONFIG_M520x) += m520x.o intc-simr.o reset.o
> diff --git a/arch/m68k/coldfire/dma.c b/arch/m68k/coldfire/dma.c
> deleted file mode 100644
> index c3279f7467d7..000000000000
> --- a/arch/m68k/coldfire/dma.c
> +++ /dev/null
> @@ -1,43 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -/***************************************************************************/
> -
> -/*
> - * dma.c -- Freescale ColdFire DMA support
> - *
> - * Copyright (C) 2007, Greg Ungerer ([email protected])
> - */
> -
> -/***************************************************************************/
> -
> -#include <linux/kernel.h>
> -#include <linux/module.h>
> -#include <asm/dma.h>
> -#include <asm/coldfire.h>
> -#include <asm/mcfsim.h>
> -#include <asm/mcfdma.h>
> -
> -/***************************************************************************/
> -
> -/*
> - * DMA channel base address table.
> - */
> -unsigned int dma_base_addr[MAX_M68K_DMA_CHANNELS] = {
> -#ifdef MCFDMA_BASE0
> - MCFDMA_BASE0,
> -#endif
> -#ifdef MCFDMA_BASE1
> - MCFDMA_BASE1,
> -#endif
> -#ifdef MCFDMA_BASE2
> - MCFDMA_BASE2,
> -#endif
> -#ifdef MCFDMA_BASE3
> - MCFDMA_BASE3,
> -#endif
> -};
> -EXPORT_SYMBOL(dma_base_addr);
> -
> -unsigned int dma_device_address[MAX_M68K_DMA_CHANNELS];
> -EXPORT_SYMBOL(dma_device_address);
> -
> -/***************************************************************************/
> diff --git a/arch/m68k/include/asm/dma.h b/arch/m68k/include/asm/dma.h
> index ae2021964e32..f6c5e0dfb4e5 100644
> --- a/arch/m68k/include/asm/dma.h
> +++ b/arch/m68k/include/asm/dma.h
> @@ -2,493 +2,10 @@
> #ifndef _M68K_DMA_H
> #define _M68K_DMA_H 1
>
> -#ifdef CONFIG_COLDFIRE
> -/*
> - * ColdFire DMA Model:
> - * ColdFire DMA supports two forms of DMA: Single and Dual address. Single
> - * address mode emits a source address, and expects that the device will either
> - * pick up the data (DMA READ) or source data (DMA WRITE). This implies that
> - * the device will place data on the correct byte(s) of the data bus, as the
> - * memory transactions are always 32 bits. This implies that only 32 bit
> - * devices will find single mode transfers useful. Dual address DMA mode
> - * performs two cycles: source read and destination write. ColdFire will
> - * align the data so that the device will always get the correct bytes, thus
> - * is useful for 8 and 16 bit devices. This is the mode that is supported
> - * below.
> - *
> - * AUG/22/2000 : added support for 32-bit Dual-Address-Mode (K) 2000
> - * Oliver Kamphenkel ([email protected])
> - *
> - * AUG/25/2000 : added support for 8, 16 and 32-bit Single-Address-Mode (K)2000
> - * Oliver Kamphenkel ([email protected])
> - *
> - * APR/18/2002 : added proper support for MCF5272 DMA controller.
> - * Arthur Shipkowski ([email protected])
> - */
> -
> -#include <asm/coldfire.h>
> -#include <asm/mcfsim.h>
> -#include <asm/mcfdma.h>
> -
> -/*
> - * Set number of channels of DMA on ColdFire for different implementations.
> - */
> -#if defined(CONFIG_M5249) || defined(CONFIG_M5307) || defined(CONFIG_M5407) || \
> - defined(CONFIG_M523x) || defined(CONFIG_M527x) || \
> - defined(CONFIG_M528x) || defined(CONFIG_M525x)
> -
> -#define MAX_M68K_DMA_CHANNELS 4
> -#elif defined(CONFIG_M5272)
> -#define MAX_M68K_DMA_CHANNELS 1
> -#elif defined(CONFIG_M53xx)
> -#define MAX_M68K_DMA_CHANNELS 0
> -#else
> -#define MAX_M68K_DMA_CHANNELS 2
> -#endif
> -
> -extern unsigned int dma_base_addr[MAX_M68K_DMA_CHANNELS];
> -extern unsigned int dma_device_address[MAX_M68K_DMA_CHANNELS];
> -
> -#if !defined(CONFIG_M5272)
> -#define DMA_MODE_WRITE_BIT 0x01 /* Memory/IO to IO/Memory select */
> -#define DMA_MODE_WORD_BIT 0x02 /* 8 or 16 bit transfers */
> -#define DMA_MODE_LONG_BIT 0x04 /* or 32 bit transfers */
> -#define DMA_MODE_SINGLE_BIT 0x08 /* single-address-mode */
> -
> -/* I/O to memory, 8 bits, mode */
> -#define DMA_MODE_READ 0
> -/* memory to I/O, 8 bits, mode */
> -#define DMA_MODE_WRITE 1
> -/* I/O to memory, 16 bits, mode */
> -#define DMA_MODE_READ_WORD 2
> -/* memory to I/O, 16 bits, mode */
> -#define DMA_MODE_WRITE_WORD 3
> -/* I/O to memory, 32 bits, mode */
> -#define DMA_MODE_READ_LONG 4
> -/* memory to I/O, 32 bits, mode */
> -#define DMA_MODE_WRITE_LONG 5
> -/* I/O to memory, 8 bits, single-address-mode */
> -#define DMA_MODE_READ_SINGLE 8
> -/* memory to I/O, 8 bits, single-address-mode */
> -#define DMA_MODE_WRITE_SINGLE 9
> -/* I/O to memory, 16 bits, single-address-mode */
> -#define DMA_MODE_READ_WORD_SINGLE 10
> -/* memory to I/O, 16 bits, single-address-mode */
> -#define DMA_MODE_WRITE_WORD_SINGLE 11
> -/* I/O to memory, 32 bits, single-address-mode */
> -#define DMA_MODE_READ_LONG_SINGLE 12
> -/* memory to I/O, 32 bits, single-address-mode */
> -#define DMA_MODE_WRITE_LONG_SINGLE 13
> -
> -#else /* CONFIG_M5272 is defined */
> -
> -/* Source static-address mode */
> -#define DMA_MODE_SRC_SA_BIT 0x01
> -/* Two bits to select between all four modes */
> -#define DMA_MODE_SSIZE_MASK 0x06
> -/* Offset to shift bits in */
> -#define DMA_MODE_SSIZE_OFF 0x01
> -/* Destination static-address mode */
> -#define DMA_MODE_DES_SA_BIT 0x10
> -/* Two bits to select between all four modes */
> -#define DMA_MODE_DSIZE_MASK 0x60
> -/* Offset to shift bits in */
> -#define DMA_MODE_DSIZE_OFF 0x05
> -/* Size modifiers */
> -#define DMA_MODE_SIZE_LONG 0x00
> -#define DMA_MODE_SIZE_BYTE 0x01
> -#define DMA_MODE_SIZE_WORD 0x02
> -#define DMA_MODE_SIZE_LINE 0x03
> -
> -/*
> - * Aliases to help speed quick ports; these may be suboptimal, however. They
> - * do not include the SINGLE mode modifiers since the MCF5272 does not have a
> - * mode where the device is in control of its addressing.
> - */
> -
> -/* I/O to memory, 8 bits, mode */
> -#define DMA_MODE_READ ((DMA_MODE_SIZE_BYTE << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_BYTE << DMA_MODE_SSIZE_OFF) | DMA_SRC_SA_BIT)
> -/* memory to I/O, 8 bits, mode */
> -#define DMA_MODE_WRITE ((DMA_MODE_SIZE_BYTE << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_BYTE << DMA_MODE_SSIZE_OFF) | DMA_DES_SA_BIT)
> -/* I/O to memory, 16 bits, mode */
> -#define DMA_MODE_READ_WORD ((DMA_MODE_SIZE_WORD << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_WORD << DMA_MODE_SSIZE_OFF) | DMA_SRC_SA_BIT)
> -/* memory to I/O, 16 bits, mode */
> -#define DMA_MODE_WRITE_WORD ((DMA_MODE_SIZE_WORD << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_WORD << DMA_MODE_SSIZE_OFF) | DMA_DES_SA_BIT)
> -/* I/O to memory, 32 bits, mode */
> -#define DMA_MODE_READ_LONG ((DMA_MODE_SIZE_LONG << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_LONG << DMA_MODE_SSIZE_OFF) | DMA_SRC_SA_BIT)
> -/* memory to I/O, 32 bits, mode */
> -#define DMA_MODE_WRITE_LONG ((DMA_MODE_SIZE_LONG << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_LONG << DMA_MODE_SSIZE_OFF) | DMA_DES_SA_BIT)
> -
> -#endif /* !defined(CONFIG_M5272) */
> -
> -#if !defined(CONFIG_M5272)
> -/* enable/disable a specific DMA channel */
> -static __inline__ void enable_dma(unsigned int dmanr)
> -{
> - volatile unsigned short *dmawp;
> -
> -#ifdef DMA_DEBUG
> - printk("enable_dma(dmanr=%d)\n", dmanr);
> -#endif
> -
> - dmawp = (unsigned short *) dma_base_addr[dmanr];
> - dmawp[MCFDMA_DCR] |= MCFDMA_DCR_EEXT;
> -}
> -
> -static __inline__ void disable_dma(unsigned int dmanr)
> -{
> - volatile unsigned short *dmawp;
> - volatile unsigned char *dmapb;
> -
> -#ifdef DMA_DEBUG
> - printk("disable_dma(dmanr=%d)\n", dmanr);
> -#endif
> -
> - dmawp = (unsigned short *) dma_base_addr[dmanr];
> - dmapb = (unsigned char *) dma_base_addr[dmanr];
> -
> - /* Turn off external requests, and stop any DMA in progress */
> - dmawp[MCFDMA_DCR] &= ~MCFDMA_DCR_EEXT;
> - dmapb[MCFDMA_DSR] = MCFDMA_DSR_DONE;
> -}
> -
> -/*
> - * Clear the 'DMA Pointer Flip Flop'.
> - * Write 0 for LSB/MSB, 1 for MSB/LSB access.
> - * Use this once to initialize the FF to a known state.
> - * After that, keep track of it. :-)
> - * --- In order to do that, the DMA routines below should ---
> - * --- only be used while interrupts are disabled! ---
> - *
> - * This is a NOP for ColdFire. Provide a stub for compatibility.
> - */
> -static __inline__ void clear_dma_ff(unsigned int dmanr)
> -{
> -}
> -
> -/* set mode (above) for a specific DMA channel */
> -static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
> -{
> -
> - volatile unsigned char *dmabp;
> - volatile unsigned short *dmawp;
> -
> -#ifdef DMA_DEBUG
> - printk("set_dma_mode(dmanr=%d,mode=%d)\n", dmanr, mode);
> -#endif
> -
> - dmabp = (unsigned char *) dma_base_addr[dmanr];
> - dmawp = (unsigned short *) dma_base_addr[dmanr];
> -
> - /* Clear config errors */
> - dmabp[MCFDMA_DSR] = MCFDMA_DSR_DONE;
> -
> - /* Set command register */
> - dmawp[MCFDMA_DCR] =
> - MCFDMA_DCR_INT | /* Enable completion irq */
> - MCFDMA_DCR_CS | /* Force one xfer per request */
> - MCFDMA_DCR_AA | /* Enable auto alignment */
> - /* single-address-mode */
> - ((mode & DMA_MODE_SINGLE_BIT) ? MCFDMA_DCR_SAA : 0) |
> - /* sets s_rw (-> r/w) high if Memory to I/0 */
> - ((mode & DMA_MODE_WRITE_BIT) ? MCFDMA_DCR_S_RW : 0) |
> - /* Memory to I/O or I/O to Memory */
> - ((mode & DMA_MODE_WRITE_BIT) ? MCFDMA_DCR_SINC : MCFDMA_DCR_DINC) |
> - /* 32 bit, 16 bit or 8 bit transfers */
> - ((mode & DMA_MODE_WORD_BIT) ? MCFDMA_DCR_SSIZE_WORD :
> - ((mode & DMA_MODE_LONG_BIT) ? MCFDMA_DCR_SSIZE_LONG :
> - MCFDMA_DCR_SSIZE_BYTE)) |
> - ((mode & DMA_MODE_WORD_BIT) ? MCFDMA_DCR_DSIZE_WORD :
> - ((mode & DMA_MODE_LONG_BIT) ? MCFDMA_DCR_DSIZE_LONG :
> - MCFDMA_DCR_DSIZE_BYTE));
> -
> -#ifdef DEBUG_DMA
> - printk("%s(%d): dmanr=%d DSR[%x]=%x DCR[%x]=%x\n", __FILE__, __LINE__,
> - dmanr, (int) &dmabp[MCFDMA_DSR], dmabp[MCFDMA_DSR],
> - (int) &dmawp[MCFDMA_DCR], dmawp[MCFDMA_DCR]);
> -#endif
> -}
> -
> -/* Set transfer address for specific DMA channel */
> -static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a)
> -{
> - volatile unsigned short *dmawp;
> - volatile unsigned int *dmalp;
> -
> -#ifdef DMA_DEBUG
> - printk("set_dma_addr(dmanr=%d,a=%x)\n", dmanr, a);
> -#endif
> -
> - dmawp = (unsigned short *) dma_base_addr[dmanr];
> - dmalp = (unsigned int *) dma_base_addr[dmanr];
> -
> - /* Determine which address registers are used for memory/device accesses */
> - if (dmawp[MCFDMA_DCR] & MCFDMA_DCR_SINC) {
> - /* Source incrementing, must be memory */
> - dmalp[MCFDMA_SAR] = a;
> - /* Set dest address, must be device */
> - dmalp[MCFDMA_DAR] = dma_device_address[dmanr];
> - } else {
> - /* Destination incrementing, must be memory */
> - dmalp[MCFDMA_DAR] = a;
> - /* Set source address, must be device */
> - dmalp[MCFDMA_SAR] = dma_device_address[dmanr];
> - }
> -
> -#ifdef DEBUG_DMA
> - printk("%s(%d): dmanr=%d DCR[%x]=%x SAR[%x]=%08x DAR[%x]=%08x\n",
> - __FILE__, __LINE__, dmanr, (int) &dmawp[MCFDMA_DCR], dmawp[MCFDMA_DCR],
> - (int) &dmalp[MCFDMA_SAR], dmalp[MCFDMA_SAR],
> - (int) &dmalp[MCFDMA_DAR], dmalp[MCFDMA_DAR]);
> -#endif
> -}
> -
> -/*
> - * Specific for Coldfire - sets device address.
> - * Should be called after the mode set call, and before set DMA address.
> - */
> -static __inline__ void set_dma_device_addr(unsigned int dmanr, unsigned int a)
> -{
> -#ifdef DMA_DEBUG
> - printk("set_dma_device_addr(dmanr=%d,a=%x)\n", dmanr, a);
> -#endif
> -
> - dma_device_address[dmanr] = a;
> -}
> -
> -/*
> - * NOTE 2: "count" represents _bytes_.
> - */
> -static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
> -{
> - volatile unsigned short *dmawp;
> -
> -#ifdef DMA_DEBUG
> - printk("set_dma_count(dmanr=%d,count=%d)\n", dmanr, count);
> -#endif
> -
> - dmawp = (unsigned short *) dma_base_addr[dmanr];
> - dmawp[MCFDMA_BCR] = (unsigned short)count;
> -}
> -
> -/*
> - * Get DMA residue count. After a DMA transfer, this
> - * should return zero. Reading this while a DMA transfer is
> - * still in progress will return unpredictable results.
> - * Otherwise, it returns the number of _bytes_ left to transfer.
> - */
> -static __inline__ int get_dma_residue(unsigned int dmanr)
> -{
> - volatile unsigned short *dmawp;
> - unsigned short count;
> -
> -#ifdef DMA_DEBUG
> - printk("get_dma_residue(dmanr=%d)\n", dmanr);
> -#endif
> -
> - dmawp = (unsigned short *) dma_base_addr[dmanr];
> - count = dmawp[MCFDMA_BCR];
> - return((int) count);
> -}
> -#else /* CONFIG_M5272 is defined */
> -
> -/*
> - * The MCF5272 DMA controller is very different than the controller defined above
> - * in terms of register mapping. For instance, with the exception of the 16-bit
> - * interrupt register (IRQ#85, for reference), all of the registers are 32-bit.
> - *
> - * The big difference, however, is the lack of device-requested DMA. All modes
> - * are dual address transfer, and there is no 'device' setup or direction bit.
> - * You can DMA between a device and memory, between memory and memory, or even between
> - * two devices directly, with any combination of incrementing and non-incrementing
> - * addresses you choose. This puts a crimp in distinguishing between the 'device
> - * address' set up by set_dma_device_addr.
> - *
> - * Therefore, there are two options. One is to use set_dma_addr and set_dma_device_addr,
> - * which will act exactly as above in -- it will look to see if the source is set to
> - * autoincrement, and if so it will make the source use the set_dma_addr value and the
> - * destination the set_dma_device_addr value. Otherwise the source will be set to the
> - * set_dma_device_addr value and the destination will get the set_dma_addr value.
> - *
> - * The other is to use the provided set_dma_src_addr and set_dma_dest_addr functions
> - * and make it explicit. Depending on what you're doing, one of these two should work
> - * for you, but don't mix them in the same transfer setup.
> - */
> -
> -/* enable/disable a specific DMA channel */
> -static __inline__ void enable_dma(unsigned int dmanr)
> -{
> - volatile unsigned int *dmalp;
> -
> -#ifdef DMA_DEBUG
> - printk("enable_dma(dmanr=%d)\n", dmanr);
> -#endif
> -
> - dmalp = (unsigned int *) dma_base_addr[dmanr];
> - dmalp[MCFDMA_DMR] |= MCFDMA_DMR_EN;
> -}
> -
> -static __inline__ void disable_dma(unsigned int dmanr)
> -{
> - volatile unsigned int *dmalp;
> -
> -#ifdef DMA_DEBUG
> - printk("disable_dma(dmanr=%d)\n", dmanr);
> -#endif
> -
> - dmalp = (unsigned int *) dma_base_addr[dmanr];
> -
> - /* Turn off external requests, and stop any DMA in progress */
> - dmalp[MCFDMA_DMR] &= ~MCFDMA_DMR_EN;
> - dmalp[MCFDMA_DMR] |= MCFDMA_DMR_RESET;
> -}
> -
> -/*
> - * Clear the 'DMA Pointer Flip Flop'.
> - * Write 0 for LSB/MSB, 1 for MSB/LSB access.
> - * Use this once to initialize the FF to a known state.
> - * After that, keep track of it. :-)
> - * --- In order to do that, the DMA routines below should ---
> - * --- only be used while interrupts are disabled! ---
> - *
> - * This is a NOP for ColdFire. Provide a stub for compatibility.
> - */
> -static __inline__ void clear_dma_ff(unsigned int dmanr)
> -{
> -}
> -
> -/* set mode (above) for a specific DMA channel */
> -static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
> -{
> -
> - volatile unsigned int *dmalp;
> - volatile unsigned short *dmawp;
> -
> -#ifdef DMA_DEBUG
> - printk("set_dma_mode(dmanr=%d,mode=%d)\n", dmanr, mode);
> -#endif
> - dmalp = (unsigned int *) dma_base_addr[dmanr];
> - dmawp = (unsigned short *) dma_base_addr[dmanr];
> -
> - /* Clear config errors */
> - dmalp[MCFDMA_DMR] |= MCFDMA_DMR_RESET;
> -
> - /* Set command register */
> - dmalp[MCFDMA_DMR] =
> - MCFDMA_DMR_RQM_DUAL | /* Mandatory Request Mode setting */
> - MCFDMA_DMR_DSTT_SD | /* Set up addressing types; set to supervisor-data. */
> - MCFDMA_DMR_SRCT_SD | /* Set up addressing types; set to supervisor-data. */
> - /* source static-address-mode */
> - ((mode & DMA_MODE_SRC_SA_BIT) ? MCFDMA_DMR_SRCM_SA : MCFDMA_DMR_SRCM_IA) |
> - /* dest static-address-mode */
> - ((mode & DMA_MODE_DES_SA_BIT) ? MCFDMA_DMR_DSTM_SA : MCFDMA_DMR_DSTM_IA) |
> - /* burst, 32 bit, 16 bit or 8 bit transfers are separately configurable on the MCF5272 */
> - (((mode & DMA_MODE_SSIZE_MASK) >> DMA_MODE_SSIZE_OFF) << MCFDMA_DMR_DSTS_OFF) |
> - (((mode & DMA_MODE_SSIZE_MASK) >> DMA_MODE_SSIZE_OFF) << MCFDMA_DMR_SRCS_OFF);
> -
> - dmawp[MCFDMA_DIR] |= MCFDMA_DIR_ASCEN; /* Enable completion interrupts */
> -
> -#ifdef DEBUG_DMA
> - printk("%s(%d): dmanr=%d DMR[%x]=%x DIR[%x]=%x\n", __FILE__, __LINE__,
> - dmanr, (int) &dmalp[MCFDMA_DMR], dmalp[MCFDMA_DMR],
> - (int) &dmawp[MCFDMA_DIR], dmawp[MCFDMA_DIR]);
> -#endif
> -}
> -
> -/* Set transfer address for specific DMA channel */
> -static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a)
> -{
> - volatile unsigned int *dmalp;
> -
> -#ifdef DMA_DEBUG
> - printk("set_dma_addr(dmanr=%d,a=%x)\n", dmanr, a);
> -#endif
> -
> - dmalp = (unsigned int *) dma_base_addr[dmanr];
> -
> - /* Determine which address registers are used for memory/device accesses */
> - if (dmalp[MCFDMA_DMR] & MCFDMA_DMR_SRCM) {
> - /* Source incrementing, must be memory */
> - dmalp[MCFDMA_DSAR] = a;
> - /* Set dest address, must be device */
> - dmalp[MCFDMA_DDAR] = dma_device_address[dmanr];
> - } else {
> - /* Destination incrementing, must be memory */
> - dmalp[MCFDMA_DDAR] = a;
> - /* Set source address, must be device */
> - dmalp[MCFDMA_DSAR] = dma_device_address[dmanr];
> - }
> -
> -#ifdef DEBUG_DMA
> - printk("%s(%d): dmanr=%d DMR[%x]=%x SAR[%x]=%08x DAR[%x]=%08x\n",
> - __FILE__, __LINE__, dmanr, (int) &dmalp[MCFDMA_DMR], dmalp[MCFDMA_DMR],
> - (int) &dmalp[MCFDMA_DSAR], dmalp[MCFDMA_DSAR],
> - (int) &dmalp[MCFDMA_DDAR], dmalp[MCFDMA_DDAR]);
> -#endif
> -}
> -
> -/*
> - * Specific for Coldfire - sets device address.
> - * Should be called after the mode set call, and before set DMA address.
> - */
> -static __inline__ void set_dma_device_addr(unsigned int dmanr, unsigned int a)
> -{
> -#ifdef DMA_DEBUG
> - printk("set_dma_device_addr(dmanr=%d,a=%x)\n", dmanr, a);
> -#endif
> -
> - dma_device_address[dmanr] = a;
> -}
> -
> -/*
> - * NOTE 2: "count" represents _bytes_.
> - *
> - * NOTE 3: While a 32-bit register, "count" is only a maximum 24-bit value.
> - */
> -static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
> -{
> - volatile unsigned int *dmalp;
> -
> -#ifdef DMA_DEBUG
> - printk("set_dma_count(dmanr=%d,count=%d)\n", dmanr, count);
> -#endif
> -
> - dmalp = (unsigned int *) dma_base_addr[dmanr];
> - dmalp[MCFDMA_DBCR] = count;
> -}
> -
> -/*
> - * Get DMA residue count. After a DMA transfer, this
> - * should return zero. Reading this while a DMA transfer is
> - * still in progress will return unpredictable results.
> - * Otherwise, it returns the number of _bytes_ left to transfer.
> - */
> -static __inline__ int get_dma_residue(unsigned int dmanr)
> -{
> - volatile unsigned int *dmalp;
> - unsigned int count;
> -
> -#ifdef DMA_DEBUG
> - printk("get_dma_residue(dmanr=%d)\n", dmanr);
> -#endif
> -
> - dmalp = (unsigned int *) dma_base_addr[dmanr];
> - count = dmalp[MCFDMA_DBCR];
> - return(count);
> -}
> -
> -#endif /* !defined(CONFIG_M5272) */
> -#endif /* CONFIG_COLDFIRE */
> -
> /* it's useless on the m68k, but unfortunately needed by the new
> bootmem allocator (but this should do it for this) */
> #define MAX_DMA_ADDRESS PAGE_OFFSET
>
> -#define MAX_DMA_CHANNELS 8
> -
> -extern int request_dma(unsigned int dmanr, const char * device_id); /* reserve a DMA channel */
> -extern void free_dma(unsigned int dmanr); /* release it again */
> -
> #ifdef CONFIG_PCI
> extern int isa_dma_bridge_buggy;
> #else
> diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
> index ecbe948f4c1a..df7f797c908a 100644
> --- a/arch/m68k/mm/motorola.c
> +++ b/arch/m68k/mm/motorola.c
> @@ -27,7 +27,6 @@
> #include <asm/pgalloc.h>
> #include <asm/machdep.h>
> #include <asm/io.h>
> -#include <asm/dma.h>
> #ifdef CONFIG_ATARI
> #include <asm/atari_stram.h>
> #endif
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index af6c3c329076..d6144978e32d 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -508,7 +508,7 @@ config MMC_OMAP_HS
>
> config MMC_WBSD
> tristate "Winbond W83L51xD SD/MMC Card Interface support"
> - depends on ISA_DMA_API && !M68K
> + depends on ISA_DMA_API
> help
> This selects the Winbond(R) W83L51xD Secure digital and
> Multimedia card Interface.
> diff --git a/sound/core/Makefile b/sound/core/Makefile
> index 350d704ced98..2762f03d9b7b 100644
> --- a/sound/core/Makefile
> +++ b/sound/core/Makefile
> @@ -9,9 +9,7 @@ ifneq ($(CONFIG_SND_PROC_FS),)
> snd-y += info.o
> snd-$(CONFIG_SND_OSSEMUL) += info_oss.o
> endif
> -ifneq ($(CONFIG_M68K),y)
> snd-$(CONFIG_ISA_DMA_API) += isadma.o
> -endif
> snd-$(CONFIG_SND_OSSEMUL) += sound_oss.o
> snd-$(CONFIG_SND_VMASTER) += vmaster.o
> snd-$(CONFIG_SND_JACK) += ctljack.o jack.o
> diff --git a/sound/isa/Kconfig b/sound/isa/Kconfig
> index 570b88e0b201..6ffa48dd5983 100644
> --- a/sound/isa/Kconfig
> +++ b/sound/isa/Kconfig
> @@ -22,7 +22,7 @@ config SND_SB16_DSP
> menuconfig SND_ISA
> bool "ISA sound devices"
> depends on ISA || COMPILE_TEST
> - depends on ISA_DMA_API && !M68K
> + depends on ISA_DMA_API
> default y
> help
> Support for sound devices connected via the ISA bus.
>
On Fri, Apr 22, 2022 at 9:48 AM Michael Schmitz <[email protected]> wrote:
> Am 21.04.2022 um 20:20 schrieb Arnd Bergmann:
> > From: Arnd Bergmann <[email protected]>
> >
> > After a build regression report, I took a look at possible users of
> > CONFIG_ISA_DMA_API on m68k and found none, which Greg confirmed. The
> > CONFIG_GENERIC_ISA_DMA option in turn is only needed to implement
> > ISA_DMA_API, and is clearly not used on the platforms with ISA support.
> >
> > The CONFIG_ISA support for AMIGA_PCMCIA is probably also unneeded,
> > but this is less clear. Unlike other PCMCIA implementations, this one
> > does not use the drivers/pcmcia subsystem at all and just supports
> > the "apne" network driver. When it was first added, one could use
> > ISA drivers on it as well, but this probably broke at some point.
>
> Hoping to clarify some of this:
>
> For the Amiga PCMCIA "apne" driver, both the definitions of
> isa_type/isa_sex and the definitions of the low-level accessor and
> address translation functions are protected by CONFIG_ISA (see
> arch/m68k/kernel/setup_mm.c and arch/m68k/include/asm/io_mm.h for details).
>
> This could conceivably be changed (only AMIGA_PCMCIA and Q40 do use
> these definitions, aside from ATARI_ROM_ISA), but as things are right
> now, neither Q40 ISA nor Amiga PCMCIA will work without CONFIG_ISA defined.
Ok, thanks for clarifying that, this makes a lot more sense now. I was wondering
what ISA devices one can actually use without DMA, but it turns out that a
lot of the older storage (pata_legacy, pata_isapnp, aha152x) and network
(3c509, 8390, cs89x0, smc9194) devices work in PIO mode, aside from
a couple of oddball special-purpose stuff (speech, busmouse, comedi,
appletalk, wan, ...).
> Regarding the Amiga PCMCIA driver's use of the drivers/pcmcia subsystem,
> I have a patch in limbo at netdev that makes use of the cftable parser
> code from drivers/pcmcia, but as far as I can recall, none of this
> depends on CONFIG_ISA.
Yes, Geert mentioned that on IRC already. Note that Dominik Brodowski
has said in the past that he would plan to eventually drop PCMCIA
support from the kernel, but I think if that happens, the cftable
parser can just be moved into the amiga_pcmcia code.
Arnd