Changes since v5:
- Added a fix to the tilcdc driver to ensure it doesn't use the
non-atomic operation. (This includes adding io{read|write}64[be]_is_nonatomic
defines).
Changes since v4:
- Add functions so the powerpc implementation of iomap.c compiles. (As
noticed by Horia)
Changes since v3:
- I noticed powerpc didn't use the appropriate functions seeing
readq/writeq were not defined when iomap.h was included. Thus I've
included a patch to adjust this
- Fixed some mistakes with a couple of the defines in io-64-nonatomic*
headers
- Fixed a typo noticed by Horia.
(earlier versions were drastically different)
Horia Geantă (1):
crypto: caam: cleanup CONFIG_64BIT ifdefs when using io{read|write}64
Logan Gunthorpe (6):
drm/tilcdc: ensure nonatomic iowrite64 is not used
powerpc: io.h: move iomap.h include so that it can use readq/writeq
defs
powerpc: iomap.c: introduce io{read|write}64_{lo_hi|hi_lo}
iomap: introduce io{read|write}64_{lo_hi|hi_lo}
io-64-nonatomic: add io{read|write}64[be]{_lo_hi|_hi_lo} macros
ntb: ntb_hw_intel: use io-64-nonatomic instead of in-driver hacks
arch/powerpc/include/asm/io.h | 6 +-
arch/powerpc/kernel/iomap.c | 40 +++++++++++
drivers/crypto/caam/regs.h | 35 ++-------
drivers/gpu/drm/tilcdc/tilcdc_regs.h | 2 +-
drivers/ntb/hw/intel/ntb_hw_intel.c | 30 +-------
include/asm-generic/iomap.h | 26 +++++--
include/linux/io-64-nonatomic-hi-lo.h | 64 +++++++++++++++++
include/linux/io-64-nonatomic-lo-hi.h | 64 +++++++++++++++++
lib/iomap.c | 132 ++++++++++++++++++++++++++++++++++
9 files changed, 331 insertions(+), 68 deletions(-)
From: Horia Geantă <[email protected]>
We can now make use of the io-64-nonatomic-lo-hi header to always
provide 64 bit IO operations. So this patch cleans up the extra
CONFIG_64BIT ifdefs.
To be consistent with CAAM engine HW spec: in case of 64-bit registers,
irrespective of device endianness, the lower address should be read from
/ written to first, followed by the upper address. Indeed the I/O
accessors in CAAM driver currently don't follow the spec, however this
is a good opportunity to fix the code.
Signed-off-by: Horia Geantă <[email protected]>
Signed-off-by: Logan Gunthorpe <[email protected]>
Cc: Horia Geantă <[email protected]>
Cc: Dan Douglass <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: "David S. Miller" <[email protected]>
---
drivers/crypto/caam/regs.h | 35 +++++------------------------------
1 file changed, 5 insertions(+), 30 deletions(-)
diff --git a/drivers/crypto/caam/regs.h b/drivers/crypto/caam/regs.h
index 84d2f838a063..0c45505458e7 100644
--- a/drivers/crypto/caam/regs.h
+++ b/drivers/crypto/caam/regs.h
@@ -9,7 +9,7 @@
#include <linux/types.h>
#include <linux/bitops.h>
-#include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
/*
* Architecture-specific register access methods
@@ -134,50 +134,25 @@ static inline void clrsetbits_32(void __iomem *reg, u32 clear, u32 set)
* base + 0x0000 : least-significant 32 bits
* base + 0x0004 : most-significant 32 bits
*/
-#ifdef CONFIG_64BIT
static inline void wr_reg64(void __iomem *reg, u64 data)
{
+#ifndef CONFIG_CRYPTO_DEV_FSL_CAAM_IMX
if (caam_little_end)
iowrite64(data, reg);
else
- iowrite64be(data, reg);
-}
-
-static inline u64 rd_reg64(void __iomem *reg)
-{
- if (caam_little_end)
- return ioread64(reg);
- else
- return ioread64be(reg);
-}
-
-#else /* CONFIG_64BIT */
-static inline void wr_reg64(void __iomem *reg, u64 data)
-{
-#ifndef CONFIG_CRYPTO_DEV_FSL_CAAM_IMX
- if (caam_little_end) {
- wr_reg32((u32 __iomem *)(reg) + 1, data >> 32);
- wr_reg32((u32 __iomem *)(reg), data);
- } else
#endif
- {
- wr_reg32((u32 __iomem *)(reg), data >> 32);
- wr_reg32((u32 __iomem *)(reg) + 1, data);
- }
+ iowrite64be(data, reg);
}
static inline u64 rd_reg64(void __iomem *reg)
{
#ifndef CONFIG_CRYPTO_DEV_FSL_CAAM_IMX
if (caam_little_end)
- return ((u64)rd_reg32((u32 __iomem *)(reg) + 1) << 32 |
- (u64)rd_reg32((u32 __iomem *)(reg)));
+ return ioread64(reg);
else
#endif
- return ((u64)rd_reg32((u32 __iomem *)(reg)) << 32 |
- (u64)rd_reg32((u32 __iomem *)(reg) + 1));
+ return ioread64be(reg);
}
-#endif /* CONFIG_64BIT */
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
#ifdef CONFIG_SOC_IMX7D
--
2.11.0
Subsequent patches in this series makes use of the readq and writeq
defines in iomap.h. However, as is, they get missed on the powerpc
platform seeing the include comes before the define. This patch
moves the include down to fix this.
Signed-off-by: Logan Gunthorpe <[email protected]>
Acked-By: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Suresh Warrier <[email protected]>
Cc: "Oliver O'Halloran" <[email protected]>
---
arch/powerpc/include/asm/io.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index 422f99cf9924..af074923d598 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -33,8 +33,6 @@ extern struct pci_dev *isa_bridge_pcidev;
#include <asm/mmu.h>
#include <asm/ppc_asm.h>
-#include <asm-generic/iomap.h>
-
#ifdef CONFIG_PPC64
#include <asm/paca.h>
#endif
@@ -663,6 +661,8 @@ static inline void name at \
#define writel_relaxed(v, addr) writel(v, addr)
#define writeq_relaxed(v, addr) writeq(v, addr)
+#include <asm-generic/iomap.h>
+
#ifdef CONFIG_PPC32
#define mmiowb()
#else
--
2.11.0
These functions will be introduced into the generic iomap.c so
they can deal with PIO accesses in hi-lo/lo-hi variants. Thus,
the powerpc version of iomap.c will need to provide the same
functions even though, in this arch, they are identical to the
regular io{read|write}64 functions.
Signed-off-by: Logan Gunthorpe <[email protected]>
Tested-by: Horia Geantă <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
---
arch/powerpc/kernel/iomap.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/arch/powerpc/kernel/iomap.c b/arch/powerpc/kernel/iomap.c
index a1854d1ded8b..b43dbadfd24f 100644
--- a/arch/powerpc/kernel/iomap.c
+++ b/arch/powerpc/kernel/iomap.c
@@ -44,12 +44,32 @@ u64 ioread64(void __iomem *addr)
{
return readq(addr);
}
+u64 ioread64_lo_hi(void __iomem *addr)
+{
+ return readq(addr);
+}
+u64 ioread64_hi_lo(void __iomem *addr)
+{
+ return readq(addr);
+}
u64 ioread64be(void __iomem *addr)
{
return readq_be(addr);
}
+u64 ioread64be_lo_hi(void __iomem *addr)
+{
+ return readq_be(addr);
+}
+u64 ioread64be_hi_lo(void __iomem *addr)
+{
+ return readq_be(addr);
+}
EXPORT_SYMBOL(ioread64);
+EXPORT_SYMBOL(ioread64_lo_hi);
+EXPORT_SYMBOL(ioread64_hi_lo);
EXPORT_SYMBOL(ioread64be);
+EXPORT_SYMBOL(ioread64be_lo_hi);
+EXPORT_SYMBOL(ioread64be_hi_lo);
#endif /* __powerpc64__ */
void iowrite8(u8 val, void __iomem *addr)
@@ -82,12 +102,32 @@ void iowrite64(u64 val, void __iomem *addr)
{
writeq(val, addr);
}
+void iowrite64_lo_hi(u64 val, void __iomem *addr)
+{
+ writeq(val, addr);
+}
+void iowrite64_hi_lo(u64 val, void __iomem *addr)
+{
+ writeq(val, addr);
+}
void iowrite64be(u64 val, void __iomem *addr)
{
writeq_be(val, addr);
}
+void iowrite64be_lo_hi(u64 val, void __iomem *addr)
+{
+ writeq_be(val, addr);
+}
+void iowrite64be_hi_lo(u64 val, void __iomem *addr)
+{
+ writeq_be(val, addr);
+}
EXPORT_SYMBOL(iowrite64);
+EXPORT_SYMBOL(iowrite64_lo_hi);
+EXPORT_SYMBOL(iowrite64_hi_lo);
EXPORT_SYMBOL(iowrite64be);
+EXPORT_SYMBOL(iowrite64be_lo_hi);
+EXPORT_SYMBOL(iowrite64be_hi_lo);
#endif /* __powerpc64__ */
/*
--
2.11.0
In order to provide non-atomic functions for io{read|write}64 that will
use readq and writeq when appropriate. We define a number of variants
of these functions in the generic iomap that will do non-atomic
operations on pio but atomic operations on mmio.
These functions are only defined if readq and writeq are defined. If
they are not, then the wrappers that always use non-atomic operations
from include/linux/io-64-nonatomic*.h will be used.
Signed-off-by: Logan Gunthorpe <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Suresh Warrier <[email protected]>
Cc: Nicholas Piggin <[email protected]>
---
arch/powerpc/include/asm/io.h | 2 +
include/asm-generic/iomap.h | 26 +++++++--
lib/iomap.c | 132 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 154 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index af074923d598..4cc420cfaa78 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -788,8 +788,10 @@ extern void __iounmap_at(void *ea, unsigned long size);
#define mmio_read16be(addr) readw_be(addr)
#define mmio_read32be(addr) readl_be(addr)
+#define mmio_read64be(addr) readq_be(addr)
#define mmio_write16be(val, addr) writew_be(val, addr)
#define mmio_write32be(val, addr) writel_be(val, addr)
+#define mmio_write64be(val, addr) writeq_be(val, addr)
#define mmio_insb(addr, dst, count) readsb(addr, dst, count)
#define mmio_insw(addr, dst, count) readsw(addr, dst, count)
#define mmio_insl(addr, dst, count) readsl(addr, dst, count)
diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
index 650fede33c25..30edebf627fe 100644
--- a/include/asm-generic/iomap.h
+++ b/include/asm-generic/iomap.h
@@ -30,9 +30,16 @@ extern unsigned int ioread16(void __iomem *);
extern unsigned int ioread16be(void __iomem *);
extern unsigned int ioread32(void __iomem *);
extern unsigned int ioread32be(void __iomem *);
-#ifdef CONFIG_64BIT
-extern u64 ioread64(void __iomem *);
-extern u64 ioread64be(void __iomem *);
+
+#ifdef readq
+#define ioread64_lo_hi ioread64_lo_hi
+#define ioread64_hi_lo ioread64_hi_lo
+#define ioread64be_lo_hi ioread64be_lo_hi
+#define ioread64be_hi_lo ioread64be_hi_lo
+extern u64 ioread64_lo_hi(void __iomem *addr);
+extern u64 ioread64_hi_lo(void __iomem *addr);
+extern u64 ioread64be_lo_hi(void __iomem *addr);
+extern u64 ioread64be_hi_lo(void __iomem *addr);
#endif
extern void iowrite8(u8, void __iomem *);
@@ -40,9 +47,16 @@ extern void iowrite16(u16, void __iomem *);
extern void iowrite16be(u16, void __iomem *);
extern void iowrite32(u32, void __iomem *);
extern void iowrite32be(u32, void __iomem *);
-#ifdef CONFIG_64BIT
-extern void iowrite64(u64, void __iomem *);
-extern void iowrite64be(u64, void __iomem *);
+
+#ifdef writeq
+#define iowrite64_lo_hi iowrite64_lo_hi
+#define iowrite64_hi_lo iowrite64_hi_lo
+#define iowrite64be_lo_hi iowrite64be_lo_hi
+#define iowrite64be_hi_lo iowrite64be_hi_lo
+extern void iowrite64_lo_hi(u64 val, void __iomem *addr);
+extern void iowrite64_hi_lo(u64 val, void __iomem *addr);
+extern void iowrite64be_lo_hi(u64 val, void __iomem *addr);
+extern void iowrite64be_hi_lo(u64 val, void __iomem *addr);
#endif
/*
diff --git a/lib/iomap.c b/lib/iomap.c
index fc3dcb4b238e..845b9c41082c 100644
--- a/lib/iomap.c
+++ b/lib/iomap.c
@@ -66,6 +66,7 @@ static void bad_io_access(unsigned long port, const char *access)
#ifndef mmio_read16be
#define mmio_read16be(addr) be16_to_cpu(__raw_readw(addr))
#define mmio_read32be(addr) be32_to_cpu(__raw_readl(addr))
+#define mmio_read64be(addr) be64_to_cpu(__raw_readq(addr))
#endif
unsigned int ioread8(void __iomem *addr)
@@ -99,6 +100,80 @@ EXPORT_SYMBOL(ioread16be);
EXPORT_SYMBOL(ioread32);
EXPORT_SYMBOL(ioread32be);
+#ifdef readq
+static u64 pio_read64_lo_hi(unsigned long port)
+{
+ u64 lo, hi;
+
+ lo = inl(port);
+ hi = inl(port + sizeof(u32));
+
+ return lo | (hi << 32);
+}
+
+static u64 pio_read64_hi_lo(unsigned long port)
+{
+ u64 lo, hi;
+
+ hi = inl(port + sizeof(u32));
+ lo = inl(port);
+
+ return lo | (hi << 32);
+}
+
+static u64 pio_read64be_lo_hi(unsigned long port)
+{
+ u64 lo, hi;
+
+ lo = pio_read32be(port + sizeof(u32));
+ hi = pio_read32be(port);
+
+ return lo | (hi << 32);
+}
+
+static u64 pio_read64be_hi_lo(unsigned long port)
+{
+ u64 lo, hi;
+
+ hi = pio_read32be(port);
+ lo = pio_read32be(port + sizeof(u32));
+
+ return lo | (hi << 32);
+}
+
+u64 ioread64_lo_hi(void __iomem *addr)
+{
+ IO_COND(addr, return pio_read64_lo_hi(port), return readq(addr));
+ return 0xffffffffffffffffULL;
+}
+
+u64 ioread64_hi_lo(void __iomem *addr)
+{
+ IO_COND(addr, return pio_read64_hi_lo(port), return readq(addr));
+ return 0xffffffffffffffffULL;
+}
+
+u64 ioread64be_lo_hi(void __iomem *addr)
+{
+ IO_COND(addr, return pio_read64be_lo_hi(port),
+ return mmio_read64be(addr));
+ return 0xffffffffffffffffULL;
+}
+
+u64 ioread64be_hi_lo(void __iomem *addr)
+{
+ IO_COND(addr, return pio_read64be_hi_lo(port),
+ return mmio_read64be(addr));
+ return 0xffffffffffffffffULL;
+}
+
+EXPORT_SYMBOL(ioread64_lo_hi);
+EXPORT_SYMBOL(ioread64_hi_lo);
+EXPORT_SYMBOL(ioread64be_lo_hi);
+EXPORT_SYMBOL(ioread64be_hi_lo);
+
+#endif /* readq */
+
#ifndef pio_write16be
#define pio_write16be(val,port) outw(swab16(val),port)
#define pio_write32be(val,port) outl(swab32(val),port)
@@ -107,6 +182,7 @@ EXPORT_SYMBOL(ioread32be);
#ifndef mmio_write16be
#define mmio_write16be(val,port) __raw_writew(be16_to_cpu(val),port)
#define mmio_write32be(val,port) __raw_writel(be32_to_cpu(val),port)
+#define mmio_write64be(val,port) __raw_writeq(be64_to_cpu(val),port)
#endif
void iowrite8(u8 val, void __iomem *addr)
@@ -135,6 +211,62 @@ EXPORT_SYMBOL(iowrite16be);
EXPORT_SYMBOL(iowrite32);
EXPORT_SYMBOL(iowrite32be);
+#ifdef writeq
+static void pio_write64_lo_hi(u64 val, unsigned long port)
+{
+ outl(val, port);
+ outl(val >> 32, port + sizeof(u32));
+}
+
+static void pio_write64_hi_lo(u64 val, unsigned long port)
+{
+ outl(val >> 32, port + sizeof(u32));
+ outl(val, port);
+}
+
+static void pio_write64be_lo_hi(u64 val, unsigned long port)
+{
+ pio_write32be(val, port + sizeof(u32));
+ pio_write32be(val >> 32, port);
+}
+
+static void pio_write64be_hi_lo(u64 val, unsigned long port)
+{
+ pio_write32be(val >> 32, port);
+ pio_write32be(val, port + sizeof(u32));
+}
+
+void iowrite64_lo_hi(u64 val, void __iomem *addr)
+{
+ IO_COND(addr, pio_write64_lo_hi(val, port),
+ writeq(val, addr));
+}
+
+void iowrite64_hi_lo(u64 val, void __iomem *addr)
+{
+ IO_COND(addr, pio_write64_hi_lo(val, port),
+ writeq(val, addr));
+}
+
+void iowrite64be_lo_hi(u64 val, void __iomem *addr)
+{
+ IO_COND(addr, pio_write64be_lo_hi(val, port),
+ mmio_write64be(val, addr));
+}
+
+void iowrite64be_hi_lo(u64 val, void __iomem *addr)
+{
+ IO_COND(addr, pio_write64be_hi_lo(val, port),
+ mmio_write64be(val, addr));
+}
+
+EXPORT_SYMBOL(iowrite64_lo_hi);
+EXPORT_SYMBOL(iowrite64_hi_lo);
+EXPORT_SYMBOL(iowrite64be_lo_hi);
+EXPORT_SYMBOL(iowrite64be_hi_lo);
+
+#endif /* readq */
+
/*
* These are the "repeat MMIO read/write" functions.
* Note the "__raw" accesses, since we don't want to
--
2.11.0
This patch adds generic io{read|write}64[be]{_lo_hi|_hi_lo} macros if
they are not already defined by the architecture. (As they are provided
by the generic iomap library).
The patch also points io{read|write}64[be] to the variant specified by the
header name.
This is because new drivers are encouraged to use ioreadXX, et al instead
of readX[1], et al -- and mixing ioreadXX with readq is pretty ugly.
[1] ldd3: section 9.4.2
Signed-off-by: Logan Gunthorpe <[email protected]>
cc: Christoph Hellwig <[email protected]>
cc: Arnd Bergmann <[email protected]>
cc: Alan Cox <[email protected]>
cc: Greg Kroah-Hartman <[email protected]>
---
include/linux/io-64-nonatomic-hi-lo.h | 64 +++++++++++++++++++++++++++++++++++
include/linux/io-64-nonatomic-lo-hi.h | 64 +++++++++++++++++++++++++++++++++++
2 files changed, 128 insertions(+)
diff --git a/include/linux/io-64-nonatomic-hi-lo.h b/include/linux/io-64-nonatomic-hi-lo.h
index defcc4644ce3..410c8b177080 100644
--- a/include/linux/io-64-nonatomic-hi-lo.h
+++ b/include/linux/io-64-nonatomic-hi-lo.h
@@ -54,4 +54,68 @@ static inline void hi_lo_writeq_relaxed(__u64 val, volatile void __iomem *addr)
#define writeq_relaxed hi_lo_writeq_relaxed
#endif
+#ifndef ioread64_hi_lo
+#define ioread64_hi_lo ioread64_hi_lo
+static inline u64 ioread64_hi_lo(void __iomem *addr)
+{
+ u32 low, high;
+
+ high = ioread32(addr + sizeof(u32));
+ low = ioread32(addr);
+
+ return low + ((u64)high << 32);
+}
+#endif
+
+#ifndef iowrite64_hi_lo
+#define iowrite64_hi_lo iowrite64_hi_lo
+static inline void iowrite64_hi_lo(u64 val, void __iomem *addr)
+{
+ iowrite32(val >> 32, addr + sizeof(u32));
+ iowrite32(val, addr);
+}
+#endif
+
+#ifndef ioread64be_hi_lo
+#define ioread64be_hi_lo ioread64be_hi_lo
+static inline u64 ioread64be_hi_lo(void __iomem *addr)
+{
+ u32 low, high;
+
+ high = ioread32be(addr);
+ low = ioread32be(addr + sizeof(u32));
+
+ return low + ((u64)high << 32);
+}
+#endif
+
+#ifndef iowrite64be_hi_lo
+#define iowrite64be_hi_lo iowrite64be_hi_lo
+static inline void iowrite64be_hi_lo(u64 val, void __iomem *addr)
+{
+ iowrite32be(val >> 32, addr);
+ iowrite32be(val, addr + sizeof(u32));
+}
+#endif
+
+#ifndef ioread64
+#define ioread64_is_nonatomic
+#define ioread64 ioread64_hi_lo
+#endif
+
+#ifndef iowrite64
+#define iowrite64_is_nonatomic
+#define iowrite64 iowrite64_hi_lo
+#endif
+
+#ifndef ioread64be
+#define ioread64be_is_nonatomic
+#define ioread64be ioread64be_hi_lo
+#endif
+
+#ifndef iowrite64be
+#define iowrite64be_is_nonatomic
+#define iowrite64be iowrite64be_hi_lo
+#endif
+
#endif /* _LINUX_IO_64_NONATOMIC_HI_LO_H_ */
diff --git a/include/linux/io-64-nonatomic-lo-hi.h b/include/linux/io-64-nonatomic-lo-hi.h
index 084461a4e5ab..acba36812be8 100644
--- a/include/linux/io-64-nonatomic-lo-hi.h
+++ b/include/linux/io-64-nonatomic-lo-hi.h
@@ -54,4 +54,68 @@ static inline void lo_hi_writeq_relaxed(__u64 val, volatile void __iomem *addr)
#define writeq_relaxed lo_hi_writeq_relaxed
#endif
+#ifndef ioread64_lo_hi
+#define ioread64_lo_hi ioread64_lo_hi
+static inline u64 ioread64_lo_hi(void __iomem *addr)
+{
+ u32 low, high;
+
+ low = ioread32(addr);
+ high = ioread32(addr + sizeof(u32));
+
+ return low + ((u64)high << 32);
+}
+#endif
+
+#ifndef iowrite64_lo_hi
+#define iowrite64_lo_hi iowrite64_lo_hi
+static inline void iowrite64_lo_hi(u64 val, void __iomem *addr)
+{
+ iowrite32(val, addr);
+ iowrite32(val >> 32, addr + sizeof(u32));
+}
+#endif
+
+#ifndef ioread64be_lo_hi
+#define ioread64be_lo_hi ioread64be_lo_hi
+static inline u64 ioread64be_lo_hi(void __iomem *addr)
+{
+ u32 low, high;
+
+ low = ioread32be(addr + sizeof(u32));
+ high = ioread32be(addr);
+
+ return low + ((u64)high << 32);
+}
+#endif
+
+#ifndef iowrite64be_lo_hi
+#define iowrite64be_lo_hi iowrite64be_lo_hi
+static inline void iowrite64be_lo_hi(u64 val, void __iomem *addr)
+{
+ iowrite32be(val, addr + sizeof(u32));
+ iowrite32be(val >> 32, addr);
+}
+#endif
+
+#ifndef ioread64
+#define ioread64_is_nonatomic
+#define ioread64 ioread64_lo_hi
+#endif
+
+#ifndef iowrite64
+#define iowrite64_is_nonatomic
+#define iowrite64 iowrite64_lo_hi
+#endif
+
+#ifndef ioread64be
+#define ioread64be_is_nonatomic
+#define ioread64be ioread64be_lo_hi
+#endif
+
+#ifndef iowrite64be
+#define iowrite64be_is_nonatomic
+#define iowrite64be iowrite64be_lo_hi
+#endif
+
#endif /* _LINUX_IO_64_NONATOMIC_LO_HI_H_ */
--
2.11.0
Add a check to ensure iowrite64 is only used if it is atomic.
It was decided in [1] that the tilcdc driver should not be using an
atomic operation (so it was left out of this patchset). However, it turns
out that through the drm code, a nonatomic header is actually included:
include/linux/io-64-nonatomic-lo-hi.h
is included from include/drm/drm_os_linux.h:9:0,
from include/drm/drmP.h:74,
from include/drm/drm_modeset_helper.h:26,
from include/drm/drm_atomic_helper.h:33,
from drivers/gpu/drm/tilcdc/tilcdc_crtc.c:19:
And thus, without this change, this patchset would inadvertantly
change the behaviour of the tilcdc driver.
[1] lkml.kernel.org/r/CAK8P3a2HhO_zCnsTzq7hmWSz5La5Thu19FWZpun16iMnyyNreQ@mail.gmail.com
Signed-off-by: Logan Gunthorpe <[email protected]>
Cc: Jyri Sarha <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Tomi Valkeinen <[email protected]>
Cc: David Airlie <[email protected]>
---
drivers/gpu/drm/tilcdc/tilcdc_regs.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_regs.h b/drivers/gpu/drm/tilcdc/tilcdc_regs.h
index 9d528c0a67a4..5048ebb86835 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_regs.h
+++ b/drivers/gpu/drm/tilcdc/tilcdc_regs.h
@@ -133,7 +133,7 @@ static inline void tilcdc_write64(struct drm_device *dev, u32 reg, u64 data)
struct tilcdc_drm_private *priv = dev->dev_private;
volatile void __iomem *addr = priv->mmio + reg;
-#ifdef iowrite64
+#if defined(iowrite64) && !defined(iowrite64_is_nonatomic)
iowrite64(data, addr);
#else
__iowmb();
--
2.11.0
Now that ioread64 and iowrite64 are available in io-64-nonatomic,
we can remove the hack at the top of ntb_hw_intel.c and replace it
with an include.
Signed-off-by: Logan Gunthorpe <[email protected]>
Acked-by: Dave Jiang <[email protected]>
Acked-by: Allen Hubbe <[email protected]>
Acked-by: Jon Mason <[email protected]>
---
drivers/ntb/hw/intel/ntb_hw_intel.c | 30 +-----------------------------
1 file changed, 1 insertion(+), 29 deletions(-)
diff --git a/drivers/ntb/hw/intel/ntb_hw_intel.c b/drivers/ntb/hw/intel/ntb_hw_intel.c
index 2557e2c05b90..606c90f59d4b 100644
--- a/drivers/ntb/hw/intel/ntb_hw_intel.c
+++ b/drivers/ntb/hw/intel/ntb_hw_intel.c
@@ -59,6 +59,7 @@
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/ntb.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
#include "ntb_hw_intel.h"
@@ -155,35 +156,6 @@ MODULE_PARM_DESC(xeon_b2b_dsd_bar5_addr32,
static inline enum ntb_topo xeon_ppd_topo(struct intel_ntb_dev *ndev, u8 ppd);
static int xeon_init_isr(struct intel_ntb_dev *ndev);
-#ifndef ioread64
-#ifdef readq
-#define ioread64 readq
-#else
-#define ioread64 _ioread64
-static inline u64 _ioread64(void __iomem *mmio)
-{
- u64 low, high;
-
- low = ioread32(mmio);
- high = ioread32(mmio + sizeof(u32));
- return low | (high << 32);
-}
-#endif
-#endif
-
-#ifndef iowrite64
-#ifdef writeq
-#define iowrite64 writeq
-#else
-#define iowrite64 _iowrite64
-static inline void _iowrite64(u64 val, void __iomem *mmio)
-{
- iowrite32(val, mmio);
- iowrite32(val >> 32, mmio + sizeof(u32));
-}
-#endif
-#endif
-
static inline int pdev_is_atom(struct pci_dev *pdev)
{
switch (pdev->device) {
--
2.11.0
On 03/08/17 21:30, Logan Gunthorpe wrote:
> Add a check to ensure iowrite64 is only used if it is atomic.
>
> It was decided in [1] that the tilcdc driver should not be using an
> atomic operation (so it was left out of this patchset). However, it turns
> out that through the drm code, a nonatomic header is actually included:
>
> include/linux/io-64-nonatomic-lo-hi.h
> is included from include/drm/drm_os_linux.h:9:0,
> from include/drm/drmP.h:74,
> from include/drm/drm_modeset_helper.h:26,
> from include/drm/drm_atomic_helper.h:33,
> from drivers/gpu/drm/tilcdc/tilcdc_crtc.c:19:
>
> And thus, without this change, this patchset would inadvertantly
> change the behaviour of the tilcdc driver.
I haven't really followed the discussion on this, but if the tilcdc's
use of iowrite64 causes (real) problems/complications elsewhere, I think
we could drop it.
The problem is that the HW has a race issue, and the two registers in
question should be written as close to each other as possible. We
thought a single 64bit write, writing to both registers in one go, would
improve that slightly, compared to two 32 bit writes.
Jyri, correct me if I'm wrong, but we have no proof that it actually
helps, and it might be that even if it helps, the difference is
theoretical. Probably if we ensure the irqs are off when we do two 32
bit writes, we're already close enough to the optimal case.
Tomi
On 04/08/17 07:03 AM, Tomi Valkeinen wrote:
> I haven't really followed the discussion on this, but if the tilcdc's
> use of iowrite64 causes (real) problems/complications elsewhere, I think
> we could drop it.
Well, that's up to you. The patch I submitted should still be correct
though, and if arm ever gets a proper atomic iowrite64 implementation it
would be good to use it. So in an annotative sense it's nice to keep the
function call in there.
Thanks,
Logan
On 08/04/17 16:03, Tomi Valkeinen wrote:
> On 03/08/17 21:30, Logan Gunthorpe wrote:
>> Add a check to ensure iowrite64 is only used if it is atomic.
>>
>> It was decided in [1] that the tilcdc driver should not be using an
>> atomic operation (so it was left out of this patchset). However, it turns
>> out that through the drm code, a nonatomic header is actually included:
>>
>> include/linux/io-64-nonatomic-lo-hi.h
>> is included from include/drm/drm_os_linux.h:9:0,
>> from include/drm/drmP.h:74,
>> from include/drm/drm_modeset_helper.h:26,
>> from include/drm/drm_atomic_helper.h:33,
>> from drivers/gpu/drm/tilcdc/tilcdc_crtc.c:19:
>>
>> And thus, without this change, this patchset would inadvertantly
>> change the behaviour of the tilcdc driver.
>
> I haven't really followed the discussion on this, but if the tilcdc's
> use of iowrite64 causes (real) problems/complications elsewhere, I think
> we could drop it.
>
> The problem is that the HW has a race issue, and the two registers in
> question should be written as close to each other as possible. We
> thought a single 64bit write, writing to both registers in one go, would
> improve that slightly, compared to two 32 bit writes.
>
> Jyri, correct me if I'm wrong, but we have no proof that it actually
> helps, and it might be that even if it helps, the difference is
> theoretical. Probably if we ensure the irqs are off when we do two 32
> bit writes, we're already close enough to the optimal case.
>
For the sake of this particular case you are right, the atomicity is
probably not that important here. But in general ARM7 has an atomic
64bit write and I think it is a shame if it can not be easily used in
linux kernel.
Best regards,
Jyri