diff options
| author | Will Deacon <will.deacon@arm.com> | 2019-02-22 13:37:21 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2019-04-08 12:00:21 +0100 |
| commit | e9e8543fecd2e1ca53616ba82fbd55a25cd2ab8a (patch) | |
| tree | a6139b9501c2b950c997f83273fcb5936c77dd2b /arch/sh/include/asm/io.h | |
| parent | 0f43ca692dcb55108ea9a59c11a1a0e359dba367 (diff) | |
sh/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
The mmiowb() macro is horribly difficult to use and drivers will continue
to work most of the time if they omit a call when it is required.
Rather than rely on driver authors getting this right, push mmiowb() into
arch_spin_unlock() for sh. If this is deemed to be a performance issue,
a subsequent optimisation could make use of ARCH_HAS_MMIOWB to elide
the barrier in cases where no I/O writes were performed inside the
critical section.
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/sh/include/asm/io.h')
| -rw-r--r-- | arch/sh/include/asm/io.h | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h index 4f7f235f15f8..c28e37a344ad 100644 --- a/arch/sh/include/asm/io.h +++ b/arch/sh/include/asm/io.h @@ -229,9 +229,6 @@ __BUILD_IOPORT_STRING(q, u64) #define IO_SPACE_LIMIT 0xffffffff -/* synco on SH-4A, otherwise a nop */ -#define mmiowb() wmb() - /* We really want to try and get these to memcpy etc */ void memcpy_fromio(void *, const volatile void __iomem *, unsigned long); void memcpy_toio(volatile void __iomem *, const void *, unsigned long); |