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 12:00:28 +0100 |
| commit | 346e91ee090b07da8d15e36bc3169ddea6968713 (patch) | |
| tree | 8ec14892fbf565049c4ffa4a23d628514da4e991 /arch/mips/include/asm/spinlock.h | |
| parent | e9e8543fecd2e1ca53616ba82fbd55a25cd2ab8a (diff) | |
| download | linux-346e91ee090b07da8d15e36bc3169ddea6968713.tar.bz2 | |
mips/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 mips. 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.
Acked-by: Paul Burton <paul.burton@mips.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/mips/include/asm/spinlock.h')
| -rw-r--r-- | arch/mips/include/asm/spinlock.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h index ee81297d9117..8a88eb265516 100644 --- a/arch/mips/include/asm/spinlock.h +++ b/arch/mips/include/asm/spinlock.h @@ -11,6 +11,21 @@ #include <asm/processor.h> #include <asm/qrwlock.h> + +#include <asm-generic/qspinlock_types.h> + +#define queued_spin_unlock queued_spin_unlock +/** + * queued_spin_unlock - release a queued spinlock + * @lock : Pointer to queued spinlock structure + */ +static inline void queued_spin_unlock(struct qspinlock *lock) +{ + /* This could be optimised with ARCH_HAS_MMIOWB */ + mmiowb(); + smp_store_release(&lock->locked, 0); +} + #include <asm/qspinlock.h> #endif /* _ASM_SPINLOCK_H */ |