diff options
| author | Will Deacon <will.deacon@arm.com> | 2019-02-22 12:59:59 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2019-04-08 11:59:47 +0100 |
| commit | 60ca1e5a200cd294a12907fa36dece4241db4ab8 (patch) | |
| tree | 2dcd2e666b2b1cad4ce0c80f263cb122bdeebc1b | |
| parent | fdcd06a8ab775cbe716ff893372bed580e4c8a1c (diff) | |
mmiowb: Hook up mmiowb helpers to spinlocks and generic I/O accessors
Removing explicit calls to mmiowb() from driver code means that we must
now call into the generic mmiowb_spin_{lock,unlock}() functions from the
core spinlock code. In order to elide barriers following critical
sections without any I/O writes, we also hook into the asm-generic I/O
routines.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
| -rw-r--r-- | include/asm-generic/io.h | 3 | ||||
| -rw-r--r-- | include/linux/spinlock.h | 11 | ||||
| -rw-r--r-- | kernel/locking/spinlock_debug.c | 6 |
3 files changed, 17 insertions, 3 deletions
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index 303871651f8a..bc490a746602 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -19,6 +19,7 @@ #include <asm-generic/iomap.h> #endif +#include <asm/mmiowb.h> #include <asm-generic/pci_iomap.h> #ifndef mmiowb @@ -49,7 +50,7 @@ /* serialize device access against a spin_unlock, usually handled there. */ #ifndef __io_aw -#define __io_aw() barrier() +#define __io_aw() mmiowb_set_pending() #endif #ifndef __io_pbw diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index e089157dcf97..ed7c4d6b8235 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -57,6 +57,7 @@ #include <linux/stringify.h> #include <linux/bottom_half.h> #include <asm/barrier.h> +#include <asm/mmiowb.h> /* @@ -178,6 +179,7 @@ static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock) { __acquire(lock); arch_spin_lock(&lock->raw_lock); + mmiowb_spin_lock(); } #ifndef arch_spin_lock_flags @@ -189,15 +191,22 @@ do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lo { __acquire(lock); arch_spin_lock_flags(&lock->raw_lock, *flags); + mmiowb_spin_lock(); } static inline int do_raw_spin_trylock(raw_spinlock_t *lock) { - return arch_spin_trylock(&(lock)->raw_lock); + int ret = arch_spin_trylock(&(lock)->raw_lock); + + if (ret) + mmiowb_spin_lock(); + + return ret; } static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) { + mmiowb_spin_unlock(); arch_spin_unlock(&lock->raw_lock); __release(lock); } diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c index 9aa0fccd5d43..399669f7eba8 100644 --- a/kernel/locking/spinlock_debug.c +++ b/kernel/locking/spinlock_debug.c @@ -111,6 +111,7 @@ void do_raw_spin_lock(raw_spinlock_t *lock) { debug_spin_lock_before(lock); arch_spin_lock(&lock->raw_lock); + mmiowb_spin_lock(); debug_spin_lock_after(lock); } @@ -118,8 +119,10 @@ int do_raw_spin_trylock(raw_spinlock_t *lock) { int ret = arch_spin_trylock(&lock->raw_lock); - if (ret) + if (ret) { + mmiowb_spin_lock(); debug_spin_lock_after(lock); + } #ifndef CONFIG_SMP /* * Must not happen on UP: @@ -131,6 +134,7 @@ int do_raw_spin_trylock(raw_spinlock_t *lock) void do_raw_spin_unlock(raw_spinlock_t *lock) { + mmiowb_spin_unlock(); debug_spin_unlock(lock); arch_spin_unlock(&lock->raw_lock); } |