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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-03 19:57:53 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-03 19:57:53 (GMT) |
commit | 776edb59317ada867dfcddde40b55648beeb0078 (patch) | |
tree | f6a6136374642323cfefd7d6399ea429f9018ade /arch/ia64 | |
parent | 59a3d4c3631e553357b7305dc09db1990aa6757c (diff) | |
parent | 3cf2f34e1a3d4d5ff209d087925cf950e52f4805 (diff) | |
download | linux-776edb59317ada867dfcddde40b55648beeb0078.tar.xz |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull core locking updates from Ingo Molnar:
"The main changes in this cycle were:
- reduced/streamlined smp_mb__*() interface that allows more usecases
and makes the existing ones less buggy, especially in rarer
architectures
- add rwsem implementation comments
- bump up lockdep limits"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
rwsem: Add comments to explain the meaning of the rwsem's count field
lockdep: Increase static allocations
arch: Mass conversion of smp_mb__*()
arch,doc: Convert smp_mb__*()
arch,xtensa: Convert smp_mb__*()
arch,x86: Convert smp_mb__*()
arch,tile: Convert smp_mb__*()
arch,sparc: Convert smp_mb__*()
arch,sh: Convert smp_mb__*()
arch,score: Convert smp_mb__*()
arch,s390: Convert smp_mb__*()
arch,powerpc: Convert smp_mb__*()
arch,parisc: Convert smp_mb__*()
arch,openrisc: Convert smp_mb__*()
arch,mn10300: Convert smp_mb__*()
arch,mips: Convert smp_mb__*()
arch,metag: Convert smp_mb__*()
arch,m68k: Convert smp_mb__*()
arch,m32r: Convert smp_mb__*()
arch,ia64: Convert smp_mb__*()
...
Diffstat (limited to 'arch/ia64')
-rw-r--r-- | arch/ia64/include/asm/atomic.h | 7 | ||||
-rw-r--r-- | arch/ia64/include/asm/barrier.h | 3 | ||||
-rw-r--r-- | arch/ia64/include/asm/bitops.h | 9 | ||||
-rw-r--r-- | arch/ia64/include/uapi/asm/cmpxchg.h | 9 |
4 files changed, 15 insertions, 13 deletions
diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h index 6e6fe18..0f8bf48 100644 --- a/arch/ia64/include/asm/atomic.h +++ b/arch/ia64/include/asm/atomic.h @@ -15,6 +15,7 @@ #include <linux/types.h> #include <asm/intrinsics.h> +#include <asm/barrier.h> #define ATOMIC_INIT(i) { (i) } @@ -208,10 +209,4 @@ atomic64_add_negative (__s64 i, atomic64_t *v) #define atomic64_inc(v) atomic64_add(1, (v)) #define atomic64_dec(v) atomic64_sub(1, (v)) -/* Atomic operations are already serializing */ -#define smp_mb__before_atomic_dec() barrier() -#define smp_mb__after_atomic_dec() barrier() -#define smp_mb__before_atomic_inc() barrier() -#define smp_mb__after_atomic_inc() barrier() - #endif /* _ASM_IA64_ATOMIC_H */ diff --git a/arch/ia64/include/asm/barrier.h b/arch/ia64/include/asm/barrier.h index d0a69aa..a48957c 100644 --- a/arch/ia64/include/asm/barrier.h +++ b/arch/ia64/include/asm/barrier.h @@ -55,6 +55,9 @@ #endif +#define smp_mb__before_atomic() barrier() +#define smp_mb__after_atomic() barrier() + /* * IA64 GCC turns volatile stores into st.rel and volatile loads into ld.acq no * need for asm trickery! diff --git a/arch/ia64/include/asm/bitops.h b/arch/ia64/include/asm/bitops.h index c27eccd..71e8145 100644 --- a/arch/ia64/include/asm/bitops.h +++ b/arch/ia64/include/asm/bitops.h @@ -16,6 +16,7 @@ #include <linux/compiler.h> #include <linux/types.h> #include <asm/intrinsics.h> +#include <asm/barrier.h> /** * set_bit - Atomically set a bit in memory @@ -65,12 +66,6 @@ __set_bit (int nr, volatile void *addr) *((__u32 *) addr + (nr >> 5)) |= (1 << (nr & 31)); } -/* - * clear_bit() has "acquire" semantics. - */ -#define smp_mb__before_clear_bit() smp_mb() -#define smp_mb__after_clear_bit() do { /* skip */; } while (0) - /** * clear_bit - Clears a bit in memory * @nr: Bit to clear @@ -78,7 +73,7 @@ __set_bit (int nr, volatile void *addr) * * clear_bit() is atomic and may not be reordered. However, it does * not contain a memory barrier, so if it is used for locking purposes, - * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() + * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic() * in order to ensure changes are visible on other processors. */ static __inline__ void diff --git a/arch/ia64/include/uapi/asm/cmpxchg.h b/arch/ia64/include/uapi/asm/cmpxchg.h index 4f37dbb..f35109b 100644 --- a/arch/ia64/include/uapi/asm/cmpxchg.h +++ b/arch/ia64/include/uapi/asm/cmpxchg.h @@ -118,6 +118,15 @@ extern long ia64_cmpxchg_called_with_bad_pointer(void); #define cmpxchg_rel(ptr, o, n) \ ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr))) +/* + * Worse still - early processor implementations actually just ignored + * the acquire/release and did a full fence all the time. Unfortunately + * this meant a lot of badly written code that used .acq when they really + * wanted .rel became legacy out in the wild - so when we made a cpu + * that strictly did the .acq or .rel ... all that code started breaking - so + * we had to back-pedal and keep the "legacy" behavior of a full fence :-( + */ + /* for compatibility with other platforms: */ #define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) #define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) |