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author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-05 10:24:52 -0800 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-05 10:24:52 -0800 |
commit | 21511abd0a248a3f225d3b611cfabb93124605a7 (patch) | |
tree | eb490f94322f3c76169ea7e5ec09524f275f390e /include/asm-ia64/bitops.h | |
parent | 39ce941ec15032c0efc3632b9f00a6b2365e1870 (diff) | |
parent | e1b0d4ba46b42909d11ea152a6b56ee76f062ca3 (diff) | |
download | talos-obmc-linux-21511abd0a248a3f225d3b611cfabb93124605a7.tar.gz talos-obmc-linux-21511abd0a248a3f225d3b611cfabb93124605a7.zip |
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] make pfm_get_task work with virtual pids
[IA64] honor notify_die() returning NOTIFY_STOP
[IA64] remove dead code: __cpu_{down,die} from !HOTPLUG_CPU
[IA64] Appoint kvm/ia64 Maintainers
[IA64] ia64_set_psr should use srlz.i
[IA64] Export three symbols for module use
[IA64] mca style cleanup
[IA64] sn_hwperf semaphore to mutex
[IA64] generalize attribute of fsyscall_gtod_data
[IA64] efi.c Add /* never reached */ annotation
[IA64] efi.c Spelling/punctuation fixes
[IA64] Make efi.c mostly fit in 80 columns
[IA64] aliasing-test: fix gcc warnings on non-ia64
[IA64] Slim-down __clear_bit_unlock
[IA64] Fix the order of atomic operations in restore_previous_kprobes on ia64
[IA64] constify function pointer tables
[IA64] fix userspace compile error in gcc_intrin.h
Diffstat (limited to 'include/asm-ia64/bitops.h')
-rw-r--r-- | include/asm-ia64/bitops.h | 50 |
1 files changed, 28 insertions, 22 deletions
diff --git a/include/asm-ia64/bitops.h b/include/asm-ia64/bitops.h index a1b9719f5fbb..953d3df9dd22 100644 --- a/include/asm-ia64/bitops.h +++ b/include/asm-ia64/bitops.h @@ -122,38 +122,40 @@ clear_bit_unlock (int nr, volatile void *addr) } /** - * __clear_bit_unlock - Non-atomically clear a bit with release + * __clear_bit_unlock - Non-atomically clears a bit in memory with release + * @nr: Bit to clear + * @addr: Address to start counting from * - * This is like clear_bit_unlock, but the implementation uses a store + * Similarly to clear_bit_unlock, the implementation uses a store * with release semantics. See also __raw_spin_unlock(). */ static __inline__ void -__clear_bit_unlock(int nr, volatile void *addr) +__clear_bit_unlock(int nr, void *addr) { - __u32 mask, new; - volatile __u32 *m; + __u32 * const m = (__u32 *) addr + (nr >> 5); + __u32 const new = *m & ~(1 << (nr & 31)); - m = (volatile __u32 *)addr + (nr >> 5); - mask = ~(1 << (nr & 31)); - new = *m & mask; - barrier(); ia64_st4_rel_nta(m, new); } /** * __clear_bit - Clears a bit in memory (non-atomic version) + * @nr: the bit to clear + * @addr: the address to start counting from + * + * Unlike clear_bit(), this function is non-atomic and may be reordered. + * If it's called on the same region of memory simultaneously, the effect + * may be that only one operation succeeds. */ static __inline__ void __clear_bit (int nr, volatile void *addr) { - volatile __u32 *p = (__u32 *) addr + (nr >> 5); - __u32 m = 1 << (nr & 31); - *p &= ~m; + *((__u32 *) addr + (nr >> 5)) &= ~(1 << (nr & 31)); } /** * change_bit - Toggle a bit in memory - * @nr: Bit to clear + * @nr: Bit to toggle * @addr: Address to start counting from * * change_bit() is atomic and may not be reordered. @@ -178,7 +180,7 @@ change_bit (int nr, volatile void *addr) /** * __change_bit - Toggle a bit in memory - * @nr: the bit to set + * @nr: the bit to toggle * @addr: the address to start counting from * * Unlike change_bit(), this function is non-atomic and may be reordered. @@ -197,7 +199,7 @@ __change_bit (int nr, volatile void *addr) * @addr: Address to count from * * This operation is atomic and cannot be reordered. - * It also implies a memory barrier. + * It also implies the acquisition side of the memory barrier. */ static __inline__ int test_and_set_bit (int nr, volatile void *addr) @@ -247,11 +249,11 @@ __test_and_set_bit (int nr, volatile void *addr) /** * test_and_clear_bit - Clear a bit and return its old value - * @nr: Bit to set + * @nr: Bit to clear * @addr: Address to count from * * This operation is atomic and cannot be reordered. - * It also implies a memory barrier. + * It also implies the acquisition side of the memory barrier. */ static __inline__ int test_and_clear_bit (int nr, volatile void *addr) @@ -272,7 +274,7 @@ test_and_clear_bit (int nr, volatile void *addr) /** * __test_and_clear_bit - Clear a bit and return its old value - * @nr: Bit to set + * @nr: Bit to clear * @addr: Address to count from * * This operation is non-atomic and can be reordered. @@ -292,11 +294,11 @@ __test_and_clear_bit(int nr, volatile void * addr) /** * test_and_change_bit - Change a bit and return its old value - * @nr: Bit to set + * @nr: Bit to change * @addr: Address to count from * * This operation is atomic and cannot be reordered. - * It also implies a memory barrier. + * It also implies the acquisition side of the memory barrier. */ static __inline__ int test_and_change_bit (int nr, volatile void *addr) @@ -315,8 +317,12 @@ test_and_change_bit (int nr, volatile void *addr) return (old & bit) != 0; } -/* - * WARNING: non atomic version. +/** + * __test_and_change_bit - Change a bit and return its old value + * @nr: Bit to change + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. */ static __inline__ int __test_and_change_bit (int nr, void *addr) |