Searched hist:"09 d4e0edd4614e787393acc582ac701c6ec3565b" (Results 1 – 4 of 4) sorted by relevance
/openbmc/linux/include/asm-generic/ |
H A D | atomic64.h | 09d4e0edd4614e787393acc582ac701c6ec3565b Fri Jun 12 16:10:05 CDT 2009 Paul Mackerras <paulus@samba.org> lib: Provide generic atomic64_t implementation
Many processor architectures have no 64-bit atomic instructions, but we need atomic64_t in order to support the perf_counter subsystem.
This adds an implementation of 64-bit atomic operations using hashed spinlocks to provide atomicity. For each atomic operation, the address of the atomic64_t variable is hashed to an index into an array of 16 spinlocks. That spinlock is taken (with interrupts disabled) around the operation, which can then be coded non-atomically within the lock.
On UP, all the spinlock manipulation goes away and we simply disable interrupts around each operation. In fact gcc eliminates the whole atomic64_lock variable as well.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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/openbmc/linux/lib/ |
H A D | atomic64.c | 09d4e0edd4614e787393acc582ac701c6ec3565b Fri Jun 12 16:10:05 CDT 2009 Paul Mackerras <paulus@samba.org> lib: Provide generic atomic64_t implementation
Many processor architectures have no 64-bit atomic instructions, but we need atomic64_t in order to support the perf_counter subsystem.
This adds an implementation of 64-bit atomic operations using hashed spinlocks to provide atomicity. For each atomic operation, the address of the atomic64_t variable is hashed to an index into an array of 16 spinlocks. That spinlock is taken (with interrupts disabled) around the operation, which can then be coded non-atomically within the lock.
On UP, all the spinlock manipulation goes away and we simply disable interrupts around each operation. In fact gcc eliminates the whole atomic64_lock variable as well.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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H A D | Kconfig | 09d4e0edd4614e787393acc582ac701c6ec3565b Fri Jun 12 16:10:05 CDT 2009 Paul Mackerras <paulus@samba.org> lib: Provide generic atomic64_t implementation
Many processor architectures have no 64-bit atomic instructions, but we need atomic64_t in order to support the perf_counter subsystem.
This adds an implementation of 64-bit atomic operations using hashed spinlocks to provide atomicity. For each atomic operation, the address of the atomic64_t variable is hashed to an index into an array of 16 spinlocks. That spinlock is taken (with interrupts disabled) around the operation, which can then be coded non-atomically within the lock.
On UP, all the spinlock manipulation goes away and we simply disable interrupts around each operation. In fact gcc eliminates the whole atomic64_lock variable as well.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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H A D | Makefile | 09d4e0edd4614e787393acc582ac701c6ec3565b Fri Jun 12 16:10:05 CDT 2009 Paul Mackerras <paulus@samba.org> lib: Provide generic atomic64_t implementation
Many processor architectures have no 64-bit atomic instructions, but we need atomic64_t in order to support the perf_counter subsystem.
This adds an implementation of 64-bit atomic operations using hashed spinlocks to provide atomicity. For each atomic operation, the address of the atomic64_t variable is hashed to an index into an array of 16 spinlocks. That spinlock is taken (with interrupts disabled) around the operation, which can then be coded non-atomically within the lock.
On UP, all the spinlock manipulation goes away and we simply disable interrupts around each operation. In fact gcc eliminates the whole atomic64_lock variable as well.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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