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| author | Will Deacon <will.deacon@arm.com> | 2016-06-27 20:43:54 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-07-07 10:10:53 +0300 |
| commit | 03e3c2b7edbe1e8758196b2c7843333eb328063d (patch) | |
| tree | f894288a88daa7d20fc00be4f294a1344ae2601e /include/linux/atomic.h | |
| parent | 885885f6b88d22f81e67ee6a61561e480b27d27a (diff) | |
| download | linux-03e3c2b7edbe1e8758196b2c7843333eb328063d.tar.xz | |
locking/barriers, arch/arm64: Implement LDXR+WFE based smp_cond_load_acquire()
smp_cond_load_acquire() is used to spin on a variable until some
expression involving that variable becomes true.
On arm64, we can build this using the LDXR and WFE instructions, since
clearing of the exclusive monitor as a result of the variable being
changed by another CPU generates an event, which will wake us up out of WFE.
This patch implements smp_cond_load_acquire() using LDXR and WFE, which
themselves are contained in an internal __cmpwait() function.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: catalin.marinas@arm.com
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1467049434-30451-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/atomic.h')
0 files changed, 0 insertions, 0 deletions