tree 318c48fdfa422908da871d25d2e47903321aabe3
parent ebd88367de80f9509bd30a09342d0a19c925b23e
author Catalin Marinas <catalin.marinas@arm.com> 1370014258 +0100
committer Catalin Marinas <catalin.marinas@arm.com> 1370624311 +0100

arm64: spinlock: retry trylock operation if strex fails on free lock

An exclusive store instruction may fail for reasons other than lock
contention (e.g. a cache eviction during the critical section) so, in
line with other architectures using similar exclusive instructions
(alpha, mips, powerpc), retry the trylock operation if the lock appears
to be free but the strex reported failure.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Tony Thompson <anthony.thompson@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>