arm64: prefetch: don't provide spin_lock_prefetch with LSE

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The LSE atomics rely on us not dirtying data at L1 if we can avoid it,
otherwise many of the potential scalability benefits are lost.

This patch replaces spin_lock_prefetch with a nop when the LSE atomics
are in use, so that users don't shoot themselves in the foot by causing
needless coherence traffic at L1.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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Will Deacon 2016-02-02 12:46:23 +00:00 • committed by Catalin Marinas

parent 5e89c55e4e

commit cd5e10bdf3

1 changed files with 5 additions and 2 deletions

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7

arch/arm64/include/asm/processor.h

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