linux/arch/arm64/include/asm/tlbbatch.h
Catalin Marinas 534eb6940a arm64: Avoid eager DVMSync reclaim batches with C1-Pro SME erratum
The C1-Pro SME DVMSync workaround currently samples mm_cpumask() from
arch_tlbbatch_add_pending(). It requires a DSB after every batched TLBI
so that the mask read is ordered after the hardware DVMSync, defeating
much of the reclaim batching benefit.

Introduce the sme_active_cpus mask tracking which CPUs run in user-space
with SME enabled and use it for batch flushing instead of accumulating
the mm_cpumask() of the unmapped pages.

Fixes: 0baba94a97 ("arm64: errata: Work around early CME DVMSync acknowledgement")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Tested-by: Joshua Liu <josliu@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-06-29 12:00:37 +01:00

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