arm64: capabilities: Introduce weak features based on local CPU
Now that we have the flexibility of defining system features based
on individual CPUs, introduce CPU feature type that can be detected
on a local SCOPE and ignores the conflict on late CPUs. This is
applicable for ARM64_HAS_NO_HW_PREFETCH, where it is fine for
the system to have CPUs without hardware prefetch turning up
later. We only suffer a performance penalty, nothing fatal.
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index d330135..a80ca94 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1010,7 +1010,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "Software prefetching using PRFM",
.capability = ARM64_HAS_NO_HW_PREFETCH,
- .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
.matches = has_no_hw_prefetch,
},
#ifdef CONFIG_ARM64_UAO