[RFC PATCH v2 02/10] arm64: cpufeature: Don't enforce system-wide SPE capability
From: Will Deacon <hidden>
Date: 2017-01-13 16:06:19
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
The statistical profiling extension (SPE) is an optional feature of ARMv8.1 and is unlikely to be supported by all of the CPUs in a heterogeneous system. This patch updates the cpufeature checks so that such systems are not tainted as unsupported. Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <redacted> --- arch/arm64/include/asm/sysreg.h | 1 + arch/arm64/kernel/cpufeature.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 98ae03f8eedd..e156e7793a65 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h@@ -190,6 +190,7 @@ #define ID_AA64MMFR2_CNP_SHIFT 0 /* id_aa64dfr0 */ +#define ID_AA64DFR0_PMSVER_SHIFT 32 #define ID_AA64DFR0_CTX_CMPS_SHIFT 28 #define ID_AA64DFR0_WRPS_SHIFT 20 #define ID_AA64DFR0_BRPS_SHIFT 12
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 47d0226620e8..c18eb78d3a00 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -180,7 +180,8 @@ static const struct arm64_ftr_bits ftr_id_mmfr0[] = { }; static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = { - ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0), + ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 36, 28, 0), + ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
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2.1.4