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Groups > linux.kernel > #1550660
| From | Mark Rutland <mark.rutland@arm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC PATCH 02/10] arm64: cpufeature: Don't enforce system-wide SPE capability |
| Date | 2017-01-04 12:10 +0100 |
| Message-ID | <sVRCa-3SA-41@gated-at.bofh.it> (permalink) |
| References | <sVBQJ-1Kc-7@gated-at.bofh.it> <sVBQJ-1Kc-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Jan 03, 2017 at 06:10:19PM +0000, Will Deacon wrote:
> 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.
>
> Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Will Deacon <will.deacon@arm.com>
I couldn't find this in the ARMV8.1 supplement, but it is in the SPE
spec. FWIW:
Acked-by: Mark Rutland <mark.rutland@arm.com>
> ---
> 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),
As a heads-up, this line will disappear with Suzuki's cpufeature updates
series, so you may spot a clash later on.
Thanks,
Mark.
> + 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),
> --
> 2.1.4
>
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[RFC PATCH 00/10] Add support for the ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 02/10] arm64: cpufeature: Don't enforce system-wide SPE capability Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
Re: [RFC PATCH 02/10] arm64: cpufeature: Don't enforce system-wide SPE capability Mark Rutland <mark.rutland@arm.com> - 2017-01-04 12:10 +0100
[RFC PATCH 05/10] genirq: export irq_get_percpu_devid_partition to modules Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 01/10] arm64: cpufeature: allow for version discrepancy in PMU implementations Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
Re: [RFC PATCH 01/10] arm64: cpufeature: allow for version discrepancy in PMU implementations Mark Rutland <mark.rutland@arm.com> - 2017-01-04 11:30 +0100
[RFC PATCH 04/10] arm64: head.S: Enable EL1 (host) access to SPE when entered at EL2 Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Peter Zijlstra <peterz@infradead.org> - 2017-01-04 11:40 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-04 20:20 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Peter Zijlstra <peterz@infradead.org> - 2017-01-05 12:40 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Kim Phillips <kim.phillips@arm.com> - 2017-01-10 23:10 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-11 13:40 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Kim Phillips <kim.phillips@arm.com> - 2017-01-11 22:10 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-13 14:40 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Marc Zyngier <marc.zyngier@arm.com> - 2017-01-12 12:40 +0100
[RFC PATCH 07/10] perf: Directly pass PERF_AUX_* flags to perf_aux_output_end Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 03/10] arm64: KVM: Save/restore the host SPE state when entering/leaving a VM Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 10/10] dt-bindings: Document devicetree binding for ARM SPE Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 08/10] perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
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