Messages in this thread Patch in this message | | | Date | Fri, 9 Feb 2018 18:22:13 +0000 | From | Dave Martin <> | Subject | Re: [PATCH v3 10/22] arm64: capabilities: Allow features based on local CPU scope |
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On Fri, Feb 09, 2018 at 05:54:49PM +0000, Suzuki K Poulose wrote: > So far we have treated the feature capabilities as system wide > and this doesn't help with features that could be detected on
doesn't -> wouldn't (since no such features exist yet)
detected to "detected locally" (maybe)
> one or more CPUs (e.g, KPTI, Software prefetch). This patch > splits the feature detection to two phases : > > 1) Local CPU features are checked on all boot time active CPUs. > 2) System wide features are checked only once after all CPUs are > active. > > Cc: Dave Martin <dave.martin@arm.com> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Otherwise,
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
> --- > arch/arm64/kernel/cpufeature.c | 17 +++++++++++------ > 1 file changed, 11 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index a6e124063e21..45bac0c4ae91 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -551,11 +551,13 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) > } > > /* > - * Run the errata work around checks on the boot CPU, once we have > - * initialised the cpu feature infrastructure. > + * Run the errata work around and local feature checks on the > + * boot CPU, once we have initialised the cpu feature infrastructure. > */ > update_cpu_capabilities(arm64_errata, SCOPE_LOCAL_CPU, > "enabling workaround for"); > + update_cpu_capabilities(arm64_features, SCOPE_LOCAL_CPU, > + "detected feature:"); > } > > static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new) > @@ -1411,15 +1413,18 @@ void check_local_cpu_capabilities(void) > > /* > * If we haven't finalised the system capabilities, this CPU gets > - * a chance to update the errata work arounds. > + * a chance to update the errata work arounds and local features. > * Otherwise, this CPU should verify that it has all the system > * advertised capabilities. > */ > - if (!sys_caps_initialised) > + if (!sys_caps_initialised) { > update_cpu_capabilities(arm64_errata, SCOPE_LOCAL_CPU, > "enabling workaround for"); > - else > + update_cpu_capabilities(arm64_features, SCOPE_LOCAL_CPU, > + "detected feature:"); > + } else { > verify_local_cpu_capabilities(); > + } > } > > DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready); > @@ -1444,7 +1449,7 @@ void __init setup_cpu_features(void) > int cls; > > /* Set the CPU feature capabilies */ > - update_cpu_capabilities(arm64_features, SCOPE_ALL, > + update_cpu_capabilities(arm64_features, SCOPE_SYSTEM, > "detected feature:"); > update_cpu_capabilities(arm64_errata, SCOPE_SYSTEM, > "enabling workaround for"); > -- > 2.14.3 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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