[PATCH v3 10/22] arm64: capabilities: Allow features based on local CPU scope
From: Dave.Martin@arm.com (Dave Martin)
Date: 2018-02-09 18:22:19
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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>
quoted hunk ↗ jump to hunk
--- 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 at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel