Messages in this thread | | | Date | Fri, 2 Sep 2016 16:52:25 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH 2/2] arm64: Use static keys for CPU features |
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On Fri, Aug 26, 2016 at 10:22:13AM +0100, Suzuki K. Poulose wrote: > On 25/08/16 18:26, Catalin Marinas wrote: > > static inline int __attribute_const__ > >diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > >index 62272eac1352..919b2d0d68ae 100644 > >--- a/arch/arm64/kernel/cpufeature.c > >+++ b/arch/arm64/kernel/cpufeature.c > >@@ -46,6 +46,9 @@ unsigned int compat_elf_hwcap2 __read_mostly; > > > > DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); > > > >+DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS); > >+EXPORT_SYMBOL(cpu_hwcap_keys); > >+ > > #define __ARM64_FTR_BITS(SIGNED, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ > > { \ > > .sign = SIGNED, \ > >diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c > >index ed1b84fe6925..6a141e399daf 100644 > >--- a/arch/arm64/kernel/cpuinfo.c > >+++ b/arch/arm64/kernel/cpuinfo.c > >@@ -377,6 +377,12 @@ void cpuinfo_store_cpu(void) > > void __init cpuinfo_store_boot_cpu(void) > > { > > struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0); > >+ > >+ /* > >+ * Initialise the static keys early as they may be enabled by > >+ * check_local_cpu_errata() -> update_cpu_capabilities(). > >+ */ > >+ jump_label_init(); > > __cpuinfo_store_cpu(info); > > Just a heads up. I have a patch [1] which moves the "check_local_cpu_errata()" > around to smp_prepare_boot_cpu(). This patch should still work fine with that > case. Only that may be we could move the jump_lable_init() to smp_prepare_boot_cpu(), > before we call "update_cpu_errata_work_arounds()" for Boot CPU.
IIUC, we wouldn't call update_cpu_errata_work_arounds() until the CPU feature infrastructure is initialised via cpuinfo_store_boot_cpu(). So I don't think moving the jump_label_init() call above is necessary.
> [1] https://lkml.kernel.org/r/1471525832-21209-4-git-send-email-suzuki.poulose@arm.com
-- Catalin
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