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| author | Catalin Marinas <catalin.marinas@arm.com> | 2016-09-05 18:25:48 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-09-07 09:41:42 +0100 |
| commit | efd9e03facd075f5b76bf82e6c785bd45d5cbf4f (patch) | |
| tree | f271f509acaba940a50d978a14713585f34b8667 /arch/arm64/kernel | |
| parent | ef0da55a84a345f323ceddda3b6c78b25de90435 (diff) | |
| download | blackbird-op-linux-efd9e03facd075f5b76bf82e6c785bd45d5cbf4f.tar.gz blackbird-op-linux-efd9e03facd075f5b76bf82e6c785bd45d5cbf4f.zip | |
arm64: Use static keys for CPU features
This patch adds static keys transparently for all the cpu_hwcaps
features by implementing an array of default-false static keys and
enabling them when detected. The cpus_have_cap() check uses the static
keys if the feature being checked is a constant, otherwise the compiler
generates the bitmap test.
Because of the early call to static_branch_enable() via
check_local_cpu_errata() -> update_cpu_capabilities(), the jump labels
are initialised in cpuinfo_store_boot_cpu().
Cc: Will Deacon <will.deacon@arm.com>
Cc: Suzuki K. Poulose <Suzuki.Poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/smp.c | 5 |
2 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index c3d7ae48f92d..9128ced913e7 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/smp.c b/arch/arm64/kernel/smp.c index d93d43352504..c3c08368a685 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -437,6 +437,11 @@ void __init smp_cpus_done(unsigned int max_cpus) void __init smp_prepare_boot_cpu(void) { set_my_cpu_offset(per_cpu_offset(smp_processor_id())); + /* + * Initialise the static keys early as they may be enabled by the + * cpufeature code. + */ + jump_label_init(); cpuinfo_store_boot_cpu(); save_boot_cpu_run_el(); } |
