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arm64: capabilities: Optimize this_cpu_has_cap 

Make use of the sorted capability list to access the capability
entry in this_cpu_has_cap() to avoid iterating over the two
tables.

Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Suzuki K Poulose 2018-11-30 17:18:04 +00:00 committed by Will Deacon
parent 82a3a21b23
commit f7bfc14a08
1 changed files with 9 additions and 22 deletions
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31
arch/arm64/kernel/cpufeature.c
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@ -1512,25 +1512,6 @@ static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
cap_set_elf_hwcap(hwcaps); cap_set_elf_hwcap(hwcaps);
} }
/*
* Check if the current CPU has a given feature capability.
* Should be called from non-preemptible context.
*/
static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array,
unsigned int cap)
{
const struct arm64_cpu_capabilities *caps;
if (WARN_ON(preemptible()))
return false;
for (caps = cap_array; caps->matches; caps++)
if (caps->capability == cap)
return caps->matches(caps, SCOPE_LOCAL_CPU);
return false;
}
static void __update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, static void __update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
u16 scope_mask, const char *info) u16 scope_mask, const char *info)
{ {
@ -1780,10 +1761,16 @@ static void __init mark_const_caps_ready(void)
static_branch_enable(&arm64_const_caps_ready); static_branch_enable(&arm64_const_caps_ready);
} }
bool this_cpu_has_cap(unsigned int cap) bool this_cpu_has_cap(unsigned int n)
{ {
return (__this_cpu_has_cap(arm64_features, cap) || if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
__this_cpu_has_cap(arm64_errata, cap)); const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
if (cap)
return cap->matches(cap, SCOPE_LOCAL_CPU);
}
return false;
} }
static void __init setup_system_capabilities(void) static void __init setup_system_capabilities(void)