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| author | Andre Przywara <andre.przywara@arm.com> | 2015-04-24 10:30:45 -0700 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-04-27 17:13:43 -0400 |
| commit | 9a21c96c4672f02cc195c69ec083b3e664bd2221 (patch) | |
| tree | e231aa73e368cc8c88474ea506244b4ea1514c05 /arch/arm64/include/asm/cpufeature.h | |
| parent | dd6903432858c88c0b277f936352af248da9fe7e (diff) | |
| download | linux-linaro-stable-9a21c96c4672f02cc195c69ec083b3e664bd2221.tar.gz | |
arm64: add cpu_capabilities bitmap
For taking note if at least one CPU in the system needs a bug
workaround or would benefit from a code optimization, we create a new
bitmap to hold (artificial) feature bits.
Since elf_hwcap is part of the userland ABI, we keep it alone and
introduce a new data structure for that (along with some accessors).
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> # v3.18.y
(cherry picked from commit 930da09f5e50dd22fb0a8600388da8677d62d671)
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'arch/arm64/include/asm/cpufeature.h')
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index cd4ac0516488..20b2b3d6b702 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -21,9 +21,29 @@ #define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap)) #define cpu_feature(x) ilog2(HWCAP_ ## x) +#define NCAPS 0 + +extern DECLARE_BITMAP(cpu_hwcaps, NCAPS); + static inline bool cpu_have_feature(unsigned int num) { return elf_hwcap & (1UL << num); } +static inline bool cpus_have_cap(unsigned int num) +{ + if (num >= NCAPS) + return false; + return test_bit(num, cpu_hwcaps); +} + +static inline void cpus_set_cap(unsigned int num) +{ + if (num >= NCAPS) + pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n", + num, NCAPS); + else + __set_bit(num, cpu_hwcaps); +} + #endif |