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| author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2016-02-23 11:31:44 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-02-25 11:33:06 +0100 |
| commit | 038dc9c66a0fe415e7f20ed38faab37b3ab92ae6 (patch) | |
| tree | aa3fb6183243638bb8323757a21349d7311ded86 /arch/arm64/mm/context.c | |
| parent | arm64: Enable CPU capability verification unconditionally (diff) | |
| download | linux-038dc9c66a0fe415e7f20ed38faab37b3ab92ae6.tar.xz linux-038dc9c66a0fe415e7f20ed38faab37b3ab92ae6.zip | |
arm64: Add helper for extracting ASIDBits
Add a helper to extract ASIDBits on the current cpu
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm/context.c')
| -rw-r--r-- | arch/arm64/mm/context.c | 36 |
1 files changed, 23 insertions, 13 deletions
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index 7275628ba59f..21f9f1ea14f7 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -40,6 +40,28 @@ static cpumask_t tlb_flush_pending; #define ASID_FIRST_VERSION (1UL << asid_bits) #define NUM_USER_ASIDS ASID_FIRST_VERSION +/* Get the ASIDBits supported by the current CPU */ +static u32 get_cpu_asid_bits(void) +{ + u32 asid; + int fld = cpuid_feature_extract_field(read_cpuid(SYS_ID_AA64MMFR0_EL1), + ID_AA64MMFR0_ASID_SHIFT); + + switch (fld) { + default: + pr_warn("CPU%d: Unknown ASID size (%d); assuming 8-bit\n", + smp_processor_id(), fld); + /* Fallthrough */ + case 0: + asid = 8; + break; + case 2: + asid = 16; + } + + return asid; +} + static void flush_context(unsigned int cpu) { int i; @@ -187,19 +209,7 @@ switch_mm_fastpath: static int asids_init(void) { - int fld = cpuid_feature_extract_field(read_cpuid(SYS_ID_AA64MMFR0_EL1), 4); - - switch (fld) { - default: - pr_warn("Unknown ASID size (%d); assuming 8-bit\n", fld); - /* Fallthrough */ - case 0: - asid_bits = 8; - break; - case 2: - asid_bits = 16; - } - + asid_bits = get_cpu_asid_bits(); /* If we end up with more CPUs than ASIDs, expect things to crash */ WARN_ON(NUM_USER_ASIDS < num_possible_cpus()); atomic64_set(&asid_generation, ASID_FIRST_VERSION); |