Commit 038dc9c6 authored by Suzuki K Poulose's avatar Suzuki K Poulose Committed by Catalin Marinas

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: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent fd9c2790
...@@ -40,6 +40,28 @@ static cpumask_t tlb_flush_pending; ...@@ -40,6 +40,28 @@ static cpumask_t tlb_flush_pending;
#define ASID_FIRST_VERSION (1UL << asid_bits) #define ASID_FIRST_VERSION (1UL << asid_bits)
#define NUM_USER_ASIDS ASID_FIRST_VERSION #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) static void flush_context(unsigned int cpu)
{ {
int i; int i;
...@@ -187,19 +209,7 @@ void check_and_switch_context(struct mm_struct *mm, unsigned int cpu) ...@@ -187,19 +209,7 @@ void check_and_switch_context(struct mm_struct *mm, unsigned int cpu)
static int asids_init(void) static int asids_init(void)
{ {
int fld = cpuid_feature_extract_field(read_cpuid(SYS_ID_AA64MMFR0_EL1), 4); asid_bits = get_cpu_asid_bits();
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;
}
/* If we end up with more CPUs than ASIDs, expect things to crash */ /* If we end up with more CPUs than ASIDs, expect things to crash */
WARN_ON(NUM_USER_ASIDS < num_possible_cpus()); WARN_ON(NUM_USER_ASIDS < num_possible_cpus());
atomic64_set(&asid_generation, ASID_FIRST_VERSION); atomic64_set(&asid_generation, ASID_FIRST_VERSION);
......
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