diff options
| -rw-r--r-- | arch/arm/mm/context.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index 3172781a8e2e..5ac09e8b4030 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -38,9 +38,9 @@ #define ASID_FIRST_VERSION (1ULL << ASID_BITS) static DEFINE_RAW_SPINLOCK(cpu_asid_lock); -static u64 cpu_last_asid = ASID_FIRST_VERSION; +static atomic64_t cpu_last_asid = ATOMIC64_INIT(ASID_FIRST_VERSION); -static DEFINE_PER_CPU(u64, active_asids); +static DEFINE_PER_CPU(atomic64_t, active_asids); static DEFINE_PER_CPU(u64, reserved_asids); static cpumask_t tlb_flush_pending; @@ -113,9 +113,10 @@ static void flush_context(unsigned int cpu) int i; /* Update the list of reserved ASIDs. */ - per_cpu(active_asids, cpu) = 0; for_each_possible_cpu(i) - per_cpu(reserved_asids, i) = per_cpu(active_asids, i); + per_cpu(reserved_asids, i) = + atomic64_xchg(&per_cpu(active_asids, i), 0); + per_cpu(reserved_asids, cpu) = 0; /* Queue a TLB invalidate and flush the I-cache if necessary. */ if (!tlb_ops_need_broadcast()) @@ -145,7 +146,8 @@ static void new_context(struct mm_struct *mm, unsigned int cpu) * Our current ASID was active during a rollover, we can * continue to use it and this was just a false alarm. */ - asid = (cpu_last_asid & ASID_MASK) | (asid & ~ASID_MASK); + asid = (atomic64_read(&cpu_last_asid) & ASID_MASK) | \ + (asid & ~ASID_MASK); } else { /* * Allocate a free ASID. If we can't find one, take a @@ -153,7 +155,7 @@ static void new_context(struct mm_struct *mm, unsigned int cpu) * as requiring flushes. */ do { - asid = ++cpu_last_asid; + asid = atomic64_inc_return(&cpu_last_asid); if ((asid & ~ASID_MASK) == 0) flush_context(cpu); } while (is_reserved_asid(asid, ~ASID_MASK)); @@ -177,17 +179,22 @@ void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk) */ cpu_set_reserved_ttbr0(); + if (!((mm->context.id ^ atomic64_read(&cpu_last_asid)) >> ASID_BITS) + && atomic64_xchg(&per_cpu(active_asids, cpu), mm->context.id)) + goto switch_mm_fastpath; + raw_spin_lock_irqsave(&cpu_asid_lock, flags); /* Check that our ASID belongs to the current generation. */ - if ((mm->context.id ^ cpu_last_asid) >> ASID_BITS) + if ((mm->context.id ^ atomic64_read(&cpu_last_asid)) >> ASID_BITS) new_context(mm, cpu); - *this_cpu_ptr(&active_asids) = mm->context.id; + atomic64_set(&per_cpu(active_asids, cpu), mm->context.id); cpumask_set_cpu(cpu, mm_cpumask(mm)); if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) local_flush_tlb_all(); raw_spin_unlock_irqrestore(&cpu_asid_lock, flags); +switch_mm_fastpath: cpu_switch_mm(mm->pgd, mm); } |