diff options
Diffstat (limited to 'arch/arm/mm/context.c')
| -rw-r--r-- | arch/arm/mm/context.c | 35 |
1 files changed, 23 insertions, 12 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index bc4a5e9ebb78..2ac37372ef52 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -34,6 +34,9 @@ * The ASID is used to tag entries in the CPU caches and TLBs. * The context ID is used by debuggers and trace logic, and * should be unique within all running processes. + * + * In big endian operation, the two 32 bit words are swapped if accesed by + * non 64-bit operations. */ #define ASID_FIRST_VERSION (1ULL << ASID_BITS) #define NUM_USER_ASIDS (ASID_FIRST_VERSION - 1) @@ -45,7 +48,7 @@ static DEFINE_RAW_SPINLOCK(cpu_asid_lock); static atomic64_t asid_generation = ATOMIC64_INIT(ASID_FIRST_VERSION); static DECLARE_BITMAP(asid_map, NUM_USER_ASIDS); -static DEFINE_PER_CPU(atomic64_t, active_asids); +DEFINE_PER_CPU(atomic64_t, active_asids); static DEFINE_PER_CPU(u64, reserved_asids); static cpumask_t tlb_flush_pending; @@ -149,9 +152,9 @@ static int is_reserved_asid(u64 asid) return 0; } -static void new_context(struct mm_struct *mm, unsigned int cpu) +static u64 new_context(struct mm_struct *mm, unsigned int cpu) { - u64 asid = mm->context.id; + u64 asid = atomic64_read(&mm->context.id); u64 generation = atomic64_read(&asid_generation); if (asid != 0 && is_reserved_asid(asid)) { @@ -178,13 +181,14 @@ static void new_context(struct mm_struct *mm, unsigned int cpu) cpumask_clear(mm_cpumask(mm)); } - mm->context.id = asid; + return asid; } void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk) { unsigned long flags; unsigned int cpu = smp_processor_id(); + u64 asid; if (unlikely(mm->context.vmalloc_seq != init_mm.context.vmalloc_seq)) __check_vmalloc_seq(mm); @@ -195,20 +199,27 @@ void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk) */ cpu_set_reserved_ttbr0(); - if (!((mm->context.id ^ atomic64_read(&asid_generation)) >> ASID_BITS) - && atomic64_xchg(&per_cpu(active_asids, cpu), mm->context.id)) + asid = atomic64_read(&mm->context.id); + if (!((asid ^ atomic64_read(&asid_generation)) >> ASID_BITS) + && atomic64_xchg(&per_cpu(active_asids, cpu), asid)) 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 ^ atomic64_read(&asid_generation)) >> ASID_BITS) - new_context(mm, cpu); - - atomic64_set(&per_cpu(active_asids, cpu), mm->context.id); - cpumask_set_cpu(cpu, mm_cpumask(mm)); + asid = atomic64_read(&mm->context.id); + if ((asid ^ atomic64_read(&asid_generation)) >> ASID_BITS) { + asid = new_context(mm, cpu); + atomic64_set(&mm->context.id, asid); + } - if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) + if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) { + local_flush_bp_all(); local_flush_tlb_all(); + dummy_flush_tlb_a15_erratum(); + } + + atomic64_set(&per_cpu(active_asids, cpu), asid); + cpumask_set_cpu(cpu, mm_cpumask(mm)); raw_spin_unlock_irqrestore(&cpu_asid_lock, flags); switch_mm_fastpath: |