1 files changed, 20 insertions, 12 deletions

diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 7a0511191f6b..2ac37372ef52 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -48,7 +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;
 
@@ -152,9 +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)) {
@@ -181,13 +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);
@@ -198,20 +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: