diff options
Diffstat (limited to 'arch/arc/include/asm/mmu_context.h')
| -rw-r--r-- | arch/arc/include/asm/mmu_context.h | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/arc/include/asm/mmu_context.h b/arch/arc/include/asm/mmu_context.h index 45f06f566b02..1fd467ef658f 100644 --- a/arch/arc/include/asm/mmu_context.h +++ b/arch/arc/include/asm/mmu_context.h @@ -80,7 +80,7 @@ static inline void get_new_mmu_context(struct mm_struct *mm) /* move to new ASID and handle rollover */ if (unlikely(!(++asid_cpu(cpu) & MM_CTXT_ASID_MASK))) { - flush_tlb_all(); + local_flush_tlb_all(); /* * Above checke for rollover of 8 bit ASID in 32 bit container. @@ -131,6 +131,21 @@ static inline void destroy_context(struct mm_struct *mm) static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { + const int cpu = smp_processor_id(); + + /* + * Note that the mm_cpumask is "aggregating" only, we don't clear it + * for the switched-out task, unlike some other arches. + * It is used to enlist cpus for sending TLB flush IPIs and not sending + * it to CPUs where a task once ran-on, could cause stale TLB entry + * re-use, specially for a multi-threaded task. + * e.g. T1 runs on C1, migrates to C3. T2 running on C2 munmaps. + * For a non-aggregating mm_cpumask, IPI not sent C1, and if T1 + * were to re-migrate to C1, it could access the unmapped region + * via any existing stale TLB entries. + */ + cpumask_set_cpu(cpu, mm_cpumask(next)); + #ifndef CONFIG_SMP /* PGD cached in MMU reg to avoid 3 mem lookups: task->mm->pgd */ write_aux_reg(ARC_REG_SCRATCH_DATA0, next->pgd); |