diff options
Diffstat (limited to 'arch/arm/include/asm/mmu_context.h')
| -rw-r--r-- | arch/arm/include/asm/mmu_context.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h index de6cefb329d..a0b3cac0547 100644 --- a/arch/arm/include/asm/mmu_context.h +++ b/arch/arm/include/asm/mmu_context.h @@ -43,12 +43,23 @@ void __check_kvm_seq(struct mm_struct *mm); #define ASID_FIRST_VERSION (1 << ASID_BITS) extern unsigned int cpu_last_asid; +#ifdef CONFIG_SMP +DECLARE_PER_CPU(struct mm_struct *, current_mm); +#endif void __init_new_context(struct task_struct *tsk, struct mm_struct *mm); void __new_context(struct mm_struct *mm); static inline void check_context(struct mm_struct *mm) { + /* + * This code is executed with interrupts enabled. Therefore, + * mm->context.id cannot be updated to the latest ASID version + * on a different CPU (and condition below not triggered) + * without first getting an IPI to reset the context. The + * alternative is to take a read_lock on mm->context.id_lock + * (after changing its type to rwlock_t). + */ if (unlikely((mm->context.id ^ cpu_last_asid) >> ASID_BITS)) __new_context(mm); @@ -108,6 +119,10 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next, __flush_icache_all(); #endif if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next) { +#ifdef CONFIG_SMP + struct mm_struct **crt_mm = &per_cpu(current_mm, cpu); + *crt_mm = next; +#endif check_context(next); cpu_switch_mm(next->pgd, next); if (cache_is_vivt()) |