diff options
| -rw-r--r-- | arch/arm/mm/context.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index 84e6f772e204..3ad0fdaa5cc1 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -78,20 +78,21 @@ void a15_erratum_get_cpumask(int this_cpu, struct mm_struct *mm, #endif #ifdef CONFIG_ARM_LPAE -static void cpu_set_reserved_ttbr0(void) -{ - /* - * Set TTBR0 to swapper_pg_dir which contains only global entries. The - * ASID is set to 0. - */ - cpu_set_ttbr(0, __pa(swapper_pg_dir)); - isb(); -} +/* + * With LPAE, the ASID and page tables are updated atomicly, so there is + * no need for a reserved set of tables (the active ASID tracking prevents + * any issues across a rollover). + */ +#define cpu_set_reserved_ttbr0() #else static void cpu_set_reserved_ttbr0(void) { u32 ttb; - /* Copy TTBR1 into TTBR0 */ + /* + * Copy TTBR1 into TTBR0. + * This points at swapper_pg_dir, which contains only global + * entries so any speculative walks are perfectly safe. + */ asm volatile( " mrc p15, 0, %0, c2, c0, 1 @ read TTBR1\n" " mcr p15, 0, %0, c2, c0, 0 @ set TTBR0\n" |