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Diffstat (limited to 'arch/arm/mm/context.c')
-rw-r--r--arch/arm/mm/context.c21
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"