ARM: 7661/1: mm: perform explicit branch predictor maintenance when required

The ARM ARM requires branch predictor maintenance if, for a given ASID,
the instructions at a specific virtual address appear to change.

From the kernel's point of view, that means:

	- Changing the kernel's view of memory (e.g. switching to the
	  identity map)
	- ASID rollover (since ASIDs will be re-allocated to new tasks)

This patch adds explicit branch predictor maintenance when either of the
two conditions above are met.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 2dffc010cc41..5ee505c937d1 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -141,6 +141,7 @@ void setup_mm_for_reboot(void)
 {
         /* Switch to the identity mapping. */
         cpu_switch_mm(idmap_pgd, &init_mm);
+        local_flush_bp_all();
 
 #ifdef CONFIG_CPU_HAS_ASID
         /*