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>

2 files changed, 2 insertions, 0 deletions

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 1bdfd87c8e41..31644f1978d5 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -285,6 +285,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void)
 	 * switch away from it before attempting any exclusive accesses.
 	 */
 	cpu_switch_mm(mm->pgd, mm);
+	local_flush_bp_all();
 	enter_lazy_tlb(mm, current);
 	local_flush_tlb_all();
 
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c
index 358bca3a995e..c59c97ea8268 100644
--- a/arch/arm/kernel/suspend.c
+++ b/arch/arm/kernel/suspend.c
@@ -68,6 +68,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
 	ret = __cpu_suspend(arg, fn);
 	if (ret == 0) {
 		cpu_switch_mm(mm->pgd, mm);
+		local_flush_bp_all();
 		local_flush_tlb_all();
 	}