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 <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Russell King <[email protected]>
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 44d4ee5..a5a4b2bc 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -212,8 +212,10 @@
atomic64_set(&mm->context.id, asid);
}
- if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending))
+ if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) {
+ local_flush_bp_all();
local_flush_tlb_all();
+ }
atomic64_set(&per_cpu(active_asids, cpu), asid);
cpumask_set_cpu(cpu, mm_cpumask(mm));
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 2dffc01..5ee505c 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -141,6 +141,7 @@
{
/* Switch to the identity mapping. */
cpu_switch_mm(idmap_pgd, &init_mm);
+ local_flush_bp_all();
#ifdef CONFIG_CPU_HAS_ASID
/*
