Commit 89c7e4b8 authored by Will Deacon's avatar Will Deacon Committed by Russell King

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: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 862c588f
......@@ -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();
......
......@@ -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();
}
......
......@@ -212,8 +212,10 @@ void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk)
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));
......
......@@ -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
/*
......
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