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

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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>
This commit is contained in:
Will Deacon
2013-02-28 17:48:40 +01:00
committed by Russell King
parent 862c588f06
commit 89c7e4b8bb
4 changed files with 6 additions and 1 deletions
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4
arch/arm/mm/context.c
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@@ -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));