Commit 4e602056 authored Jan 29, 2018 by Will Deacon Committed by Catalin Marinas Feb 06, 2018

arm64: mm: Permit transitioning from Global to Non-Global without BBM



Break-before-make is not needed when transitioning from Global to
Non-Global mappings, provided that the contiguous hint is not being used.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent 41acec62

arch/arm64/mm/mmu.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -118,6 +118,10 @@ static bool pgattr_change_is_safe(u64 old, u64 new)
		if ((old \| new) & PTE_CONT)
		return false;

		/* Transitioning from Global to Non-Global is safe */
		if (((old ^ new) == PTE_NG) && (new & PTE_NG))
		return true;

		return ((old ^ new) & ~mask) == 0;
		}

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