Commit 4d9088b0 authored Nov 10, 2014 by Mitchel Humpherys Committed by Matt Wagantall May 30, 2015

iommu/arm-smmu: enable unidentified stream faults on unmapped access

Currently when an SMMU client accesses an unmapped address the SMMU does
a bypass and propagates the request. This can make it difficult to
debug problems when clients are accessing bogus addresses. Enable the
sCR0 bit that causes the SMMU to raise an unidentified stream fault
rather than falling back to bypass when no mapping is found.

Change-Id: Ia0e40010c79b8a75954ae13ae60aca2d82ff76b6
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

parent 8cd0b952

drivers/iommu/arm-smmu.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -2158,8 +2158,11 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
		/* Disable TLB broadcasting. */
		reg \|= (sCR0_VMIDPNE \| sCR0_PTM);

		/* Enable client access, but bypass when no mapping is found */
		reg &= ~(sCR0_CLIENTPD \| sCR0_USFCFG);
		/* Enable client access */
		reg &= ~sCR0_CLIENTPD;

		/* Raise an unidentified stream fault on unmapped access */
		reg \|= sCR0_USFCFG;

		/* Disable forced broadcasting */
		reg &= ~sCR0_FB;