Commit 16d3905b authored Apr 29, 2016 by Mitchel Humpherys

iommu/iommu-debug: Do a software table walk if ATOS fails



It's hard to tell whether ATOS failed due to a misconfiguration in
hardware or software.  Add a software table walk to help narrow down the
reasons for the failure.  If the software walk succeeds then there's
something wrong in hardware.  If the software walk fails then there's
something wrong in software.

CRs-Fixed: 1014916
Change-Id: I49dd61856ad08e1890791b3e5c180350a5eaa648
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

parent c7746cb5

drivers/iommu/iommu-debug.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -882,10 +882,14 @@ static ssize_t iommu_debug_atos_read(struct file file, char __user ubuf,
		memset(buf, 0, 100);

		phys = iommu_iova_to_phys_hard(ddev->domain, ddev->iova);
		if (!phys)
		if (!phys) {
		strlcpy(buf, "FAIL\n", 100);
		else
		phys = iommu_iova_to_phys(ddev->domain, ddev->iova);
		dev_err(ddev->dev, "ATOS for %pa failed. Software walk returned: %pa\n",
		&ddev->iova, &phys);
		} else {
		snprintf(buf, 100, "%pa\n", &phys);
		}

		buflen = strlen(buf);
		if (copy_to_user(ubuf, buf, buflen)) {