Commit 5d52f482 authored by David Woodhouse's avatar David Woodhouse
Browse files

iommu/vt-d: Fix SVM IOTLB flush handling 



Change the 'pages' parameter to 'unsigned long' to avoid overflow.

Fix the device-IOTLB flush parameter calculation — the size of the IOTLB
flush is indicated by the position of the least significant zero bit in
the address field. For example, a value of 0x12345f000 will flush from
0x123440000 to 0x12347ffff (256KiB).

Finally, the cap_pgsel_inv() is not relevant to SVM; the spec says that
*all* implementations must support page-selective invaliation for
"first-level" translations. So don't check for it.

Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent b9997e38

drivers/iommu/intel-svm.c

+15 −20
Original line number Diff line number Diff line
@@ -147,13 +147,11 @@ int intel_svm_finish_prq(struct intel_iommu *iommu) 
}



static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_dev *sdev,

				       unsigned long address, int pages, int ih, int gl)

				       unsigned long address, unsigned long pages, int ih, int gl)

{

	struct qi_desc desc;

	int mask = ilog2(__roundup_pow_of_two(pages));



	if (pages == -1 || !cap_pgsel_inv(svm->iommu->cap) ||

	    mask > cap_max_amask_val(svm->iommu->cap)) {

	if (pages == -1) {

		/* For global kernel pages we have to flush them in *all* PASIDs

		 * because that's the only option the hardware gives us. Despite

		 * the fact that they are actually only accessible through one. */
@@ -165,31 +163,28 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d 
				QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) | QI_EIOTLB_TYPE;

		desc.high = 0;

	} else {

		int mask = ilog2(__roundup_pow_of_two(pages));



		desc.low = QI_EIOTLB_PASID(svm->pasid) | QI_EIOTLB_DID(sdev->did) |

			QI_EIOTLB_GRAN(QI_GRAN_PSI_PASID) | QI_EIOTLB_TYPE;

		desc.high = QI_EIOTLB_ADDR(address) | QI_EIOTLB_GL(gl) |

			QI_EIOTLB_IH(ih) | QI_EIOTLB_AM(mask);

	}



	qi_submit_sync(&desc, svm->iommu);



	if (sdev->dev_iotlb) {

		desc.low = QI_DEV_EIOTLB_PASID(svm->pasid) | QI_DEV_EIOTLB_SID(sdev->sid) |

			QI_DEV_EIOTLB_QDEP(sdev->qdep) | QI_DEIOTLB_TYPE;

		if (mask) {

			unsigned long adr, delta;



			/* Least significant zero bits in the address indicate the

			 * range of the request. So mask them out according to the

			 * size. */

			adr = address & ((1<<(VTD_PAGE_SHIFT + mask)) - 1);



			/* Now ensure that we round down further if the original

			 * request was not aligned w.r.t. its size */

			delta = address - adr;

			if (delta + (pages << VTD_PAGE_SHIFT) >= (1 << (VTD_PAGE_SHIFT + mask)))

				adr &= ~(1 << (VTD_PAGE_SHIFT + mask));

			desc.high = QI_DEV_EIOTLB_ADDR(adr) | QI_DEV_EIOTLB_SIZE;

		if (pages == -1) {

			desc.high = QI_DEV_EIOTLB_ADDR(-1ULL >> 1) | QI_DEV_EIOTLB_SIZE;

		} else if (pages > 1) {

			/* The least significant zero bit indicates the size. So,

			 * for example, an "address" value of 0x12345f000 will

			 * flush from 0x123440000 to 0x12347ffff (256KiB). */

			unsigned long last = address + ((unsigned long)(pages - 1) << VTD_PAGE_SHIFT);

			unsigned long mask = __rounddown_pow_of_two(address ^ last);;



			desc.high = QI_DEV_EIOTLB_ADDR((address & ~mask) | (mask - 1)) | QI_DEV_EIOTLB_SIZE;

		} else {

			desc.high = QI_DEV_EIOTLB_ADDR(address);

		}
@@ -198,7 +193,7 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d 
}



static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,

				  int pages, int ih, int gl)

				  unsigned long pages, int ih, int gl)

{

	struct intel_svm_dev *sdev;

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