Commit 4df7b226 authored by Lu Baolu's avatar Lu Baolu Committed by Will Deacon
Browse files

Revert "iommu: Add quirk for Intel graphic devices in map_sg" 



This reverts commit 65f746e8.

As commit 8a473dba ("drm/i915: Fix DMA mapped scatterlist walks") and
commit 934941ed ("drm/i915: Fix DMA mapped scatterlist lookup") fixed
the DMA scatterlist limitations in the i915 driver, remove this temporary
workaround.

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Tom Murphy <murphyt7@tcd.ie>
Cc: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20201231005323.2178523-4-baolu.lu@linux.intel.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 1efd17e7

drivers/iommu/dma-iommu.c

+0 −27
Original line number Diff line number Diff line
@@ -863,33 +863,6 @@ static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents, 
	unsigned int cur_len = 0, max_len = dma_get_max_seg_size(dev);

	int i, count = 0;



	/*

	 * The Intel graphic driver is used to assume that the returned

	 * sg list is not combound. This blocks the efforts of converting

	 * Intel IOMMU driver to dma-iommu api's. Add this quirk to make the

	 * device driver work and should be removed once it's fixed in i915

	 * driver.

	 */

	if (IS_ENABLED(CONFIG_DRM_I915) && dev_is_pci(dev) &&

	    to_pci_dev(dev)->vendor == PCI_VENDOR_ID_INTEL &&

	    (to_pci_dev(dev)->class >> 16) == PCI_BASE_CLASS_DISPLAY) {

		for_each_sg(sg, s, nents, i) {

			unsigned int s_iova_off = sg_dma_address(s);

			unsigned int s_length = sg_dma_len(s);

			unsigned int s_iova_len = s->length;



			s->offset += s_iova_off;

			s->length = s_length;

			sg_dma_address(s) = dma_addr + s_iova_off;

			sg_dma_len(s) = s_length;

			dma_addr += s_iova_len;



			pr_info_once("sg combining disabled due to i915 driver\n");

		}



		return nents;

	}



	for_each_sg(sg, s, nents, i) {

		/* Restore this segment's original unaligned fields first */

		unsigned int s_iova_off = sg_dma_address(s);