[PATCH 4/5] Revert "iommu: Add quirk for Intel graphic devices in map_sg"

Lu Baolu
2020-12-31T01:03:43Z

This reverts commit 65f746e8285f0a67d43517d86fedb9e29ead49f2.

As commit 8a473dbadccfc ("drm/i915: Fix DMA mapped scatterlist walks") and
commit 934941ed5a307 ("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: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/dma-iommu.c | 27 ---------------------------
1 file changed, 27 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index f0305e6aac1b..4078358ed66e 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -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);
--
2.25.1