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| author |   Tvrtko Ursulin <tvrtko.ursulin@intel.com> | 2020-10-06 10:25:07 +0100 |
|---|---|---|
| committer | Tvrtko Ursulin <tvrtko.ursulin@intel.com> | 2020-10-06 12:49:07 +0100 |
| commit | 8a473dbadccfc6206150de3db3223c40785da348 (patch) | |
| tree | 88f40523da4eed82e95f7ec9730c39402751a960 /drivers/gpu/drm/i915/gt/gen6_ppgtt.c | |
| parent | drm/i915/gt: Scrub HW state on remove (diff) | |
| download | linux-dev-8a473dbadccfc6206150de3db3223c40785da348.tar.xz linux-dev-8a473dbadccfc6206150de3db3223c40785da348.zip | |
drm/i915: Fix DMA mapped scatterlist walks
When walking DMA mapped scatterlists sg_dma_len has to be used since it
can be different (coalesced) from the backing store entry.
This also means we have to end the walk when encountering a zero length
DMA entry and cannot rely on the normal sg list end marker.
Both issues were there in theory for some time but were hidden by the fact
Intel IOMMU driver was never coalescing entries. As there are ongoing
efforts to change this we need to start handling it.
v2:
* Use unsigned int for local storing sg_dma_len. (Logan)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
References: 85d1225ec066 ("drm/i915: Introduce & use new lightweight SGL iterators")
References: b31144c0daa8 ("drm/i915: Micro-optimise gen6_ppgtt_insert_entries()")
Reported-by: Tom Murphy <murphyt7@tcd.ie>
Suggested-by: Tom Murphy <murphyt7@tcd.ie> # __sgt_iter
Suggested-by: Logan Gunthorpe <logang@deltatee.com> # __sgt_iter
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201006092508.1064287-1-tvrtko.ursulin@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/gt/gen6_ppgtt.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/gen6_ppgtt.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c index fd0d24d28763..c0d17f87b00f 100644 --- a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c +++ b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c @@ -131,17 +131,17 @@ static void gen6_ppgtt_insert_entries(struct i915_address_space *vm, vaddr = kmap_atomic_px(i915_pt_entry(pd, act_pt)); do { - GEM_BUG_ON(iter.sg->length < I915_GTT_PAGE_SIZE); + GEM_BUG_ON(sg_dma_len(iter.sg) < I915_GTT_PAGE_SIZE); vaddr[act_pte] = pte_encode | GEN6_PTE_ADDR_ENCODE(iter.dma); iter.dma += I915_GTT_PAGE_SIZE; if (iter.dma == iter.max) { iter.sg = __sg_next(iter.sg); - if (!iter.sg) + if (!iter.sg || sg_dma_len(iter.sg) == 0) break; iter.dma = sg_dma_address(iter.sg); - iter.max = iter.dma + iter.sg->length; + iter.max = iter.dma + sg_dma_len(iter.sg); } if (++act_pte == GEN6_PTES) { |