[PATCH] nouveau: remove bogus uses of DMA_ATTR_SKIP_CPU_SYNC

From: Christoph Hellwig
Date: Wed Jul 03 2019 - 16:35:15 EST


DMA_ATTR_SKIP_CPU_SYNC should only be used when the driver manually
performs dma cache maintainance operations using the dma_sync_*
calls. Nouveau doesn't do that, and generally just assumes DMA
is coherent. Use plain dma_map_page which doesn't make this code
correct but at least a little less wrong and simpler.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_dmem.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index b9ced2e61667..a5d9b537cbaf 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -186,9 +186,8 @@ nouveau_dmem_fault_alloc_and_copy(struct vm_area_struct *vma,
}

fault->dma[fault->npages] =
- dma_map_page_attrs(dev, dpage, 0, PAGE_SIZE,
- PCI_DMA_BIDIRECTIONAL,
- DMA_ATTR_SKIP_CPU_SYNC);
+ dma_map_page(dev, dpage, 0, PAGE_SIZE,
+ PCI_DMA_BIDIRECTIONAL);
if (dma_mapping_error(dev, fault->dma[fault->npages])) {
dst_pfns[i] = MIGRATE_PFN_ERROR;
__free_page(dpage);
@@ -706,9 +705,8 @@ nouveau_dmem_migrate_alloc_and_copy(struct vm_area_struct *vma,
}

migrate->dma[migrate->dma_nr] =
- dma_map_page_attrs(dev, spage, 0, PAGE_SIZE,
- PCI_DMA_BIDIRECTIONAL,
- DMA_ATTR_SKIP_CPU_SYNC);
+ dma_map_page(dev, spage, 0, PAGE_SIZE,
+ PCI_DMA_BIDIRECTIONAL);
if (dma_mapping_error(dev, migrate->dma[migrate->dma_nr])) {
nouveau_dmem_page_free_locked(drm, dpage);
dst_pfns[i] = 0;
--
2.20.1