NOUVEAU HACK FOR P2P AND IOMMUwip-hmm-p2p

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>

1 files changed, 55 insertions, 7 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 33e75b9f1a94..776a57efa4ed 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -1071,20 +1071,27 @@ static long nouveau_dmem_p2p_map(struct hmm_devmem *devmem,
 	struct drm_device *drm_dev = dev_get_drvdata(devmem->device);
 	const unsigned long page_size = 1UL << range->page_shift;
 	struct nouveau_drm *drm = nouveau_drm(drm_dev);
-	unsigned long i;
+	unsigned long i, mapped;
 	uint64_t *pfns;
+	long ret;
 
+#if 0
 	if (!device_test_p2p(device, devmem->device))
 		return 0;
+#endif
 
 	pfns = &range->pfns[(addr - range->start) >> range->page_shift];
 	for (i = 0; addr < range->end; i++, addr += page_size) {
+		enum dma_data_direction dir = DMA_FROM_DEVICE;
 		struct nouveau_dmem_chunk *chunk;
 		struct page *page;
+		phys_addr_t pa;
 
 		/* Check if range is being invalidated */
-		if (!range->valid)
-			return 0;
+		if (!range->valid) {
+			ret = -EBUSY;
+			goto unmap;
+		}
 
 		page = hmm_pfn_to_page(range, pfns[i]);
 		if (page == NULL)
@@ -1097,10 +1104,50 @@ static long nouveau_dmem_p2p_map(struct hmm_devmem *devmem,
 		if (!chunk->p2p)
 			return i;
 
+		/* If it is read and write than map bi-directional. */
+		if (range->pfns[i] & range->values[HMM_PFN_WRITE])
+			dir = DMA_BIDIRECTIONAL;
+
+#if 0
 		pas[i] = nouveau_dmem_page_to_bar_pa(chunk, drm, page);
+#else
+		pa = nouveau_dmem_page_to_bar_pa(chunk, drm, page);
+		pas[i] = dma_map_resource(device, pa, PAGE_SIZE, dir, 0);
+		if (dma_mapping_error(device, pas[i])) {
+			ret = -EFAULT;
+			goto unmap;
+		}
+#endif
 	}
 
 	return i;
+
+unmap:
+	mapped = i;
+	addr = range->start;
+	for (i = 0; i < mapped; i++, addr += page_size) {
+		enum dma_data_direction dir = DMA_FROM_DEVICE;
+		struct page *page;
+
+		page = hmm_pfn_to_page(range, pfns[i]);
+		if (page == NULL)
+			continue;
+
+		if (!nouveau_dmem_page(drm, page))
+			return i;
+
+		/* If it is read and write than map bi-directional. */
+		if (range->pfns[i] & range->values[HMM_PFN_WRITE])
+			dir = DMA_BIDIRECTIONAL;
+
+#if 0
+		pas[i] = nouveau_dmem_page_to_bar_pa(chunk, drm, page);
+#else
+		dma_unmap_resource(device, pas[i], PAGE_SIZE, dir, 0);
+#endif
+	}
+
+	return ret;
 }
 
 static unsigned long nouveau_dmem_p2p_unmap(struct hmm_devmem *devmem,
@@ -1117,12 +1164,9 @@ static unsigned long nouveau_dmem_p2p_unmap(struct hmm_devmem *devmem,
 
 	pfns = &range->pfns[(addr - range->start) >> range->page_shift];
 	for (i = 0; addr < range->end; i++, addr += page_size) {
+		enum dma_data_direction dir = DMA_FROM_DEVICE;
 		struct page *page;
 
-		/* Check if range is being invalidated */
-		if (!range->valid)
-			return 0;
-
 		page = hmm_pfn_to_page(range, pfns[i]);
 		if (page == NULL)
 			continue;
@@ -1130,6 +1174,10 @@ static unsigned long nouveau_dmem_p2p_unmap(struct hmm_devmem *devmem,
 		if (!nouveau_dmem_page(drm, page))
 			return i;
 		/* Nothing to do as we do not support IOMMU yet. */
+		/* If it is read and write than map bi-directional. */
+		if (range->pfns[i] & range->values[HMM_PFN_WRITE])
+			dir = DMA_BIDIRECTIONAL;
+		dma_unmap_resource(device, pas[i], PAGE_SIZE, dir, 0);
 	}
 
 	return i;