[PATCH 6/9] nouveau/dmem: Only map migrating pages

From: Alistair Popple
Date: Mon Feb 08 2021 - 20:11:34 EST


Only pages which were actually migrated should be mapped on the GPU.
migrate_vma_pages() clears MIGRATE_PFN_MIGRATE in the src_pfn array, so
test this prior to mapping the pages on the GPU. If any pages failed to
migrate don't install any mappings - the GPU will demand fault any as
required.

Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_dmem.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 92987daa5e17..9579bd001f11 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -618,8 +618,9 @@ static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm,
dma_addr_t *dma_addrs, u64 *pfns)
{
struct nouveau_fence *fence;
- unsigned long addr = args->start, nr_dma = 0, i;
+ unsigned long addr = args->start, nr_dma = 0, i, npages;

+ npages = (args->start - args->end) >> PAGE_SHIFT;
for (i = 0; addr < args->end; i++) {
args->dst[i] = nouveau_dmem_migrate_copy_one(drm, svmm,
args->src[i], dma_addrs + nr_dma, pfns + i);
@@ -631,7 +632,17 @@ static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm,
nouveau_fence_new(drm->dmem->migrate.chan, false, &fence);
migrate_vma_pages(args);
nouveau_dmem_fence_done(&fence);
- nouveau_pfns_map(svmm, args->vma->vm_mm, args->start, pfns, i);
+
+ for (i = 0; i < npages; i++)
+ if (!(args->src[i] & MIGRATE_PFN_MIGRATE))
+ break;
+
+ /*
+ * If all pages were migrated successfully map them on the GPU. If any
+ * failed just let the GPU fault to create the mapping.
+ */
+ if (i == npages)
+ nouveau_pfns_map(svmm, args->vma->vm_mm, args->start, pfns, npages);

while (nr_dma--) {
dma_unmap_page(drm->dev->dev, dma_addrs[nr_dma], PAGE_SIZE,
--
2.20.1