[PATCH 5.15 10/69] nouveau/svm: Fix to migrate all requested pages

Greg Kroah-Hartman
2022-08-01T12:04:08Z

From: Alistair Popple <apopple@nvidia.com>

commit 66cee9097e2b74ff3c8cc040ce5717c521a0c3fa upstream.

Users may request that pages from an OpenCL SVM allocation be migrated
to the GPU with clEnqueueSVMMigrateMem(). In Nouveau this will call into
nouveau_dmem_migrate_vma() to do the migration. If the total range to be
migrated exceeds SG_MAX_SINGLE_ALLOC the pages will be migrated in
chunks of size SG_MAX_SINGLE_ALLOC. However a typo in updating the
starting address means that only the first chunk will get migrated.

Fix the calculation so that the entire range will get migrated if
possible.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
Fixes: e3d8b0890469 ("drm/nouveau/svm: map pages after migration")
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220720062745.960701-1-apopple@nvidia.com
Cc: <stable@vger.kernel.org> # v5.8+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/nouveau/nouveau_dmem.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -679,7 +679,11 @@ nouveau_dmem_migrate_vma(struct nouveau_
goto out_free_dma;

for (i = 0; i < npages; i += max) {
- args.end = start + (max << PAGE_SHIFT);
+ if (args.start + (max << PAGE_SHIFT) > end)
+ args.end = end;
+ else
+ args.end = args.start + (max << PAGE_SHIFT);
+
ret = migrate_vma_setup(&args);
if (ret)
goto out_free_pfns;