[PATCH 1/1] drm/ttm: fix offset in VMAs with a pg_offs in ttm_bo_vm_access

[Felix Kuehling]

VMAs with a pg_offs that's offset from the start of the vma_node need
to adjust the offset within the BO accordingly. This matches the
offset calculation in ttm_bo_vm_fault_reserved.

Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
Tested-by: Laurent Morichetti <laurent.morichetti at amd.com>
---
 drivers/gpu/drm/ttm/ttm_bo_vm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 389128b8c4dd..60b41447bec8 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -405,8 +405,10 @@ static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
 		     void *buf, int len, int write)
 {
-	unsigned long offset = (addr) - vma->vm_start;
 	struct ttm_buffer_object *bo = vma->vm_private_data;
+	unsigned long offset = (addr) - vma->vm_start +
+		((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))
+		 << PAGE_SHIFT);
 	int ret;
 
 	if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->num_pages)
-- 
2.17.1