drm/amdgpu: fix userptr put_page handling

Move calling put_page into the unpopulate callback. Otherwise we mess up the pages
reference count when it is unbound multiple times.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

3 files changed, 16 insertions, 5 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 5809f55e0d9d..cc6de0b46326 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1793,6 +1793,7 @@ void amdgpu_cs_report_moved_bytes(struct amdgpu_device *adev, u64 num_bytes,
 void amdgpu_ttm_placement_from_domain(struct amdgpu_bo *abo, u32 domain);
 bool amdgpu_ttm_bo_is_amdgpu_bo(struct ttm_buffer_object *bo);
 int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages);
+void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages);
 int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
                                      uint32_t flags);
 bool amdgpu_ttm_tt_has_userptr(struct ttm_tt *ttm);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 233b6f2f8427..e58db0c69c6a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -474,10 +474,8 @@ static int amdgpu_cs_list_validate(struct amdgpu_cs_parser *p,
 
                 /* Check if we have user pages and nobody bound the BO already */
                 if (lobj->user_pages && bo->tbo.ttm->state != tt_bound) {
-                        size_t size = sizeof(struct page *);
-
-                        size *= bo->tbo.ttm->num_pages;
-                        memcpy(bo->tbo.ttm->pages, lobj->user_pages, size);
+                        amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm,
+                                                     lobj->user_pages);
                         binding_userptr = true;
                 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 841a5699bef0..28e121984332 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -664,6 +664,18 @@ release_pages:
         return r;
 }
 
+void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages)
+{
+        unsigned i;
+
+        for (i = 0; i < ttm->num_pages; ++i) {
+                if (ttm->pages[i])
+                        put_page(ttm->pages[i]);
+
+                ttm->pages[i] = pages ? pages[i] : NULL;
+        }
+}
+
 static void amdgpu_trace_dma_map(struct ttm_tt *ttm)
 {
         struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev);
@@ -738,7 +750,6 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
                         set_page_dirty(page);
 
                 mark_page_accessed(page);
-                put_page(page);
         }
 
         amdgpu_trace_dma_unmap(ttm);
@@ -971,6 +982,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_tt *ttm)
         bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);
 
         if (gtt && gtt->userptr) {
+                amdgpu_ttm_tt_set_user_pages(ttm, NULL);
                 kfree(ttm->sg);
                 ttm->page_flags &= ~TTM_PAGE_FLAG_SG;
                 return;