[PATCH] drm/ttm: callback move_notify any time bo placement change v2

[j.gli...@gmail.com]

From: Jerome Glisse <jgli...@redhat.com>

Previously we were calling back move_notify in error path when the
bo is returned to it's original position or when destroy the bo.
When destroying the bo set the new mem placement as NULL when calling
back in the driver.

Updating nouveau to deal with NULL placement properly.

v2: reserve the object before calling move_notify in bo destroy path
    at that point ttm should be the only piece of code interacting
    with the object so atomic_set is safe here.

Reviewed-by: Jerome Glisse <jglisse at redhat.com>
---
 drivers/gpu/drm/nouveau/nouveau_bo.c |    4 ++--
 drivers/gpu/drm/ttm/ttm_bo.c         |    9 +++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c 
b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 857bca4..f12dd0f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -815,10 +815,10 @@ nouveau_bo_move_ntfy(struct ttm_buffer_object *bo, struct 
ttm_mem_reg *new_mem)
        struct nouveau_vma *vma;

        list_for_each_entry(vma, &nvbo->vma_list, head) {
-               if (new_mem->mem_type == TTM_PL_VRAM) {
+               if (new_mem && new_mem->mem_type == TTM_PL_VRAM) {
                        nouveau_vm_map(vma, new_mem->mm_node);
                } else
-               if (new_mem->mem_type == TTM_PL_TT &&
+               if (new_mem && new_mem->mem_type == TTM_PL_TT &&
                    nvbo->page_shift == vma->vm->spg_shift) {
                        nouveau_vm_map_sg(vma, 0, new_mem->
                                          num_pages << PAGE_SHIFT,
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index de7ad99..c15bcc3 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -147,6 +147,12 @@ static void ttm_bo_release_list(struct kref *list_kref)
        BUG_ON(!list_empty(&bo->lru));
        BUG_ON(!list_empty(&bo->ddestroy));

+       /* force bo to reserved, at this point we should be the only owner */
+       atomic_set(&bo->reserved, 1);
+       if (bdev->driver->move_notify)
+               bdev->driver->move_notify(bo, NULL);
+       atomic_set(&bo->reserved, 0);
+
        if (bo->ttm)
                ttm_tt_destroy(bo->ttm);
        atomic_dec(&bo->glob->bo_count);
@@ -437,6 +443,9 @@ moved:
        return 0;

 out_err:
+       if (bdev->driver->move_notify)
+               bdev->driver->move_notify(bo, &bo->mem);
+
        new_man = &bdev->man[bo->mem.mem_type];
        if ((new_man->flags & TTM_MEMTYPE_FLAG_FIXED) && bo->ttm) {
                ttm_tt_unbind(bo->ttm);
-- 
1.7.7.1