drm/ttm: rework bulk move handling v5

Instead of providing the bulk move structure for each LRU update set
this as property of the BO. This should avoid costly bulk move rebuilds
with some games under RADV.

v2: some name polishing, add a few more kerneldoc words.
v3: add some lockdep
v4: fix bugs, handle pin/unpin as well
v5: improve kerneldoc

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220321132601.2161-5-christian.koenig@amd.com

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 5859ed0..57ac118 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1498,7 +1498,6 @@ static struct ttm_device_funcs amdgpu_bo_driver = {
        .io_mem_reserve = &amdgpu_ttm_io_mem_reserve,
        .io_mem_pfn = amdgpu_ttm_io_mem_pfn,
        .access_memory = &amdgpu_ttm_access_memory,
-       .del_from_lru_notify = &amdgpu_vm_del_from_lru_notify
 };
 
 /*

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index f2ce5a0..28f5e8b 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -375,7 +375,7 @@ static void amdgpu_vm_bo_base_init(struct amdgpu_vm_bo_base *base,
        if (bo->tbo.base.resv != vm->root.bo->tbo.base.resv)
                return;
 
-       vm->bulk_moveable = false;
+       ttm_bo_set_bulk_move(&bo->tbo, &vm->lru_bulk_move);
        if (bo->tbo.type == ttm_bo_type_kernel && bo->parent)
                amdgpu_vm_bo_relocated(base);
        else
@@ -638,36 +638,6 @@ void amdgpu_vm_get_pd_bo(struct amdgpu_vm *vm,
 }
 
 /**
- * amdgpu_vm_del_from_lru_notify - update bulk_moveable flag
- *
- * @bo: BO which was removed from the LRU
- *
- * Make sure the bulk_moveable flag is updated when a BO is removed from the
- * LRU.
- */
-void amdgpu_vm_del_from_lru_notify(struct ttm_buffer_object *bo)
-{
-       struct amdgpu_bo *abo;
-       struct amdgpu_vm_bo_base *bo_base;
-
-       if (!amdgpu_bo_is_amdgpu_bo(bo))
-               return;
-
-       if (bo->pin_count)
-               return;
-
-       abo = ttm_to_amdgpu_bo(bo);
-       if (!abo->parent)
-               return;
-       for (bo_base = abo->vm_bo; bo_base; bo_base = bo_base->next) {
-               struct amdgpu_vm *vm = bo_base->vm;
-
-               if (abo->tbo.base.resv == vm->root.bo->tbo.base.resv)
-                       vm->bulk_moveable = false;
-       }
-
-}
-/**
  * amdgpu_vm_move_to_lru_tail - move all BOs to the end of LRU
  *
  * @adev: amdgpu device pointer
@@ -679,33 +649,9 @@ void amdgpu_vm_del_from_lru_notify(struct ttm_buffer_object *bo)
 void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
                                struct amdgpu_vm *vm)
 {
-       struct amdgpu_vm_bo_base *bo_base;
-
-       if (vm->bulk_moveable) {
-               spin_lock(&adev->mman.bdev.lru_lock);
-               ttm_lru_bulk_move_tail(&vm->lru_bulk_move);
-               spin_unlock(&adev->mman.bdev.lru_lock);
-               return;
-       }
-
-       ttm_lru_bulk_move_init(&vm->lru_bulk_move);
-
        spin_lock(&adev->mman.bdev.lru_lock);
-       list_for_each_entry(bo_base, &vm->idle, vm_status) {
-               struct amdgpu_bo *bo = bo_base->bo;
-               struct amdgpu_bo *shadow = amdgpu_bo_shadowed(bo);
-
-               if (!bo->parent)
-                       continue;
-
-               ttm_bo_move_to_lru_tail(&bo->tbo, &vm->lru_bulk_move);
-               if (shadow)
-                       ttm_bo_move_to_lru_tail(&shadow->tbo,
-                                               &vm->lru_bulk_move);
-       }
+       ttm_lru_bulk_move_tail(&vm->lru_bulk_move);
        spin_unlock(&adev->mman.bdev.lru_lock);
-
-       vm->bulk_moveable = true;
 }
 
 /**
@@ -728,8 +674,6 @@ int amdgpu_vm_validate_pt_bos(struct amdgpu_device *adev, struct amdgpu_vm *vm,
        struct amdgpu_vm_bo_base *bo_base, *tmp;
        int r;
 
-       vm->bulk_moveable &= list_empty(&vm->evicted);
-
        list_for_each_entry_safe(bo_base, tmp, &vm->evicted, vm_status) {
                struct amdgpu_bo *bo = bo_base->bo;
                struct amdgpu_bo *shadow = amdgpu_bo_shadowed(bo);
@@ -1047,10 +991,16 @@ static void amdgpu_vm_free_table(struct amdgpu_vm_bo_base *entry)
 
        if (!entry->bo)
                return;
+
        shadow = amdgpu_bo_shadowed(entry->bo);
+       if (shadow) {
+               ttm_bo_set_bulk_move(&shadow->tbo, NULL);
+               amdgpu_bo_unref(&shadow);
+       }
+
+       ttm_bo_set_bulk_move(&entry->bo->tbo, NULL);
        entry->bo->vm_bo = NULL;
        list_del(&entry->vm_status);
-       amdgpu_bo_unref(&shadow);
        amdgpu_bo_unref(&entry->bo);
 }
 
@@ -1070,8 +1020,6 @@ static void amdgpu_vm_free_pts(struct amdgpu_device *adev,
        struct amdgpu_vm_pt_cursor cursor;
        struct amdgpu_vm_bo_base *entry;
 
-       vm->bulk_moveable = false;
-
        for_each_amdgpu_vm_pt_dfs_safe(adev, vm, start, cursor, entry)
                amdgpu_vm_free_table(entry);
 
@@ -2651,7 +2599,7 @@ void amdgpu_vm_bo_rmv(struct amdgpu_device *adev,
 
        if (bo) {
                if (bo->tbo.base.resv == vm->root.bo->tbo.base.resv)
-                       vm->bulk_moveable = false;
+                       ttm_bo_set_bulk_move(&bo->tbo, NULL);
 
                for (base = &bo_va->base.bo->vm_bo; *base;
                     base = &(*base)->next) {

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 85fcfb8..4d23668 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -317,8 +317,6 @@ struct amdgpu_vm {
 
        /* Store positions of group of BOs */
        struct ttm_lru_bulk_move lru_bulk_move;
-       /* mark whether can do the bulk move */
-       bool                    bulk_moveable;
        /* Flag to indicate if VM is used for compute */
        bool                    is_compute_context;
 };
@@ -454,7 +452,6 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm);
 
 void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
                                struct amdgpu_vm *vm);
-void amdgpu_vm_del_from_lru_notify(struct ttm_buffer_object *bo);
 void amdgpu_vm_get_memory(struct amdgpu_vm *vm, uint64_t *vram_mem,
                                uint64_t *gtt_mem, uint64_t *cpu_mem);
 

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index 582e8dc..6fc1920 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -849,7 +849,7 @@ void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj)
                        bo->priority = I915_TTM_PRIO_NO_PAGES;
        }
 
-       ttm_bo_move_to_lru_tail(bo, NULL);
+       ttm_bo_move_to_lru_tail(bo);
        spin_unlock(&bo->bdev->lru_lock);
 }
 

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index fe0fa5f..e5fd0f2 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -69,16 +69,55 @@ static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
        }
 }
 
-void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
-                            struct ttm_lru_bulk_move *bulk)
+/**
+ * ttm_bo_move_to_lru_tail
+ *
+ * @bo: The buffer object.
+ *
+ * Move this BO to the tail of all lru lists used to lookup and reserve an
+ * object. This function must be called with struct ttm_global::lru_lock
+ * held, and is used to make a BO less likely to be considered for eviction.
+ */
+void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo)
 {
        dma_resv_assert_held(bo->base.resv);
 
        if (bo->resource)
-               ttm_resource_move_to_lru_tail(bo->resource, bulk);
+               ttm_resource_move_to_lru_tail(bo->resource);
 }
 EXPORT_SYMBOL(ttm_bo_move_to_lru_tail);
 
+/**
+ * ttm_bo_set_bulk_move - update BOs bulk move object
+ *
+ * @bo: The buffer object.
+ *
+ * Update the BOs bulk move object, making sure that resources are added/removed
+ * as well. A bulk move allows to move many resource on the LRU at once,
+ * resulting in much less overhead of maintaining the LRU.
+ * The only requirement is that the resources stay together on the LRU and are
+ * never separated. This is enforces by setting the bulk_move structure on a BO.
+ * ttm_lru_bulk_move_tail() should be used to move all resources to the tail of
+ * their LRU list.
+ */
+void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
+                         struct ttm_lru_bulk_move *bulk)
+{
+       dma_resv_assert_held(bo->base.resv);
+
+       if (bo->bulk_move == bulk)
+               return;
+
+       spin_lock(&bo->bdev->lru_lock);
+       if (bo->bulk_move && bo->resource)
+               ttm_lru_bulk_move_del(bo->bulk_move, bo->resource);
+       bo->bulk_move = bulk;
+       if (bo->bulk_move && bo->resource)
+               ttm_lru_bulk_move_add(bo->bulk_move, bo->resource);
+       spin_unlock(&bo->bdev->lru_lock);
+}
+EXPORT_SYMBOL(ttm_bo_set_bulk_move);
+
 static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
                                  struct ttm_resource *mem, bool evict,
                                  struct ttm_operation_ctx *ctx,
@@ -316,6 +355,7 @@ static void ttm_bo_release(struct kref *kref)
        int ret;
 
        WARN_ON_ONCE(bo->pin_count);
+       WARN_ON_ONCE(bo->bulk_move);
 
        if (!bo->deleted) {
                ret = ttm_bo_individualize_resv(bo);
@@ -352,7 +392,7 @@ static void ttm_bo_release(struct kref *kref)
                 */
                if (bo->pin_count) {
                        bo->pin_count = 0;
-                       ttm_resource_move_to_lru_tail(bo->resource, NULL);
+                       ttm_resource_move_to_lru_tail(bo->resource);
                }
 
                kref_init(&bo->kref);
@@ -644,7 +684,8 @@ void ttm_bo_pin(struct ttm_buffer_object *bo)
 {
        dma_resv_assert_held(bo->base.resv);
        WARN_ON_ONCE(!kref_read(&bo->kref));
-       ++bo->pin_count;
+       if (!(bo->pin_count++) && bo->bulk_move && bo->resource)
+               ttm_lru_bulk_move_del(bo->bulk_move, bo->resource);
 }
 EXPORT_SYMBOL(ttm_bo_pin);
 
@@ -658,10 +699,11 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo)
 {
        dma_resv_assert_held(bo->base.resv);
        WARN_ON_ONCE(!kref_read(&bo->kref));
-       if (bo->pin_count)
-               --bo->pin_count;
-       else
-               WARN_ON_ONCE(true);
+       if (WARN_ON_ONCE(!bo->pin_count))
+               return;
+
+       if (!(--bo->pin_count) && bo->bulk_move && bo->resource)
+               ttm_lru_bulk_move_add(bo->bulk_move, bo->resource);
 }
 EXPORT_SYMBOL(ttm_bo_unpin);
 
@@ -906,6 +948,7 @@ int ttm_bo_init_reserved(struct ttm_device *bdev,
        bo->moving = NULL;
        bo->pin_count = 0;
        bo->sg = sg;
+       bo->bulk_move = NULL;
        if (resv) {
                bo->base.resv = resv;
                dma_resv_assert_held(bo->base.resv);

diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index 19df735..492ba31 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -73,42 +73,77 @@ void ttm_lru_bulk_move_tail(struct ttm_lru_bulk_move *bulk)
 }
 EXPORT_SYMBOL(ttm_lru_bulk_move_tail);
 
-/* Record a resource position in a bulk move structure */
-static void ttm_lru_bulk_move_set_pos(struct ttm_lru_bulk_move_pos *pos,
-                                     struct ttm_resource *res)
+/* Return the bulk move pos object for this resource */
+static struct ttm_lru_bulk_move_pos *
+ttm_lru_bulk_move_pos(struct ttm_lru_bulk_move *bulk, struct ttm_resource *res)
 {
-       if (!pos->first)
+       return &bulk->pos[res->mem_type][res->bo->priority];
+}
+
+/* Move the resource to the tail of the bulk move range */
+static void ttm_lru_bulk_move_pos_tail(struct ttm_lru_bulk_move_pos *pos,
+                                      struct ttm_resource *res)
+{
+       if (pos->last != res) {
+               list_move(&res->lru, &pos->last->lru);
+               pos->last = res;
+       }
+}
+
+/* Add the resource to a bulk_move cursor */
+void ttm_lru_bulk_move_add(struct ttm_lru_bulk_move *bulk,
+                          struct ttm_resource *res)
+{
+       struct ttm_lru_bulk_move_pos *pos = ttm_lru_bulk_move_pos(bulk, res);
+
+       if (!pos->first) {
                pos->first = res;
-       pos->last = res;
+               pos->last = res;
+       } else {
+               ttm_lru_bulk_move_pos_tail(pos, res);
+       }
+}
+
+/* Remove the resource from a bulk_move range */
+void ttm_lru_bulk_move_del(struct ttm_lru_bulk_move *bulk,
+                          struct ttm_resource *res)
+{
+       struct ttm_lru_bulk_move_pos *pos = ttm_lru_bulk_move_pos(bulk, res);
+
+       if (unlikely(pos->first == res && pos->last == res)) {
+               pos->first = NULL;
+               pos->last = NULL;
+       } else if (pos->first == res) {
+               pos->first = list_next_entry(res, lru);
+       } else if (pos->last == res) {
+               pos->last = list_prev_entry(res, lru);
+       } else {
+               list_move(&res->lru, &pos->last->lru);
+       }
 }
 
-/* Move a resource to the LRU tail and track the bulk position */
-void ttm_resource_move_to_lru_tail(struct ttm_resource *res,
-                                  struct ttm_lru_bulk_move *bulk)
+/* Move a resource to the LRU or bulk tail */
+void ttm_resource_move_to_lru_tail(struct ttm_resource *res)
 {
        struct ttm_buffer_object *bo = res->bo;
        struct ttm_device *bdev = bo->bdev;
-       struct ttm_resource_manager *man;
 
        lockdep_assert_held(&bo->bdev->lru_lock);
 
        if (bo->pin_count) {
                list_move_tail(&res->lru, &bdev->pinned);
-               if (bdev->funcs->del_from_lru_notify)
-                       bdev->funcs->del_from_lru_notify(res->bo);
-               return;
-       }
 
-       man = ttm_manager_type(bdev, res->mem_type);
-       list_move_tail(&res->lru, &man->lru[bo->priority]);
+       } else  if (bo->bulk_move) {
+               struct ttm_lru_bulk_move_pos *pos =
+                       ttm_lru_bulk_move_pos(bo->bulk_move, res);
 
-       if (bdev->funcs->del_from_lru_notify)
-               bdev->funcs->del_from_lru_notify(bo);
-
-       if (!bulk)
-               return;
+               ttm_lru_bulk_move_pos_tail(pos, res);
+       } else {
+               struct ttm_resource_manager *man;
 
-       ttm_lru_bulk_move_set_pos(&bulk->pos[res->mem_type][bo->priority], res);
+               man = ttm_manager_type(bdev, res->mem_type);
+               list_move_tail(&res->lru, &man->lru[bo->priority]);
+       }
 }
 
 /**
@@ -139,7 +174,10 @@ void ttm_resource_init(struct ttm_buffer_object *bo,
        man = ttm_manager_type(bo->bdev, place->mem_type);
        spin_lock(&bo->bdev->lru_lock);
        man->usage += res->num_pages << PAGE_SHIFT;
-       ttm_resource_move_to_lru_tail(res, NULL);
+       if (bo->bulk_move)
+               ttm_lru_bulk_move_add(bo->bulk_move, res);
+       else
+               ttm_resource_move_to_lru_tail(res);
        spin_unlock(&bo->bdev->lru_lock);
 }
 EXPORT_SYMBOL(ttm_resource_init);
@@ -161,8 +199,6 @@ void ttm_resource_fini(struct ttm_resource_manager *man,
 
        spin_lock(&bdev->lru_lock);
        list_del_init(&res->lru);
-       if (res->bo && bdev->funcs->del_from_lru_notify)
-               bdev->funcs->del_from_lru_notify(res->bo);
        man->usage -= res->num_pages << PAGE_SHIFT;
        spin_unlock(&bdev->lru_lock);
 }
@@ -185,6 +221,12 @@ void ttm_resource_free(struct ttm_buffer_object *bo, struct ttm_resource **res)
        if (!*res)
                return;
 
+       if (bo->bulk_move) {
+               spin_lock(&bo->bdev->lru_lock);
+               ttm_lru_bulk_move_del(bo->bulk_move, *res);
+               spin_unlock(&bo->bdev->lru_lock);
+       }
+
        man = ttm_manager_type(bo->bdev, (*res)->mem_type);
        man->func->free(man, *res);
        *res = NULL;

diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 885b769..c61e1e5 100644 (file)
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -135,6 +135,7 @@ struct ttm_buffer_object {
        struct ttm_resource *resource;
        struct ttm_tt *ttm;
        bool deleted;
+       struct ttm_lru_bulk_move *bulk_move;
 
        /**
         * Members protected by the bdev::lru_lock.
@@ -287,18 +288,9 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
  */
 void ttm_bo_put(struct ttm_buffer_object *bo);
 
-/**
- * ttm_bo_move_to_lru_tail
- *
- * @bo: The buffer object.
- * @bulk: optional bulk move structure to remember BO positions
- *
- * Move this BO to the tail of all lru lists used to lookup and reserve an
- * object. This function must be called with struct ttm_global::lru_lock
- * held, and is used to make a BO less likely to be considered for eviction.
- */
-void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
-                            struct ttm_lru_bulk_move *bulk);
+void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
+void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
+                         struct ttm_lru_bulk_move *bulk);
 
 /**
  * ttm_bo_lock_delayed_workqueue

diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 6c7352e..059a595 100644 (file)
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -155,7 +155,7 @@ static inline void
 ttm_bo_move_to_lru_tail_unlocked(struct ttm_buffer_object *bo)
 {
        spin_lock(&bo->bdev->lru_lock);
-       ttm_bo_move_to_lru_tail(bo, NULL);
+       ttm_bo_move_to_lru_tail(bo);
        spin_unlock(&bo->bdev->lru_lock);
 }
 

diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
index 425150f..95b3c04 100644 (file)
--- a/include/drm/ttm/ttm_device.h
+++ b/include/drm/ttm/ttm_device.h
@@ -199,15 +199,6 @@ struct ttm_device_funcs {
                             void *buf, int len, int write);
 
        /**
-        * struct ttm_bo_driver member del_from_lru_notify
-        *
-        * @bo: the buffer object deleted from lru
-        *
-        * notify driver that a BO was deleted from LRU.
-        */
-       void (*del_from_lru_notify)(struct ttm_buffer_object *bo);
-
-       /**
         * Notify the driver that we're about to release a BO
         *
         * @bo: BO that is about to be released

diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
index 62e7bb7..4ca960b 100644 (file)
--- a/include/drm/ttm/ttm_resource.h
+++ b/include/drm/ttm/ttm_resource.h
@@ -206,7 +206,7 @@ struct ttm_resource_cursor {
  * @first: first res in the bulk move range
  * @last: last res in the bulk move range
  *
- * Positions for a lru bulk move.
+ * Range of resources for a lru bulk move.
  */
 struct ttm_lru_bulk_move_pos {
        struct ttm_resource *first;
@@ -220,7 +220,7 @@ struct ttm_lru_bulk_move_pos {
  * @vram: first/last lru entry for resources in the VRAM domain
  *
  * Container for the current bulk move state. Should be used with
- * ttm_lru_bulk_move_init() and ttm_bo_move_to_lru_tail().
+ * ttm_lru_bulk_move_init() and ttm_bo_set_bulk_move().
  */
 struct ttm_lru_bulk_move {
        struct ttm_lru_bulk_move_pos pos[TTM_NUM_MEM_TYPES][TTM_MAX_BO_PRIORITY];
@@ -313,10 +313,13 @@ ttm_resource_manager_cleanup(struct ttm_resource_manager *man)
 }
 
 void ttm_lru_bulk_move_init(struct ttm_lru_bulk_move *bulk);
+void ttm_lru_bulk_move_add(struct ttm_lru_bulk_move *bulk,
+                          struct ttm_resource *res);
+void ttm_lru_bulk_move_del(struct ttm_lru_bulk_move *bulk,
+                          struct ttm_resource *res);
 void ttm_lru_bulk_move_tail(struct ttm_lru_bulk_move *bulk);
 
-void ttm_resource_move_to_lru_tail(struct ttm_resource *res,
-                                  struct ttm_lru_bulk_move *bulk);
+void ttm_resource_move_to_lru_tail(struct ttm_resource *res);
 
 void ttm_resource_init(struct ttm_buffer_object *bo,
                        const struct ttm_place *place,