drm/i915: Defer assignment of obj->gtt_space until after all possible mallocs

As we may invoke the shrinker whilst trying to allocate memory to hold
the gtt_space for this object, we need to be careful not to mark the
drm_mm_node as activated (by assigning it to this object) before we
have finished our sequence of allocations.

Note: We also need to move the binding of the object into the actual
pagetables down a bit. The best way seems to be to move it out into
the callsites.

Reported-by: Imre Deak <imre.deak@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Added small note to commit message to summarize review
discussion.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e9c8006..71b5129 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2918,11 +2918,10 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 
  search_free:
        if (map_and_fenceable)
-               free_space =
-                       drm_mm_search_free_in_range_color(&dev_priv->mm.gtt_space,
-                                                         size, alignment, obj->cache_level,
-                                                         0, dev_priv->mm.gtt_mappable_end,
-                                                         false);
+               free_space = drm_mm_search_free_in_range_color(&dev_priv->mm.gtt_space,
+                                                              size, alignment, obj->cache_level,
+                                                              0, dev_priv->mm.gtt_mappable_end,
+                                                              false);
        else
                free_space = drm_mm_search_free_color(&dev_priv->mm.gtt_space,
                                                      size, alignment, obj->cache_level,
@@ -2930,18 +2929,18 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 
        if (free_space != NULL) {
                if (map_and_fenceable)
-                       obj->gtt_space =
+                       free_space =
                                drm_mm_get_block_range_generic(free_space,
                                                               size, alignment, obj->cache_level,
                                                               0, dev_priv->mm.gtt_mappable_end,
                                                               false);
                else
-                       obj->gtt_space =
+                       free_space =
                                drm_mm_get_block_generic(free_space,
                                                         size, alignment, obj->cache_level,
                                                         false);
        }
-       if (obj->gtt_space == NULL) {
+       if (free_space == NULL) {
                ret = i915_gem_evict_something(dev, size, alignment,
                                               obj->cache_level,
                                               map_and_fenceable,
@@ -2954,34 +2953,29 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
                goto search_free;
        }
        if (WARN_ON(!i915_gem_valid_gtt_space(dev,
-                                             obj->gtt_space,
+                                             free_space,
                                              obj->cache_level))) {
                i915_gem_object_unpin_pages(obj);
-               drm_mm_put_block(obj->gtt_space);
-               obj->gtt_space = NULL;
+               drm_mm_put_block(free_space);
                return -EINVAL;
        }
 
-
        ret = i915_gem_gtt_prepare_object(obj);
        if (ret) {
                i915_gem_object_unpin_pages(obj);
-               drm_mm_put_block(obj->gtt_space);
-               obj->gtt_space = NULL;
+               drm_mm_put_block(free_space);
                return ret;
        }
 
-       if (!dev_priv->mm.aliasing_ppgtt)
-               i915_gem_gtt_bind_object(obj, obj->cache_level);
-
        list_move_tail(&obj->gtt_list, &dev_priv->mm.bound_list);
        list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 
-       obj->gtt_offset = obj->gtt_space->start;
+       obj->gtt_space = free_space;
+       obj->gtt_offset = free_space->start;
 
        fenceable =
-               obj->gtt_space->size == fence_size &&
-               (obj->gtt_space->start & (fence_alignment - 1)) == 0;
+               free_space->size == fence_size &&
+               (free_space->start & (fence_alignment - 1)) == 0;
 
        mappable =
                obj->gtt_offset + obj->base.size <= dev_priv->mm.gtt_mappable_end;
@@ -3452,11 +3446,16 @@ i915_gem_object_pin(struct drm_i915_gem_object *obj,
        }
 
        if (obj->gtt_space == NULL) {
+               struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
+
                ret = i915_gem_object_bind_to_gtt(obj, alignment,
                                                  map_and_fenceable,
                                                  nonblocking);
                if (ret)
                        return ret;
+
+               if (!dev_priv->mm.aliasing_ppgtt)
+                       i915_gem_gtt_bind_object(obj, obj->cache_level);
        }
 
        if (!obj->has_global_gtt_mapping && map_and_fenceable)