drm/i915: Introduce drm_i915_gem_object_ops
In order to specialise functions depending upon the type of object, we
can attach vfuncs to each object via a new ->ops pointer.
For instance, this will be used in future patches to only bind pages from
a dma-buf for the duration that the object is used by the GPU - and so
prevent them from pinning those pages for the entire of the object.
v2: Bonus comments.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 26c6959..ada8ea1 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -899,9 +899,29 @@
I915_CACHE_LLC_MLC, /* gen6+, in docs at least! */
};
+struct drm_i915_gem_object_ops {
+ /* Interface between the GEM object and its backing storage.
+ * get_pages() is called once prior to the use of the associated set
+ * of pages before to binding them into the GTT, and put_pages() is
+ * called after we no longer need them. As we expect there to be
+ * associated cost with migrating pages between the backing storage
+ * and making them available for the GPU (e.g. clflush), we may hold
+ * onto the pages after they are no longer referenced by the GPU
+ * in case they may be used again shortly (for example migrating the
+ * pages to a different memory domain within the GTT). put_pages()
+ * will therefore most likely be called when the object itself is
+ * being released or under memory pressure (where we attempt to
+ * reap pages for the shrinker).
+ */
+ int (*get_pages)(struct drm_i915_gem_object *);
+ void (*put_pages)(struct drm_i915_gem_object *);
+};
+
struct drm_i915_gem_object {
struct drm_gem_object base;
+ const struct drm_i915_gem_object_ops *ops;
+
/** Current space allocated to this object in the GTT, if any. */
struct drm_mm_node *gtt_space;
struct list_head gtt_list;
@@ -1306,7 +1326,8 @@
struct drm_file *file_priv);
void i915_gem_load(struct drm_device *dev);
int i915_gem_init_object(struct drm_gem_object *obj);
-void i915_gem_object_init(struct drm_i915_gem_object *obj);
+void i915_gem_object_init(struct drm_i915_gem_object *obj,
+ const struct drm_i915_gem_object_ops *ops);
struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
size_t size);
void i915_gem_free_object(struct drm_gem_object *obj);
@@ -1319,7 +1340,7 @@
void i915_gem_release_mmap(struct drm_i915_gem_object *obj);
void i915_gem_lastclose(struct drm_device *dev);
-int __must_check i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj);
+int __must_check i915_gem_object_get_pages(struct drm_i915_gem_object *obj);
int __must_check i915_mutex_lock_interruptible(struct drm_device *dev);
int i915_gem_object_sync(struct drm_i915_gem_object *obj,
struct intel_ring_buffer *to);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 87a64e5..4b2ee7c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1650,18 +1650,12 @@
return obj->madv == I915_MADV_DONTNEED;
}
-static int
+static void
i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
{
int page_count = obj->base.size / PAGE_SIZE;
int ret, i;
- BUG_ON(obj->gtt_space);
-
- if (obj->pages == NULL)
- return 0;
-
- BUG_ON(obj->gtt_space);
BUG_ON(obj->madv == __I915_MADV_PURGED);
ret = i915_gem_object_set_to_cpu_domain(obj, true);
@@ -1693,9 +1687,21 @@
drm_free_large(obj->pages);
obj->pages = NULL;
+}
+
+static int
+i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
+{
+ const struct drm_i915_gem_object_ops *ops = obj->ops;
+
+ if (obj->sg_table || obj->pages == NULL)
+ return 0;
+
+ BUG_ON(obj->gtt_space);
+
+ ops->put_pages(obj);
list_del(&obj->gtt_list);
-
if (i915_gem_object_is_purgeable(obj))
i915_gem_object_truncate(obj);
@@ -1712,7 +1718,7 @@
&dev_priv->mm.unbound_list,
gtt_list) {
if (i915_gem_object_is_purgeable(obj) &&
- i915_gem_object_put_pages_gtt(obj) == 0) {
+ i915_gem_object_put_pages(obj) == 0) {
count += obj->base.size >> PAGE_SHIFT;
if (count >= target)
return count;
@@ -1724,7 +1730,7 @@
mm_list) {
if (i915_gem_object_is_purgeable(obj) &&
i915_gem_object_unbind(obj) == 0 &&
- i915_gem_object_put_pages_gtt(obj) == 0) {
+ i915_gem_object_put_pages(obj) == 0) {
count += obj->base.size >> PAGE_SHIFT;
if (count >= target)
return count;
@@ -1742,10 +1748,10 @@
i915_gem_evict_everything(dev_priv->dev);
list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list, gtt_list)
- i915_gem_object_put_pages_gtt(obj);
+ i915_gem_object_put_pages(obj);
}
-int
+static int
i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
@@ -1754,9 +1760,6 @@
struct page *page;
gfp_t gfp;
- if (obj->pages || obj->sg_table)
- return 0;
-
/* Assert that the object is not currently in any GPU domain. As it
* wasn't in the GTT, there shouldn't be any way it could have been in
* a GPU cache
@@ -1806,7 +1809,6 @@
if (i915_gem_object_needs_bit17_swizzle(obj))
i915_gem_object_do_bit_17_swizzle(obj);
- list_add_tail(&obj->gtt_list, &dev_priv->mm.unbound_list);
return 0;
err_pages:
@@ -1818,6 +1820,31 @@
return PTR_ERR(page);
}
+/* Ensure that the associated pages are gathered from the backing storage
+ * and pinned into our object. i915_gem_object_get_pages() may be called
+ * multiple times before they are released by a single call to
+ * i915_gem_object_put_pages() - once the pages are no longer referenced
+ * either as a result of memory pressure (reaping pages under the shrinker)
+ * or as the object is itself released.
+ */
+int
+i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
+{
+ struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
+ const struct drm_i915_gem_object_ops *ops = obj->ops;
+ int ret;
+
+ if (obj->sg_table || obj->pages)
+ return 0;
+
+ ret = ops->get_pages(obj);
+ if (ret)
+ return ret;
+
+ list_add_tail(&obj->gtt_list, &dev_priv->mm.unbound_list);
+ return 0;
+}
+
void
i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
struct intel_ring_buffer *ring,
@@ -2071,7 +2098,6 @@
obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
}
-
/* The fence registers are invalidated so clear them out */
i915_gem_reset_fences(dev);
}
@@ -2871,7 +2897,7 @@
return -E2BIG;
}
- ret = i915_gem_object_get_pages_gtt(obj);
+ ret = i915_gem_object_get_pages(obj);
if (ret)
return ret;
@@ -3610,15 +3636,16 @@
return ret;
}
-void i915_gem_object_init(struct drm_i915_gem_object *obj)
+void i915_gem_object_init(struct drm_i915_gem_object *obj,
+ const struct drm_i915_gem_object_ops *ops)
{
- obj->base.driver_private = NULL;
-
INIT_LIST_HEAD(&obj->mm_list);
INIT_LIST_HEAD(&obj->gtt_list);
INIT_LIST_HEAD(&obj->ring_list);
INIT_LIST_HEAD(&obj->exec_list);
+ obj->ops = ops;
+
obj->fence_reg = I915_FENCE_REG_NONE;
obj->madv = I915_MADV_WILLNEED;
/* Avoid an unnecessary call to unbind on the first bind. */
@@ -3627,6 +3654,11 @@
i915_gem_info_add_obj(obj->base.dev->dev_private, obj->base.size);
}
+static const struct drm_i915_gem_object_ops i915_gem_object_ops = {
+ .get_pages = i915_gem_object_get_pages_gtt,
+ .put_pages = i915_gem_object_put_pages_gtt,
+};
+
struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
size_t size)
{
@@ -3653,7 +3685,7 @@
mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
mapping_set_gfp_mask(mapping, mask);
- i915_gem_object_init(obj);
+ i915_gem_object_init(obj, &i915_gem_object_ops);
obj->base.write_domain = I915_GEM_DOMAIN_CPU;
obj->base.read_domains = I915_GEM_DOMAIN_CPU;
@@ -3711,7 +3743,7 @@
dev_priv->mm.interruptible = was_interruptible;
}
- i915_gem_object_put_pages_gtt(obj);
+ i915_gem_object_put_pages(obj);
i915_gem_object_free_mmap_offset(obj);
drm_gem_object_release(&obj->base);
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 43c9530..e4f1141 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -41,7 +41,7 @@
if (ret)
return ERR_PTR(ret);
- ret = i915_gem_object_get_pages_gtt(obj);
+ ret = i915_gem_object_get_pages(obj);
if (ret) {
sg = ERR_PTR(ret);
goto out;
@@ -89,7 +89,7 @@
goto out_unlock;
}
- ret = i915_gem_object_get_pages_gtt(obj);
+ ret = i915_gem_object_get_pages(obj);
if (ret) {
mutex_unlock(&dev->struct_mutex);
return ERR_PTR(ret);