drm/i915: Extract i915_gem_shrinker.c

Two code changes:
- Extract i915_gem_shrinker_init.
- Inline i915_gem_object_is_purgeable since we open-code it everywhere
  else too.

This already has the benefit of pulling all the shrinker code
together, next patch adds a bit of kerneldoc.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

4 files changed, 306 insertions, 277 deletions

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index d3ebaf204408..a69002e2257d 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -28,6 +28,7 @@ i915-y += i915_cmd_parser.o \
 	  i915_gem_execbuffer.o \
 	  i915_gem_gtt.o \
 	  i915_gem.o \
+	  i915_gem_shrinker.o \
 	  i915_gem_stolen.o \
 	  i915_gem_tiling.o \
 	  i915_gem_userptr.o \
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b156bc30c9c9..eb38cd1ef216 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2600,12 +2600,6 @@ int i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
 int i915_gem_wait_ioctl(struct drm_device *dev, void *data,
 			struct drm_file *file_priv);
 void i915_gem_load(struct drm_device *dev);
-unsigned long i915_gem_shrink(struct drm_i915_private *dev_priv,
-			      long target,
-			      unsigned flags);
-#define I915_SHRINK_PURGEABLE 0x1
-#define I915_SHRINK_UNBOUND 0x2
-#define I915_SHRINK_BOUND 0x4
 void *i915_gem_object_alloc(struct drm_device *dev);
 void i915_gem_object_free(struct drm_i915_gem_object *obj);
 void i915_gem_object_init(struct drm_i915_gem_object *obj,
@@ -2953,6 +2947,17 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 					       u32 gtt_offset,
 					       u32 size);
 
+/* i915_gem_shrinker.c */
+unsigned long i915_gem_shrink(struct drm_i915_private *dev_priv,
+			      long target,
+			      unsigned flags);
+#define I915_SHRINK_PURGEABLE 0x1
+#define I915_SHRINK_UNBOUND 0x2
+#define I915_SHRINK_BOUND 0x4
+unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv);
+void i915_gem_shrinker_init(struct drm_i915_private *dev_priv);
+
+
 /* i915_gem_tiling.c */
 static inline bool i915_gem_object_needs_bit17_swizzle(struct drm_i915_gem_object *obj)
 {
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 979dc42b72f0..092f25cfb8d5 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1,5 +1,5 @@
 /*
- * Copyright © 2008 Intel Corporation
+ * Copyright © 2008-2015 Intel Corporation
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -32,7 +32,6 @@
 #include "i915_vgpu.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
-#include <linux/oom.h>
 #include <linux/shmem_fs.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
@@ -53,15 +52,6 @@ static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
 					 struct drm_i915_fence_reg *fence,
 					 bool enable);
 
-static unsigned long i915_gem_shrinker_count(struct shrinker *shrinker,
-					     struct shrink_control *sc);
-static unsigned long i915_gem_shrinker_scan(struct shrinker *shrinker,
-					    struct shrink_control *sc);
-static int i915_gem_shrinker_oom(struct notifier_block *nb,
-				 unsigned long event,
-				 void *ptr);
-static unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv);
-
 static bool cpu_cache_is_coherent(struct drm_device *dev,
 				  enum i915_cache_level level)
 {
@@ -1936,12 +1926,6 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
 	return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);
 }
 
-static inline int
-i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj)
-{
-	return obj->madv == I915_MADV_DONTNEED;
-}
-
 /* Immediately discard the backing storage */
 static void
 i915_gem_object_truncate(struct drm_i915_gem_object *obj)
@@ -2047,85 +2031,6 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
 	return 0;
 }
 
-unsigned long
-i915_gem_shrink(struct drm_i915_private *dev_priv,
-		long target, unsigned flags)
-{
-	const struct {
-		struct list_head *list;
-		unsigned int bit;
-	} phases[] = {
-		{ &dev_priv->mm.unbound_list, I915_SHRINK_UNBOUND },
-		{ &dev_priv->mm.bound_list, I915_SHRINK_BOUND },
-		{ NULL, 0 },
-	}, *phase;
-	unsigned long count = 0;
-
-	/*
-	 * As we may completely rewrite the (un)bound list whilst unbinding
-	 * (due to retiring requests) we have to strictly process only
-	 * one element of the list at the time, and recheck the list
-	 * on every iteration.
-	 *
-	 * In particular, we must hold a reference whilst removing the
-	 * object as we may end up waiting for and/or retiring the objects.
-	 * This might release the final reference (held by the active list)
-	 * and result in the object being freed from under us. This is
-	 * similar to the precautions the eviction code must take whilst
-	 * removing objects.
-	 *
-	 * Also note that although these lists do not hold a reference to
-	 * the object we can safely grab one here: The final object
-	 * unreferencing and the bound_list are both protected by the
-	 * dev->struct_mutex and so we won't ever be able to observe an
-	 * object on the bound_list with a reference count equals 0.
-	 */
-	for (phase = phases; phase->list; phase++) {
-		struct list_head still_in_list;
-
-		if ((flags & phase->bit) == 0)
-			continue;
-
-		INIT_LIST_HEAD(&still_in_list);
-		while (count < target && !list_empty(phase->list)) {
-			struct drm_i915_gem_object *obj;
-			struct i915_vma *vma, *v;
-
-			obj = list_first_entry(phase->list,
-					       typeof(*obj), global_list);
-			list_move_tail(&obj->global_list, &still_in_list);
-
-			if (flags & I915_SHRINK_PURGEABLE &&
-			    !i915_gem_object_is_purgeable(obj))
-				continue;
-
-			drm_gem_object_reference(&obj->base);
-
-			/* For the unbound phase, this should be a no-op! */
-			list_for_each_entry_safe(vma, v,
-						 &obj->vma_list, vma_link)
-				if (i915_vma_unbind(vma))
-					break;
-
-			if (i915_gem_object_put_pages(obj) == 0)
-				count += obj->base.size >> PAGE_SHIFT;
-
-			drm_gem_object_unreference(&obj->base);
-		}
-		list_splice(&still_in_list, phase->list);
-	}
-
-	return count;
-}
-
-static unsigned long
-i915_gem_shrink_all(struct drm_i915_private *dev_priv)
-{
-	i915_gem_evict_everything(dev_priv->dev);
-	return i915_gem_shrink(dev_priv, LONG_MAX,
-			       I915_SHRINK_BOUND | I915_SHRINK_UNBOUND);
-}
-
 static int
 i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 {
@@ -4425,7 +4330,7 @@ i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
 		obj->madv = args->madv;
 
 	/* if the object is no longer attached, discard its backing storage */
-	if (i915_gem_object_is_purgeable(obj) && obj->pages == NULL)
+	if (obj->madv == I915_MADV_DONTNEED && obj->pages == NULL)
 		i915_gem_object_truncate(obj);
 
 	args->retained = obj->madv != __I915_MADV_PURGED;
@@ -5064,13 +4969,7 @@ i915_gem_load(struct drm_device *dev)
 
 	dev_priv->mm.interruptible = true;
 
-	dev_priv->mm.shrinker.scan_objects = i915_gem_shrinker_scan;
-	dev_priv->mm.shrinker.count_objects = i915_gem_shrinker_count;
-	dev_priv->mm.shrinker.seeks = DEFAULT_SEEKS;
-	register_shrinker(&dev_priv->mm.shrinker);
-
-	dev_priv->mm.oom_notifier.notifier_call = i915_gem_shrinker_oom;
-	register_oom_notifier(&dev_priv->mm.oom_notifier);
+	i915_gem_shrinker_init(dev_priv);
 
 	i915_gem_batch_pool_init(dev, &dev_priv->mm.batch_pool);
 
@@ -5162,77 +5061,6 @@ void i915_gem_track_fb(struct drm_i915_gem_object *old,
 	}
 }
 
-static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
-{
-	if (!mutex_is_locked(mutex))
-		return false;
-
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES)
-	return mutex->owner == task;
-#else
-	/* Since UP may be pre-empted, we cannot assume that we own the lock */
-	return false;
-#endif
-}
-
-static bool i915_gem_shrinker_lock(struct drm_device *dev, bool *unlock)
-{
-	if (!mutex_trylock(&dev->struct_mutex)) {
-		if (!mutex_is_locked_by(&dev->struct_mutex, current))
-			return false;
-
-		if (to_i915(dev)->mm.shrinker_no_lock_stealing)
-			return false;
-
-		*unlock = false;
-	} else
-		*unlock = true;
-
-	return true;
-}
-
-static int num_vma_bound(struct drm_i915_gem_object *obj)
-{
-	struct i915_vma *vma;
-	int count = 0;
-
-	list_for_each_entry(vma, &obj->vma_list, vma_link)
-		if (drm_mm_node_allocated(&vma->node))
-			count++;
-
-	return count;
-}
-
-static unsigned long
-i915_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
-{
-	struct drm_i915_private *dev_priv =
-		container_of(shrinker, struct drm_i915_private, mm.shrinker);
-	struct drm_device *dev = dev_priv->dev;
-	struct drm_i915_gem_object *obj;
-	unsigned long count;
-	bool unlock;
-
-	if (!i915_gem_shrinker_lock(dev, &unlock))
-		return 0;
-
-	count = 0;
-	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list)
-		if (obj->pages_pin_count == 0)
-			count += obj->base.size >> PAGE_SHIFT;
-
-	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
-		if (!i915_gem_obj_is_pinned(obj) &&
-		    obj->pages_pin_count == num_vma_bound(obj))
-			count += obj->base.size >> PAGE_SHIFT;
-	}
-
-	if (unlock)
-		mutex_unlock(&dev->struct_mutex);
-
-	return count;
-}
-
 /* All the new VM stuff */
 unsigned long
 i915_gem_obj_offset(struct drm_i915_gem_object *o,
@@ -5333,102 +5161,6 @@ unsigned long i915_gem_obj_size(struct drm_i915_gem_object *o,
 	return 0;
 }
 
-static unsigned long
-i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
-{
-	struct drm_i915_private *dev_priv =
-		container_of(shrinker, struct drm_i915_private, mm.shrinker);
-	struct drm_device *dev = dev_priv->dev;
-	unsigned long freed;
-	bool unlock;
-
-	if (!i915_gem_shrinker_lock(dev, &unlock))
-		return SHRINK_STOP;
-
-	freed = i915_gem_shrink(dev_priv,
-				sc->nr_to_scan,
-				I915_SHRINK_BOUND |
-				I915_SHRINK_UNBOUND |
-				I915_SHRINK_PURGEABLE);
-	if (freed < sc->nr_to_scan)
-		freed += i915_gem_shrink(dev_priv,
-					 sc->nr_to_scan - freed,
-					 I915_SHRINK_BOUND |
-					 I915_SHRINK_UNBOUND);
-	if (unlock)
-		mutex_unlock(&dev->struct_mutex);
-
-	return freed;
-}
-
-static int
-i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
-{
-	struct drm_i915_private *dev_priv =
-		container_of(nb, struct drm_i915_private, mm.oom_notifier);
-	struct drm_device *dev = dev_priv->dev;
-	struct drm_i915_gem_object *obj;
-	unsigned long timeout = msecs_to_jiffies(5000) + 1;
-	unsigned long pinned, bound, unbound, freed_pages;
-	bool was_interruptible;
-	bool unlock;
-
-	while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) {
-		schedule_timeout_killable(1);
-		if (fatal_signal_pending(current))
-			return NOTIFY_DONE;
-	}
-	if (timeout == 0) {
-		pr_err("Unable to purge GPU memory due lock contention.\n");
-		return NOTIFY_DONE;
-	}
-
-	was_interruptible = dev_priv->mm.interruptible;
-	dev_priv->mm.interruptible = false;
-
-	freed_pages = i915_gem_shrink_all(dev_priv);
-
-	dev_priv->mm.interruptible = was_interruptible;
-
-	/* Because we may be allocating inside our own driver, we cannot
-	 * assert that there are no objects with pinned pages that are not
-	 * being pointed to by hardware.
-	 */
-	unbound = bound = pinned = 0;
-	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) {
-		if (!obj->base.filp) /* not backed by a freeable object */
-			continue;
-
-		if (obj->pages_pin_count)
-			pinned += obj->base.size;
-		else
-			unbound += obj->base.size;
-	}
-	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
-		if (!obj->base.filp)
-			continue;
-
-		if (obj->pages_pin_count)
-			pinned += obj->base.size;
-		else
-			bound += obj->base.size;
-	}
-
-	if (unlock)
-		mutex_unlock(&dev->struct_mutex);
-
-	if (freed_pages || unbound || bound)
-		pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n",
-			freed_pages << PAGE_SHIFT, pinned);
-	if (unbound || bound)
-		pr_err("%lu and %lu bytes still available in the "
-		       "bound and unbound GPU page lists.\n",
-		       bound, unbound);
-
-	*(unsigned long *)ptr += freed_pages;
-	return NOTIFY_DONE;
-}
-
 bool i915_gem_obj_is_pinned(struct drm_i915_gem_object *obj)
 {
 	struct i915_vma *vma;
diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
new file mode 100644
index 000000000000..9ac78b3d6899
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -0,0 +1,291 @@
+/*
+ * Copyright © 2008-2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/oom.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/pci.h>
+#include <linux/dma-buf.h>
+#include <drm/drmP.h>
+#include <drm/i915_drm.h>
+
+#include "i915_drv.h"
+#include "i915_trace.h"
+
+static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
+{
+	if (!mutex_is_locked(mutex))
+		return false;
+
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES)
+	return mutex->owner == task;
+#else
+	/* Since UP may be pre-empted, we cannot assume that we own the lock */
+	return false;
+#endif
+}
+
+unsigned long
+i915_gem_shrink(struct drm_i915_private *dev_priv,
+		long target, unsigned flags)
+{
+	const struct {
+		struct list_head *list;
+		unsigned int bit;
+	} phases[] = {
+		{ &dev_priv->mm.unbound_list, I915_SHRINK_UNBOUND },
+		{ &dev_priv->mm.bound_list, I915_SHRINK_BOUND },
+		{ NULL, 0 },
+	}, *phase;
+	unsigned long count = 0;
+
+	/*
+	 * As we may completely rewrite the (un)bound list whilst unbinding
+	 * (due to retiring requests) we have to strictly process only
+	 * one element of the list at the time, and recheck the list
+	 * on every iteration.
+	 *
+	 * In particular, we must hold a reference whilst removing the
+	 * object as we may end up waiting for and/or retiring the objects.
+	 * This might release the final reference (held by the active list)
+	 * and result in the object being freed from under us. This is
+	 * similar to the precautions the eviction code must take whilst
+	 * removing objects.
+	 *
+	 * Also note that although these lists do not hold a reference to
+	 * the object we can safely grab one here: The final object
+	 * unreferencing and the bound_list are both protected by the
+	 * dev->struct_mutex and so we won't ever be able to observe an
+	 * object on the bound_list with a reference count equals 0.
+	 */
+	for (phase = phases; phase->list; phase++) {
+		struct list_head still_in_list;
+
+		if ((flags & phase->bit) == 0)
+			continue;
+
+		INIT_LIST_HEAD(&still_in_list);
+		while (count < target && !list_empty(phase->list)) {
+			struct drm_i915_gem_object *obj;
+			struct i915_vma *vma, *v;
+
+			obj = list_first_entry(phase->list,
+					       typeof(*obj), global_list);
+			list_move_tail(&obj->global_list, &still_in_list);
+
+			if (flags & I915_SHRINK_PURGEABLE &&
+			    obj->madv != I915_MADV_DONTNEED)
+				continue;
+
+			drm_gem_object_reference(&obj->base);
+
+			/* For the unbound phase, this should be a no-op! */
+			list_for_each_entry_safe(vma, v,
+						 &obj->vma_list, vma_link)
+				if (i915_vma_unbind(vma))
+					break;
+
+			if (i915_gem_object_put_pages(obj) == 0)
+				count += obj->base.size >> PAGE_SHIFT;
+
+			drm_gem_object_unreference(&obj->base);
+		}
+		list_splice(&still_in_list, phase->list);
+	}
+
+	return count;
+}
+
+unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv)
+{
+	i915_gem_evict_everything(dev_priv->dev);
+	return i915_gem_shrink(dev_priv, LONG_MAX,
+			       I915_SHRINK_BOUND | I915_SHRINK_UNBOUND);
+}
+
+static bool i915_gem_shrinker_lock(struct drm_device *dev, bool *unlock)
+{
+	if (!mutex_trylock(&dev->struct_mutex)) {
+		if (!mutex_is_locked_by(&dev->struct_mutex, current))
+			return false;
+
+		if (to_i915(dev)->mm.shrinker_no_lock_stealing)
+			return false;
+
+		*unlock = false;
+	} else
+		*unlock = true;
+
+	return true;
+}
+
+static int num_vma_bound(struct drm_i915_gem_object *obj)
+{
+	struct i915_vma *vma;
+	int count = 0;
+
+	list_for_each_entry(vma, &obj->vma_list, vma_link)
+		if (drm_mm_node_allocated(&vma->node))
+			count++;
+
+	return count;
+}
+
+static unsigned long
+i915_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
+{
+	struct drm_i915_private *dev_priv =
+		container_of(shrinker, struct drm_i915_private, mm.shrinker);
+	struct drm_device *dev = dev_priv->dev;
+	struct drm_i915_gem_object *obj;
+	unsigned long count;
+	bool unlock;
+
+	if (!i915_gem_shrinker_lock(dev, &unlock))
+		return 0;
+
+	count = 0;
+	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list)
+		if (obj->pages_pin_count == 0)
+			count += obj->base.size >> PAGE_SHIFT;
+
+	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
+		if (!i915_gem_obj_is_pinned(obj) &&
+		    obj->pages_pin_count == num_vma_bound(obj))
+			count += obj->base.size >> PAGE_SHIFT;
+	}
+
+	if (unlock)
+		mutex_unlock(&dev->struct_mutex);
+
+	return count;
+}
+
+static unsigned long
+i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
+{
+	struct drm_i915_private *dev_priv =
+		container_of(shrinker, struct drm_i915_private, mm.shrinker);
+	struct drm_device *dev = dev_priv->dev;
+	unsigned long freed;
+	bool unlock;
+
+	if (!i915_gem_shrinker_lock(dev, &unlock))
+		return SHRINK_STOP;
+
+	freed = i915_gem_shrink(dev_priv,
+				sc->nr_to_scan,
+				I915_SHRINK_BOUND |
+				I915_SHRINK_UNBOUND |
+				I915_SHRINK_PURGEABLE);
+	if (freed < sc->nr_to_scan)
+		freed += i915_gem_shrink(dev_priv,
+					 sc->nr_to_scan - freed,
+					 I915_SHRINK_BOUND |
+					 I915_SHRINK_UNBOUND);
+	if (unlock)
+		mutex_unlock(&dev->struct_mutex);
+
+	return freed;
+}
+
+static int
+i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
+{
+	struct drm_i915_private *dev_priv =
+		container_of(nb, struct drm_i915_private, mm.oom_notifier);
+	struct drm_device *dev = dev_priv->dev;
+	struct drm_i915_gem_object *obj;
+	unsigned long timeout = msecs_to_jiffies(5000) + 1;
+	unsigned long pinned, bound, unbound, freed_pages;
+	bool was_interruptible;
+	bool unlock;
+
+	while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) {
+		schedule_timeout_killable(1);
+		if (fatal_signal_pending(current))
+			return NOTIFY_DONE;
+	}
+	if (timeout == 0) {
+		pr_err("Unable to purge GPU memory due lock contention.\n");
+		return NOTIFY_DONE;
+	}
+
+	was_interruptible = dev_priv->mm.interruptible;
+	dev_priv->mm.interruptible = false;
+
+	freed_pages = i915_gem_shrink_all(dev_priv);
+
+	dev_priv->mm.interruptible = was_interruptible;
+
+	/* Because we may be allocating inside our own driver, we cannot
+	 * assert that there are no objects with pinned pages that are not
+	 * being pointed to by hardware.
+	 */
+	unbound = bound = pinned = 0;
+	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) {
+		if (!obj->base.filp) /* not backed by a freeable object */
+			continue;
+
+		if (obj->pages_pin_count)
+			pinned += obj->base.size;
+		else
+			unbound += obj->base.size;
+	}
+	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
+		if (!obj->base.filp)
+			continue;
+
+		if (obj->pages_pin_count)
+			pinned += obj->base.size;
+		else
+			bound += obj->base.size;
+	}
+
+	if (unlock)
+		mutex_unlock(&dev->struct_mutex);
+
+	if (freed_pages || unbound || bound)
+		pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n",
+			freed_pages << PAGE_SHIFT, pinned);
+	if (unbound || bound)
+		pr_err("%lu and %lu bytes still available in the "
+		       "bound and unbound GPU page lists.\n",
+		       bound, unbound);
+
+	*(unsigned long *)ptr += freed_pages;
+	return NOTIFY_DONE;
+}
+
+void i915_gem_shrinker_init(struct drm_i915_private *dev_priv)
+{
+	dev_priv->mm.shrinker.scan_objects = i915_gem_shrinker_scan;
+	dev_priv->mm.shrinker.count_objects = i915_gem_shrinker_count;
+	dev_priv->mm.shrinker.seeks = DEFAULT_SEEKS;
+	register_shrinker(&dev_priv->mm.shrinker);
+
+	dev_priv->mm.oom_notifier.notifier_call = i915_gem_shrinker_oom;
+	register_oom_notifier(&dev_priv->mm.oom_notifier);
+}