[deliverable/linux.git] / drivers / gpu / drm / i915 / i915_gem_shrinker.c

/*
 * 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
}

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++;
		if (vma->pin_count)
			count++;
	}

	return count;
}

static bool swap_available(void)
{
	return get_nr_swap_pages() > 0;
}

static bool can_release_pages(struct drm_i915_gem_object *obj)
{
	/* Only report true if by unbinding the object and putting its pages
	 * we can actually make forward progress towards freeing physical
	 * pages.
	 *
	 * If the pages are pinned for any other reason than being bound
	 * to the GPU, simply unbinding from the GPU is not going to succeed
	 * in releasing our pin count on the pages themselves.
	 */
	if (obj->pages_pin_count != num_vma_bound(obj))
		return false;

	/* We can only return physical pages to the system if we can either
	 * discard the contents (because the user has marked them as being
	 * purgeable) or if we can move their contents out to swap.
	 */
	return swap_available() || obj->madv == I915_MADV_DONTNEED;
}

/**
 * i915_gem_shrink - Shrink buffer object caches
 * @dev_priv: i915 device
 * @target: amount of memory to make available, in pages
 * @flags: control flags for selecting cache types
 *
 * This function is the main interface to the shrinker. It will try to release
 * up to @target pages of main memory backing storage from buffer objects.
 * Selection of the specific caches can be done with @flags. This is e.g. useful
 * when purgeable objects should be removed from caches preferentially.
 *
 * Note that it's not guaranteed that released amount is actually available as
 * free system memory - the pages might still be in-used to due to other reasons
 * (like cpu mmaps) or the mm core has reused them before we could grab them.
 * Therefore code that needs to explicitly shrink buffer objects caches (e.g. to
 * avoid deadlocks in memory reclaim) must fall back to i915_gem_shrink_all().
 *
 * Also note that any kind of pinning (both per-vma address space pins and
 * backing storage pins at the buffer object level) result in the shrinker code
 * having to skip the object.
 *
 * Returns:
 * The number of pages of backing storage actually released.
 */
unsigned long
i915_gem_shrink(struct drm_i915_private *dev_priv,
		unsigned 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;

	trace_i915_gem_shrink(dev_priv, target, flags);
	i915_gem_retire_requests(dev_priv->dev);

	/*
	 * 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;

			if ((flags & I915_SHRINK_ACTIVE) == 0 && obj->active)
				continue;

			if (!can_release_pages(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);
	}

	i915_gem_retire_requests(dev_priv->dev);

	return count;
}

/**
 * i915_gem_shrink_all - Shrink buffer object caches completely
 * @dev_priv: i915 device
 *
 * This is a simple wraper around i915_gem_shrink() to aggressively shrink all
 * caches completely. It also first waits for and retires all outstanding
 * requests to also be able to release backing storage for active objects.
 *
 * This should only be used in code to intentionally quiescent the gpu or as a
 * last-ditch effort when memory seems to have run out.
 *
 * Returns:
 * The number of pages of backing storage actually released.
 */
unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv)
{
	return i915_gem_shrink(dev_priv, -1UL,
			       I915_SHRINK_BOUND |
			       I915_SHRINK_UNBOUND |
			       I915_SHRINK_ACTIVE);
}

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 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 (!obj->active && can_release_pages(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;
}

/**
 * i915_gem_shrinker_init - Initialize i915 shrinker
 * @dev_priv: i915 device
 *
 * This function registers and sets up the i915 shrinker and OOM handler.
 */
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;
	WARN_ON(register_shrinker(&dev_priv->mm.shrinker));

	dev_priv->mm.oom_notifier.notifier_call = i915_gem_shrinker_oom;
	WARN_ON(register_oom_notifier(&dev_priv->mm.oom_notifier));
}

/**
 * i915_gem_shrinker_cleanup - Clean up i915 shrinker
 * @dev_priv: i915 device
 *
 * This function unregisters the i915 shrinker and OOM handler.
 */
void i915_gem_shrinker_cleanup(struct drm_i915_private *dev_priv)
{
	WARN_ON(unregister_oom_notifier(&dev_priv->mm.oom_notifier));
	unregister_shrinker(&dev_priv->mm.shrinker);
}
Commit	Line	Data
be6a0376 DV	1	/*
	2	* Copyright © 2008-2015 Intel Corporation
	3	*
	4	* Permission is hereby granted, free of charge, to any person obtaining a
	5	* copy of this software and associated documentation files (the "Software"),
	6	* to deal in the Software without restriction, including without limitation
	7	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	8	* and/or sell copies of the Software, and to permit persons to whom the
	9	* Software is furnished to do so, subject to the following conditions:
	10	*
	11	* The above copyright notice and this permission notice (including the next
	12	* paragraph) shall be included in all copies or substantial portions of the
	13	* Software.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	16	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	18	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	19	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	20	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	21	* IN THE SOFTWARE.
	22	*
	23	*/
	24
	25	#include <linux/oom.h>
	26	#include <linux/shmem_fs.h>
	27	#include <linux/slab.h>
	28	#include <linux/swap.h>
	29	#include <linux/pci.h>
	30	#include <linux/dma-buf.h>
	31	#include <drm/drmP.h>
	32	#include <drm/i915_drm.h>
	33
	34	#include "i915_drv.h"
	35	#include "i915_trace.h"
	36
	37	static bool mutex_is_locked_by(struct mutex mutex, struct task_struct task)
	38	{
	39	if (!mutex_is_locked(mutex))
	40	return false;
	41
	42	#if defined(CONFIG_SMP) \|\| defined(CONFIG_DEBUG_MUTEXES)
	43	return mutex->owner == task;
	44	#else
	45	/* Since UP may be pre-empted, we cannot assume that we own the lock */
	46	return false;
	47	#endif
	48	}
	49
c1a415e2 CW	50	static int num_vma_bound(struct drm_i915_gem_object *obj)
	51	{
	52	struct i915_vma *vma;
	53	int count = 0;
	54
	55	list_for_each_entry(vma, &obj->vma_list, vma_link) {
	56	if (drm_mm_node_allocated(&vma->node))
	57	count++;
	58	if (vma->pin_count)
	59	count++;
	60	}
	61
	62	return count;
	63	}
	64
	65	static bool swap_available(void)
	66	{
	67	return get_nr_swap_pages() > 0;
	68	}
	69
	70	static bool can_release_pages(struct drm_i915_gem_object *obj)
	71	{
	72	/* Only report true if by unbinding the object and putting its pages
	73	* we can actually make forward progress towards freeing physical
	74	* pages.
	75	*
	76	* If the pages are pinned for any other reason than being bound
	77	* to the GPU, simply unbinding from the GPU is not going to succeed
	78	* in releasing our pin count on the pages themselves.
	79	*/
	80	if (obj->pages_pin_count != num_vma_bound(obj))
	81	return false;
	82
	83	/* We can only return physical pages to the system if we can either
	84	* discard the contents (because the user has marked them as being
	85	* purgeable) or if we can move their contents out to swap.
	86	*/
	87	return swap_available() \|\| obj->madv == I915_MADV_DONTNEED;
	88	}
	89
eb0b44ad DV	90	/**
	91	* i915_gem_shrink - Shrink buffer object caches
	92	* @dev_priv: i915 device
	93	* @target: amount of memory to make available, in pages
	94	* @flags: control flags for selecting cache types
	95	*
	96	* This function is the main interface to the shrinker. It will try to release
	97	* up to @target pages of main memory backing storage from buffer objects.
	98	* Selection of the specific caches can be done with @flags. This is e.g. useful
	99	* when purgeable objects should be removed from caches preferentially.
	100	*
	101	* Note that it's not guaranteed that released amount is actually available as
	102	* free system memory - the pages might still be in-used to due to other reasons
	103	* (like cpu mmaps) or the mm core has reused them before we could grab them.
	104	* Therefore code that needs to explicitly shrink buffer objects caches (e.g. to
	105	* avoid deadlocks in memory reclaim) must fall back to i915_gem_shrink_all().
	106	*
	107	* Also note that any kind of pinning (both per-vma address space pins and
	108	* backing storage pins at the buffer object level) result in the shrinker code
	109	* having to skip the object.
	110	*
	111	* Returns:
	112	* The number of pages of backing storage actually released.
	113	*/
be6a0376 DV	114	unsigned long
be6a0376 DV	115	i915_gem_shrink(struct drm_i915_private *dev_priv,
14387540	116	unsigned long target, unsigned flags)
be6a0376 DV	117	{
	118	const struct {
	119	struct list_head *list;
	120	unsigned int bit;
	121	} phases[] = {
	122	{ &dev_priv->mm.unbound_list, I915_SHRINK_UNBOUND },
	123	{ &dev_priv->mm.bound_list, I915_SHRINK_BOUND },
	124	{ NULL, 0 },
	125	}, *phase;
	126	unsigned long count = 0;
	127
3abafa53	128	trace_i915_gem_shrink(dev_priv, target, flags);
c9c0f5ea	129	i915_gem_retire_requests(dev_priv->dev);
3abafa53	130
be6a0376 DV	131	/*
	132	* As we may completely rewrite the (un)bound list whilst unbinding
	133	* (due to retiring requests) we have to strictly process only
	134	* one element of the list at the time, and recheck the list
	135	* on every iteration.
	136	*
	137	* In particular, we must hold a reference whilst removing the
	138	* object as we may end up waiting for and/or retiring the objects.
	139	* This might release the final reference (held by the active list)
	140	* and result in the object being freed from under us. This is
	141	* similar to the precautions the eviction code must take whilst
	142	* removing objects.
	143	*
	144	* Also note that although these lists do not hold a reference to
	145	* the object we can safely grab one here: The final object
	146	* unreferencing and the bound_list are both protected by the
	147	* dev->struct_mutex and so we won't ever be able to observe an
	148	* object on the bound_list with a reference count equals 0.
	149	*/
	150	for (phase = phases; phase->list; phase++) {
	151	struct list_head still_in_list;
	152
	153	if ((flags & phase->bit) == 0)
	154	continue;
	155
	156	INIT_LIST_HEAD(&still_in_list);
	157	while (count < target && !list_empty(phase->list)) {
	158	struct drm_i915_gem_object *obj;
	159	struct i915_vma vma, v;
	160
	161	obj = list_first_entry(phase->list,
	162	typeof(*obj), global_list);
	163	list_move_tail(&obj->global_list, &still_in_list);
	164
	165	if (flags & I915_SHRINK_PURGEABLE &&
	166	obj->madv != I915_MADV_DONTNEED)
	167	continue;
	168
5763ff04 CW	169	if ((flags & I915_SHRINK_ACTIVE) == 0 && obj->active)
	170	continue;
	171
c1a415e2 CW	172	if (!can_release_pages(obj))
	173	continue;
	174
be6a0376 DV	175	drm_gem_object_reference(&obj->base);
	176
	177	/* For the unbound phase, this should be a no-op! */
	178	list_for_each_entry_safe(vma, v,
	179	&obj->vma_list, vma_link)
	180	if (i915_vma_unbind(vma))
	181	break;
	182
	183	if (i915_gem_object_put_pages(obj) == 0)
	184	count += obj->base.size >> PAGE_SHIFT;
	185
	186	drm_gem_object_unreference(&obj->base);
	187	}
	188	list_splice(&still_in_list, phase->list);
	189	}
	190
c9c0f5ea CW	191	i915_gem_retire_requests(dev_priv->dev);
c9c0f5ea CW	192
be6a0376 DV	193	return count;
	194	}
	195
eb0b44ad	196	/**
1f2449cd	197	* i915_gem_shrink_all - Shrink buffer object caches completely
eb0b44ad DV	198	* @dev_priv: i915 device
	199	*
	200	* This is a simple wraper around i915_gem_shrink() to aggressively shrink all
	201	* caches completely. It also first waits for and retires all outstanding
	202	* requests to also be able to release backing storage for active objects.
	203	*
	204	* This should only be used in code to intentionally quiescent the gpu or as a
	205	* last-ditch effort when memory seems to have run out.
	206	*
	207	* Returns:
	208	* The number of pages of backing storage actually released.
	209	*/
be6a0376 DV	210	unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv)
be6a0376 DV	211	{
14387540	212	return i915_gem_shrink(dev_priv, -1UL,
5763ff04 CW	213	I915_SHRINK_BOUND \|
	214	I915_SHRINK_UNBOUND \|
	215	I915_SHRINK_ACTIVE);
be6a0376 DV	216	}
	217
	218	static bool i915_gem_shrinker_lock(struct drm_device dev, bool unlock)
	219	{
	220	if (!mutex_trylock(&dev->struct_mutex)) {
	221	if (!mutex_is_locked_by(&dev->struct_mutex, current))
	222	return false;
	223
	224	if (to_i915(dev)->mm.shrinker_no_lock_stealing)
	225	return false;
	226
	227	*unlock = false;
	228	} else
	229	*unlock = true;
	230
	231	return true;
	232	}
	233
be6a0376 DV	234	static unsigned long
	235	i915_gem_shrinker_count(struct shrinker shrinker, struct shrink_control sc)
	236	{
	237	struct drm_i915_private *dev_priv =
	238	container_of(shrinker, struct drm_i915_private, mm.shrinker);
	239	struct drm_device *dev = dev_priv->dev;
	240	struct drm_i915_gem_object *obj;
	241	unsigned long count;
	242	bool unlock;
	243
	244	if (!i915_gem_shrinker_lock(dev, &unlock))
	245	return 0;
	246
	247	count = 0;
	248	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list)
	249	if (obj->pages_pin_count == 0)
	250	count += obj->base.size >> PAGE_SHIFT;
	251
	252	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
c1a415e2	253	if (!obj->active && can_release_pages(obj))
be6a0376 DV	254	count += obj->base.size >> PAGE_SHIFT;
	255	}
	256
	257	if (unlock)
	258	mutex_unlock(&dev->struct_mutex);
	259
	260	return count;
	261	}
	262
	263	static unsigned long
	264	i915_gem_shrinker_scan(struct shrinker shrinker, struct shrink_control sc)
	265	{
	266	struct drm_i915_private *dev_priv =
	267	container_of(shrinker, struct drm_i915_private, mm.shrinker);
	268	struct drm_device *dev = dev_priv->dev;
	269	unsigned long freed;
	270	bool unlock;
	271
	272	if (!i915_gem_shrinker_lock(dev, &unlock))
	273	return SHRINK_STOP;
	274
	275	freed = i915_gem_shrink(dev_priv,
	276	sc->nr_to_scan,
	277	I915_SHRINK_BOUND \|
	278	I915_SHRINK_UNBOUND \|
	279	I915_SHRINK_PURGEABLE);
	280	if (freed < sc->nr_to_scan)
	281	freed += i915_gem_shrink(dev_priv,
	282	sc->nr_to_scan - freed,
	283	I915_SHRINK_BOUND \|
	284	I915_SHRINK_UNBOUND);
	285	if (unlock)
	286	mutex_unlock(&dev->struct_mutex);
	287
	288	return freed;
	289	}
	290
	291	static int
	292	i915_gem_shrinker_oom(struct notifier_block nb, unsigned long event, void ptr)
	293	{
	294	struct drm_i915_private *dev_priv =
	295	container_of(nb, struct drm_i915_private, mm.oom_notifier);
	296	struct drm_device *dev = dev_priv->dev;
	297	struct drm_i915_gem_object *obj;
	298	unsigned long timeout = msecs_to_jiffies(5000) + 1;
	299	unsigned long pinned, bound, unbound, freed_pages;
	300	bool was_interruptible;
	301	bool unlock;
	302
	303	while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) {
	304	schedule_timeout_killable(1);
	305	if (fatal_signal_pending(current))
	306	return NOTIFY_DONE;
	307	}
	308	if (timeout == 0) {
	309	pr_err("Unable to purge GPU memory due lock contention.\n");
	310	return NOTIFY_DONE;
	311	}
	312
	313	was_interruptible = dev_priv->mm.interruptible;
	314	dev_priv->mm.interruptible = false;
	315
	316	freed_pages = i915_gem_shrink_all(dev_priv);
	317
318	dev_priv->mm.interruptible = was_interruptible;
319
320	/* Because we may be allocating inside our own driver, we cannot
321	* assert that there are no objects with pinned pages that are not
322	* being pointed to by hardware.
323	*/
324	unbound = bound = pinned = 0;
325	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) {
326	if (!obj->base.filp) /* not backed by a freeable object */
327	continue;
328
329	if (obj->pages_pin_count)
330	pinned += obj->base.size;
331	else
332	unbound += obj->base.size;
333	}
334	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
335	if (!obj->base.filp)
336	continue;
337
338	if (obj->pages_pin_count)
339	pinned += obj->base.size;
340	else
341	bound += obj->base.size;
342	}
343
344	if (unlock)
345	mutex_unlock(&dev->struct_mutex);
346
347	if (freed_pages \|\| unbound \|\| bound)
348	pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n",
349	freed_pages << PAGE_SHIFT, pinned);
350	if (unbound \|\| bound)
351	pr_err("%lu and %lu bytes still available in the "
352	"bound and unbound GPU page lists.\n",
353	bound, unbound);
354
355	(unsigned long )ptr += freed_pages;
356	return NOTIFY_DONE;
357	}
358
eb0b44ad DV	359	/**
	360	* i915_gem_shrinker_init - Initialize i915 shrinker
	361	* @dev_priv: i915 device
	362	*
	363	* This function registers and sets up the i915 shrinker and OOM handler.
	364	*/
be6a0376 DV	365	void i915_gem_shrinker_init(struct drm_i915_private *dev_priv)
	366	{
	367	dev_priv->mm.shrinker.scan_objects = i915_gem_shrinker_scan;
	368	dev_priv->mm.shrinker.count_objects = i915_gem_shrinker_count;
	369	dev_priv->mm.shrinker.seeks = DEFAULT_SEEKS;
a8a40589	370	WARN_ON(register_shrinker(&dev_priv->mm.shrinker));
be6a0376 DV	371
be6a0376 DV	372	dev_priv->mm.oom_notifier.notifier_call = i915_gem_shrinker_oom;
a8a40589 ID	373	WARN_ON(register_oom_notifier(&dev_priv->mm.oom_notifier));
	374	}
	375
	376	/**
	377	* i915_gem_shrinker_cleanup - Clean up i915 shrinker
	378	* @dev_priv: i915 device
	379	*
	380	* This function unregisters the i915 shrinker and OOM handler.
	381	*/
	382	void i915_gem_shrinker_cleanup(struct drm_i915_private *dev_priv)
	383	{
	384	WARN_ON(unregister_oom_notifier(&dev_priv->mm.oom_notifier));
	385	unregister_shrinker(&dev_priv->mm.shrinker);
be6a0376	386	}