[mirror_ubuntu-bionic-kernel.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 <linux/vmalloc.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, obj_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, obj_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 (can_release_pages(obj))
			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;
}

struct shrinker_lock_uninterruptible {
	bool was_interruptible;
	bool unlock;
};

static bool
i915_gem_shrinker_lock_uninterruptible(struct drm_i915_private *dev_priv,
				       struct shrinker_lock_uninterruptible *slu,
				       int timeout_ms)
{
	unsigned long timeout = msecs_to_jiffies(timeout_ms) + 1;

	while (!i915_gem_shrinker_lock(dev_priv->dev, &slu->unlock)) {
		schedule_timeout_killable(1);
		if (fatal_signal_pending(current))
			return false;
		if (--timeout == 0) {
			pr_err("Unable to lock GPU to purge memory.\n");
			return false;
		}
	}

	slu->was_interruptible = dev_priv->mm.interruptible;
	dev_priv->mm.interruptible = false;
	return true;
}

static void
i915_gem_shrinker_unlock_uninterruptible(struct drm_i915_private *dev_priv,
					 struct shrinker_lock_uninterruptible *slu)
{
	dev_priv->mm.interruptible = slu->was_interruptible;
	if (slu->unlock)
		mutex_unlock(&dev_priv->dev->struct_mutex);
}

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 shrinker_lock_uninterruptible slu;
	struct drm_i915_gem_object *obj;
	unsigned long pinned, bound, unbound, freed_pages;

	if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
		return NOTIFY_DONE;

	freed_pages = i915_gem_shrink_all(dev_priv);

	/* 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;
	}

	i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);

	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;
}

static int
i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
{
	struct drm_i915_private *dev_priv =
		container_of(nb, struct drm_i915_private, mm.vmap_notifier);
	struct shrinker_lock_uninterruptible slu;
	unsigned long freed_pages;

	if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
		return NOTIFY_DONE;

	freed_pages = i915_gem_shrink_all(dev_priv);

	i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);

	*(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));

	dev_priv->mm.vmap_notifier.notifier_call = i915_gem_shrinker_vmap;
	WARN_ON(register_vmap_purge_notifier(&dev_priv->mm.vmap_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_vmap_purge_notifier(&dev_priv->mm.vmap_notifier));
	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>
e87666b5	31	#include <linux/vmalloc.h>
be6a0376 DV	32	#include <drm/drmP.h>
	33	#include <drm/i915_drm.h>
	34
	35	#include "i915_drv.h"
	36	#include "i915_trace.h"
	37
	38	static bool mutex_is_locked_by(struct mutex mutex, struct task_struct task)
	39	{
	40	if (!mutex_is_locked(mutex))
	41	return false;
	42
	43	#if defined(CONFIG_SMP) \|\| defined(CONFIG_DEBUG_MUTEXES)
	44	return mutex->owner == task;
	45	#else
	46	/* Since UP may be pre-empted, we cannot assume that we own the lock */
	47	return false;
	48	#endif
	49	}
	50
c1a415e2 CW	51	static int num_vma_bound(struct drm_i915_gem_object *obj)
	52	{
	53	struct i915_vma *vma;
	54	int count = 0;
	55
1c7f4bca	56	list_for_each_entry(vma, &obj->vma_list, obj_link) {
c1a415e2 CW	57	if (drm_mm_node_allocated(&vma->node))
	58	count++;
	59	if (vma->pin_count)
	60	count++;
	61	}
	62
	63	return count;
	64	}
	65
	66	static bool swap_available(void)
	67	{
	68	return get_nr_swap_pages() > 0;
	69	}
	70
	71	static bool can_release_pages(struct drm_i915_gem_object *obj)
	72	{
	73	/* Only report true if by unbinding the object and putting its pages
	74	* we can actually make forward progress towards freeing physical
	75	* pages.
	76	*
	77	* If the pages are pinned for any other reason than being bound
	78	* to the GPU, simply unbinding from the GPU is not going to succeed
	79	* in releasing our pin count on the pages themselves.
	80	*/
	81	if (obj->pages_pin_count != num_vma_bound(obj))
	82	return false;
	83
	84	/* We can only return physical pages to the system if we can either
	85	* discard the contents (because the user has marked them as being
	86	* purgeable) or if we can move their contents out to swap.
	87	*/
	88	return swap_available() \|\| obj->madv == I915_MADV_DONTNEED;
	89	}
	90
eb0b44ad DV	91	/**
	92	* i915_gem_shrink - Shrink buffer object caches
	93	* @dev_priv: i915 device
	94	* @target: amount of memory to make available, in pages
	95	* @flags: control flags for selecting cache types
	96	*
	97	* This function is the main interface to the shrinker. It will try to release
	98	* up to @target pages of main memory backing storage from buffer objects.
	99	* Selection of the specific caches can be done with @flags. This is e.g. useful
	100	* when purgeable objects should be removed from caches preferentially.
	101	*
	102	* Note that it's not guaranteed that released amount is actually available as
	103	* free system memory - the pages might still be in-used to due to other reasons
	104	* (like cpu mmaps) or the mm core has reused them before we could grab them.
	105	* Therefore code that needs to explicitly shrink buffer objects caches (e.g. to
	106	* avoid deadlocks in memory reclaim) must fall back to i915_gem_shrink_all().
	107	*
	108	* Also note that any kind of pinning (both per-vma address space pins and
	109	* backing storage pins at the buffer object level) result in the shrinker code
	110	* having to skip the object.
	111	*
	112	* Returns:
	113	* The number of pages of backing storage actually released.
	114	*/
be6a0376 DV	115	unsigned long
be6a0376 DV	116	i915_gem_shrink(struct drm_i915_private *dev_priv,
14387540	117	unsigned long target, unsigned flags)
be6a0376 DV	118	{
	119	const struct {
	120	struct list_head *list;
	121	unsigned int bit;
	122	} phases[] = {
	123	{ &dev_priv->mm.unbound_list, I915_SHRINK_UNBOUND },
	124	{ &dev_priv->mm.bound_list, I915_SHRINK_BOUND },
	125	{ NULL, 0 },
	126	}, *phase;
	127	unsigned long count = 0;
	128
3abafa53	129	trace_i915_gem_shrink(dev_priv, target, flags);
c9c0f5ea	130	i915_gem_retire_requests(dev_priv->dev);
3abafa53	131
be6a0376 DV	132	/*
	133	* As we may completely rewrite the (un)bound list whilst unbinding
	134	* (due to retiring requests) we have to strictly process only
	135	* one element of the list at the time, and recheck the list
	136	* on every iteration.
	137	*
	138	* In particular, we must hold a reference whilst removing the
	139	* object as we may end up waiting for and/or retiring the objects.
	140	* This might release the final reference (held by the active list)
	141	* and result in the object being freed from under us. This is
	142	* similar to the precautions the eviction code must take whilst
	143	* removing objects.
	144	*
	145	* Also note that although these lists do not hold a reference to
	146	* the object we can safely grab one here: The final object
	147	* unreferencing and the bound_list are both protected by the
	148	* dev->struct_mutex and so we won't ever be able to observe an
	149	* object on the bound_list with a reference count equals 0.
	150	*/
	151	for (phase = phases; phase->list; phase++) {
	152	struct list_head still_in_list;
	153
	154	if ((flags & phase->bit) == 0)
	155	continue;
	156
	157	INIT_LIST_HEAD(&still_in_list);
	158	while (count < target && !list_empty(phase->list)) {
	159	struct drm_i915_gem_object *obj;
	160	struct i915_vma vma, v;
	161
	162	obj = list_first_entry(phase->list,
	163	typeof(*obj), global_list);
	164	list_move_tail(&obj->global_list, &still_in_list);
	165
	166	if (flags & I915_SHRINK_PURGEABLE &&
	167	obj->madv != I915_MADV_DONTNEED)
	168	continue;
	169
5763ff04 CW	170	if ((flags & I915_SHRINK_ACTIVE) == 0 && obj->active)
	171	continue;
	172
c1a415e2 CW	173	if (!can_release_pages(obj))
	174	continue;
	175
be6a0376 DV	176	drm_gem_object_reference(&obj->base);
	177
	178	/* For the unbound phase, this should be a no-op! */
	179	list_for_each_entry_safe(vma, v,
1c7f4bca	180	&obj->vma_list, obj_link)
be6a0376 DV	181	if (i915_vma_unbind(vma))
	182	break;
	183
	184	if (i915_gem_object_put_pages(obj) == 0)
	185	count += obj->base.size >> PAGE_SHIFT;
	186
	187	drm_gem_object_unreference(&obj->base);
	188	}
	189	list_splice(&still_in_list, phase->list);
	190	}
	191
c9c0f5ea CW	192	i915_gem_retire_requests(dev_priv->dev);
c9c0f5ea CW	193
be6a0376 DV	194	return count;
	195	}
	196
eb0b44ad	197	/**
1f2449cd	198	* i915_gem_shrink_all - Shrink buffer object caches completely
eb0b44ad DV	199	* @dev_priv: i915 device
	200	*
	201	* This is a simple wraper around i915_gem_shrink() to aggressively shrink all
	202	* caches completely. It also first waits for and retires all outstanding
	203	* requests to also be able to release backing storage for active objects.
	204	*
	205	* This should only be used in code to intentionally quiescent the gpu or as a
	206	* last-ditch effort when memory seems to have run out.
	207	*
	208	* Returns:
	209	* The number of pages of backing storage actually released.
	210	*/
be6a0376 DV	211	unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv)
be6a0376 DV	212	{
14387540	213	return i915_gem_shrink(dev_priv, -1UL,
5763ff04 CW	214	I915_SHRINK_BOUND \|
	215	I915_SHRINK_UNBOUND \|
	216	I915_SHRINK_ACTIVE);
be6a0376 DV	217	}
	218
	219	static bool i915_gem_shrinker_lock(struct drm_device dev, bool unlock)
	220	{
	221	if (!mutex_trylock(&dev->struct_mutex)) {
	222	if (!mutex_is_locked_by(&dev->struct_mutex, current))
	223	return false;
	224
	225	if (to_i915(dev)->mm.shrinker_no_lock_stealing)
	226	return false;
	227
	228	*unlock = false;
	229	} else
	230	*unlock = true;
	231
	232	return true;
	233	}
	234
be6a0376 DV	235	static unsigned long
	236	i915_gem_shrinker_count(struct shrinker shrinker, struct shrink_control sc)
	237	{
	238	struct drm_i915_private *dev_priv =
	239	container_of(shrinker, struct drm_i915_private, mm.shrinker);
	240	struct drm_device *dev = dev_priv->dev;
	241	struct drm_i915_gem_object *obj;
	242	unsigned long count;
	243	bool unlock;
	244
	245	if (!i915_gem_shrinker_lock(dev, &unlock))
	246	return 0;
	247
	248	count = 0;
	249	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list)
6f0ac204	250	if (can_release_pages(obj))
be6a0376 DV	251	count += obj->base.size >> PAGE_SHIFT;
	252
	253	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
c1a415e2	254	if (!obj->active && can_release_pages(obj))
be6a0376 DV	255	count += obj->base.size >> PAGE_SHIFT;
	256	}
	257
	258	if (unlock)
	259	mutex_unlock(&dev->struct_mutex);
	260
	261	return count;
	262	}
	263
	264	static unsigned long
	265	i915_gem_shrinker_scan(struct shrinker shrinker, struct shrink_control sc)
	266	{
	267	struct drm_i915_private *dev_priv =
	268	container_of(shrinker, struct drm_i915_private, mm.shrinker);
	269	struct drm_device *dev = dev_priv->dev;
	270	unsigned long freed;
	271	bool unlock;
	272
	273	if (!i915_gem_shrinker_lock(dev, &unlock))
	274	return SHRINK_STOP;
	275
	276	freed = i915_gem_shrink(dev_priv,
	277	sc->nr_to_scan,
	278	I915_SHRINK_BOUND \|
	279	I915_SHRINK_UNBOUND \|
	280	I915_SHRINK_PURGEABLE);
	281	if (freed < sc->nr_to_scan)
	282	freed += i915_gem_shrink(dev_priv,
	283	sc->nr_to_scan - freed,
	284	I915_SHRINK_BOUND \|
	285	I915_SHRINK_UNBOUND);
	286	if (unlock)
	287	mutex_unlock(&dev->struct_mutex);
	288
	289	return freed;
	290	}
	291
168cf367 CW	292	struct shrinker_lock_uninterruptible {
	293	bool was_interruptible;
	294	bool unlock;
	295	};
	296
	297	static bool
	298	i915_gem_shrinker_lock_uninterruptible(struct drm_i915_private *dev_priv,
	299	struct shrinker_lock_uninterruptible *slu,
	300	int timeout_ms)
	301	{
	302	unsigned long timeout = msecs_to_jiffies(timeout_ms) + 1;
	303
	304	while (!i915_gem_shrinker_lock(dev_priv->dev, &slu->unlock)) {
	305	schedule_timeout_killable(1);
	306	if (fatal_signal_pending(current))
	307	return false;
	308	if (--timeout == 0) {
	309	pr_err("Unable to lock GPU to purge memory.\n");
	310	return false;
	311	}
	312	}
	313
	314	slu->was_interruptible = dev_priv->mm.interruptible;
	315	dev_priv->mm.interruptible = false;
	316	return true;
	317	}
	318
	319	static void
	320	i915_gem_shrinker_unlock_uninterruptible(struct drm_i915_private *dev_priv,
	321	struct shrinker_lock_uninterruptible *slu)
	322	{
	323	dev_priv->mm.interruptible = slu->was_interruptible;
	324	if (slu->unlock)
	325	mutex_unlock(&dev_priv->dev->struct_mutex);
	326	}
	327
be6a0376 DV	328	static int
	329	i915_gem_shrinker_oom(struct notifier_block nb, unsigned long event, void ptr)
	330	{
	331	struct drm_i915_private *dev_priv =
	332	container_of(nb, struct drm_i915_private, mm.oom_notifier);
168cf367	333	struct shrinker_lock_uninterruptible slu;
be6a0376	334	struct drm_i915_gem_object *obj;
be6a0376	335	unsigned long pinned, bound, unbound, freed_pages;
be6a0376	336
168cf367	337	if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
be6a0376	338	return NOTIFY_DONE;
be6a0376 DV	339
	340	freed_pages = i915_gem_shrink_all(dev_priv);
	341
be6a0376 DV	342	/* Because we may be allocating inside our own driver, we cannot
	343	* assert that there are no objects with pinned pages that are not
	344	* being pointed to by hardware.
	345	*/
	346	unbound = bound = pinned = 0;
	347	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) {
	348	if (!obj->base.filp) /* not backed by a freeable object */
	349	continue;
	350
	351	if (obj->pages_pin_count)
	352	pinned += obj->base.size;
	353	else
	354	unbound += obj->base.size;
	355	}
	356	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
	357	if (!obj->base.filp)
	358	continue;
	359
	360	if (obj->pages_pin_count)
	361	pinned += obj->base.size;
	362	else
	363	bound += obj->base.size;
	364	}
	365
168cf367	366	i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);
be6a0376 DV	367
	368	if (freed_pages \|\| unbound \|\| bound)
	369	pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n",
	370	freed_pages << PAGE_SHIFT, pinned);
	371	if (unbound \|\| bound)
	372	pr_err("%lu and %lu bytes still available in the "
	373	"bound and unbound GPU page lists.\n",
	374	bound, unbound);
	375
	376	(unsigned long )ptr += freed_pages;
	377	return NOTIFY_DONE;
	378	}
	379
e87666b5 CW	380	static int
	381	i915_gem_shrinker_vmap(struct notifier_block nb, unsigned long event, void ptr)
	382	{
	383	struct drm_i915_private *dev_priv =
	384	container_of(nb, struct drm_i915_private, mm.vmap_notifier);
168cf367	385	struct shrinker_lock_uninterruptible slu;
e87666b5	386	unsigned long freed_pages;
e87666b5	387
168cf367	388	if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
e87666b5	389	return NOTIFY_DONE;
e87666b5 CW	390
	391	freed_pages = i915_gem_shrink_all(dev_priv);
	392
168cf367	393	i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);
e87666b5 CW	394
	395	(unsigned long )ptr += freed_pages;
	396	return NOTIFY_DONE;
	397	}
	398
eb0b44ad DV	399	/**
	400	* i915_gem_shrinker_init - Initialize i915 shrinker
	401	* @dev_priv: i915 device
	402	*
	403	* This function registers and sets up the i915 shrinker and OOM handler.
	404	*/
be6a0376 DV	405	void i915_gem_shrinker_init(struct drm_i915_private *dev_priv)
	406	{
	407	dev_priv->mm.shrinker.scan_objects = i915_gem_shrinker_scan;
	408	dev_priv->mm.shrinker.count_objects = i915_gem_shrinker_count;
	409	dev_priv->mm.shrinker.seeks = DEFAULT_SEEKS;
a8a40589	410	WARN_ON(register_shrinker(&dev_priv->mm.shrinker));
be6a0376 DV	411
be6a0376 DV	412	dev_priv->mm.oom_notifier.notifier_call = i915_gem_shrinker_oom;
a8a40589	413	WARN_ON(register_oom_notifier(&dev_priv->mm.oom_notifier));
e87666b5 CW	414
	415	dev_priv->mm.vmap_notifier.notifier_call = i915_gem_shrinker_vmap;
	416	WARN_ON(register_vmap_purge_notifier(&dev_priv->mm.vmap_notifier));
a8a40589 ID	417	}
	418
	419	/**
	420	* i915_gem_shrinker_cleanup - Clean up i915 shrinker
	421	* @dev_priv: i915 device
	422	*
	423	* This function unregisters the i915 shrinker and OOM handler.
	424	*/
	425	void i915_gem_shrinker_cleanup(struct drm_i915_private *dev_priv)
	426	{
e87666b5	427	WARN_ON(unregister_vmap_purge_notifier(&dev_priv->mm.vmap_notifier));
a8a40589 ID	428	WARN_ON(unregister_oom_notifier(&dev_priv->mm.oom_notifier));
a8a40589 ID	429	unregister_shrinker(&dev_priv->mm.shrinker);
be6a0376	430	}