[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 <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_DEBUG_MUTEXES) || defined(CONFIG_MUTEX_SPIN_ON_OWNER)
	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 shmemfs objects are backed by swap */
	if (!obj->base.filp)
		return false;

	/* 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);

	/*
	 * Unbinding of objects will require HW access; Let us not wake the
	 * device just to recover a little memory. If absolutely necessary,
	 * we will force the wake during oom-notifier.
	 */
	if ((flags & I915_SHRINK_BOUND) &&
	    !intel_runtime_pm_get_if_in_use(dev_priv))
		flags &= ~I915_SHRINK_BOUND;

	/*
	 * 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_VMAPS &&
			    !is_vmalloc_addr(obj->mapping))
				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);
	}

	if (flags & I915_SHRINK_BOUND)
		intel_runtime_pm_put(dev_priv);

	i915_gem_retire_requests(dev_priv);

	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->drm;
	struct drm_i915_gem_object *obj;
	unsigned long count;
	bool unlock;

	if (!i915_gem_shrinker_lock(dev, &unlock))
		return 0;

	i915_gem_retire_requests(dev_priv);

	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->drm;
	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->drm, &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->drm.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 unevictable, bound, unbound, freed_pages;

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

	intel_runtime_pm_get(dev_priv);
	freed_pages = i915_gem_shrink_all(dev_priv);
	intel_runtime_pm_put(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 = unevictable = 0;
	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) {
		if (!can_release_pages(obj))
			unevictable += obj->base.size >> PAGE_SHIFT;
		else
			unbound += obj->base.size >> PAGE_SHIFT;
	}
	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
		if (!can_release_pages(obj))
			unevictable += obj->base.size >> PAGE_SHIFT;
		else
			bound += obj->base.size >> PAGE_SHIFT;
	}

	i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);

	if (freed_pages || unbound || bound)
		pr_info("Purging GPU memory, %lu pages freed, "
			"%lu pages still pinned.\n",
			freed_pages, unevictable);
	if (unbound || bound)
		pr_err("%lu and %lu pages 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;
	struct i915_vma *vma, *next;
	unsigned long freed_pages = 0;
	int ret;

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

	/* Force everything onto the inactive lists */
	ret = i915_gem_wait_for_idle(dev_priv);
	if (ret)
		goto out;

	intel_runtime_pm_get(dev_priv);
	freed_pages += i915_gem_shrink(dev_priv, -1UL,
				       I915_SHRINK_BOUND |
				       I915_SHRINK_UNBOUND |
				       I915_SHRINK_ACTIVE |
				       I915_SHRINK_VMAPS);
	intel_runtime_pm_put(dev_priv);

	/* We also want to clear any cached iomaps as they wrap vmap */
	list_for_each_entry_safe(vma, next,
				 &dev_priv->ggtt.base.inactive_list, vm_link) {
		unsigned long count = vma->node.size >> PAGE_SHIFT;
		if (vma->iomap && i915_vma_unbind(vma) == 0)
			freed_pages += count;
	}

out:
	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
b1924006	43	#if defined(CONFIG_DEBUG_MUTEXES) \|\| defined(CONFIG_MUTEX_SPIN_ON_OWNER)
be6a0376 DV	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	{
1bec9b0b CW	73	/* Only shmemfs objects are backed by swap */
	74	if (!obj->base.filp)
	75	return false;
	76
c1a415e2 CW	77	/* Only report true if by unbinding the object and putting its pages
	78	* we can actually make forward progress towards freeing physical
	79	* pages.
	80	*
	81	* If the pages are pinned for any other reason than being bound
	82	* to the GPU, simply unbinding from the GPU is not going to succeed
	83	* in releasing our pin count on the pages themselves.
	84	*/
	85	if (obj->pages_pin_count != num_vma_bound(obj))
	86	return false;
	87
	88	/* We can only return physical pages to the system if we can either
	89	* discard the contents (because the user has marked them as being
	90	* purgeable) or if we can move their contents out to swap.
	91	*/
	92	return swap_available() \|\| obj->madv == I915_MADV_DONTNEED;
	93	}
	94
eb0b44ad DV	95	/**
	96	* i915_gem_shrink - Shrink buffer object caches
	97	* @dev_priv: i915 device
	98	* @target: amount of memory to make available, in pages
	99	* @flags: control flags for selecting cache types
	100	*
	101	* This function is the main interface to the shrinker. It will try to release
	102	* up to @target pages of main memory backing storage from buffer objects.
	103	* Selection of the specific caches can be done with @flags. This is e.g. useful
	104	* when purgeable objects should be removed from caches preferentially.
	105	*
	106	* Note that it's not guaranteed that released amount is actually available as
	107	* free system memory - the pages might still be in-used to due to other reasons
	108	* (like cpu mmaps) or the mm core has reused them before we could grab them.
	109	* Therefore code that needs to explicitly shrink buffer objects caches (e.g. to
	110	* avoid deadlocks in memory reclaim) must fall back to i915_gem_shrink_all().
	111	*
	112	* Also note that any kind of pinning (both per-vma address space pins and
	113	* backing storage pins at the buffer object level) result in the shrinker code
	114	* having to skip the object.
	115	*
	116	* Returns:
	117	* The number of pages of backing storage actually released.
	118	*/
be6a0376 DV	119	unsigned long
be6a0376 DV	120	i915_gem_shrink(struct drm_i915_private *dev_priv,
14387540	121	unsigned long target, unsigned flags)
be6a0376 DV	122	{
	123	const struct {
	124	struct list_head *list;
	125	unsigned int bit;
	126	} phases[] = {
	127	{ &dev_priv->mm.unbound_list, I915_SHRINK_UNBOUND },
	128	{ &dev_priv->mm.bound_list, I915_SHRINK_BOUND },
	129	{ NULL, 0 },
	130	}, *phase;
	131	unsigned long count = 0;
	132
3abafa53	133	trace_i915_gem_shrink(dev_priv, target, flags);
c033666a	134	i915_gem_retire_requests(dev_priv);
3abafa53	135
178a30c9 PP	136	/*
	137	* Unbinding of objects will require HW access; Let us not wake the
	138	* device just to recover a little memory. If absolutely necessary,
	139	* we will force the wake during oom-notifier.
	140	*/
	141	if ((flags & I915_SHRINK_BOUND) &&
	142	!intel_runtime_pm_get_if_in_use(dev_priv))
	143	flags &= ~I915_SHRINK_BOUND;
	144
be6a0376 DV	145	/*
	146	* As we may completely rewrite the (un)bound list whilst unbinding
	147	* (due to retiring requests) we have to strictly process only
	148	* one element of the list at the time, and recheck the list
	149	* on every iteration.
	150	*
	151	* In particular, we must hold a reference whilst removing the
	152	* object as we may end up waiting for and/or retiring the objects.
	153	* This might release the final reference (held by the active list)
	154	* and result in the object being freed from under us. This is
	155	* similar to the precautions the eviction code must take whilst
	156	* removing objects.
	157	*
	158	* Also note that although these lists do not hold a reference to
	159	* the object we can safely grab one here: The final object
	160	* unreferencing and the bound_list are both protected by the
	161	* dev->struct_mutex and so we won't ever be able to observe an
	162	* object on the bound_list with a reference count equals 0.
	163	*/
	164	for (phase = phases; phase->list; phase++) {
	165	struct list_head still_in_list;
	166
	167	if ((flags & phase->bit) == 0)
	168	continue;
	169
	170	INIT_LIST_HEAD(&still_in_list);
	171	while (count < target && !list_empty(phase->list)) {
	172	struct drm_i915_gem_object *obj;
	173	struct i915_vma vma, v;
	174
	175	obj = list_first_entry(phase->list,
	176	typeof(*obj), global_list);
	177	list_move_tail(&obj->global_list, &still_in_list);
	178
	179	if (flags & I915_SHRINK_PURGEABLE &&
	180	obj->madv != I915_MADV_DONTNEED)
	181	continue;
	182
eae2c43b CW	183	if (flags & I915_SHRINK_VMAPS &&
	184	!is_vmalloc_addr(obj->mapping))
	185	continue;
	186
5763ff04 CW	187	if ((flags & I915_SHRINK_ACTIVE) == 0 && obj->active)
	188	continue;
	189
c1a415e2 CW	190	if (!can_release_pages(obj))
	191	continue;
	192
be6a0376 DV	193	drm_gem_object_reference(&obj->base);
	194
	195	/* For the unbound phase, this should be a no-op! */
	196	list_for_each_entry_safe(vma, v,
1c7f4bca	197	&obj->vma_list, obj_link)
be6a0376 DV	198	if (i915_vma_unbind(vma))
	199	break;
	200
	201	if (i915_gem_object_put_pages(obj) == 0)
	202	count += obj->base.size >> PAGE_SHIFT;
	203
	204	drm_gem_object_unreference(&obj->base);
	205	}
	206	list_splice(&still_in_list, phase->list);
	207	}
	208
178a30c9 PP	209	if (flags & I915_SHRINK_BOUND)
	210	intel_runtime_pm_put(dev_priv);
	211
c033666a	212	i915_gem_retire_requests(dev_priv);
c9c0f5ea	213
be6a0376 DV	214	return count;
	215	}
	216
eb0b44ad	217	/**
1f2449cd	218	* i915_gem_shrink_all - Shrink buffer object caches completely
eb0b44ad DV	219	* @dev_priv: i915 device
	220	*
	221	* This is a simple wraper around i915_gem_shrink() to aggressively shrink all
	222	* caches completely. It also first waits for and retires all outstanding
	223	* requests to also be able to release backing storage for active objects.
	224	*
	225	* This should only be used in code to intentionally quiescent the gpu or as a
	226	* last-ditch effort when memory seems to have run out.
	227	*
	228	* Returns:
	229	* The number of pages of backing storage actually released.
	230	*/
be6a0376 DV	231	unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv)
be6a0376 DV	232	{
14387540	233	return i915_gem_shrink(dev_priv, -1UL,
5763ff04 CW	234	I915_SHRINK_BOUND \|
	235	I915_SHRINK_UNBOUND \|
	236	I915_SHRINK_ACTIVE);
be6a0376 DV	237	}
	238
	239	static bool i915_gem_shrinker_lock(struct drm_device dev, bool unlock)
	240	{
	241	if (!mutex_trylock(&dev->struct_mutex)) {
	242	if (!mutex_is_locked_by(&dev->struct_mutex, current))
	243	return false;
	244
	245	if (to_i915(dev)->mm.shrinker_no_lock_stealing)
	246	return false;
	247
	248	*unlock = false;
	249	} else
	250	*unlock = true;
	251
	252	return true;
	253	}
	254
be6a0376 DV	255	static unsigned long
	256	i915_gem_shrinker_count(struct shrinker shrinker, struct shrink_control sc)
	257	{
	258	struct drm_i915_private *dev_priv =
	259	container_of(shrinker, struct drm_i915_private, mm.shrinker);
91c8a326	260	struct drm_device *dev = &dev_priv->drm;
be6a0376 DV	261	struct drm_i915_gem_object *obj;
	262	unsigned long count;
	263	bool unlock;
	264
	265	if (!i915_gem_shrinker_lock(dev, &unlock))
	266	return 0;
	267
bed50aea CW	268	i915_gem_retire_requests(dev_priv);
bed50aea CW	269
be6a0376 DV	270	count = 0;
be6a0376 DV	271	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list)
6f0ac204	272	if (can_release_pages(obj))
be6a0376 DV	273	count += obj->base.size >> PAGE_SHIFT;
	274
	275	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
c1a415e2	276	if (!obj->active && can_release_pages(obj))
be6a0376 DV	277	count += obj->base.size >> PAGE_SHIFT;
	278	}
	279
	280	if (unlock)
	281	mutex_unlock(&dev->struct_mutex);
	282
	283	return count;
	284	}
	285
	286	static unsigned long
	287	i915_gem_shrinker_scan(struct shrinker shrinker, struct shrink_control sc)
	288	{
	289	struct drm_i915_private *dev_priv =
	290	container_of(shrinker, struct drm_i915_private, mm.shrinker);
91c8a326	291	struct drm_device *dev = &dev_priv->drm;
be6a0376 DV	292	unsigned long freed;
	293	bool unlock;
	294
	295	if (!i915_gem_shrinker_lock(dev, &unlock))
	296	return SHRINK_STOP;
	297
	298	freed = i915_gem_shrink(dev_priv,
	299	sc->nr_to_scan,
	300	I915_SHRINK_BOUND \|
	301	I915_SHRINK_UNBOUND \|
	302	I915_SHRINK_PURGEABLE);
	303	if (freed < sc->nr_to_scan)
	304	freed += i915_gem_shrink(dev_priv,
	305	sc->nr_to_scan - freed,
	306	I915_SHRINK_BOUND \|
	307	I915_SHRINK_UNBOUND);
	308	if (unlock)
	309	mutex_unlock(&dev->struct_mutex);
	310
	311	return freed;
	312	}
	313
168cf367 CW	314	struct shrinker_lock_uninterruptible {
	315	bool was_interruptible;
	316	bool unlock;
	317	};
	318
	319	static bool
	320	i915_gem_shrinker_lock_uninterruptible(struct drm_i915_private *dev_priv,
	321	struct shrinker_lock_uninterruptible *slu,
	322	int timeout_ms)
	323	{
	324	unsigned long timeout = msecs_to_jiffies(timeout_ms) + 1;
	325
91c8a326	326	while (!i915_gem_shrinker_lock(&dev_priv->drm, &slu->unlock)) {
168cf367 CW	327	schedule_timeout_killable(1);
	328	if (fatal_signal_pending(current))
	329	return false;
	330	if (--timeout == 0) {
	331	pr_err("Unable to lock GPU to purge memory.\n");
	332	return false;
	333	}
	334	}
	335
	336	slu->was_interruptible = dev_priv->mm.interruptible;
	337	dev_priv->mm.interruptible = false;
	338	return true;
	339	}
	340
	341	static void
	342	i915_gem_shrinker_unlock_uninterruptible(struct drm_i915_private *dev_priv,
	343	struct shrinker_lock_uninterruptible *slu)
	344	{
	345	dev_priv->mm.interruptible = slu->was_interruptible;
	346	if (slu->unlock)
91c8a326	347	mutex_unlock(&dev_priv->drm.struct_mutex);
168cf367 CW	348	}
168cf367 CW	349
be6a0376 DV	350	static int
	351	i915_gem_shrinker_oom(struct notifier_block nb, unsigned long event, void ptr)
	352	{
	353	struct drm_i915_private *dev_priv =
	354	container_of(nb, struct drm_i915_private, mm.oom_notifier);
168cf367	355	struct shrinker_lock_uninterruptible slu;
be6a0376	356	struct drm_i915_gem_object *obj;
1768d455	357	unsigned long unevictable, bound, unbound, freed_pages;
be6a0376	358
168cf367	359	if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
be6a0376	360	return NOTIFY_DONE;
be6a0376	361
ea9d9768	362	intel_runtime_pm_get(dev_priv);
be6a0376	363	freed_pages = i915_gem_shrink_all(dev_priv);
ea9d9768	364	intel_runtime_pm_put(dev_priv);
be6a0376	365
be6a0376 DV	366	/* Because we may be allocating inside our own driver, we cannot
	367	* assert that there are no objects with pinned pages that are not
	368	* being pointed to by hardware.
	369	*/
1768d455	370	unbound = bound = unevictable = 0;
be6a0376	371	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) {
1768d455 CW	372	if (!can_release_pages(obj))
1768d455 CW	373	unevictable += obj->base.size >> PAGE_SHIFT;
be6a0376	374	else
1768d455	375	unbound += obj->base.size >> PAGE_SHIFT;
be6a0376 DV	376	}
be6a0376 DV	377	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
1768d455 CW	378	if (!can_release_pages(obj))
1768d455 CW	379	unevictable += obj->base.size >> PAGE_SHIFT;
be6a0376	380	else
1768d455	381	bound += obj->base.size >> PAGE_SHIFT;
be6a0376 DV	382	}
be6a0376 DV	383
168cf367	384	i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);
be6a0376 DV	385
be6a0376 DV	386	if (freed_pages \|\| unbound \|\| bound)
1768d455 CW	387	pr_info("Purging GPU memory, %lu pages freed, "
	388	"%lu pages still pinned.\n",
	389	freed_pages, unevictable);
be6a0376	390	if (unbound \|\| bound)
1768d455	391	pr_err("%lu and %lu pages still available in the "
be6a0376 DV	392	"bound and unbound GPU page lists.\n",
	393	bound, unbound);
	394
	395	(unsigned long )ptr += freed_pages;
	396	return NOTIFY_DONE;
	397	}
	398
e87666b5 CW	399	static int
	400	i915_gem_shrinker_vmap(struct notifier_block nb, unsigned long event, void ptr)
	401	{
	402	struct drm_i915_private *dev_priv =
	403	container_of(nb, struct drm_i915_private, mm.vmap_notifier);
168cf367	404	struct shrinker_lock_uninterruptible slu;
8ef8561f CW	405	struct i915_vma vma, next;
	406	unsigned long freed_pages = 0;
	407	int ret;
e87666b5	408
168cf367	409	if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
e87666b5	410	return NOTIFY_DONE;
e87666b5	411
8ef8561f	412	/* Force everything onto the inactive lists */
6e5a5beb	413	ret = i915_gem_wait_for_idle(dev_priv);
8ef8561f CW	414	if (ret)
	415	goto out;
	416
ea9d9768	417	intel_runtime_pm_get(dev_priv);
8ef8561f CW	418	freed_pages += i915_gem_shrink(dev_priv, -1UL,
	419	I915_SHRINK_BOUND \|
	420	I915_SHRINK_UNBOUND \|
	421	I915_SHRINK_ACTIVE \|
	422	I915_SHRINK_VMAPS);
ea9d9768	423	intel_runtime_pm_put(dev_priv);
8ef8561f CW	424
	425	/* We also want to clear any cached iomaps as they wrap vmap */
	426	list_for_each_entry_safe(vma, next,
	427	&dev_priv->ggtt.base.inactive_list, vm_link) {
	428	unsigned long count = vma->node.size >> PAGE_SHIFT;
	429	if (vma->iomap && i915_vma_unbind(vma) == 0)
	430	freed_pages += count;
	431	}
e87666b5	432
8ef8561f	433	out:
168cf367	434	i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);
e87666b5 CW	435
	436	(unsigned long )ptr += freed_pages;
	437	return NOTIFY_DONE;
	438	}
	439
eb0b44ad DV	440	/**
	441	* i915_gem_shrinker_init - Initialize i915 shrinker
	442	* @dev_priv: i915 device
	443	*
	444	* This function registers and sets up the i915 shrinker and OOM handler.
	445	*/
be6a0376 DV	446	void i915_gem_shrinker_init(struct drm_i915_private *dev_priv)
	447	{
	448	dev_priv->mm.shrinker.scan_objects = i915_gem_shrinker_scan;
	449	dev_priv->mm.shrinker.count_objects = i915_gem_shrinker_count;
	450	dev_priv->mm.shrinker.seeks = DEFAULT_SEEKS;
a8a40589	451	WARN_ON(register_shrinker(&dev_priv->mm.shrinker));
be6a0376 DV	452
be6a0376 DV	453	dev_priv->mm.oom_notifier.notifier_call = i915_gem_shrinker_oom;
a8a40589	454	WARN_ON(register_oom_notifier(&dev_priv->mm.oom_notifier));
e87666b5 CW	455
	456	dev_priv->mm.vmap_notifier.notifier_call = i915_gem_shrinker_vmap;
	457	WARN_ON(register_vmap_purge_notifier(&dev_priv->mm.vmap_notifier));
a8a40589 ID	458	}
	459
	460	/**
	461	* i915_gem_shrinker_cleanup - Clean up i915 shrinker
	462	* @dev_priv: i915 device
	463	*
	464	* This function unregisters the i915 shrinker and OOM handler.
	465	*/
	466	void i915_gem_shrinker_cleanup(struct drm_i915_private *dev_priv)
	467	{
e87666b5	468	WARN_ON(unregister_vmap_purge_notifier(&dev_priv->mm.vmap_notifier));
a8a40589 ID	469	WARN_ON(unregister_oom_notifier(&dev_priv->mm.oom_notifier));
a8a40589 ID	470	unregister_shrinker(&dev_priv->mm.shrinker);
be6a0376	471	}