text:
/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */

#include "ttm/ttm_module.h"
#include "ttm/ttm_bo_driver.h"
#include "ttm/ttm_placement.h"
#include <linux/jiffies.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/file.h>
#include <linux/module.h>

#define TTM_ASSERT_LOCKED(param)
#define TTM_DEBUG(fmt, arg...)
#define TTM_BO_HASH_ORDER 13

static int ttm_bo_setup_vm(struct ttm_buffer_object *bo);
static int ttm_bo_swapout(struct ttm_mem_shrink *shrink);
static void ttm_bo_global_kobj_release(struct kobject *kobj);

static struct attribute ttm_bo_count = {
	.name = "bo_count",
	.mode = S_IRUGO
};

static ssize_t ttm_bo_global_show(struct kobject *kobj,
				  struct attribute *attr,
				  char *buffer)
{
	struct ttm_bo_global *glob =
		container_of(kobj, struct ttm_bo_global, kobj);

	return snprintf(buffer, PAGE_SIZE, "%lu\n",
			(unsigned long) atomic_read(&glob->bo_count));
}

static struct attribute *ttm_bo_global_attrs[] = {
	&ttm_bo_count,
	NULL
};

static struct sysfs_ops ttm_bo_global_ops = {
	.show = &ttm_bo_global_show
};

static struct kobj_type ttm_bo_glob_kobj_type  = {
	.release = &ttm_bo_global_kobj_release,
	.sysfs_ops = &ttm_bo_global_ops,
	.default_attrs = ttm_bo_global_attrs
};

static inline uint32_t ttm_bo_type_flags(unsigned type)
{
	return 1 << (type);
}

static void ttm_bo_release_list(struct kref *list_kref)
{
	struct ttm_buffer_object *bo =
	    container_of(list_kref, struct ttm_buffer_object, list_kref);
	struct ttm_bo_device *bdev = bo->bdev;

	BUG_ON(atomic_read(&bo->list_kref.refcount));
	BUG_ON(atomic_read(&bo->kref.refcount));
	BUG_ON(atomic_read(&bo->cpu_writers));
	BUG_ON(bo->sync_obj != NULL);
	BUG_ON(bo->mem.mm_node != NULL);
	BUG_ON(!list_empty(&bo->lru));
	BUG_ON(!list_empty(&bo->ddestroy));

	if (bo->ttm)
		ttm_tt_destroy(bo->ttm);
	atomic_dec(&bo->glob->bo_count);
	if (bo->destroy)
		bo->destroy(bo);
	else {
		ttm_mem_global_free(bdev->glob->mem_glob, bo->acc_size);
		kfree(bo);
	}
}

int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo, bool interruptible)
{

	if (interruptible) {
		int ret = 0;

		ret = wait_event_interruptible(bo->event_queue,
					       atomic_read(&bo->reserved) == 0);
		if (unlikely(ret != 0))
			return -ERESTART;
	} else {
		wait_event(bo->event_queue, atomic_read(&bo->reserved) == 0);
	}
	return 0;
}

static void ttm_bo_add_to_lru(struct ttm_buffer_object *bo)
{
	struct ttm_bo_device *bdev = bo->bdev;
	struct ttm_mem_type_manager *man;

	BUG_ON(!atomic_read(&bo->reserved));

	if (!(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {

		BUG_ON(!list_empty(&bo->lru));

		man = &bdev->man[bo->mem.mem_type];
		list_add_tail(&bo->lru, &man->lru);
		kref_get(&bo->list_kref);

		if (bo->ttm != NULL) {
			list_add_tail(&bo->swap, &bo->glob->swap_lru);
			kref_get(&bo->list_kref);
		}
	}
}

/**
 * Call with the lru_lock held.
 */

static int ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
{
	int put_count = 0;

	if (!list_empty(&bo->swap)) {
		list_del_init(&bo->swap);
		++put_count;
	}
	if (!list_empty(&bo->lru)) {
		list_del_init(&bo->lru);
		++put_count;
	}

	/*
	 * TODO: Add a driver hook to delete from
	 * driver-specific LRU's here.
	 */

	return put_count;
}

int ttm_bo_reserve_locked(struct ttm_buffer_object *bo,
			  bool interruptible,
			  bool no_wait, bool use_sequence, uint32_t sequence)
{
	struct ttm_bo_global *glob = bo->glob;
	int ret;

	while (unlikely(atomic_cmpxchg(&bo->reserved, 0, 1) != 0)) {
		if (use_sequence && bo->seq_valid &&
			(sequence - bo->val_seq < (1 << 31))) {
			return -EAGAIN;
		}

		if (no_wait)
			return -EBUSY;

		spin_unlock(&glob->lru_lock);
		ret = ttm_bo_wait_unreserved(bo, interruptible);
		spin_lock(&glob->lru_lock);

		if (unlikely(ret))
			return ret;
	}

	if (use_sequence) {
		bo->val_seq = sequence;
		bo->seq_valid = true;
	} else {
		bo->seq_valid = false;
	}

	return 0;
}
EXPORT_SYMBOL(ttm_bo_reserve);

static void ttm_bo_ref_bug(struct kref *list_kref)
{
	BUG();
}

int ttm_bo_reserve(struct ttm_buffer_object *bo,
		   bool interruptible,
		   bool no_wait, bool use_sequence, uint32_t sequence)
{
	struct ttm_bo_global *glob = bo->glob;
	int put_count = 0;
	int ret;

	spin_lock(&glob->lru_lock);
	ret = ttm_bo_reserve_locked(bo, interruptible, no_wait, use_sequence,
				    sequence);
	if (likely(ret == 0))
		put_count = ttm_bo_del_from_lru(bo);
	spin_unlock(&glob->lru_lock);

	while (put_count--)
		kref_put(&bo->list_kref, ttm_bo_ref_bug);

	return ret;
}

void ttm_bo_unreserve(struct ttm_buffer_object *bo)
{
	struct ttm_bo_global *glob = bo->glob;

	spin_lock(&glob->lru_lock);
	ttm_bo_add_to_lru(bo);
	atomic_set(&bo->reserved, 0);
	wake_up_all(&bo->event_queue);
	spin_unlock(&glob->lru_lock);
}
EXPORT_SYMBOL(ttm_bo_unreserve);

/*
 * Call bo->mutex locked.
 */

static int ttm_bo_add_ttm(struct ttm_buffer_object *bo, bool zero_alloc)
{
	struct ttm_bo_device *bdev = bo->bdev;
	struct ttm_bo_global *glob = bo->glob;
	int ret = 0;
	uint32_t page_flags = 0;

	TTM_ASSERT_LOCKED(&bo->mutex);
	bo->ttm = NULL;

	if (bdev->need_dma32)
		page_flags |= TTM_PAGE_FLAG_DMA32;

	switch (bo->type) {
	case ttm_bo_type_device:
		if (zero_alloc)
			page_flags |= TTM_PAGE_FLAG_ZERO_ALLOC;
	case ttm_bo_type_kernel:
		bo->ttm = ttm_tt_create(bdev, bo->num_pages << PAGE_SHIFT,
					page_flags, glob->dummy_read_page);
		if (unlikely(bo->ttm == NULL))
			ret = -ENOMEM;
		break;
	case ttm_bo_type_user:
		bo->ttm = ttm_tt_create(bdev, bo->num_pages << PAGE_SHIFT,
					page_flags | TTM_PAGE_FLAG_USER,
					glob->dummy_read_page);
		if (unlikely(bo->ttm == NULL))
			ret = -ENOMEM;
		break;

		ret = ttm_tt_set_user(bo->ttm, current,
				      bo->buffer_start, bo->num_pages);
		if (unlikely(ret != 0))
			ttm_tt_destroy(bo->ttm);
		break;
	default:
		printk(KERN_ERR TTM_PFX "Illegal buffer object type\n");
		ret = -EINVAL;
		break;
	}

	return ret;
}

static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
				  struct ttm_mem_reg *mem,
				  bool evict, bool interruptible, bool no_wait)
{
	struct ttm_bo_device *bdev = bo->bdev;
	bool old_is_pci = ttm_mem_reg_is_pci(bdev, &bo->mem);
	bool new_is_pci = ttm_mem_reg_is_pci(bdev, mem);
	struct ttm_mem_type_manager *old_man = &bdev->man[bo->mem.mem_type];
	struct ttm_mem_type_manager *new_man = &bdev->man[mem->mem_type];
	int ret = 0;

	if (old_is_pci || new_is_pci ||
	    ((mem->placement & bo->mem.placement & TTM_PL_MASK_CACHING) == 0))
		ttm_bo_unmap_virtual(bo);

	/*
	 * Create and bind a ttm if required.
	 */

	if (!(new_man->flags & TTM_MEMTYPE_FLAG_FIXED) && (bo->ttm == NULL)) {
		ret = ttm_bo_add_ttm(bo, false);
		if (ret)
			goto out_err;

		ret = ttm_tt_set_placement_caching(bo->ttm, mem->placement);
		if (ret)
			goto out_err;

		if (mem->mem_type != TTM_PL_SYSTEM) {
			ret = ttm_tt_bind(bo->ttm, mem);
			if (ret)
				goto out_err;
		}

		if (bo->mem.mem_type == TTM_PL_SYSTEM) {

			struct ttm_mem_reg *old_mem = &bo->mem;
			uint32_t save_flags = old_mem->placement;

			*old_mem = *mem;
			mem->mm_node = NULL;
			ttm_flag_masked(&save_flags, mem->placement,
					TTM_PL_MASK_MEMTYPE);
			goto moved;
		}

	}

	if (bdev->driver->move_notify)
		bdev->driver->move_notify(bo, mem);

	if (!(old_man->flags & TTM_MEMTYPE_FLAG_FIXED) &&
	    !(new_man->flags & TTM_MEMTYPE_FLAG_FIXED))
		ret = ttm_bo_move_ttm(bo, evict, no_wait, mem);
	else if (bdev->driver->move)
		ret = bdev->driver->move(bo, evict, interruptible,
					 no_wait, mem);
	else
		ret = ttm_bo_move_memcpy(bo, evict, no_wait, mem);

	if (ret)
		goto out_err;

moved:
	if (bo->evicted) {
		ret = bdev->driver->invalidate_caches(bdev, bo->mem.placement);
		if (ret)
			printk(KERN_ERR TTM_PFX "Can not flush read caches\n");
		bo->evicted = false;
	}

	if (bo->mem.mm_node) {
		spin_lock(&bo->lock);
		bo->offset = (bo->mem.mm_node->start << PAGE_SHIFT) +
		    bdev->man[bo->mem.mem_type].gpu_offset;
		bo->cur_placement = bo->mem.placement;
		spin_unlock(&bo->lock);
	}

	return 0;

out_err:
	new_man = &bdev->man[bo->mem.mem_type];
	if ((new_man->flags & TTM_MEMTYPE_FLAG_FIXED) && bo->ttm) {
		ttm_tt_unbind(bo->ttm);
		ttm_tt_destroy(bo->ttm);
		bo->ttm = NULL;
	}

	return ret;
}

/**
 * If bo idle, remove from delayed- and lru lists, and unref.
 * If not idle, and already on delayed list, do nothing.
 * If not idle, and not on delayed list, put on delayed list,
 *   up the list_kref and schedule a delayed list check.
 */

static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
{
	struct ttm_bo_device *bdev = bo->bdev;
	struct ttm_bo_global *glob = bo->glob;
	struct ttm_bo_driver *driver = bdev->driver;
	int ret;

	spin_lock(&bo->lock);
	(void) ttm_bo_wait(bo, false, false, !remove_all);

	if (!bo->sync_obj) {
		int put_count;

		spin_unlock(&bo->lock);

		spin_lock(&glob->lru_lock);
		ret = ttm_bo_reserve_locked(bo, false, false, false, 0);
		BUG_ON(ret);
		if (bo->ttm)
			ttm_tt_unbind(bo->ttm);

		if (!list_empty(&bo->ddestroy)) {
			list_del_init(&bo->ddestroy);
			kref_put(&bo->list_kref, ttm_bo_ref_bug);
		}
		if (bo->mem.mm_node) {
			drm_mm_put_block(bo->mem.mm_node);
			bo->mem.mm_node = NULL;
		}
		put_count = ttm_bo_del_from_lru(bo);
		spin_unlock(&glob->lru_lock);

		atomic_set(&bo->reserved, 0);

		while (put_count--)
			kref_put(&bo->list_kref, ttm_bo_release_list);

		return 0;
	}

	spin_lock(&glob->lru_lock);
	if (list_empty(&bo->ddestroy)) {
		void *sync_obj = bo->sync_obj;
		void *sync_obj_arg = bo->sync_obj_arg;

		kref_get(&bo->list_kref);
		list_add_tail(&bo->ddestroy, &bdev->ddestroy);
		spin_unlock(&glob->lru_lock);
		spin_unlock(&bo->lock);

		if (sync_obj)
			driver->sync_obj_flush(sync_obj, sync_obj_arg);
		schedule_delayed_work(&bdev->wq,
				      ((HZ / 100) < 1) ? 1 : HZ / 100);
		ret = 0;

	} else {
		spin_unlock(&glob->lru_lock);
		spin_unlock(&bo->lock);
		ret = -EBUSY;
	}

	return ret;
}

/**
 * Traverse the delayed list, and call ttm_bo_cleanup_refs on all
 * encountered buffers.
 */

static int ttm_bo_delayed_delete(struct ttm_bo_device *bdev, bool remove_all)
{
	struct ttm_bo_global *glob = bdev->glob;
	struct ttm_buffer_object *entry, *nentry;
	struct list_head *list, *next;
	int ret;

	spin_lock(&glob->lru_lock);
	list_for_each_safe(list, next, &bdev->ddestroy) {
		entry = list_entry(list, struct ttm_buffer_object, ddestroy);
		nentry = NULL;

		/*
		 * Protect the next list entry from destruction while we
		 * unlock the lru_lock.
		 */

		if (next != &bdev->ddestroy) {
			nentry = list_entry(next, struct ttm_buffer_object,
					    ddestroy);
			kref_get(&nentry->list_kref);
		}
		kref_get(&entry->list_kref);

		spin_unlock(&glob->lru_lock);
		ret = ttm_bo_cleanup_refs(entry, remove_all);
		kref_put(&entry->list_kref, ttm_bo_release_list);

		spin_lock(&glob->lru_lock);
		if (nentry) {
			bool next_onlist = !list_empty(next);
			spin_unlock(&glob->lru_lock);
			kref_put(&nentry->list_kref, ttm_bo_release_list);
			spin_lock(&glob->lru_lock);
			/*
			 * Someone might have raced us and removed the
			 * next entry from the list. We don't bother restarting
			 * list traversal.
			 */

			if (!next_onlist)
				break;
		}
		if (ret)
			break;
	}
	ret = !list_empty(&bdev->ddestroy);
	spin_unlock(&glob->lru_lock);

	return ret;
}

static void ttm_bo_delayed_workqueue(struct work_struct *work)
{
	struct ttm_bo_device *bdev =
	    container_of(work, struct ttm_bo_device, wq.work);

	if (ttm_bo_delayed_delete(bdev, false)) {
		schedule_delayed_work(&bdev->wq,
				      ((HZ / 100) < 1) ? 1 : HZ / 100);
	}
}

static void ttm_bo_release(struct kref *kref)
{
	struct ttm_buffer_object *bo =
	    container_of(kref, struct ttm_buffer_object, kref);
	struct ttm_bo_device *bdev = bo->bdev;

	if (likely(bo->vm_node != NULL)) {
		rb_erase(&bo->vm_rb, &bdev->addr_space_rb);
		drm_mm_put_block(bo->vm_node);
		bo->vm_node = NULL;
	}
	write_unlock(&bdev->vm_lock);
	ttm_bo_cleanup_refs(bo, false);
	kref_put(&bo->list_kref, ttm_bo_release_list);
	write_lock(&bdev->vm_lock);
}

void ttm_bo_unref(struct ttm_buffer_object **p_bo)
{
	struct ttm_buffer_object *bo = *p_bo;
	struct ttm_bo_device *bdev = bo->bdev;

	*p_bo = NULL;
	write_lock(&bdev->vm_lock);
	kref_put(&bo->kref, ttm_bo_release);
	write_unlock(&bdev->vm_lock);
}
EXPORT_SYMBOL(ttm_bo_unref);

static int ttm_bo_evict(struct ttm_buffer_object *bo, unsigned mem_type,
			bool interruptible, bool no_wait)
{
	int ret = 0;
	struct ttm_bo_device *bdev = bo->bdev;
	struct ttm_bo_global *glob = bo->glob;
	struct ttm_mem_reg evict_mem;
	uint32_t proposed_placement;

	if (bo->mem.mem_type != mem_type)
		goto out;

	spin_lock(&bo->lock);
	ret = ttm_bo_wait(bo, false, interruptible, no_wait);
	spin_unlock(&bo->lock);

	if (unlikely(ret != 0)) {
		if (ret != -ERESTART) {
			printk(KERN_ERR TTM_PFX
			       "Failed to expire sync object before "
			       "buffer eviction.\n");
		}
		goto out;
	}

	BUG_ON(!atomic_read(&bo->reserved));

	evict_mem = bo->mem;
	evict_mem.mm_node = NULL;

	proposed_placement = bdev->driver->evict_flags(bo);

	ret = ttm_bo_mem_space(bo, proposed_placement,
			       &evict_mem, interruptible, no_wait);
	if (unlikely(ret != 0 && ret != -ERESTART))
		ret = ttm_bo_mem_space(bo, TTM_PL_FLAG_SYSTEM,
				       &evict_mem, interruptible, no_wait);

	if (ret) {
		if (ret != -ERESTART)
			printk(KERN_ERR TTM_PFX
			       "Failed to find memory space for "
			       "buffer 0x%p eviction.\n", bo);
		goto out;
	}

	ret = ttm_bo_handle_move_mem(bo, &evict_mem, true, interruptible,
				     no_wait);
	if (ret) {
		if (ret != -ERESTART)
			printk(KERN_ERR TTM_PFX "Buffer eviction failed\n");
		goto out;
	}

	spin_lock(&glob->lru_lock);
	if (evict_mem.mm_node) {
		drm_mm_put_block(evict_mem.mm_node);
		evict_mem.mm_node = NULL;
	}
	spin_unlock(&glob->lru_lock);
	bo->evicted = true;
out:
	return ret;
}

/**
 * Repeatedly evict memory from the LRU for @mem_type until we create enough
 * space, or we've evicted everything and there isn't enough space.
 */
static int ttm_bo_mem_force_space(struct ttm_bo_device *bdev,
				  struct ttm_mem_reg *mem,
				  uint32_t mem_type,
				  bool interruptible, bool no_wait)
{
	struct ttm_bo_global *glob = bdev->glob;
	struct drm_mm_node *node;
	struct ttm_buffer_object *entry;
	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
	struct list_head *lru;
	unsigned long num_pages = mem->num_pages;
	int put_count = 0;
	int ret;

retry_pre_get:
	ret = drm_mm_pre_get(&man->manager);
	if (unlikely(ret != 0))
		return ret;

	spin_lock(&glob->lru_lock);
	do {
		node = drm_mm_search_free(&man->manager, num_pages,
					  mem->page_alignment, 1);
		if (node)
			break;

		lru = &man->lru;
		if (list_empty(lru))
			break;

		entry = list_first_entry(lru, struct ttm_buffer_object, lru);
		kref_get(&entry->list_kref);

		ret =
		    ttm_bo_reserve_locked(entry, interruptible, no_wait,
					  false, 0);

		if (likely(ret == 0))
			put_count = ttm_bo_del_from_lru(entry);

		spin_unlock(&glob->lru_lock);

		if (unlikely(ret != 0))
			return ret;

		while (put_count--)
			kref_put(&entry->list_kref, ttm_bo_ref_bug);

		ret = ttm_bo_evict(entry, mem_type, interruptible, no_wait);

		ttm_bo_unreserve(entry);

		kref_put(&entry->list_kref, ttm_bo_release_list);
		if (ret)
			return ret;

		spin_lock(&glob->lru_lock);
	} while (1);

	if (!node) {
		spin_unlock(&glob->lru_lock);
		return -ENOMEM;
	}

	node = drm_mm_get_block_atomic(node, num_pages, mem->page_alignment);
	if (unlikely(!node)) {
		spin_unlock(&glob->lru_lock);
		goto retry_pre_get;
	}

	spin_unlock(&glob->lru_lock);
	mem->mm_node = node;
	mem->mem_type = mem_type;
	return 0;
}

static uint32_t ttm_bo_select_caching(struct ttm_mem_type_manager *man,
				      uint32_t cur_placement,
				      uint32_t proposed_placement)
{
	uint32_t caching = proposed_placement & TTM_PL_MASK_CACHING;
	uint32_t result = proposed_placement & ~TTM_PL_MASK_CACHING;

	/**
	 * Keep current caching if possible.
	 */

	if ((cur_placement & caching) != 0)
		result |= (cur_placement & caching);
	else if ((man->default_caching & caching) != 0)
		result |= man->default_caching;
	else if ((TTM_PL_FLAG_CACHED & caching) != 0)
		result |= TTM_PL_FLAG_CACHED;
	else if ((TTM_PL_FLAG_WC & caching) != 0)
		result |= TTM_PL_FLAG_WC;
	else if ((TTM_PL_FLAG_UNCACHED & caching) != 0)
		result |= TTM_PL_FLAG_UNCACHED;

	return result;
}

static bool ttm_bo_mt_compatible(struct ttm_mem_type_manager *man,
				 bool disallow_fixed,
				 uint32_t mem_type,
				 uint32_t proposed_placement,
				 uint32_t *masked_placement)
{
	uint32_t cur_flags = ttm_bo_type_flags(mem_type);

	if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) && disallow_fixed)
		return false;

	if ((cur_flags & proposed_placement & TTM_PL_MASK_MEM) == 0)
		return false;

	if ((proposed_placement & man->available_caching) == 0)
		return false;

	cur_flags |= (proposed_placement & man->available_caching);

	*masked_placement = cur_flags;
	return true;
}

/**
 * Creates space for memory region @mem according to its type.
 *
 * This function first searches for free space in compatible memory types in
 * the priority order defined by the driver.  If free space isn't found, then
 * ttm_bo_mem_force_space is attempted in priority order to evict and find
 * space.
 */
int ttm_bo_mem_space(struct ttm_buffer_object *bo,
		     uint32_t proposed_placement,
		     struct ttm_mem_reg *mem,
		     bool interruptible, bool no_wait)
{
	struct ttm_bo_device *bdev = bo->bdev;
	struct ttm_bo_global *glob = bo->glob;
	struct ttm_mem_type_manager *man;

	uint32_t num_prios = bdev->driver->num_mem_type_prio;
	const uint32_t *prios = bdev->driver->mem_type_prio;
	uint32_t i;
	uint32_t mem_type = TTM_PL_SYSTEM;
	uint32_t cur_flags = 0;
	bool type_found = false;
	bool type_ok = false;
	bool has_eagain = false;
	struct drm_mm_node *node = NULL;
	int ret;

	mem->mm_node = NULL;
	for (i = 0; i < num_prios; ++i) {
		mem_type = prios[i];
		man = &bdev->man[mem_type];

		type_ok = ttm_bo_mt_compatible(man,
					       bo->type == ttm_bo_type_user,
					       mem_type, proposed_placement,
					       &cur_flags);

		if (!type_ok)
			continue;

		cur_flags = ttm_bo_select_caching(man, bo->mem.placement,
						  cur_flags);

		if (mem_type == TTM_PL_SYSTEM)
			break;

		if (man->has_type && man->use_type) {
			type_found = true;
			do {
				ret = drm_mm_pre_get(&man->manager);
				if (unlikely(ret))
					return ret;

				spin_lock(&glob->lru_lock);
				node = drm_mm_search_free(&man->manager,
							  mem->num_pages,
							  mem->page_alignment,
							  1);
				if (unlikely(!node)) {
					spin_unlock(&glob->lru_lock);
					break;
				}
				node = drm_mm_get_block_atomic(node,
							       mem->num_pages,
							       mem->
							       page_alignment);
				spin_unlock(&glob->lru_lock);
			} while (!node);
		}
		if (node)
			break;
	}

	if ((type_ok && (mem_type == TTM_PL_SYSTEM)) || node) {
		mem->mm_node = node;
		mem->mem_type = mem_type;
		mem->placement = cur_flags;
		return 0;
	}

	if (!type_found)
		return -EINVAL;

	num_prios = bdev->driver->num_mem_busy_prio;
	prios = bdev->driver->mem_busy_prio;

	for (i = 0; i < num_prios; ++i) {
		mem_type = prios[i];
		man = &bdev->man[mem_type];

		if (!man->has_type)
			continue;

		if (!ttm_bo_mt_compatible(man,
					  bo->type == ttm_bo_type_user,
					  mem_type,
					  proposed_placement, &cur_flags))
			continue;

		cur_flags = ttm_bo_select_caching(man, bo->mem.placement,
						  cur_flags);

		ret = ttm_bo_mem_force_space(bdev, mem, mem_type,
					     interruptible, no_wait);

		if (ret == 0 && mem->mm_node) {
			mem->placement = cur_flags;
			return 0;
		}

		if (ret == -ERESTART)
			has_eagain = true;
	}

	ret = (has_eagain) ? -ERESTART : -ENOMEM;
	return ret;
}
EXPORT_SYMBOL(ttm_bo_mem_space);

int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait)
{
	int ret = 0;

	if ((atomic_read(&bo->cpu_writers) > 0) && no_wait)
		return -EBUSY;

	ret = wait_event_interruptible(bo->event_queue,
				       atomic_read(&bo->cpu_writers) == 0);

	if (ret == -ERESTARTSYS)
		ret = -ERESTART;

	return ret;
}

int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
		       uint32_t proposed_placement,
		       bool interruptible, bool no_wait)
{
	struct ttm_bo_global *glob = bo->glob;
	int ret = 0;
	struct ttm_mem_reg mem;

	BUG_ON(!atomic_read(&bo->reserved));

	/*
	 * FIXME: It's possible to pipeline buffer moves.
	 * Have the driver move function wait for idle when necessary,
	 * instead of doing it here.
	 */

	spin_lock(&bo->lock);
	ret = ttm_bo_wait(bo, false, interruptible, no_wait);
	spin_unlock(&bo->lock);

	if (ret)
		return ret;

	mem.num_pages = bo->num_pages;
	mem.size = mem.num_pages << PAGE_SHIFT;
	mem.page_alignment = bo->mem.page_alignment;

	/*
	 * Determine where to move the buffer.
	 */

	ret = ttm_bo_mem_space(bo, proposed_placement, &mem,
			       interruptible, no_wait);
	if (ret)
		goto out_unlock;

	ret = ttm_bo_handle_move_mem(bo, &mem, false, interruptible, no_wait);

out_unlock:
	if (ret && mem.mm_node) {
		spin_lock(&glob->lru_lock);
		drm_mm_put_block(mem.mm_node);
		spin_unlock(&glob->lru_lock);
	}
	return ret;
}

static int ttm_bo_mem_compat(uint32_t proposed_placement,
			     struct ttm_mem_reg *mem)
{
	if ((proposed_placement & mem->placement & TTM_PL_MASK_MEM) == 0)
		return 0;
	if ((proposed_placement & mem->placement & TTM_PL_MASK_CACHING) == 0)
		return 0;

	return 1;
}

int ttm_buffer_object_validate(struct ttm_buffer_object *bo,
			       uint32_t proposed_placement,
			       bool interruptible, bool no_wait)
{
	int ret;

	BUG_ON(!atomic_read(&bo->reserved));
	bo->proposed_placement = proposed_placement;

	TTM_DEBUG("Proposed placement 0x%08lx, Old flags 0x%08lx\n",
		  (unsigned long)proposed_placement,
		  (unsigned long)bo->mem.placement);

	/*
	 * Check whether we need to move buffer.
	 */

	if (!ttm_bo_mem_compat(bo->proposed_placement, &bo->mem)) {
		ret = ttm_bo_move_buffer(bo, bo->proposed_placement,
					 interruptible, no_wait);
		if (ret) {
			if (ret != -ERESTART)
				printk(KERN_ERR TTM_PFX
				       "Failed moving buffer. "
				       "Proposed placement 0x%08x\n",
				       bo->proposed_placement);
			if (ret == -ENOMEM)
				printk(KERN_ERR TTM_PFX
				       "Out of aperture space or "
				       "DRM memory quota.\n");
			return ret;
		}
	}

	/*
	 * We might need to add a TTM.
	 */

	if (bo->mem.mem_type == TTM_PL_SYSTEM && bo->ttm == NULL) {
		ret = ttm_bo_add_ttm(bo, true);
		if (ret)
			return ret;
	}
	/*
	 * Validation has succeeded, move the access and other
	 * non-mapping-related flag bits from the proposed flags to
	 * the active flags
	 */

	ttm_flag_masked(&bo->mem.placement, bo->proposed_placement,
			~TTM_PL_MASK_MEMTYPE);

	return 0;
}
EXPORT_SYMBOL(ttm_buffer_object_validate);

int
ttm_bo_check_placement(struct ttm_buffer_object *bo,
		       uint32_t set_flags, uint32_t clr_flags)
{
	uint32_t new_mask = set_flags | clr_flags;

	if ((bo->type == ttm_bo_type_user) &&
	    (clr_flags & TTM_PL_FLAG_CACHED)) {
		printk(KERN_ERR TTM_PFX
		       "User buffers require cache-coherent memory.\n");
		return -EINVAL;
	}

	if (!capable(CAP_SYS_ADMIN)) {
		if (new_mask & TTM_PL_FLAG_NO_EVICT) {
			printk(KERN_ERR TTM_PFX "Need to be root to modify"
			       " NO_EVICT status.\n");
			return -EINVAL;
		}

		if ((clr_flags & bo->mem.placement & TTM_PL_MASK_MEMTYPE) &&
		    (bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
			printk(KERN_ERR TTM_PFX
			       "Incompatible memory specification"
			       " for NO_EVICT buffer.\n");
			return -EINVAL;
		}
	}
	return 0;
}

int ttm_buffer_object_init(struct ttm_bo_device *bdev,
			   struct ttm_buffer_object *bo,
			   unsigned long size,
			   enum ttm_bo_type type,
			   uint32_t flags,
			   uint32_t page_alignment,
			   unsigned long buffer_start,
			   bool interruptible,
			   struct file *persistant_swap_storage,
			   size_t acc_size,
			   void (*destroy) (struct ttm_buffer_object *))
{
	int ret = 0;
	unsigned long num_pages;

	size += buffer_start & ~PAGE_MASK;
	num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
	if (num_pages == 0) {
		printk(KERN_ERR TTM_PFX "Illegal buffer object size.\n");
		return -EINVAL;
	}
	bo->destroy = destroy;

	spin_lock_init(&bo->lock);
	kref_init(&bo->kref);
	kref_init(&bo->list_kref);
	atomic_set(&bo->cpu_writers, 0);
	atomic_set(&bo->reserved, 1);
	init_waitqueue_head(&bo->event_queue);
	INIT_LIST_HEAD(&bo->lru);
	INIT_LIST_HEAD(&bo->ddestroy);
	INIT_LIST_HEAD(&bo->swap);
	bo->bdev = bdev;
	bo->glob = bdev->glob;
	bo->type = type;
	bo->num_pages = num_pages;
	bo->mem.mem_type = TTM_PL_SYSTEM;
	bo->mem.num_pages = bo->num_pages;
	bo->mem.mm_node = NULL;
	bo->mem.page_alignment = page_alignment;
	bo->buffer_start = buffer_start & PAGE_MASK;
	bo->priv_flags = 0;
	bo->mem.placement = (TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED);
	bo->seq_valid = false;
	bo->persistant_swap_storage = persistant_swap_storage;
	bo->acc_size = acc_size;
	atomic_inc(&bo->glob->bo_count);

	ret = ttm_bo_check_placement(bo, flags, 0ULL);
	if (unlikely(ret != 0))
		goto out_err;

	/*
	 * If no caching attributes are set, accept any form of caching.
	 */

	if ((flags & TTM_PL_MASK_CACHING) == 0)
		flags |= TTM_PL_MASK_CACHING;

	/*
	 * For ttm_bo_type_device buffers, allocate
	 * address space from the device.
	 */

	if (bo->type == ttm_bo_type_device) {
		ret = ttm_bo_setup_vm(bo);
		if (ret)
			goto out_err;
	}

	ret = ttm_buffer_object_validate(bo, flags, interruptible, false);
	if (ret)
		goto out_err;

	ttm_bo_unreserve(bo);
	return 0;

out_err:
	ttm_bo_unreserve(bo);
	ttm_bo_unref(&bo);

	return ret;
}
EXPORT_SYMBOL(ttm_buffer_object_init);

static inline size_t ttm_bo_size(struct ttm_bo_global *glob,
				 unsigned long num_pages)
{
	size_t page_array_size = (num_pages * sizeof(void *) + PAGE_SIZE - 1) &
	    PAGE_MASK;

	return glob->ttm_bo_size + 2 * page_array_size;
}

int ttm_buffer_object_create(struct ttm_bo_device *bdev,
			     unsigned long size,
			     enum ttm_bo_type type,
			     uint32_t flags,
			     uint32_t page_alignment,
			     unsigned long buffer_start,
			     bool interruptible,
			     struct file *persistant_swap_storage,
			     struct ttm_buffer_object **p_bo)
{
	struct ttm_buffer_object *bo;
	int ret;
	struct ttm_mem_global *mem_glob = bdev->glob->mem_glob;

	size_t acc_size =
	    ttm_bo_size(bdev->glob, (size + PAGE_SIZE - 1) >> PAGE_SHIFT);
	ret = ttm_mem_global_alloc(mem_glob, acc_size, false, false);
	if (unlikely(ret != 0))
		return ret;

	bo = kzalloc(sizeof(*bo), GFP_KERNEL);

	if (unlikely(bo == NULL)) {
		ttm_mem_global_free(mem_glob, acc_size);
		return -ENOMEM;
	}

	ret = ttm_buffer_object_init(bdev, bo, size, type, flags,
				     page_alignment, buffer_start,
				     interruptible,
				     persistant_swap_storage, acc_size, NULL);
	if (likely(ret == 0))
		*p_bo = bo;

	return ret;
}

static int ttm_bo_leave_list(struct ttm_buffer_object *bo,
			     uint32_t mem_type, bool allow_errors)
{
	int ret;

	spin_lock(&bo->lock);
	ret = ttm_bo_wait(bo, false, false, false);
	spin_unlock(&bo->lock);

	if (ret && allow_errors)
		goto out;

	if (bo->mem.mem_type == mem_type)
		ret = ttm_bo_evict(bo, mem_type, false, false);

	if (ret) {
		if (allow_errors) {
			goto out;
		} else {
			ret = 0;
			printk(KERN_ERR TTM_PFX "Cleanup eviction failed\n");
		}
	}

out:
	return ret;
}

static int ttm_bo_force_list_clean(struct ttm_bo_device *bdev,
				   struct list_head *head,
				   unsigned mem_type, bool allow_errors)
{
	struct ttm_bo_global *glob = bdev->glob;
	struct ttm_buffer_object *entry;
	int ret;
	int put_count;

	/*
	 * Can't use standard list traversal since we're unlocking.
	 */

	spin_lock(&glob->lru_lock);

	while (!list_empty(head)) {
		entry = list_first_entry(head, struct ttm_buffer_object, lru);
		kref_get(&entry->list_kref);
		ret = ttm_bo_reserve_locked(entry, false, false, false, 0);
		put_count = ttm_bo_del_from_lru(entry);
		spin_unlock(&glob->lru_lock);
		while (put_count--)
			kref_put(&entry->list_kref, ttm_bo_ref_bug);
		BUG_ON(ret);
		ret = ttm_bo_leave_list(entry, mem_type, allow_errors);
		ttm_bo_unreserve(entry);
		kref_put(&entry->list_kref, ttm_bo_release_list);
		spin_lock(&glob->lru_lock);
	}

	spin_unlock(&glob->lru_lock);

	return 0;
}

int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type)
{
	struct ttm_bo_global *glob = bdev->glob;
	struct ttm_mem_type_manager *man;
	int ret = -EINVAL;

	if (mem_type >= TTM_NUM_MEM_TYPES) {
		printk(KERN_ERR TTM_PFX "Illegal memory type %d\n", mem_type);
		return ret;
	}
	man = &bdev->man[mem_type];

	if (!man->has_type) {
		printk(KERN_ERR TTM_PFX "Trying to take down uninitialized "
		       "memory manager type %u\n", mem_type);
		return ret;
	}

	man->use_type = false;
	man->has_type = false;

	ret = 0;
	if (mem_type > 0) {
		ttm_bo_force_list_clean(bdev, &man->lru, mem_type, false);

		spin_lock(&glob->lru_lock);
		if (drm_mm_clean(&man->manager))
			drm_mm_takedown(&man->manager);
		else
			ret = -EBUSY;

		spin_unlock(&glob->lru_lock);
	}

	return ret;
}
EXPORT_SYMBOL(ttm_bo_clean_mm);

int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type)
{
	struct ttm_mem_type_manager *man = &bdev->man[mem_type];

	if (mem_type == 0 || mem_type >= TTM_NUM_MEM_TYPES) {
		printk(KERN_ERR TTM_PFX
		       "Illegal memory manager memory type %u.\n",
		       mem_type);
		return -EINVAL;
	}

	if (!man->has_type) {
		printk(KERN_ERR TTM_PFX
		       "Memory type %u has not been initialized.\n",
		       mem_type);
		return 0;
	}

	return ttm_bo_force_list_clean(bdev, &man->lru, mem_type, true);
}
EXPORT_SYMBOL(ttm_bo_evict_mm);

int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
		   unsigned long p_offset, unsigned long p_size)
{
	int ret = -EINVAL;
	struct ttm_mem_type_manager *man;

	if (type >= TTM_NUM_MEM_TYPES) {
		printk(KERN_ERR TTM_PFX "Illegal memory type %d\n", type);
		return ret;
	}

	man = &bdev->man[type];
	if (man->has_type) {
		printk(KERN_ERR TTM_PFX
		       "Memory manager already initialized for type %d\n",
		       type);
		return ret;
	}

	ret = bdev->driver->init_mem_type(bdev, type, man);
	if (ret)
		return ret;

	ret = 0;
	if (type != TTM_PL_SYSTEM) {
		if (!p_size) {
			printk(KERN_ERR TTM_PFX
			       "Zero size memory manager type %d\n",
			       type);
			return ret;
		}
		ret = drm_mm_init(&man->manager, p_offset, p_size);
		if (ret)
			return ret;
	}
	man->has_type = true;
	man->use_type = true;
	man->size = p_size;

	INIT_LIST_HEAD(&man->lru);

	return 0;
}
EXPORT_SYMBOL(ttm_bo_init_mm);

static void ttm_bo_global_kobj_release(struct kobject *kobj)
{
	struct ttm_bo_global *glob =
		container_of(kobj, struct ttm_bo_global, kobj);

	ttm_mem_unregister_shrink(glob->mem_glob, &glob->shrink);
	__free_page(glob->dummy_read_page);
	kfree(glob);
}

void ttm_bo_global_release(struct ttm_global_reference *ref)
{
	struct ttm_bo_global *glob = ref->object;

	kobject_del(&glob->kobj);
	kobject_put(&glob->kobj);
}
EXPORT_SYMBOL(ttm_bo_global_release);

int ttm_bo_global_init(struct ttm_global_reference *ref)
{
	struct ttm_bo_global_ref *bo_ref =
		container_of(ref, struct ttm_bo_global_ref, ref);
	struct ttm_bo_global *glob = ref->object;
	int ret;

	mutex_init(&glob->device_list_mutex);
	spin_lock_init(&glob->lru_lock);
	glob->mem_glob = bo_ref->mem_glob;
	glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);

	if (unlikely(glob->dummy_read_page == NULL)) {
		ret = -ENOMEM;
		goto out_no_drp;
	}

	INIT_LIST_HEAD(&glob->swap_lru);
	INIT_LIST_HEAD(&glob->device_list);

	ttm_mem_init_shrink(&glob->shrink, ttm_bo_swapout);
	ret = ttm_mem_register_shrink(glob->mem_glob, &glob->shrink);
	if (unlikely(ret != 0)) {
		printk(KERN_ERR TTM_PFX
		       "Could not register buffer object swapout.\n");
		goto out_no_shrink;
	}

	glob->ttm_bo_extra_size =
		ttm_round_pot(sizeof(struct ttm_tt)) +
		ttm_round_pot(sizeof(struct ttm_backend));

	glob->ttm_bo_size = glob->ttm_bo_extra_size +
		ttm_round_pot(sizeof(struct ttm_buffer_object));

	atomic_set(&glob->bo_count, 0);

	kobject_init(&glob->kobj, &ttm_bo_glob_kobj_type);
	ret = kobject_add(&glob->kobj, ttm_get_kobj(), "buffer_objects");
	if (unlikely(ret != 0))
		kobject_put(&glob->kobj);
	return ret;
out_no_shrink:
	__free_page(glob->dummy_read_page);
out_no_drp:
	kfree(glob);
	return ret;
}
EXPORT_SYMBOL(ttm_bo_global_init);

int ttm_bo_device_release(struct ttm_bo_device *bdev)
{
	int ret = 0;
	unsigned i = TTM_NUM_MEM_TYPES;
	struct ttm_mem_type_manager *man;
	struct ttm_bo_global *glob = bdev->glob;

	while (i--) {
		man = &bdev->man[i];
		if (man->has_type) {
			man->use_type = false;
			if ((i != TTM_PL_SYSTEM) && ttm_bo_clean_mm(bdev, i)) {
				ret = -EBUSY;
				printk(KERN_ERR TTM_PFX
				       "DRM memory manager type %d "
				       "is not clean.\n", i);
			}
			man->has_type = false;
		}
	}

	mutex_lock(&glob->device_list_mutex);
	list_del(&bdev->device_list);
	mutex_unlock(&glob->device_list_mutex);

	if (!cancel_delayed_work(&bdev->wq))
		flush_scheduled_work();

	while (ttm_bo_delayed_delete(bdev, true))
		;

	spin_lock(&glob->lru_lock);
	if (list_empty(&bdev->ddestroy))
		TTM_DEBUG("Delayed destroy list was clean\n");

	if (list_empty(&bdev->man[0].lru))
		TTM_DEBUG("Swap list was clean\n");
	spin_unlock(&glob->lru_lock);

	BUG_ON(!drm_mm_clean(&bdev->addr_space_mm));
	write_lock(&bdev->vm_lock);
	drm_mm_takedown(&bdev->addr_space_mm);
	write_unlock(&bdev->vm_lock);

	return ret;
}
EXPORT_SYMBOL(ttm_bo_device_release);

int ttm_bo_device_init(struct ttm_bo_device *bdev,
		       struct ttm_bo_global *glob,
		       struct ttm_bo_driver *driver,
		       uint64_t file_page_offset,
		       bool need_dma32)
{
	int ret = -EINVAL;

	rwlock_init(&bdev->vm_lock);
	bdev->driver = driver;

	memset(bdev->man, 0, sizeof(bdev->man));

	/*
	 * Initialize the system memory buffer type.
	 * Other types need to be driver / IOCTL initialized.
	 */
	ret = ttm_bo_init_mm(bdev, TTM_PL_SYSTEM, 0, 0);
	if (unlikely(ret != 0))
		goto out_no_sys;

	bdev->addr_space_rb = RB_ROOT;
	ret = drm_mm_init(&bdev->addr_space_mm, file_page_offset, 0x10000000);
	if (unlikely(ret != 0))
		goto out_no_addr_mm;

	INIT_DELAYED_WORK(&bdev->wq, ttm_bo_delayed_workqueue);
	bdev->nice_mode = true;
	INIT_LIST_HEAD(&bdev->ddestroy);
	bdev->dev_mapping = NULL;
	bdev->glob = glob;
	bdev->need_dma32 = need_dma32;

	mutex_lock(&glob->device_list_mutex);
	list_add_tail(&bdev->device_list, &glob->device_list);
	mutex_unlock(&glob->device_list_mutex);

	return 0;
out_no_addr_mm:
	ttm_bo_clean_mm(bdev, 0);
out_no_sys:
	return ret;
}
EXPORT_SYMBOL(ttm_bo_device_init);

/*
 * buffer object vm functions.
 */

bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
{
	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];

	if (!(man->flags & TTM_MEMTYPE_FLAG_FIXED)) {
		if (mem->mem_type == TTM_PL_SYSTEM)
			return false;

		if (man->flags & TTM_MEMTYPE_FLAG_CMA)
			return false;

		if (mem->placement & TTM_PL_FLAG_CACHED)
			return false;
	}
	return true;
}

int ttm_bo_pci_offset(struct ttm_bo_device *bdev,
		      struct ttm_mem_reg *mem,
		      unsigned long *bus_base,
		      unsigned long *bus_offset, unsigned long *bus_size)
{
	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];

	*bus_size = 0;
	if (!(man->flags & TTM_MEMTYPE_FLAG_MAPPABLE))
		return -EINVAL;

	if (ttm_mem_reg_is_pci(bdev, mem)) {
		*bus_offset = mem->mm_node->start << PAGE_SHIFT;
		*bus_size = mem->num_pages << PAGE_SHIFT;
		*bus_base = man->io_offset;
	}

	return 0;
}

void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
{
	struct ttm_bo_device *bdev = bo->bdev;
	loff_t offset = (loff_t) bo->addr_space_offset;
	loff_t holelen = ((loff_t) bo->mem.num_pages) << PAGE_SHIFT;

	if (!bdev->dev_mapping)
		return;

	unmap_mapping_range(bdev->dev_mapping, offset, holelen, 1);
}
EXPORT_SYMBOL(ttm_bo_unmap_virtual);

static void ttm_bo_vm_insert_rb(struct ttm_buffer_object *bo)
{
	struct ttm_bo_device *bdev = bo->bdev;
	struct rb_node **cur = &bdev->addr_space_rb.rb_node;
	struct rb_node *parent = NULL;
	struct ttm_buffer_object *cur_bo;
	unsigned long offset = bo->vm_node->start;
	unsigned long cur_offset;

	while (*cur) {
		parent = *cur;
		cur_bo = rb_entry(parent, struct ttm_buffer_object, vm_rb);
		cur_offset = cur_bo->vm_node->start;
		if (offset < cur_offset)
			cur = &parent->rb_left;
		else if (offset > cur_offset)
			cur = &parent->rb_right;
		else
			BUG();
	}

	rb_link_node(&bo->vm_rb, parent, cur);
	rb_insert_color(&bo->vm_rb, &bdev->addr_space_rb);
}

/**
 * ttm_bo_setup_vm:
 *
 * @bo: the buffer to allocate address space for
 *
 * Allocate address space in the drm device so that applications
 * can mmap the buffer and access the contents. This only
 * applies to ttm_bo_type_device objects as others are not
 * placed in the drm device address space.
 */

static int ttm_bo_setup_vm(struct ttm_buffer_object *bo)
{
	struct ttm_bo_device *bdev = bo->bdev;
	int ret;

retry_pre_get:
	ret = drm_mm_pre_get(&bdev->addr_space_mm);
	if (unlikely(ret != 0))
		return ret;

	write_lock(&bdev->vm_lock);
	bo->vm_node = drm_mm_search_free(&bdev->addr_space_mm,
					 bo->mem.num_pages, 0, 0);

	if (unlikely(bo->vm_node == NULL)) {
		ret = -ENOMEM;
		goto out_unlock;
	}

	bo->vm_node = drm_mm_get_block_atomic(bo->vm_node,
					      bo->mem.num_pages, 0);

	if (unlikely(bo->vm_node == NULL)) {
		write_unlock(&bdev->vm_lock);
		goto retry_pre_get;
	}

	ttm_bo_vm_insert_rb(bo);
	write_unlock(&bdev->vm_lock);
	bo->addr_space_offset = ((uint64_t) bo->vm_node->start) << PAGE_SHIFT;

	return 0;
out_unlock:
	write_unlock(&bdev->vm_lock);
	return ret;
}

int ttm_bo_wait(struct ttm_buffer_object *bo,
		bool lazy, bool interruptible, bool no_wait)
{
	struct ttm_bo_driver *driver = bo->bdev->driver;
	void *sync_obj;
	void *sync_obj_arg;
	int ret = 0;

	if (likely(bo->sync_obj == NULL))
		return 0;

	while (bo->sync_obj) {

		if (driver->sync_obj_signaled(bo->sync_obj, bo->sync_obj_arg)) {
			void *tmp_obj = bo->sync_obj;
			bo->sync_obj = NULL;
			clear_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
			spin_unlock(&bo->lock);
			driver->sync_obj_unref(&tmp_obj);
			spin_lock(&bo->lock);
			continue;
		}

		if (no_wait)
			return -EBUSY;

		sync_obj = driver->sync_obj_ref(bo->sync_obj);
		sync_obj_arg = bo->sync_obj_arg;
		spin_unlock(&bo->lock);
		ret = driver->sync_obj_wait(sync_obj, sync_obj_arg,
					    lazy, interruptible);
		if (unlikely(ret != 0)) {
			driver->sync_obj_unref(&sync_obj);
			spin_lock(&bo->lock);
			return ret;
		}
		spin_lock(&bo->lock);
		if (likely(bo->sync_obj == sync_obj &&
			   bo->sync_obj_arg == sync_obj_arg)) {
			void *tmp_obj = bo->sync_obj;
			bo->sync_obj = NULL;
			clear_bit(TTM_BO_PRIV_FLAG_MOVING,
				  &bo->priv_flags);
			spin_unlock(&bo->lock);
			driver->sync_obj_unref(&sync_obj);
			driver->sync_obj_unref(&tmp_obj);
			spin_lock(&bo->lock);
		} else {
			spin_unlock(&bo->lock);
			driver->sync_obj_unref(&sync_obj);
			spin_lock(&bo->lock);
		}
	}
	return 0;
}
EXPORT_SYMBOL(ttm_bo_wait);

void ttm_bo_unblock_reservation(struct ttm_buffer_object *bo)
{
	atomic_set(&bo->reserved, 0);
	wake_up_all(&bo->event_queue);
}

int ttm_bo_block_reservation(struct ttm_buffer_object *bo, bool interruptible,
			     bool no_wait)
{
	int ret;

	while (unlikely(atomic_cmpxchg(&bo->reserved, 0, 1) != 0)) {
		if (no_wait)
			return -EBUSY;
		else if (interruptible) {
			ret = wait_event_interruptible
			    (bo->event_queue, atomic_read(&bo->reserved) == 0);
			if (unlikely(ret != 0))
				return -ERESTART;
		} else {
			wait_event(bo->event_queue,
				   atomic_read(&bo->reserved) == 0);
		}
	}
	return 0;
}

int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
{
	int ret = 0;

	/*
	 * Using ttm_bo_reserve instead of ttm_bo_block_reservation
	 * makes sure the lru lists are updated.
	 */

	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
	if (unlikely(ret != 0))
		return ret;
	spin_lock(&bo->lock);
	ret = ttm_bo_wait(bo, false, true, no_wait);
	spin_unlock(&bo->lock);
	if (likely(ret == 0))
		atomic_inc(&bo->cpu_writers);
	ttm_bo_unreserve(bo);
	return ret;
}

void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo)
{
	if (atomic_dec_and_test(&bo->cpu_writers))
		wake_up_all(&bo->event_queue);
}

/**
 * A buffer object shrink method that tries to swap out the first
 * buffer object on the bo_global::swap_lru list.
 */

static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
{
	struct ttm_bo_global *glob =
	    container_of(shrink, struct ttm_bo_global, shrink);
	struct ttm_buffer_object *bo;
	int ret = -EBUSY;
	int put_count;
	uint32_t swap_placement = (TTM_PL_FLAG_CACHED | TTM_PL_FLAG_SYSTEM);

	spin_lock(&glob->lru_lock);
	while (ret == -EBUSY) {
		if (unlikely(list_empty(&glob->swap_lru))) {
			spin_unlock(&glob->lru_lock);
			return -EBUSY;
		}

		bo = list_first_entry(&glob->swap_lru,
				      struct ttm_buffer_object, swap);
		kref_get(&bo->list_kref);

		/**
		 * Reserve buffer. Since we unlock while sleeping, we need
		 * to re-check that nobody removed us from the swap-list while
		 * we slept.
		 */

		ret = ttm_bo_reserve_locked(bo, false, true, false, 0);
		if (unlikely(ret == -EBUSY)) {
			spin_unlock(&glob->lru_lock);
			ttm_bo_wait_unreserved(bo, false);
			kref_put(&bo->list_kref, ttm_bo_release_list);
			spin_lock(&glob->lru_lock);
		}
	}

	BUG_ON(ret != 0);
	put_count = ttm_bo_del_from_lru(bo);
	spin_unlock(&glob->lru_lock);

	while (put_count--)
		kref_put(&bo->list_kref, ttm_bo_ref_bug);

	/**
	 * Wait for GPU, then move to system cached.
	 */

	spin_lock(&bo->lock);
	ret = ttm_bo_wait(bo, false, false, false);
	spin_unlock(&bo->lock);

	if (unlikely(ret != 0))
		goto out;

	if ((bo->mem.placement & swap_placement) != swap_placement) {
		struct ttm_mem_reg evict_mem;

		evict_mem = bo->mem;
		evict_mem.mm_node = NULL;
		evict_mem.placement = TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED;
		evict_mem.mem_type = TTM_PL_SYSTEM;

		ret = ttm_bo_handle_move_mem(bo, &evict_mem, true,
					     false, false);
		if (unlikely(ret != 0))
			goto out;
	}

	ttm_bo_unmap_virtual(bo);

	/**
	 * Swap out. Buffer will be swapped in again as soon as
	 * anyone tries to access a ttm page.
	 */

	ret = ttm_tt_swapout(bo->ttm, bo->persistant_swap_storage);
out:

	/**
	 *
	 * Unreserve without putting on LRU to avoid swapping out an
	 * already swapped buffer.
	 */

	atomic_set(&bo->reserved, 0);
	wake_up_all(&bo->event_queue);
	kref_put(&bo->list_kref, ttm_bo_release_list);
	return ret;
}

void ttm_bo_swapout_all(struct ttm_bo_device *bdev)
{
	while (ttm_bo_swapout(&bdev->glob->shrink) == 0)
		;
}


text:
<?php

/**
 * A service class for contacting Google's Geocoding API (V3)
 *
 * @author Peter Bailey <peter.bailey@jwt.com>
 *
 * @package GoogleGeocoding
 * @subpackage Core
 *
 * @see http://code.google.com/apis/maps/documentation/geocoding/
 */
class GoogleGeocodeServiceV3
{
  const SERVICE_URL = 'http://maps.googleapis.com/maps/api/geocode/';
  const DEFAULT_RESPONSE_CLASS = 'GoogleGeocodeResponseV3';
  const FORMAT_JSON = 'json';
  const FORMAT_XML  = 'xml';

  /**
   * A Google API Key
   *
   * @var string
   */
  protected $apiKey;

  /**
   * How this service will communicate with the API
   *
   * @var GoogleServiceCommunicator
   */
  protected $communicator;

  /**
   * Standard defaults for all requests
   *
   * @var array
   */
  protected $requestDefaults = array(
      'language' => 'en'
    , 'sensor'   => 'false'
  );

  /**
   * The class to return geocoding requests as
   *
   * @var string
   */
  protected $responseClass = self::DEFAULT_RESPONSE_CLASS;

  /**
   * Constructor
   *
   * @param GoogleServiceCommunicator $communicator
   * @param string $apiKey API key is only required for Premier accounts
   * @param array $defaults Defaults for all requests
   */
  public function __construct(
      GoogleServiceCommunicator $communicator
    , $apiKey = null
    , array $defaults = array() )
  {
    $this->communicator = $communicator;
    $this->apiKey = $apiKey;
    $this->setRequestDefaults( $defaults );
  }

  /**
   * Set defaults for subsequent requests
   *
   * @param array $defaults
   */
  public function setRequestDefaults( array $defaults )
  {
    $this->requestDefaults = array_merge( $this->requestDefaults, $defaults );
  }

  /**
   * Set the response class
   *
   * @param string $className Class that inherits from GoogleGeocodeResponseV3
   *
   * @throws GoogleGeocodeException
   */
  public function setResponseClass( $className )
  {
    try {
      $rc = new ReflectionClass( $className );
      if ( !$rc->isSubclassOf( self::DEFAULT_RESPONSE_CLASS ) )
      {
        throw new GoogleGeocodeException(
          "$className must inherit from " . self::DEFAULT_RESPONSE_CLASS
        );
      }
    }
    catch ( ReflectionException $e )
    {
      throw new GoogleGeocodeException( 'Not a valid response class' );
    }
    $this->responseClass = $className;
  }

  /**
   * Geocodes the requested location
   *
   * @param string $location Address or location to geocode
   * @param string $format Response format. "json" or "xml"
   *
   * @return GoogleGeocodeResponseV3
   */
  public function geocode( $location, $format=self::FORMAT_JSON )
  {
    return new $this->responseClass( $this->communicator->requestUrl(
      $this->generateUrl( $location, $format )
    ), $format );
  }

  /**
   * Reverse geocodes the requested coordinate
   *
   * @param float $lat Latitude of desired point
   * @param float $lng Longitude of desired point
   * @param string $format Response format. "json" or "xml"
   *
   * @return GoogleGeocodeResponseV3
   */
  public function reverseGeocode( $lat, $lng, $format = self::FORMAT_JSON )
  {
    return new $this->responseClass( $this->communicator->requestUrl(
      $this->generateReverseUrl( $lat, $lng, $format )
    ), $format );
  }

  /**
   * Set the region bias for all subsequent requests
   *
   * @param string $region
   *
   * @see setRequestDefaults()
   */
  public function biasRegion( $region )
  {
    $this->setRequestDefaults( array( 'region' => $region ) );
  }

  /**
   * Set the viewport bias for all subsequent requests
   *
   * @param float|string $swLat
   * @param float|string $swLng
   * @param float|string $neLat
   * @param float|string $neLng
   *
   * @see setRequestDefaults()
   */
  public function biasViewport( $swLat, $swLng, $neLat, $neLng )
  {
    $swLat = trim( $swLat );
    $swLng = trim( $swLng );
    $neLat = trim( $neLat );
    $neLng = trim( $neLng );
    $this->setRequestDefaults( array( 'bounds' => "$swLat,$swLng|$neLat,$neLng" ) );
  }

  /**
   * Set the viewport bias for all subsequest reqeusts with the bounds object
   * from another result
   *
   * @param stdClass $bounds
   *
   * @see biasViewport()
   */
  public function biasViewportByBoundsObject( stdClass $bounds )
  {
    $this->biasViewport(
        $bounds->southwest->lat
      , $bounds->southwest->lng
      , $bounds->northeast->lat
      , $bounds->northeast->lng
    );
  }

  /**
   * Remove the region biasing
   */
  public function removeRegionBias()
  {
    unset( $this->requestDefaults['region'] );
  }

  /**
   * Remove the viewport biasing
   */
  public function removeViewportBias()
  {
    unset( $this->requestDefaults['bounds'] );
  }

  /**
   * Generate a URL representing the REST call to geocode an address
   *
   * @param string $location
   * @param string $format
   *
   * @return string
   */
  public function generateUrl( $location, $format )
  {
    return $this->buildUrl( array_merge( $this->requestDefaults, array(
        'address' => $location
    ) ), $format );
  }

  /**
   * Generate a URL representing the REST call to reverse geocode a coordinate
   *
   * @param float $lat
   * @param float $lng
   * @param string $format
   *
   * @return string
   */
  public function generateReverseUrl( $lat, $lng, $format )
  {
    return $this->buildUrl( array_merge( $this->requestDefaults, array(
        'latlng' => $lat . ',' . $lng
    ) ), $format );
  }

  /**
   * Build a request URL with the given parameters
   *
   * @param array $params
   * @param string $format
   *
   * @return string
   */
  protected function buildUrl( array $params, $format )
  {
    if ( null != $this->apiKey )
    {
      $params['key'] = $this->apiKey;
    }
    return self::SERVICE_URL . $format . '?' . http_build_query( $params, '', '&' );
  }
}

redpajama_set_name: RedPajamaGithub


text:
include 'my_skin.inc'

SKIN_PARAMS \
  height          = bmp_base.height,\                       ; skin height
  margins         = [8:1:53:1],\                            ; margins [left:top:right:bottom]
  colors active   = [binner=0x006A9D:\                      ; border inner color
                     bouter=0x006A9D:\                      ; border outer color
                     bframe=0xB0BAC4],\                     ; border frame color
  colors inactive = [binner=0x006A9D:\                      ; border inner color
                     bouter=0x006A9D:\                      ; border outer color
                     bframe=0xE0E4E9],\                     ; border frame color
  dtp             = 'Mistificator1.DTP'                     ; dtp colors

SKIN_BUTTONS \
  close    = [-23:4][19:18],\                               ; buttons coordinates
  minimize = [-45:4][19:18]                                 ; [left:top][width:height]

SKIN_BITMAPS \
  left active   = bmp_left,\                                ; skin bitmaps pointers
  left inactive = bmp_left1,\
  oper active   = bmp_oper,\
  oper inactive = bmp_oper1,\
  base active   = bmp_base,\
  base inactive = bmp_base1

BITMAP bmp_left ,'active/left.bmp'                          ; skin bitmaps
BITMAP bmp_oper ,'active/oper.bmp'
BITMAP bmp_base ,'active/base.bmp'
BITMAP bmp_left1,'inactive/left.bmp'
BITMAP bmp_oper1,'inactive/oper.bmp'
BITMAP bmp_base1,'inactive/base.bmp'


text:
package mop

import (
	`bytes`
	`fmt`
	`reflect`
	`regexp`
	`strings`
	`text/template`
	`time`
)

// Column describes formatting rules for individual column within the list
// of stock quotes.
type Column struct {
	width     int                 // Column width.
	name      string              // The name of the field in the Stock struct.
	title     string              // Column title to display in the header.
	formatter func(string) string // Optional function to format the contents of the column.
}

// Layout is used to format and display all the collected data, i.e. market
// updates and the list of stock quotes.
type Layout struct {
	columns        []Column           // List of stock quotes columns.
	sorter         *Sorter            // Pointer to sorting receiver.
	regex          *regexp.Regexp     // Pointer to regular expression to align decimal points.
	marketTemplate *template.Template // Pointer to template to format market data.
	quotesTemplate *template.Template // Pointer to template to format the list of stock quotes.
}

// Creates the layout and assigns the default values that stay unchanged.
func NewLayout() *Layout {
	layout := &Layout{}
	layout.columns = []Column{
		{-7, `Ticker`, `Ticker`, nil},
		{10, `LastTrade`, `Last`, currency},
		{10, `Change`, `Change`, currency},
		{10, `ChangePct`, `Change%`, last},
		{10, `Open`, `Open`, currency},
		{10, `Low`, `Low`, currency},
		{10, `High`, `High`, currency},
		{10, `Low52`, `52w Low`, currency},
		{10, `High52`, `52w High`, currency},
		{11, `Volume`, `Volume`, nil},
		{11, `AvgVolume`, `AvgVolume`, nil},
		{9, `PeRatio`, `P/E`, blank},
		{9, `Dividend`, `Dividend`, zero},
		{9, `Yield`, `Yield`, percent},
		{11, `MarketCap`, `MktCap`, currency},
	}
	layout.regex = regexp.MustCompile(`(\.\d+)[BMK]?$`)
	layout.marketTemplate = buildMarketTemplate()
	layout.quotesTemplate = buildQuotesTemplate()

	return layout
}

// Market merges given market data structure with the market template and
// returns formatted string that includes highlighting markup.
func (layout *Layout) Market(market *Market) string {
	if ok, err := market.Ok(); !ok { // If there was an error fetching market data...
		return err // then simply return the error string.
	}

	highlight(market.Dow, market.Sp500, market.Nasdaq,
		market.Tokyo, market.HongKong, market.London, market.Frankfurt,
		market.Yield, market.Oil, market.Euro, market.Gold)
	buffer := new(bytes.Buffer)
	layout.marketTemplate.Execute(buffer, market)

	return buffer.String()
}

// Quotes uses quotes template to format timestamp, stock quotes header,
// and the list of given stock quotes. It returns formatted string with
// all the necessary markup.
func (layout *Layout) Quotes(quotes *Quotes) string {
	if ok, err := quotes.Ok(); !ok { // If there was an error fetching stock quotes...
		return err // then simply return the error string.
	}

	vars := struct {
		Now    string  // Current timestamp.
		Header string  // Formatted header line.
		Stocks []Stock // List of formatted stock quotes.
	}{
		time.Now().Format(`3:04:05pm PST`),
		layout.Header(quotes.profile),
		layout.prettify(quotes),
	}

	buffer := new(bytes.Buffer)
	layout.quotesTemplate.Execute(buffer, vars)

	return buffer.String()
}

// Header iterates over column titles and formats the header line. The
// formatting includes placing an arrow next to the sorted column title.
// When the column editor is active it knows how to highlight currently
// selected column title.
func (layout *Layout) Header(profile *Profile) string {
	str, selectedColumn := ``, profile.selectedColumn

	for i, col := range layout.columns {
		arrow := arrowFor(i, profile)
		if i != selectedColumn {
			str += fmt.Sprintf(`%*s`, col.width, arrow+col.title)
		} else {
			str += fmt.Sprintf(`<r>%*s</r>`, col.width, arrow+col.title)
		}
	}

	return `<u>` + str + `</u>`
}

// TotalColumns is the utility method for the column editor that returns
// total number of columns.
func (layout *Layout) TotalColumns() int {
	return len(layout.columns)
}

//-----------------------------------------------------------------------------
func (layout *Layout) prettify(quotes *Quotes) []Stock {
	pretty := make([]Stock, len(quotes.stocks))
	//
	// Iterate over the list of stocks and properly format all its columns.
	//
	for i, stock := range quotes.stocks {
		pretty[i].Advancing = stock.Advancing
		//
		// Iterate over the list of stock columns. For each column name:
		// - Get current column value.
		// - If the column has the formatter method then call it.
		// - Set the column value padding it to the given width.
		//
		for _, column := range layout.columns {
			// ex. value = stock.Change
			value := reflect.ValueOf(&stock).Elem().FieldByName(column.name).String()
			if column.formatter != nil {
				// ex. value = currency(value)
				value = column.formatter(value)
			}
			// ex. pretty[i].Change = layout.pad(value, 10)
			reflect.ValueOf(&pretty[i]).Elem().FieldByName(column.name).SetString(layout.pad(value, column.width))
		}
	}

	profile := quotes.profile
	if layout.sorter == nil { // Initialize sorter on first invocation.
		layout.sorter = NewSorter(profile)
	}
	layout.sorter.SortByCurrentColumn(pretty)
	//
	// Group stocks by advancing/declining unless sorted by Chanage or Change%
	// in which case the grouping has been done already.
	//
	if profile.Grouped && (profile.SortColumn < 2 || profile.SortColumn > 3) {
		pretty = group(pretty)
	}

	return pretty
}

//-----------------------------------------------------------------------------
func (layout *Layout) pad(str string, width int) string {
	match := layout.regex.FindStringSubmatch(str)
	if len(match) > 0 {
		switch len(match[1]) {
		case 2:
			str = strings.Replace(str, match[1], match[1]+`0`, 1)
		case 4, 5:
			str = strings.Replace(str, match[1], match[1][0:3], 1)
		}
	}

	return fmt.Sprintf(`%*s`, width, str)
}

//-----------------------------------------------------------------------------
func buildMarketTemplate() *template.Template {
	markup := `<yellow>Dow</> {{.Dow.change}} ({{.Dow.percent}}) at {{.Dow.latest}} <yellow>S&P 500</> {{.Sp500.change}} ({{.Sp500.percent}}) at {{.Sp500.latest}} <yellow>NASDAQ</> {{.Nasdaq.change}} ({{.Nasdaq.percent}}) at {{.Nasdaq.latest}}
<yellow>Tokyo</> {{.Tokyo.change}} ({{.Tokyo.percent}}) at {{.Tokyo.latest}} <yellow>HK</> {{.HongKong.change}} ({{.HongKong.percent}}) at {{.HongKong.latest}} <yellow>London</> {{.London.change}} ({{.London.percent}}) at {{.London.latest}} <yellow>Frankfurt</> {{.Frankfurt.change}} ({{.Frankfurt.percent}}) at {{.Frankfurt.latest}} {{if .IsClosed}}<right>U.S. markets closed</right>{{end}}
<yellow>10-Year Yield</> {{.Yield.latest}}% ({{.Yield.change}}) <yellow>Euro</> ${{.Euro.latest}} ({{.Euro.change}}%) <yellow>Yen</> ¥{{.Yen.latest}} ({{.Yen.change}}%) <yellow>Oil</> ${{.Oil.latest}} ({{.Oil.change}}%) <yellow>Gold</> ${{.Gold.latest}} ({{.Gold.change}}%)`

	return template.Must(template.New(`market`).Parse(markup))
}

//-----------------------------------------------------------------------------
func buildQuotesTemplate() *template.Template {
	markup := `<right><white>{{.Now}}</></right>

{{.Header}}
{{range.Stocks}}{{if .Advancing}}<green>{{end}}{{.Ticker}}{{.LastTrade}}{{.Change}}{{.ChangePct}}{{.Open}}{{.Low}}{{.High}}{{.Low52}}{{.High52}}{{.Volume}}{{.AvgVolume}}{{.PeRatio}}{{.Dividend}}{{.Yield}}{{.MarketCap}}</>
{{end}}`

	return template.Must(template.New(`quotes`).Parse(markup))
}

//-----------------------------------------------------------------------------
func highlight(collections ...map[string]string) {
	for _, collection := range collections {
		if collection[`change`][0:1] != `-` {
			collection[`change`] = `<green>` + collection[`change`] + `</>`
		}
	}
}

//-----------------------------------------------------------------------------
func group(stocks []Stock) []Stock {
	grouped := make([]Stock, len(stocks))
	current := 0

	for _, stock := range stocks {
		if stock.Advancing {
			grouped[current] = stock
			current++
		}
	}
	for _, stock := range stocks {
		if !stock.Advancing {
			grouped[current] = stock
			current++
		}
	}

	return grouped
}

//-----------------------------------------------------------------------------
func arrowFor(column int, profile *Profile) string {
	if column == profile.SortColumn {
		if profile.Ascending {
			return string('\U00002191')
		}
		return string('\U00002193')
	}
	return ``
}

//-----------------------------------------------------------------------------
func blank(str string) string {
	if len(str) == 3 && str[0:3] == `N/A` {
		return `-`
	}

	return str
}

//-----------------------------------------------------------------------------
func zero(str string) string {
	if str == `0.00` {
		return `-`
	}

	return currency(str)
}

//-----------------------------------------------------------------------------
func last(str string) string {
	if len(str) >= 6 && str[0:6] == `N/A - ` {
		return str[6:]
	}

	return percent(str)
}

//-----------------------------------------------------------------------------
func currency(str string) string {
	if str == `N/A` {
		return `-`
	}
	if sign := str[0:1]; sign == `+` || sign == `-` {
		return sign + `$` + str[1:]
	}

	return `$` + str
}

// Returns percent value truncated at 2 decimal points.
//-----------------------------------------------------------------------------
func percent(str string) string {
	if str == `N/A` {
		return `-`
	}

	split := strings.Split(str, ".")
	if len(split) == 2 {
		digits := len(split[1])
		if digits > 2 {
			digits = 2
		}
		str = split[0] + "." + split[1][0:digits]
	}
	if str[len(str)-1] != '%' {
		str += `%`
	}
	return str
}


text:
//
//  UIImage+animatedGIF.h
//  LXFCommonCode
//
//  Created by 林洵锋 on 2017/3/2.
//  Copyright © 2017年 LXF. All rights reserved.
//
//  GitHub: https://github.com/LinXunFeng
//  简书: http://www.jianshu.com/users/31e85e7a22a2

#import <UIKit/UIKit.h>

/**
 UIImage (animatedGIF)

 This category adds class methods to `UIImage` to create an animated `UIImage` from an animated GIF.
 */
@interface UIImage (animatedGIF)

/*
 UIImage *animation = [UIImage animatedImageWithAnimatedGIFData:theData];

 I interpret `theData` as a GIF.  I create an animated `UIImage` using the source images in the GIF.

 The GIF stores a separate duration for each frame, in units of centiseconds (hundredths of a second).  However, a `UIImage` only has a single, total `duration` property, which is a floating-point number.

 To handle this mismatch, I add each source image (from the GIF) to `animation` a varying number of times to match the ratios between the frame durations in the GIF.

 For example, suppose the GIF contains three frames.  Frame 0 has duration 3.  Frame 1 has duration 9.  Frame 2 has duration 15.  I divide each duration by the greatest common denominator of all the durations, which is 3, and add each frame the resulting number of times.  Thus `animation` will contain frame 0 3/3 = 1 time, then frame 1 9/3 = 3 times, then frame 2 15/3 = 5 times.  I set `animation.duration` to (3+9+15)/100 = 0.27 seconds.
 */
+ (UIImage *)animatedImageWithAnimatedGIFData:(NSData *)theData;

/*
 UIImage *image = [UIImage animatedImageWithAnimatedGIFURL:theURL];

 I interpret the contents of `theURL` as a GIF.  I create an animated `UIImage` using the source images in the GIF.

 I operate exactly like `+[UIImage animatedImageWithAnimatedGIFData:]`, except that I read the data from `theURL`.  If `theURL` is not a `file:` URL, you probably want to call me on a background thread or GCD queue to avoid blocking the main thread.
 */
+ (UIImage *)animatedImageWithAnimatedGIFURL:(NSURL *)theURL;

@end


text:
class Answer < ActiveRecord::Base
  validates :text, :user_id, :question_id, presence: true
  validates :user_id, uniqueness: { scope: :question_id }

  belongs_to :user
  belongs_to :question
  has_many :votes, as: :votable
  has_many :comments, as: :commentable

  include Countable
  include ActionView::Helpers::DateHelper
end