/**************************************************************************
 *
 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
 *
 **************************************************************************/
/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */

#define pr_fmt(fmt) "[TTM] " fmt

#include <drm/ttm/ttm_module.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/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>
#include <linux/atomic.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 inline int ttm_mem_type_from_flags(uint32_t flags, uint32_t *mem_type)
{
        int i;

        for (i = 0; i <= TTM_PL_PRIV5; i++)
                if (flags & (1 << i)) {
                        *mem_type = i;
                        return 0;
                }
        return -EINVAL;
}

static void ttm_mem_type_debug(struct ttm_bo_device *bdev, int mem_type)
{
        struct ttm_mem_type_manager *man = &bdev->man[mem_type];

        pr_err("    has_type: %d\n", man->has_type);
        pr_err("    use_type: %d\n", man->use_type);
        pr_err("    flags: 0x%08X\n", man->flags);
        pr_err("    gpu_offset: 0x%08lX\n", man->gpu_offset);
        pr_err("    size: %llu\n", man->size);
        pr_err("    available_caching: 0x%08X\n", man->available_caching);
        pr_err("    default_caching: 0x%08X\n", man->default_caching);
        if (mem_type != TTM_PL_SYSTEM)
                (*man->func->debug)(man, TTM_PFX);
}

static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
                                        struct ttm_placement *placement)
{
        int i, ret, mem_type;

        pr_err("No space for %p (%lu pages, %luK, %luM)\n",
               bo, bo->mem.num_pages, bo->mem.size >> 10,
               bo->mem.size >> 20);
        for (i = 0; i < placement->num_placement; i++) {
                ret = ttm_mem_type_from_flags(placement->placement[i],
                                                &mem_type);
                if (ret)
                        return;
                pr_err("  placement[%d]=0x%08X (%d)\n",
                       i, placement->placement[i], mem_type);
                ttm_mem_type_debug(bo->bdev, mem_type);
        }
}

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 const 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;
        size_t acc_size = bo->acc_size;

        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 {
                kfree(bo);
        }
        ttm_mem_global_free(bdev->glob->mem_glob, acc_size);
}

int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo, bool interruptible)
{
        if (interruptible) {
                return wait_event_interruptible(bo->event_queue,
                                               atomic_read(&bo->reserved) == 0);
        } else {
                wait_event(bo->event_queue, atomic_read(&bo->reserved) == 0);
                return 0;
        }
}
EXPORT_SYMBOL(ttm_bo_wait_unreserved);

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);
                }
        }
}

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)) {
                /**
                 * Deadlock avoidance for multi-bo reserving.
                 */
                if (use_sequence && bo->seq_valid) {
                        /**
                         * We've already reserved this one.
                         */
                        if (unlikely(sequence == bo->val_seq))
                                return -EDEADLK;
                        /**
                         * Already reserved by a thread that will not back
                         * off for us. We need to back off.
                         */
                        if (unlikely(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) {
                /**
                 * Wake up waiters that may need to recheck for deadlock,
                 * if we decreased the sequence number.
                 */
                if (unlikely((bo->val_seq - sequence < (1 << 31))
                             || !bo->seq_valid))
                        wake_up_all(&bo->event_queue);

                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();
}

void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
                         bool never_free)
{
        kref_sub(&bo->list_kref, count,
                 (never_free) ? ttm_bo_ref_bug : ttm_bo_release_list);
}

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);

        ttm_bo_list_ref_sub(bo, put_count, true);

        return ret;
}

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

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

        spin_lock(&glob->lru_lock);
        ttm_bo_unreserve_locked(bo);
        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 = bdev->driver->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_sg:
                bo->ttm = bdev->driver->ttm_tt_create(bdev, bo->num_pages << PAGE_SHIFT,
                                                      page_flags | TTM_PAGE_FLAG_SG,
                                                      glob->dummy_read_page);
                if (unlikely(bo->ttm == NULL)) {
                        ret = -ENOMEM;
                        break;
                }
                bo->ttm->sg = bo->sg;
                break;
        default:
                pr_err("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_reserve, bool no_wait_gpu)
{
        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)) {
                ret = ttm_mem_io_lock(old_man, true);
                if (unlikely(ret != 0))
                        goto out_err;
                ttm_bo_unmap_virtual_locked(bo);
                ttm_mem_io_unlock(old_man);
        }

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

        if (!(new_man->flags & TTM_MEMTYPE_FLAG_FIXED)) {
                if (bo->ttm == NULL) {
                        bool zero = !(old_man->flags & TTM_MEMTYPE_FLAG_FIXED);
                        ret = ttm_bo_add_ttm(bo, zero);
                        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) {
                        if (bdev->driver->move_notify)
                                bdev->driver->move_notify(bo, mem);
                        bo->mem = *mem;
                        mem->mm_node = NULL;
                        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_reserve, no_wait_gpu, mem);
        else if (bdev->driver->move)
                ret = bdev->driver->move(bo, evict, interruptible,
                                         no_wait_reserve, no_wait_gpu, mem);
        else
                ret = ttm_bo_move_memcpy(bo, evict, no_wait_reserve, no_wait_gpu, mem);

        if (ret) {
                if (bdev->driver->move_notify) {
                        struct ttm_mem_reg tmp_mem = *mem;
                        *mem = bo->mem;
                        bo->mem = tmp_mem;
                        bdev->driver->move_notify(bo, mem);
                        bo->mem = *mem;
                }

                goto out_err;
        }

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

        if (bo->mem.mm_node) {
                bo->offset = (bo->mem.start << PAGE_SHIFT) +
                    bdev->man[bo->mem.mem_type].gpu_offset;
                bo->cur_placement = bo->mem.placement;
        } else
                bo->offset = 0;

        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;
}

/**
 * Call bo::reserved.
 * Will release GPU memory type usage on destruction.
 * This is the place to put in driver specific hooks to release
 * driver private resources.
 * Will release the bo::reserved lock.
 */

static void ttm_bo_cleanup_memtype_use(struct ttm_buffer_object *bo)
{
        if (bo->bdev->driver->move_notify)
                bo->bdev->driver->move_notify(bo, NULL);

        if (bo->ttm) {
                ttm_tt_unbind(bo->ttm);
                ttm_tt_destroy(bo->ttm);
                bo->ttm = NULL;
        }
        ttm_bo_mem_put(bo, &bo->mem);

        atomic_set(&bo->reserved, 0);

        /*
         * Make processes trying to reserve really pick it up.
         */
        smp_mb__after_atomic_dec();
        wake_up_all(&bo->event_queue);
}

static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
{
        struct ttm_bo_device *bdev = bo->bdev;
        struct ttm_bo_global *glob = bo->glob;
        struct ttm_bo_driver *driver;
        void *sync_obj = NULL;
        void *sync_obj_arg;
        int put_count;
        int ret;

        spin_lock(&bdev->fence_lock);
        (void) ttm_bo_wait(bo, false, false, true);
        if (!bo->sync_obj) {

                spin_lock(&glob->lru_lock);

                /**
                 * Lock inversion between bo:reserve and bdev::fence_lock here,
                 * but that's OK, since we're only trylocking.
                 */

                ret = ttm_bo_reserve_locked(bo, false, true, false, 0);

                if (unlikely(ret == -EBUSY))
                        goto queue;

                spin_unlock(&bdev->fence_lock);
                put_count = ttm_bo_del_from_lru(bo);

                spin_unlock(&glob->lru_lock);
                ttm_bo_cleanup_memtype_use(bo);

                ttm_bo_list_ref_sub(bo, put_count, true);

                return;
        } else {
                spin_lock(&glob->lru_lock);
        }
queue:
        driver = bdev->driver;
        if (bo->sync_obj)
                sync_obj = driver->sync_obj_ref(bo->sync_obj);
        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(&bdev->fence_lock);

        if (sync_obj) {
                driver->sync_obj_flush(sync_obj, sync_obj_arg);
                driver->sync_obj_unref(&sync_obj);
        }
        schedule_delayed_work(&bdev->wq,
                              ((HZ / 100) < 1) ? 1 : HZ / 100);
}

/**
 * function ttm_bo_cleanup_refs
 * If bo idle, remove from delayed- and lru lists, and unref.
 * If not idle, do nothing.
 *
 * @interruptible         Any sleeps should occur interruptibly.
 * @no_wait_reserve       Never wait for reserve. Return -EBUSY instead.
 * @no_wait_gpu           Never wait for gpu. Return -EBUSY instead.
 */

static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
                               bool interruptible,
                               bool no_wait_reserve,
                               bool no_wait_gpu)
{
        struct ttm_bo_device *bdev = bo->bdev;
        struct ttm_bo_global *glob = bo->glob;
        int put_count;
        int ret = 0;

retry:
        spin_lock(&bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
        spin_unlock(&bdev->fence_lock);

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

retry_reserve:
        spin_lock(&glob->lru_lock);

        if (unlikely(list_empty(&bo->ddestroy))) {
                spin_unlock(&glob->lru_lock);
                return 0;
        }

        ret = ttm_bo_reserve_locked(bo, false, true, false, 0);

        if (unlikely(ret == -EBUSY)) {
                spin_unlock(&glob->lru_lock);
                if (likely(!no_wait_reserve))
                        ret = ttm_bo_wait_unreserved(bo, interruptible);
                if (unlikely(ret != 0))
                        return ret;

                goto retry_reserve;
        }

        BUG_ON(ret != 0);

        /**
         * We can re-check for sync object without taking
         * the bo::lock since setting the sync object requires
         * also bo::reserved. A busy object at this point may
         * be caused by another thread recently starting an accelerated
         * eviction.
         */

        if (unlikely(bo->sync_obj)) {
                atomic_set(&bo->reserved, 0);
                wake_up_all(&bo->event_queue);
                spin_unlock(&glob->lru_lock);
                goto retry;
        }

        put_count = ttm_bo_del_from_lru(bo);
        list_del_init(&bo->ddestroy);
        ++put_count;

        spin_unlock(&glob->lru_lock);
        ttm_bo_cleanup_memtype_use(bo);

        ttm_bo_list_ref_sub(bo, put_count, true);

        return 0;
}

/**
 * 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 = NULL;
        int ret = 0;

        spin_lock(&glob->lru_lock);
        if (list_empty(&bdev->ddestroy))
                goto out_unlock;

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

        for (;;) {
                struct ttm_buffer_object *nentry = NULL;

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

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

                if (ret || !entry)
                        goto out;

                spin_lock(&glob->lru_lock);
                if (list_empty(&entry->ddestroy))
                        break;
        }

out_unlock:
        spin_unlock(&glob->lru_lock);
out:
        if (entry)
                kref_put(&entry->list_kref, ttm_bo_release_list);
        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;
        struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];

        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_mem_io_lock(man, false);
        ttm_mem_io_free_vm(bo);
        ttm_mem_io_unlock(man);
        ttm_bo_cleanup_refs_or_queue(bo);
        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);

int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev)
{
        return cancel_delayed_work_sync(&bdev->wq);
}
EXPORT_SYMBOL(ttm_bo_lock_delayed_workqueue);

void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev, int resched)
{
        if (resched)
                schedule_delayed_work(&bdev->wq,
                                      ((HZ / 100) < 1) ? 1 : HZ / 100);
}
EXPORT_SYMBOL(ttm_bo_unlock_delayed_workqueue);

static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
                        bool no_wait_reserve, bool no_wait_gpu)
{
        struct ttm_bo_device *bdev = bo->bdev;
        struct ttm_mem_reg evict_mem;
        struct ttm_placement placement;
        int ret = 0;

        spin_lock(&bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
        spin_unlock(&bdev->fence_lock);

        if (unlikely(ret != 0)) {
                if (ret != -ERESTARTSYS) {
                        pr_err("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;
        evict_mem.bus.io_reserved_vm = false;
        evict_mem.bus.io_reserved_count = 0;

        placement.fpfn = 0;
        placement.lpfn = 0;
        placement.num_placement = 0;
        placement.num_busy_placement = 0;
        bdev->driver->evict_flags(bo, &placement);
        ret = ttm_bo_mem_space(bo, &placement, &evict_mem, interruptible,
                                no_wait_reserve, no_wait_gpu);
        if (ret) {
                if (ret != -ERESTARTSYS) {
                        pr_err("Failed to find memory space for buffer 0x%p eviction\n",
                               bo);
                        ttm_bo_mem_space_debug(bo, &placement);
                }
                goto out;
        }

        ret = ttm_bo_handle_move_mem(bo, &evict_mem, true, interruptible,
                                     no_wait_reserve, no_wait_gpu);
        if (ret) {
                if (ret != -ERESTARTSYS)
                        pr_err("Buffer eviction failed\n");
                ttm_bo_mem_put(bo, &evict_mem);
                goto out;
        }
        bo->evicted = true;
out:
        return ret;
}

static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
                                uint32_t mem_type,
                                bool interruptible, bool no_wait_reserve,
                                bool no_wait_gpu)
{
        struct ttm_bo_global *glob = bdev->glob;
        struct ttm_mem_type_manager *man = &bdev->man[mem_type];
        struct ttm_buffer_object *bo;
        int ret, put_count = 0;

retry:
        spin_lock(&glob->lru_lock);
        if (list_empty(&man->lru)) {
                spin_unlock(&glob->lru_lock);
                return -EBUSY;
        }

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

        if (!list_empty(&bo->ddestroy)) {
                spin_unlock(&glob->lru_lock);
                ret = ttm_bo_cleanup_refs(bo, interruptible,
                                          no_wait_reserve, no_wait_gpu);
                kref_put(&bo->list_kref, ttm_bo_release_list);

                return ret;
        }

        ret = ttm_bo_reserve_locked(bo, false, true, false, 0);

        if (unlikely(ret == -EBUSY)) {
                spin_unlock(&glob->lru_lock);
                if (likely(!no_wait_reserve))
                        ret = ttm_bo_wait_unreserved(bo, interruptible);

                kref_put(&bo->list_kref, ttm_bo_release_list);

                /**
                 * We *need* to retry after releasing the lru lock.
                 */

                if (unlikely(ret != 0))
                        return ret;
                goto retry;
        }

        put_count = ttm_bo_del_from_lru(bo);
        spin_unlock(&glob->lru_lock);

        BUG_ON(ret != 0);

        ttm_bo_list_ref_sub(bo, put_count, true);

        ret = ttm_bo_evict(bo, interruptible, no_wait_reserve, no_wait_gpu);
        ttm_bo_unreserve(bo);

        kref_put(&bo->list_kref, ttm_bo_release_list);
        return ret;
}

void ttm_bo_mem_put(struct ttm_buffer_object *bo, struct ttm_mem_reg *mem)
{
        struct ttm_mem_type_manager *man = &bo->bdev->man[mem->mem_type];

        if (mem->mm_node)
                (*man->func->put_node)(man, mem);
}
EXPORT_SYMBOL(ttm_bo_mem_put);

/**
 * 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_buffer_object *bo,
                                        uint32_t mem_type,
                                        struct ttm_placement *placement,
                                        struct ttm_mem_reg *mem,
                                        bool interruptible,
                                        bool no_wait_reserve,
                                        bool no_wait_gpu)
{
        struct ttm_bo_device *bdev = bo->bdev;
        struct ttm_mem_type_manager *man = &bdev->man[mem_type];
        int ret;

        do {
                ret = (*man->func->get_node)(man, bo, placement, mem);
                if (unlikely(ret != 0))
                        return ret;
                if (mem->mm_node)
                        break;
                ret = ttm_mem_evict_first(bdev, mem_type, interruptible,
                                                no_wait_reserve, no_wait_gpu);
                if (unlikely(ret != 0))
                        return ret;
        } while (1);
        if (mem->mm_node == NULL)
                return -ENOMEM;
        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,
                                 uint32_t mem_type,
                                 uint32_t proposed_placement,
                                 uint32_t *masked_placement)
{
        uint32_t cur_flags = ttm_bo_type_flags(mem_type);

        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,
                        struct ttm_placement *placement,
                        struct ttm_mem_reg *mem,
                        bool interruptible, bool no_wait_reserve,
                        bool no_wait_gpu)
{
        struct ttm_bo_device *bdev = bo->bdev;
        struct ttm_mem_type_manager *man;
        uint32_t mem_type = TTM_PL_SYSTEM;
        uint32_t cur_flags = 0;
        bool type_found = false;
        bool type_ok = false;
        bool has_erestartsys = false;
        int i, ret;

        mem->mm_node = NULL;
        for (i = 0; i < placement->num_placement; ++i) {
                ret = ttm_mem_type_from_flags(placement->placement[i],
                                                &mem_type);
                if (ret)
                        return ret;
                man = &bdev->man[mem_type];

                type_ok = ttm_bo_mt_compatible(man,
                                                mem_type,
                                                placement->placement[i],
                                                &cur_flags);

                if (!type_ok)
                        continue;

                cur_flags = ttm_bo_select_caching(man, bo->mem.placement,
                                                  cur_flags);
                /*
                 * Use the access and other non-mapping-related flag bits from
                 * the memory placement flags to the current flags
                 */
                ttm_flag_masked(&cur_flags, placement->placement[i],
                                ~TTM_PL_MASK_MEMTYPE);

                if (mem_type == TTM_PL_SYSTEM)
                        break;

                if (man->has_type && man->use_type) {
                        type_found = true;
                        ret = (*man->func->get_node)(man, bo, placement, mem);
                        if (unlikely(ret))
                                return ret;
                }
                if (mem->mm_node)
                        break;

        }

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

        if (!type_found)
                return -EINVAL;

        for (i = 0; i < placement->num_busy_placement; ++i) {
                ret = ttm_mem_type_from_flags(placement->busy_placement[i],
                                                &mem_type);
                if (ret)
                        return ret;
                man = &bdev->man[mem_type];
                if (!man->has_type)
                        continue;
                if (!ttm_bo_mt_compatible(man,
                                                mem_type,
                                                placement->busy_placement[i],
                                                &cur_flags))
                        continue;

                cur_flags = ttm_bo_select_caching(man, bo->mem.placement,
                                                  cur_flags);
                /*
                 * Use the access and other non-mapping-related flag bits from
                 * the memory placement flags to the current flags
                 */
                ttm_flag_masked(&cur_flags, placement->busy_placement[i],
                                ~TTM_PL_MASK_MEMTYPE);


                if (mem_type == TTM_PL_SYSTEM) {
                        mem->mem_type = mem_type;
                        mem->placement = cur_flags;
                        mem->mm_node = NULL;
                        return 0;
                }

                ret = ttm_bo_mem_force_space(bo, mem_type, placement, mem,
                                                interruptible, no_wait_reserve, no_wait_gpu);
                if (ret == 0 && mem->mm_node) {
                        mem->placement = cur_flags;
                        return 0;
                }
                if (ret == -ERESTARTSYS)
                        has_erestartsys = true;
        }
        ret = (has_erestartsys) ? -ERESTARTSYS : -ENOMEM;
        return ret;
}
EXPORT_SYMBOL(ttm_bo_mem_space);

int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait)
{
        if ((atomic_read(&bo->cpu_writers) > 0) && no_wait)
                return -EBUSY;

        return wait_event_interruptible(bo->event_queue,
                                        atomic_read(&bo->cpu_writers) == 0);
}
EXPORT_SYMBOL(ttm_bo_wait_cpu);

int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
                        struct ttm_placement *placement,
                        bool interruptible, bool no_wait_reserve,
                        bool no_wait_gpu)
{
        int ret = 0;
        struct ttm_mem_reg mem;
        struct ttm_bo_device *bdev = bo->bdev;

        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(&bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
        spin_unlock(&bdev->fence_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;
        mem.bus.io_reserved_vm = false;
        mem.bus.io_reserved_count = 0;
        /*
         * Determine where to move the buffer.
         */
        ret = ttm_bo_mem_space(bo, placement, &mem, interruptible, no_wait_reserve, no_wait_gpu);
        if (ret)
                goto out_unlock;
        ret = ttm_bo_handle_move_mem(bo, &mem, false, interruptible, no_wait_reserve, no_wait_gpu);
out_unlock:
        if (ret && mem.mm_node)
                ttm_bo_mem_put(bo, &mem);
        return ret;
}

static int ttm_bo_mem_compat(struct ttm_placement *placement,
                             struct ttm_mem_reg *mem)
{
        int i;

        if (mem->mm_node && placement->lpfn != 0 &&
            (mem->start < placement->fpfn ||
             mem->start + mem->num_pages > placement->lpfn))
                return -1;

        for (i = 0; i < placement->num_placement; i++) {
                if ((placement->placement[i] & mem->placement &
                        TTM_PL_MASK_CACHING) &&
                        (placement->placement[i] & mem->placement &
                        TTM_PL_MASK_MEM))
                        return i;
        }
        return -1;
}

int ttm_bo_validate(struct ttm_buffer_object *bo,
                        struct ttm_placement *placement,
                        bool interruptible, bool no_wait_reserve,
                        bool no_wait_gpu)
{
        int ret;

        BUG_ON(!atomic_read(&bo->reserved));
        /* Check that range is valid */
        if (placement->lpfn || placement->fpfn)
                if (placement->fpfn > placement->lpfn ||
                        (placement->lpfn - placement->fpfn) < bo->num_pages)
                        return -EINVAL;
        /*
         * Check whether we need to move buffer.
         */
        ret = ttm_bo_mem_compat(placement, &bo->mem);
        if (ret < 0) {
                ret = ttm_bo_move_buffer(bo, placement, interruptible, no_wait_reserve, no_wait_gpu);
                if (ret)
                        return ret;
        } else {
                /*
                 * Use the access and other non-mapping-related flag bits from
                 * the compatible memory placement flags to the active flags
                 */
                ttm_flag_masked(&bo->mem.placement, placement->placement[ret],
                                ~TTM_PL_MASK_MEMTYPE);
        }
        /*
         * 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;
        }
        return 0;
}
EXPORT_SYMBOL(ttm_bo_validate);

int ttm_bo_check_placement(struct ttm_buffer_object *bo,
                                struct ttm_placement *placement)
{
        BUG_ON((placement->fpfn || placement->lpfn) &&
               (bo->mem.num_pages > (placement->lpfn - placement->fpfn)));

        return 0;
}

int ttm_bo_init(struct ttm_bo_device *bdev,
                struct ttm_buffer_object *bo,
                unsigned long size,
                enum ttm_bo_type type,
                struct ttm_placement *placement,
                uint32_t page_alignment,
                unsigned long buffer_start,
                bool interruptible,
                struct file *persistent_swap_storage,
                size_t acc_size,
                struct sg_table *sg,
                void (*destroy) (struct ttm_buffer_object *))
{
        int ret = 0;
        unsigned long num_pages;
        struct ttm_mem_global *mem_glob = bdev->glob->mem_glob;

        ret = ttm_mem_global_alloc(mem_glob, acc_size, false, false);
        if (ret) {
                pr_err("Out of kernel memory\n");
                if (destroy)
                        (*destroy)(bo);
                else
                        kfree(bo);
                return -ENOMEM;
        }

        size += buffer_start & ~PAGE_MASK;
        num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
        if (num_pages == 0) {
                pr_err("Illegal buffer object size\n");
                if (destroy)
                        (*destroy)(bo);
                else
                        kfree(bo);
                ttm_mem_global_free(mem_glob, acc_size);
                return -EINVAL;
        }
        bo->destroy = destroy;

        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);
        INIT_LIST_HEAD(&bo->io_reserve_lru);
        bo->bdev = bdev;
        bo->glob = bdev->glob;
        bo->type = type;
        bo->num_pages = num_pages;
        bo->mem.size = num_pages << PAGE_SHIFT;
        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->mem.bus.io_reserved_vm = false;
        bo->mem.bus.io_reserved_count = 0;
        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->persistent_swap_storage = persistent_swap_storage;
        bo->acc_size = acc_size;
        bo->sg = sg;
        atomic_inc(&bo->glob->bo_count);

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

        /*
         * For ttm_bo_type_device buffers, allocate
         * address space from the device.
         */
        if (bo->type == ttm_bo_type_device ||
            bo->type == ttm_bo_type_sg) {
                ret = ttm_bo_setup_vm(bo);
                if (ret)
                        goto out_err;
        }

        ret = ttm_bo_validate(bo, placement, interruptible, false, 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_bo_init);

size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
                       unsigned long bo_size,
                       unsigned struct_size)
{
        unsigned npages = (PAGE_ALIGN(bo_size)) >> PAGE_SHIFT;
        size_t size = 0;

        size += ttm_round_pot(struct_size);
        size += PAGE_ALIGN(npages * sizeof(void *));
        size += ttm_round_pot(sizeof(struct ttm_tt));
        return size;
}
EXPORT_SYMBOL(ttm_bo_acc_size);

size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
                           unsigned long bo_size,
                           unsigned struct_size)
{
        unsigned npages = (PAGE_ALIGN(bo_size)) >> PAGE_SHIFT;
        size_t size = 0;

        size += ttm_round_pot(struct_size);
        size += PAGE_ALIGN(npages * sizeof(void *));
        size += PAGE_ALIGN(npages * sizeof(dma_addr_t));
        size += ttm_round_pot(sizeof(struct ttm_dma_tt));
        return size;
}
EXPORT_SYMBOL(ttm_bo_dma_acc_size);

int ttm_bo_create(struct ttm_bo_device *bdev,
                        unsigned long size,
                        enum ttm_bo_type type,
                        struct ttm_placement *placement,
                        uint32_t page_alignment,
                        unsigned long buffer_start,
                        bool interruptible,
                        struct file *persistent_swap_storage,
                        struct ttm_buffer_object **p_bo)
{
        struct ttm_buffer_object *bo;
        size_t acc_size;
        int ret;

        bo = kzalloc(sizeof(*bo), GFP_KERNEL);
        if (unlikely(bo == NULL))
                return -ENOMEM;

        acc_size = ttm_bo_acc_size(bdev, size, sizeof(struct ttm_buffer_object));
        ret = ttm_bo_init(bdev, bo, size, type, placement, page_alignment,
                                buffer_start, interruptible,
                          persistent_swap_storage, acc_size, NULL, NULL);
        if (likely(ret == 0))
                *p_bo = bo;

        return ret;
}
EXPORT_SYMBOL(ttm_bo_create);

static int ttm_bo_force_list_clean(struct ttm_bo_device *bdev,
                                        unsigned mem_type, bool allow_errors)
{
        struct ttm_mem_type_manager *man = &bdev->man[mem_type];
        struct ttm_bo_global *glob = bdev->glob;
        int ret;

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

        spin_lock(&glob->lru_lock);
        while (!list_empty(&man->lru)) {
                spin_unlock(&glob->lru_lock);
                ret = ttm_mem_evict_first(bdev, mem_type, false, false, false);
                if (ret) {
                        if (allow_errors) {
                                return ret;
                        } else {
                                pr_err("Cleanup eviction failed\n");
                        }
                }
                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_mem_type_manager *man;
        int ret = -EINVAL;

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

        if (!man->has_type) {
                pr_err("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, mem_type, false);

                ret = (*man->func->takedown)(man);
        }

        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) {
                pr_err("Illegal memory manager memory type %u\n", mem_type);
                return -EINVAL;
        }

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

        return ttm_bo_force_list_clean(bdev, mem_type, true);
}
EXPORT_SYMBOL(ttm_bo_evict_mm);

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

        BUG_ON(type >= TTM_NUM_MEM_TYPES);
        man = &bdev->man[type];
        BUG_ON(man->has_type);
        man->io_reserve_fastpath = true;
        man->use_io_reserve_lru = false;
        mutex_init(&man->io_reserve_mutex);
        INIT_LIST_HEAD(&man->io_reserve_lru);

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

        ret = 0;
        if (type != TTM_PL_SYSTEM) {
                ret = (*man->func->init)(man, 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 drm_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 drm_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)) {
                pr_err("Could not register buffer object swapout\n");
                goto out_no_shrink;
        }

        atomic_set(&glob->bo_count, 0);

        ret = kobject_init_and_add(
                &glob->kobj, &ttm_bo_glob_kobj_type, 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;
                                pr_err("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);

        cancel_delayed_work_sync(&bdev->wq);

        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);
        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;
        bdev->val_seq = 0;
        spin_lock_init(&bdev->fence_lock);
        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;
}

void ttm_bo_unmap_virtual_locked(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);
        ttm_mem_io_free_vm(bo);
}

void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
{
        struct ttm_bo_device *bdev = bo->bdev;
        struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];

        ttm_mem_io_lock(man, false);
        ttm_bo_unmap_virtual_locked(bo);
        ttm_mem_io_unlock(man);
}


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;
        struct ttm_bo_device *bdev = bo->bdev;
        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(&bdev->fence_lock);
                        driver->sync_obj_unref(&tmp_obj);
                        spin_lock(&bdev->fence_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(&bdev->fence_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(&bdev->fence_lock);
                        return ret;
                }
                spin_lock(&bdev->fence_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(&bdev->fence_lock);
                        driver->sync_obj_unref(&sync_obj);
                        driver->sync_obj_unref(&tmp_obj);
                        spin_lock(&bdev->fence_lock);
                } else {
                        spin_unlock(&bdev->fence_lock);
                        driver->sync_obj_unref(&sync_obj);
                        spin_lock(&bdev->fence_lock);
                }
        }
        return 0;
}
EXPORT_SYMBOL(ttm_bo_wait);

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

        /*
         * Using ttm_bo_reserve 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(&bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, true, no_wait);
        spin_unlock(&bdev->fence_lock);
        if (likely(ret == 0))
                atomic_inc(&bo->cpu_writers);
        ttm_bo_unreserve(bo);
        return ret;
}
EXPORT_SYMBOL(ttm_bo_synccpu_write_grab);

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);
}
EXPORT_SYMBOL(ttm_bo_synccpu_write_release);

/**
 * 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);

                if (!list_empty(&bo->ddestroy)) {
                        spin_unlock(&glob->lru_lock);
                        (void) ttm_bo_cleanup_refs(bo, false, false, false);
                        kref_put(&bo->list_kref, ttm_bo_release_list);
                        spin_lock(&glob->lru_lock);
                        continue;
                }

                /**
                 * 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);

        ttm_bo_list_ref_sub(bo, put_count, true);

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

        spin_lock(&bo->bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, false, false);
        spin_unlock(&bo->bdev->fence_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, 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.
         */

        if (bo->bdev->driver->swap_notify)
                bo->bdev->driver->swap_notify(bo);

        ret = ttm_tt_swapout(bo->ttm, bo->persistent_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)
                ;
}
EXPORT_SYMBOL(ttm_bo_swapout_all);