ttm_bo.c

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/**************************************************************************
 *
 * 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)) {
        if (use_sequence && bo->seq_valid) {
            if (unlikely(sequence == bo->val_seq))
                return -EDEADLK;
            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) {
        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;
}

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);

        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);
}

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);

    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;
}

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);

        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);

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;

    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;
}

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);
}

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);

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;
        }

        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);

    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);

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

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

    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);