/**************************************************************************
 *
 * 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>
 */

#include <sys/cdefs.h>
#include <dev/drm2/drmP.h>
#include <dev/drm2/ttm/ttm_module.h>
#include <dev/drm2/ttm/ttm_bo_driver.h>
#include <dev/drm2/ttm/ttm_placement.h>
#include <vm/vm_pageout.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 ttm_bo_global *glob);

MALLOC_DEFINE(M_TTM_BO, "ttm_bo", "TTM Buffer Objects");

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];

        printf("    has_type: %d\n", man->has_type);
        printf("    use_type: %d\n", man->use_type);
        printf("    flags: 0x%08X\n", man->flags);
        printf("    gpu_offset: 0x%08lX\n", man->gpu_offset);
        printf("    size: %ju\n", (uintmax_t)man->size);
        printf("    available_caching: 0x%08X\n", man->available_caching);
        printf("    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;

        printf("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;
                printf("  placement[%d]=0x%08X (%d)\n",
                       i, placement->placement[i], mem_type);
                ttm_mem_type_debug(bo->bdev, mem_type);
        }
}

#if 0
static ssize_t ttm_bo_global_show(struct ttm_bo_global *glob,
    char *buffer)
{

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

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

static void ttm_bo_release_list(struct ttm_buffer_object *bo)
{
        struct ttm_bo_device *bdev = bo->bdev;
        size_t acc_size = bo->acc_size;

        MPASS(atomic_read(&bo->list_kref) == 0);
        MPASS(atomic_read(&bo->kref) == 0);
        MPASS(atomic_read(&bo->cpu_writers) == 0);
        MPASS(bo->sync_obj == NULL);
        MPASS(bo->mem.mm_node == NULL);
        MPASS(list_empty(&bo->lru));
        MPASS(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 {
                free(bo, M_TTM_BO);
        }
        ttm_mem_global_free(bdev->glob->mem_glob, acc_size);
}

static int
ttm_bo_wait_unreserved_locked(struct ttm_buffer_object *bo, bool interruptible)
{
        const char *wmsg;
        int flags, ret;

        ret = 0;
        if (interruptible) {
                flags = PCATCH;
                wmsg = "ttbowi";
        } else {
                flags = 0;
                wmsg = "ttbowu";
        }
        while (ttm_bo_is_reserved(bo)) {
                ret = -msleep(bo, &bo->glob->lru_lock, flags, wmsg, 0);
                if (ret == -EINTR || ret == -ERESTART)
                        ret = -ERESTARTSYS;
                if (ret != 0)
                        break;
        }
        return (ret);
}

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

        MPASS(ttm_bo_is_reserved(bo));

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

                MPASS(list_empty(&bo->lru));

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

                if (bo->ttm != NULL) {
                        list_add_tail(&bo->swap, &bo->glob->swap_lru);
                        refcount_acquire(&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_nolru(struct ttm_buffer_object *bo,
                          bool interruptible,
                          bool no_wait, bool use_sequence, uint32_t sequence)
{
        int ret;

        while (unlikely(atomic_xchg(&bo->reserved, 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 < (1U << 31)))
                                return -EAGAIN;
                }

                if (no_wait)
                        return -EBUSY;

                ret = ttm_bo_wait_unreserved_locked(bo, interruptible);

                if (unlikely(ret))
                        return ret;
        }

        if (use_sequence) {
                bool wake_up = false;
                /**
                 * Wake up waiters that may need to recheck for deadlock,
                 * if we decreased the sequence number.
                 */
                if (unlikely((bo->val_seq - sequence < (1U << 31))
                             || !bo->seq_valid))
                        wake_up = true;

                /*
                 * In the worst case with memory ordering these values can be
                 * seen in the wrong order. However since we call wake_up_all
                 * in that case, this will hopefully not pose a problem,
                 * and the worst case would only cause someone to accidentally
                 * hit -EAGAIN in ttm_bo_reserve when they see old value of
                 * val_seq. However this would only happen if seq_valid was
                 * written before val_seq was, and just means some slightly
                 * increased cpu usage
                 */
                bo->val_seq = sequence;
                bo->seq_valid = true;
                if (wake_up)
                        wakeup(bo);
        } else {
                bo->seq_valid = false;
        }

        return 0;
}

void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
                         bool never_free)
{
        u_int old;

        old = atomic_fetchadd_int(&bo->list_kref, -count);
        if (old <= count) {
                if (never_free)
                        panic("ttm_bo_ref_buf");
                ttm_bo_release_list(bo);
        }
}

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;

        mtx_lock(&bo->glob->lru_lock);
        ret = ttm_bo_reserve_nolru(bo, interruptible, no_wait, use_sequence,
                                   sequence);
        if (likely(ret == 0)) {
                put_count = ttm_bo_del_from_lru(bo);
                mtx_unlock(&glob->lru_lock);
                ttm_bo_list_ref_sub(bo, put_count, true);
        } else
                mtx_unlock(&bo->glob->lru_lock);

        return ret;
}

int ttm_bo_reserve_slowpath_nolru(struct ttm_buffer_object *bo,
                                  bool interruptible, uint32_t sequence)
{
        bool wake_up = false;
        int ret;

        while (unlikely(atomic_xchg(&bo->reserved, 1) != 0)) {
                if (bo->seq_valid && sequence == bo->val_seq) {
                        DRM_ERROR(
                            "%s: bo->seq_valid && sequence == bo->val_seq",
                            __func__);
                }

                ret = ttm_bo_wait_unreserved_locked(bo, interruptible);

                if (unlikely(ret))
                        return ret;
        }

        if ((bo->val_seq - sequence < (1U << 31)) || !bo->seq_valid)
                wake_up = true;

        /**
         * Wake up waiters that may need to recheck for deadlock,
         * if we decreased the sequence number.
         */
        bo->val_seq = sequence;
        bo->seq_valid = true;
        if (wake_up)
                wakeup(bo);

        return 0;
}

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

        mtx_lock(&glob->lru_lock);
        ret = ttm_bo_reserve_slowpath_nolru(bo, interruptible, sequence);
        if (likely(!ret)) {
                put_count = ttm_bo_del_from_lru(bo);
                mtx_unlock(&glob->lru_lock);
                ttm_bo_list_ref_sub(bo, put_count, true);
        } else
                mtx_unlock(&glob->lru_lock);
        return ret;
}

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

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

        mtx_lock(&glob->lru_lock);
        ttm_bo_unreserve_locked(bo);
        mtx_unlock(&glob->lru_lock);
}

/*
 * 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:
                printf("[TTM] 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_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_gpu, mem);
        else if (bdev->driver->move)
                ret = bdev->driver->move(bo, evict, interruptible,
                                         no_wait_gpu, mem);
        else
                ret = ttm_bo_move_memcpy(bo, evict, 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;
                        *mem = tmp_mem;
                }

                goto out_err;
        }

moved:
        if (bo->evicted) {
                ret = bdev->driver->invalidate_caches(bdev, bo->mem.placement);
                if (ret)
                        printf("[TTM] 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);
        wakeup(&bo);

        /*
         * Since the final reference to this bo may not be dropped by
         * the current task we have to put a memory barrier here to make
         * sure the changes done in this function are always visible.
         *
         * This function only needs protection against the final kref_put.
         */
        mb();
}

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 = bdev->driver;
        void *sync_obj = NULL;
        int put_count;
        int ret;

        mtx_lock(&glob->lru_lock);
        ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);

        mtx_lock(&bdev->fence_lock);
        (void) ttm_bo_wait(bo, false, false, true);
        if (!ret && !bo->sync_obj) {
                mtx_unlock(&bdev->fence_lock);
                put_count = ttm_bo_del_from_lru(bo);

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

                ttm_bo_list_ref_sub(bo, put_count, true);

                return;
        }
        if (bo->sync_obj)
                sync_obj = driver->sync_obj_ref(bo->sync_obj);
        mtx_unlock(&bdev->fence_lock);

        if (!ret) {
                atomic_set(&bo->reserved, 0);
                wakeup(bo);
        }

        refcount_acquire(&bo->list_kref);
        list_add_tail(&bo->ddestroy, &bdev->ddestroy);
        mtx_unlock(&glob->lru_lock);

        if (sync_obj) {
                driver->sync_obj_flush(sync_obj);
                driver->sync_obj_unref(&sync_obj);
        }
        taskqueue_enqueue_timeout(taskqueue_thread, &bdev->wq,
            ((hz / 100) < 1) ? 1 : hz / 100);
}

/**
 * function ttm_bo_cleanup_refs_and_unlock
 * If bo idle, remove from delayed- and lru lists, and unref.
 * If not idle, do nothing.
 *
 * Must be called with lru_lock and reservation held, this function
 * will drop both before returning.
 *
 * @interruptible         Any sleeps should occur interruptibly.
 * @no_wait_gpu           Never wait for gpu. Return -EBUSY instead.
 */

static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
                                          bool interruptible,
                                          bool no_wait_gpu)
{
        struct ttm_bo_device *bdev = bo->bdev;
        struct ttm_bo_driver *driver = bdev->driver;
        struct ttm_bo_global *glob = bo->glob;
        int put_count;
        int ret;

        mtx_lock(&bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, false, true);

        if (ret && !no_wait_gpu) {
                void *sync_obj;

                /*
                 * Take a reference to the fence and unreserve,
                 * at this point the buffer should be dead, so
                 * no new sync objects can be attached.
                 */
                sync_obj = driver->sync_obj_ref(bo->sync_obj);
                mtx_unlock(&bdev->fence_lock);

                atomic_set(&bo->reserved, 0);
                wakeup(bo);
                mtx_unlock(&glob->lru_lock);

                ret = driver->sync_obj_wait(sync_obj, false, interruptible);
                driver->sync_obj_unref(&sync_obj);
                if (ret)
                        return ret;

                /*
                 * remove sync_obj with ttm_bo_wait, the wait should be
                 * finished, and no new wait object should have been added.
                 */
                mtx_lock(&bdev->fence_lock);
                ret = ttm_bo_wait(bo, false, false, true);
                mtx_unlock(&bdev->fence_lock);
                if (ret)
                        return ret;

                mtx_lock(&glob->lru_lock);
                ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);

                /*
                 * We raced, and lost, someone else holds the reservation now,
                 * and is probably busy in ttm_bo_cleanup_memtype_use.
                 *
                 * Even if it's not the case, because we finished waiting any
                 * delayed destruction would succeed, so just return success
                 * here.
                 */
                if (ret) {
                        mtx_unlock(&glob->lru_lock);
                        return 0;
                }
        } else
                mtx_unlock(&bdev->fence_lock);

        if (ret || unlikely(list_empty(&bo->ddestroy))) {
                atomic_set(&bo->reserved, 0);
                wakeup(bo);
                mtx_unlock(&glob->lru_lock);
                return ret;
        }

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

        mtx_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;

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

        entry = list_first_entry(&bdev->ddestroy,
                struct ttm_buffer_object, ddestroy);
        refcount_acquire(&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);
                        refcount_acquire(&nentry->list_kref);
                }

                ret = ttm_bo_reserve_nolru(entry, false, true, false, 0);
                if (remove_all && ret) {
                        ret = ttm_bo_reserve_nolru(entry, false, false,
                                                   false, 0);
                }

                if (!ret)
                        ret = ttm_bo_cleanup_refs_and_unlock(entry, false,
                                                             !remove_all);
                else
                        mtx_unlock(&glob->lru_lock);

                if (refcount_release(&entry->list_kref))
                        ttm_bo_release_list(entry);
                entry = nentry;

                if (ret || !entry)
                        goto out;

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

out_unlock:
        mtx_unlock(&glob->lru_lock);
out:
        if (entry && refcount_release(&entry->list_kref))
                ttm_bo_release_list(entry);
        return ret;
}

static void ttm_bo_delayed_workqueue(void *arg, int pending __unused)
{
        struct ttm_bo_device *bdev = arg;

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

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

        rw_wlock(&bdev->vm_lock);
        if (likely(bo->vm_node != NULL)) {
                RB_REMOVE(ttm_bo_device_buffer_objects,
                    &bdev->addr_space_rb, bo);
                drm_mm_put_block(bo->vm_node);
                bo->vm_node = NULL;
        }
        rw_wunlock(&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);
        if (refcount_release(&bo->list_kref))
                ttm_bo_release_list(bo);
}

void ttm_bo_unref(struct ttm_buffer_object **p_bo)
{
        struct ttm_buffer_object *bo = *p_bo;

        *p_bo = NULL;
        if (refcount_release(&bo->kref))
                ttm_bo_release(bo);
}

int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev)
{
        int pending;

        if (taskqueue_cancel_timeout(taskqueue_thread, &bdev->wq, &pending))
                taskqueue_drain_timeout(taskqueue_thread, &bdev->wq);
        return (pending);
}

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

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

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

        if (unlikely(ret != 0)) {
                if (ret != -ERESTARTSYS) {
                        printf("[TTM] Failed to expire sync object before buffer eviction\n");
                }
                goto out;
        }

        MPASS(ttm_bo_is_reserved(bo));

        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_gpu);
        if (ret) {
                if (ret != -ERESTARTSYS) {
                        printf("[TTM] 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_gpu);
        if (ret) {
                if (ret != -ERESTARTSYS)
                        printf("[TTM] 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_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 = -EBUSY, put_count;

        mtx_lock(&glob->lru_lock);
        list_for_each_entry(bo, &man->lru, lru) {
                ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);
                if (!ret)
                        break;
        }

        if (ret) {
                mtx_unlock(&glob->lru_lock);
                return ret;
        }

        refcount_acquire(&bo->list_kref);

        if (!list_empty(&bo->ddestroy)) {
                ret = ttm_bo_cleanup_refs_and_unlock(bo, interruptible,
                                                     no_wait_gpu);
                if (refcount_release(&bo->list_kref))
                        ttm_bo_release_list(bo);
                return ret;
        }

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

        MPASS(ret == 0);

        ttm_bo_list_ref_sub(bo, put_count, true);

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

        if (refcount_release(&bo->list_kref))
                ttm_bo_release_list(bo);
        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);
}

/**
 * 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_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_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_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_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;
}

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

        MPASS(ttm_bo_is_reserved(bo));

        /*
         * FIXME: It's possible to pipeline buffer moves.
         * Have the driver move function wait for idle when necessary,
         * instead of doing it here.
         */
        mtx_lock(&bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
        mtx_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_gpu);
        if (ret)
                goto out_unlock;
        ret = ttm_bo_handle_move_mem(bo, &mem, false,
                                     interruptible, 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_gpu)
{
        int ret;

        MPASS(ttm_bo_is_reserved(bo));
        /* 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_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;
}

int ttm_bo_check_placement(struct ttm_buffer_object *bo,
                                struct ttm_placement *placement)
{
        MPASS(!((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,
                bool interruptible,
                struct vm_object *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) {
                printf("[TTM] Out of kernel memory\n");
                if (destroy)
                        (*destroy)(bo);
                else
                        free(bo, M_TTM_BO);
                return -ENOMEM;
        }

        num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
        if (num_pages == 0) {
                printf("[TTM] Illegal buffer object size\n");
                if (destroy)
                        (*destroy)(bo);
                else
                        free(bo, M_TTM_BO);
                ttm_mem_global_free(mem_glob, acc_size);
                return -EINVAL;
        }
        bo->destroy = destroy;

        refcount_init(&bo->kref, 1);
        refcount_init(&bo->list_kref, 1);
        atomic_set(&bo->cpu_writers, 0);
        atomic_set(&bo->reserved, 1);
        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->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);
        if (ret)
                goto out_err;

        ttm_bo_unreserve(bo);
        return 0;

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

        return ret;
}

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;
}

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;
}

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,
                        bool interruptible,
                        struct vm_object *persistent_swap_storage,
                        struct ttm_buffer_object **p_bo)
{
        struct ttm_buffer_object *bo;
        size_t acc_size;
        int ret;

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

        return ret;
}

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.
         */

        mtx_lock(&glob->lru_lock);
        while (!list_empty(&man->lru)) {
                mtx_unlock(&glob->lru_lock);
                ret = ttm_mem_evict_first(bdev, mem_type, false, false);
                if (ret) {
                        if (allow_errors) {
                                return ret;
                        } else {
                                printf("[TTM] Cleanup eviction failed\n");
                        }
                }
                mtx_lock(&glob->lru_lock);
        }
        mtx_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) {
                printf("[TTM] Illegal memory type %d\n", mem_type);
                return ret;
        }
        man = &bdev->man[mem_type];

        if (!man->has_type) {
                printf("[TTM] 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;
}

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) {
                printf("[TTM] Illegal memory manager memory type %u\n", mem_type);
                return -EINVAL;
        }

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

        return ttm_bo_force_list_clean(bdev, mem_type, true);
}

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;

        MPASS(type < TTM_NUM_MEM_TYPES);
        man = &bdev->man[type];
        MPASS(!man->has_type);
        man->io_reserve_fastpath = true;
        man->use_io_reserve_lru = false;
        sx_init(&man->io_reserve_mutex, "ttmman");
        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;
}

static void ttm_bo_global_kobj_release(struct ttm_bo_global *glob)
{

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

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

        if (refcount_release(&glob->kobj_ref))
                ttm_bo_global_kobj_release(glob);
}

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;
        int tries;

        sx_init(&glob->device_list_mutex, "ttmdlm");
        mtx_init(&glob->lru_lock, "ttmlru", NULL, MTX_DEF);
        glob->mem_glob = bo_ref->mem_glob;
        tries = 0;
retry:
        glob->dummy_read_page = vm_page_alloc_noobj_contig(0, 1, 0,
            VM_MAX_ADDRESS, PAGE_SIZE, 0, VM_MEMATTR_UNCACHEABLE);

        if (unlikely(glob->dummy_read_page == NULL)) {
                if (tries < 1 && (vm_page_reclaim_contig(0, 1, 0,
                    VM_MAX_ADDRESS, PAGE_SIZE, 0) == 0)) {
                        tries++;
                        goto retry;
                }
                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)) {
                printf("[TTM] Could not register buffer object swapout\n");
                goto out_no_shrink;
        }

        atomic_set(&glob->bo_count, 0);

        refcount_init(&glob->kobj_ref, 1);
        return (0);

out_no_shrink:
        vm_page_free(glob->dummy_read_page);
out_no_drp:
        free(glob, M_DRM_GLOBAL);
        return ret;
}

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;
                                printf("[TTM] DRM memory manager type %d is not clean\n",
                                       i);
                        }
                        man->has_type = false;
                }
        }

        sx_xlock(&glob->device_list_mutex);
        list_del(&bdev->device_list);
        sx_xunlock(&glob->device_list_mutex);

        if (taskqueue_cancel_timeout(taskqueue_thread, &bdev->wq, NULL))
                taskqueue_drain_timeout(taskqueue_thread, &bdev->wq);

        while (ttm_bo_delayed_delete(bdev, true))
                ;

        mtx_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");
        mtx_unlock(&glob->lru_lock);

        MPASS(drm_mm_clean(&bdev->addr_space_mm));
        rw_wlock(&bdev->vm_lock);
        drm_mm_takedown(&bdev->addr_space_mm);
        rw_wunlock(&bdev->vm_lock);

        return ret;
}

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;

        rw_init(&bdev->vm_lock, "ttmvml");
        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;

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

        TIMEOUT_TASK_INIT(taskqueue_thread, &bdev->wq, 0,
            ttm_bo_delayed_workqueue, bdev);
        INIT_LIST_HEAD(&bdev->ddestroy);
        bdev->dev_mapping = NULL;
        bdev->glob = glob;
        bdev->need_dma32 = need_dma32;
        bdev->val_seq = 0;
        mtx_init(&bdev->fence_lock, "ttmfence", NULL, MTX_DEF);
        sx_xlock(&glob->device_list_mutex);
        list_add_tail(&bdev->device_list, &glob->device_list);
        sx_xunlock(&glob->device_list_mutex);

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

/*
 * 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)
{

        ttm_bo_release_mmap(bo);
        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);
}

static void ttm_bo_vm_insert_rb(struct ttm_buffer_object *bo)
{
        struct ttm_bo_device *bdev = bo->bdev;

        /* The caller acquired bdev->vm_lock. */
        RB_INSERT(ttm_bo_device_buffer_objects, &bdev->addr_space_rb, bo);
}

/**
 * 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;

        rw_wlock(&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)) {
                rw_wunlock(&bdev->vm_lock);
                goto retry_pre_get;
        }

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

        return 0;
out_unlock:
        rw_wunlock(&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;
        int ret = 0;

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

        while (bo->sync_obj) {

                if (driver->sync_obj_signaled(bo->sync_obj)) {
                        void *tmp_obj = bo->sync_obj;
                        bo->sync_obj = NULL;
                        clear_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
                        mtx_unlock(&bdev->fence_lock);
                        driver->sync_obj_unref(&tmp_obj);
                        mtx_lock(&bdev->fence_lock);
                        continue;
                }

                if (no_wait)
                        return -EBUSY;

                sync_obj = driver->sync_obj_ref(bo->sync_obj);
                mtx_unlock(&bdev->fence_lock);
                ret = driver->sync_obj_wait(sync_obj,
                                            lazy, interruptible);
                if (unlikely(ret != 0)) {
                        driver->sync_obj_unref(&sync_obj);
                        mtx_lock(&bdev->fence_lock);
                        return ret;
                }
                mtx_lock(&bdev->fence_lock);
                if (likely(bo->sync_obj == sync_obj)) {
                        void *tmp_obj = bo->sync_obj;
                        bo->sync_obj = NULL;
                        clear_bit(TTM_BO_PRIV_FLAG_MOVING,
                                  &bo->priv_flags);
                        mtx_unlock(&bdev->fence_lock);
                        driver->sync_obj_unref(&sync_obj);
                        driver->sync_obj_unref(&tmp_obj);
                        mtx_lock(&bdev->fence_lock);
                } else {
                        mtx_unlock(&bdev->fence_lock);
                        driver->sync_obj_unref(&sync_obj);
                        mtx_lock(&bdev->fence_lock);
                }
        }
        return 0;
}

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;
        mtx_lock(&bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, true, no_wait);
        mtx_unlock(&bdev->fence_lock);
        if (likely(ret == 0))
                atomic_inc(&bo->cpu_writers);
        ttm_bo_unreserve(bo);
        return ret;
}

void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo)
{
        atomic_dec(&bo->cpu_writers);
}

/**
 * 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);

        mtx_lock(&glob->lru_lock);
        list_for_each_entry(bo, &glob->swap_lru, swap) {
                ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);
                if (!ret)
                        break;
        }

        if (ret) {
                mtx_unlock(&glob->lru_lock);
                return ret;
        }

        refcount_acquire(&bo->list_kref);

        if (!list_empty(&bo->ddestroy)) {
                ret = ttm_bo_cleanup_refs_and_unlock(bo, false, false);
                if (refcount_release(&bo->list_kref))
                        ttm_bo_release_list(bo);
                return ret;
        }

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

        ttm_bo_list_ref_sub(bo, put_count, true);

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

        mtx_lock(&bo->bdev->fence_lock);
        ret = ttm_bo_wait(bo, false, false, false);
        mtx_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);
                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);
        wakeup(bo);
        if (refcount_release(&bo->list_kref))
                ttm_bo_release_list(bo);
        return ret;
}

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