// SPDX-License-Identifier: GPL-2.0 OR MIT
/**************************************************************************
 *
 * Copyright (c) 2009-2024 Broadcom. All Rights Reserved. The term
 * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
 *
 * 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.
 *
 **************************************************************************/

#include <drm/ttm/ttm_placement.h>

#include "vmwgfx_binding.h"
#include "vmwgfx_bo.h"
#include "vmwgfx_drv.h"
#include "vmwgfx_resource_priv.h"

#define VMW_RES_EVICT_ERR_COUNT 10

/**
 * vmw_resource_mob_attach - Mark a resource as attached to its backing mob
 * @res: The resource
 */
void vmw_resource_mob_attach(struct vmw_resource *res)
{
        struct vmw_bo *gbo = res->guest_memory_bo;
        struct rb_node **new = &gbo->res_tree.rb_node, *parent = NULL;

        dma_resv_assert_held(gbo->tbo.base.resv);
        res->used_prio = (res->res_dirty) ? res->func->dirty_prio :
                res->func->prio;

        while (*new) {
                struct vmw_resource *this =
                        container_of(*new, struct vmw_resource, mob_node);

                parent = *new;
                new = (res->guest_memory_offset < this->guest_memory_offset) ?
                        &((*new)->rb_left) : &((*new)->rb_right);
        }

        rb_link_node(&res->mob_node, parent, new);
        rb_insert_color(&res->mob_node, &gbo->res_tree);
        vmw_bo_del_detached_resource(gbo, res);

        vmw_bo_prio_add(gbo, res->used_prio);
}

/**
 * vmw_resource_mob_detach - Mark a resource as detached from its backing mob
 * @res: The resource
 */
void vmw_resource_mob_detach(struct vmw_resource *res)
{
        struct vmw_bo *gbo = res->guest_memory_bo;

        dma_resv_assert_held(gbo->tbo.base.resv);
        if (vmw_resource_mob_attached(res)) {
                rb_erase(&res->mob_node, &gbo->res_tree);
                RB_CLEAR_NODE(&res->mob_node);
                vmw_bo_prio_del(gbo, res->used_prio);
        }
}

struct vmw_resource *vmw_resource_reference(struct vmw_resource *res)
{
        kref_get(&res->kref);
        return res;
}

struct vmw_resource *
vmw_resource_reference_unless_doomed(struct vmw_resource *res)
{
        return kref_get_unless_zero(&res->kref) ? res : NULL;
}

/**
 * vmw_resource_release_id - release a resource id to the id manager.
 *
 * @res: Pointer to the resource.
 *
 * Release the resource id to the resource id manager and set it to -1
 */
void vmw_resource_release_id(struct vmw_resource *res)
{
        struct vmw_private *dev_priv = res->dev_priv;
        struct idr *idr = &dev_priv->res_idr[res->func->res_type];

        spin_lock(&dev_priv->resource_lock);
        if (res->id != -1)
                idr_remove(idr, res->id);
        res->id = -1;
        spin_unlock(&dev_priv->resource_lock);
}

static void vmw_resource_release(struct kref *kref)
{
        struct vmw_resource *res =
            container_of(kref, struct vmw_resource, kref);
        struct vmw_private *dev_priv = res->dev_priv;
        int id;
        int ret;
        struct idr *idr = &dev_priv->res_idr[res->func->res_type];

        spin_lock(&dev_priv->resource_lock);
        list_del_init(&res->lru_head);
        spin_unlock(&dev_priv->resource_lock);
        if (res->guest_memory_bo) {
                struct ttm_buffer_object *bo = &res->guest_memory_bo->tbo;

                ret = ttm_bo_reserve(bo, false, false, NULL);
                BUG_ON(ret);
                if (vmw_resource_mob_attached(res) &&
                    res->func->unbind != NULL) {
                        struct ttm_validate_buffer val_buf;

                        val_buf.bo = bo;
                        val_buf.num_shared = 0;
                        res->func->unbind(res, false, &val_buf);
                }
                res->guest_memory_size = false;
                vmw_resource_mob_detach(res);
                if (res->dirty)
                        res->func->dirty_free(res);
                if (res->coherent)
                        vmw_bo_dirty_release(res->guest_memory_bo);
                ttm_bo_unreserve(bo);
                vmw_user_bo_unref(&res->guest_memory_bo);
        }

        if (likely(res->hw_destroy != NULL)) {
                mutex_lock(&dev_priv->binding_mutex);
                vmw_binding_res_list_kill(&res->binding_head);
                mutex_unlock(&dev_priv->binding_mutex);
                res->hw_destroy(res);
        }

        id = res->id;
        if (res->res_free != NULL)
                res->res_free(res);
        else
                kfree(res);

        spin_lock(&dev_priv->resource_lock);
        if (id != -1)
                idr_remove(idr, id);
        spin_unlock(&dev_priv->resource_lock);
}

void vmw_resource_unreference(struct vmw_resource **p_res)
{
        struct vmw_resource *res = *p_res;

        *p_res = NULL;
        kref_put(&res->kref, vmw_resource_release);
}


/**
 * vmw_resource_alloc_id - release a resource id to the id manager.
 *
 * @res: Pointer to the resource.
 *
 * Allocate the lowest free resource from the resource manager, and set
 * @res->id to that id. Returns 0 on success and -ENOMEM on failure.
 */
int vmw_resource_alloc_id(struct vmw_resource *res)
{
        struct vmw_private *dev_priv = res->dev_priv;
        int ret;
        struct idr *idr = &dev_priv->res_idr[res->func->res_type];

        BUG_ON(res->id != -1);

        idr_preload(GFP_KERNEL);
        spin_lock(&dev_priv->resource_lock);

        ret = idr_alloc(idr, res, 1, 0, GFP_NOWAIT);
        if (ret >= 0)
                res->id = ret;

        spin_unlock(&dev_priv->resource_lock);
        idr_preload_end();
        return ret < 0 ? ret : 0;
}

/**
 * vmw_resource_init - initialize a struct vmw_resource
 *
 * @dev_priv:       Pointer to a device private struct.
 * @res:            The struct vmw_resource to initialize.
 * @delay_id:       Boolean whether to defer device id allocation until
 *                  the first validation.
 * @res_free:       Resource destructor.
 * @func:           Resource function table.
 */
int vmw_resource_init(struct vmw_private *dev_priv, struct vmw_resource *res,
                      bool delay_id,
                      void (*res_free) (struct vmw_resource *res),
                      const struct vmw_res_func *func)
{
        kref_init(&res->kref);
        res->hw_destroy = NULL;
        res->res_free = res_free;
        res->dev_priv = dev_priv;
        res->func = func;
        RB_CLEAR_NODE(&res->mob_node);
        INIT_LIST_HEAD(&res->lru_head);
        INIT_LIST_HEAD(&res->binding_head);
        res->id = -1;
        res->guest_memory_bo = NULL;
        res->guest_memory_offset = 0;
        res->guest_memory_dirty = false;
        res->res_dirty = false;
        res->coherent = false;
        res->used_prio = 3;
        res->dirty = NULL;
        if (delay_id)
                return 0;
        else
                return vmw_resource_alloc_id(res);
}


/**
 * vmw_user_resource_lookup_handle - lookup a struct resource from a
 * TTM user-space handle and perform basic type checks
 *
 * @dev_priv:     Pointer to a device private struct
 * @tfile:        Pointer to a struct ttm_object_file identifying the caller
 * @handle:       The TTM user-space handle
 * @converter:    Pointer to an object describing the resource type
 * @p_res:        On successful return the location pointed to will contain
 *                a pointer to a refcounted struct vmw_resource.
 *
 * If the handle can't be found or is associated with an incorrect resource
 * type, -EINVAL will be returned.
 */
int vmw_user_resource_lookup_handle(struct vmw_private *dev_priv,
                                    struct ttm_object_file *tfile,
                                    uint32_t handle,
                                    const struct vmw_user_resource_conv
                                    *converter,
                                    struct vmw_resource **p_res)
{
        struct ttm_base_object *base;
        struct vmw_resource *res;
        int ret = -EINVAL;

        base = ttm_base_object_lookup(tfile, handle);
        if (unlikely(!base))
                return -EINVAL;

        if (unlikely(ttm_base_object_type(base) != converter->object_type))
                goto out_bad_resource;

        res = converter->base_obj_to_res(base);
        vmw_resource_reference(res);

        *p_res = res;
        ret = 0;

out_bad_resource:
        ttm_base_object_unref(&base);

        return ret;
}

/*
 * Helper function that looks either a surface or bo.
 *
 * The pointer this pointed at by out_surf and out_buf needs to be null.
 */
int vmw_user_object_lookup(struct vmw_private *dev_priv,
                           struct drm_file *filp,
                           u32 handle,
                           struct vmw_user_object *uo)
{
        struct ttm_object_file *tfile = vmw_fpriv(filp)->tfile;
        struct vmw_resource *res;
        int ret;

        WARN_ON(uo->surface || uo->buffer);

        ret = vmw_user_resource_lookup_handle(dev_priv, tfile, handle,
                                              user_surface_converter,
                                              &res);
        if (!ret) {
                uo->surface = vmw_res_to_srf(res);
                return 0;
        }

        uo->surface = NULL;
        ret = vmw_user_bo_lookup(filp, handle, &uo->buffer);
        if (!ret && !uo->buffer->is_dumb) {
                uo->surface = vmw_lookup_surface_for_buffer(dev_priv,
                                                            uo->buffer,
                                                            handle);
                if (uo->surface)
                        vmw_user_bo_unref(&uo->buffer);
        }

        return ret;
}

/**
 * vmw_resource_buf_alloc - Allocate a guest memory buffer for a resource.
 *
 * @res:            The resource for which to allocate a gbo buffer.
 * @interruptible:  Whether any sleeps during allocation should be
 *                  performed while interruptible.
 */
static int vmw_resource_buf_alloc(struct vmw_resource *res,
                                  bool interruptible)
{
        unsigned long size = PFN_ALIGN(res->guest_memory_size);
        struct vmw_bo *gbo;
        struct vmw_bo_params bo_params = {
                .domain = res->func->domain,
                .busy_domain = res->func->busy_domain,
                .bo_type = ttm_bo_type_device,
                .size = res->guest_memory_size,
                .pin = false
        };
        int ret;

        if (likely(res->guest_memory_bo)) {
                BUG_ON(res->guest_memory_bo->tbo.base.size < size);
                return 0;
        }

        ret = vmw_bo_create(res->dev_priv, &bo_params, &gbo);
        if (unlikely(ret != 0))
                goto out_no_bo;

        res->guest_memory_bo = gbo;

out_no_bo:
        return ret;
}

/**
 * vmw_resource_do_validate - Make a resource up-to-date and visible
 *                            to the device.
 *
 * @res:            The resource to make visible to the device.
 * @val_buf:        Information about a buffer possibly
 *                  containing backup data if a bind operation is needed.
 * @dirtying:       Transfer dirty regions.
 *
 * On hardware resource shortage, this function returns -EBUSY and
 * should be retried once resources have been freed up.
 */
static int vmw_resource_do_validate(struct vmw_resource *res,
                                    struct ttm_validate_buffer *val_buf,
                                    bool dirtying)
{
        int ret = 0;
        const struct vmw_res_func *func = res->func;

        if (unlikely(res->id == -1)) {
                ret = func->create(res);
                if (unlikely(ret != 0))
                        return ret;
        }

        if (func->bind &&
            ((func->needs_guest_memory && !vmw_resource_mob_attached(res) &&
              val_buf->bo) ||
             (!func->needs_guest_memory && val_buf->bo))) {
                ret = func->bind(res, val_buf);
                if (unlikely(ret != 0))
                        goto out_bind_failed;
                if (func->needs_guest_memory)
                        vmw_resource_mob_attach(res);
        }

        /*
         * Handle the case where the backup mob is marked coherent but
         * the resource isn't.
         */
        if (func->dirty_alloc && vmw_resource_mob_attached(res) &&
            !res->coherent) {
                if (res->guest_memory_bo->dirty && !res->dirty) {
                        ret = func->dirty_alloc(res);
                        if (ret)
                                return ret;
                } else if (!res->guest_memory_bo->dirty && res->dirty) {
                        func->dirty_free(res);
                }
        }

        /*
         * Transfer the dirty regions to the resource and update
         * the resource.
         */
        if (res->dirty) {
                if (dirtying && !res->res_dirty) {
                        pgoff_t start = res->guest_memory_offset >> PAGE_SHIFT;
                        pgoff_t end = __KERNEL_DIV_ROUND_UP
                                (res->guest_memory_offset + res->guest_memory_size,
                                 PAGE_SIZE);

                        vmw_bo_dirty_unmap(res->guest_memory_bo, start, end);
                }

                vmw_bo_dirty_transfer_to_res(res);
                return func->dirty_sync(res);
        }

        return 0;

out_bind_failed:
        func->destroy(res);

        return ret;
}

/**
 * vmw_resource_unreserve - Unreserve a resource previously reserved for
 * command submission.
 *
 * @res:               Pointer to the struct vmw_resource to unreserve.
 * @dirty_set:         Change dirty status of the resource.
 * @dirty:             When changing dirty status indicates the new status.
 * @switch_guest_memory: Guest memory buffer has been switched.
 * @new_guest_memory_bo: Pointer to new guest memory buffer if command submission
 *                     switched. May be NULL.
 * @new_guest_memory_offset: New gbo offset if @switch_guest_memory is true.
 *
 * Currently unreserving a resource means putting it back on the device's
 * resource lru list, so that it can be evicted if necessary.
 */
void vmw_resource_unreserve(struct vmw_resource *res,
                            bool dirty_set,
                            bool dirty,
                            bool switch_guest_memory,
                            struct vmw_bo *new_guest_memory_bo,
                            unsigned long new_guest_memory_offset)
{
        struct vmw_private *dev_priv = res->dev_priv;

        if (!list_empty(&res->lru_head))
                return;

        if (switch_guest_memory && new_guest_memory_bo != res->guest_memory_bo) {
                if (res->guest_memory_bo) {
                        vmw_resource_mob_detach(res);
                        if (res->coherent)
                                vmw_bo_dirty_release(res->guest_memory_bo);
                        vmw_user_bo_unref(&res->guest_memory_bo);
                }

                if (new_guest_memory_bo) {
                        res->guest_memory_bo = vmw_user_bo_ref(new_guest_memory_bo);

                        /*
                         * The validation code should already have added a
                         * dirty tracker here.
                         */
                        WARN_ON(res->coherent && !new_guest_memory_bo->dirty);

                        vmw_resource_mob_attach(res);
                } else {
                        res->guest_memory_bo = NULL;
                }
        } else if (switch_guest_memory && res->coherent) {
                vmw_bo_dirty_release(res->guest_memory_bo);
        }

        if (switch_guest_memory)
                res->guest_memory_offset = new_guest_memory_offset;

        if (dirty_set)
                res->res_dirty = dirty;

        if (!res->func->may_evict || res->id == -1 || res->pin_count)
                return;

        spin_lock(&dev_priv->resource_lock);
        list_add_tail(&res->lru_head,
                      &res->dev_priv->res_lru[res->func->res_type]);
        spin_unlock(&dev_priv->resource_lock);
}

/**
 * vmw_resource_check_buffer - Check whether a backup buffer is needed
 *                             for a resource and in that case, allocate
 *                             one, reserve and validate it.
 *
 * @ticket:         The ww acquire context to use, or NULL if trylocking.
 * @res:            The resource for which to allocate a backup buffer.
 * @interruptible:  Whether any sleeps during allocation should be
 *                  performed while interruptible.
 * @val_buf:        On successful return contains data about the
 *                  reserved and validated backup buffer.
 */
static int
vmw_resource_check_buffer(struct ww_acquire_ctx *ticket,
                          struct vmw_resource *res,
                          bool interruptible,
                          struct ttm_validate_buffer *val_buf)
{
        struct ttm_operation_ctx ctx = { true, false };
        struct list_head val_list;
        bool guest_memory_dirty = false;
        int ret;

        if (unlikely(!res->guest_memory_bo)) {
                ret = vmw_resource_buf_alloc(res, interruptible);
                if (unlikely(ret != 0))
                        return ret;
        }

        INIT_LIST_HEAD(&val_list);
        val_buf->bo = &res->guest_memory_bo->tbo;
        val_buf->num_shared = 0;
        drm_gem_object_get(&val_buf->bo->base);
        list_add_tail(&val_buf->head, &val_list);
        ret = ttm_eu_reserve_buffers(ticket, &val_list, interruptible, NULL);
        if (unlikely(ret != 0))
                goto out_no_reserve;

        if (res->func->needs_guest_memory && !vmw_resource_mob_attached(res))
                return 0;

        guest_memory_dirty = res->guest_memory_dirty;
        vmw_bo_placement_set(res->guest_memory_bo, res->func->domain,
                             res->func->busy_domain);
        ret = ttm_bo_validate(&res->guest_memory_bo->tbo,
                              &res->guest_memory_bo->placement,
                              &ctx);

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

        return 0;

out_no_validate:
        ttm_eu_backoff_reservation(ticket, &val_list);
out_no_reserve:
        drm_gem_object_put(&val_buf->bo->base);
        val_buf->bo = NULL;
        if (guest_memory_dirty)
                vmw_user_bo_unref(&res->guest_memory_bo);

        return ret;
}

/*
 * vmw_resource_reserve - Reserve a resource for command submission
 *
 * @res:            The resource to reserve.
 *
 * This function takes the resource off the LRU list and make sure
 * a guest memory buffer is present for guest-backed resources.
 * However, the buffer may not be bound to the resource at this
 * point.
 *
 */
int vmw_resource_reserve(struct vmw_resource *res, bool interruptible,
                         bool no_guest_memory)
{
        struct vmw_private *dev_priv = res->dev_priv;
        int ret;

        spin_lock(&dev_priv->resource_lock);
        list_del_init(&res->lru_head);
        spin_unlock(&dev_priv->resource_lock);

        if (res->func->needs_guest_memory && !res->guest_memory_bo &&
            !no_guest_memory) {
                ret = vmw_resource_buf_alloc(res, interruptible);
                if (unlikely(ret != 0)) {
                        DRM_ERROR("Failed to allocate a guest memory buffer "
                                  "of size %lu. bytes\n",
                                  (unsigned long) res->guest_memory_size);
                        return ret;
                }
        }

        return 0;
}

/**
 * vmw_resource_backoff_reservation - Unreserve and unreference a
 *                                    guest memory buffer
 *.
 * @ticket:         The ww acquire ctx used for reservation.
 * @val_buf:        Guest memory buffer information.
 */
static void
vmw_resource_backoff_reservation(struct ww_acquire_ctx *ticket,
                                 struct ttm_validate_buffer *val_buf)
{
        struct list_head val_list;

        if (likely(val_buf->bo == NULL))
                return;

        INIT_LIST_HEAD(&val_list);
        list_add_tail(&val_buf->head, &val_list);
        ttm_eu_backoff_reservation(ticket, &val_list);
        drm_gem_object_put(&val_buf->bo->base);
        val_buf->bo = NULL;
}

/**
 * vmw_resource_do_evict - Evict a resource, and transfer its data
 *                         to a backup buffer.
 *
 * @ticket:         The ww acquire ticket to use, or NULL if trylocking.
 * @res:            The resource to evict.
 * @interruptible:  Whether to wait interruptible.
 */
static int vmw_resource_do_evict(struct ww_acquire_ctx *ticket,
                                 struct vmw_resource *res, bool interruptible)
{
        struct ttm_validate_buffer val_buf;
        const struct vmw_res_func *func = res->func;
        int ret;

        BUG_ON(!func->may_evict);

        val_buf.bo = NULL;
        val_buf.num_shared = 0;
        ret = vmw_resource_check_buffer(ticket, res, interruptible, &val_buf);
        if (unlikely(ret != 0))
                return ret;

        if (unlikely(func->unbind != NULL &&
                     (!func->needs_guest_memory || vmw_resource_mob_attached(res)))) {
                ret = func->unbind(res, res->res_dirty, &val_buf);
                if (unlikely(ret != 0))
                        goto out_no_unbind;
                vmw_resource_mob_detach(res);
        }
        ret = func->destroy(res);
        res->guest_memory_dirty = true;
        res->res_dirty = false;
out_no_unbind:
        vmw_resource_backoff_reservation(ticket, &val_buf);

        return ret;
}


/**
 * vmw_resource_validate - Make a resource up-to-date and visible
 *                         to the device.
 * @res: The resource to make visible to the device.
 * @intr: Perform waits interruptible if possible.
 * @dirtying: Pending GPU operation will dirty the resource
 *
 * On successful return, any backup DMA buffer pointed to by @res->backup will
 * be reserved and validated.
 * On hardware resource shortage, this function will repeatedly evict
 * resources of the same type until the validation succeeds.
 *
 * Return: Zero on success, -ERESTARTSYS if interrupted, negative error code
 * on failure.
 */
int vmw_resource_validate(struct vmw_resource *res, bool intr,
                          bool dirtying)
{
        int ret;
        struct vmw_resource *evict_res;
        struct vmw_private *dev_priv = res->dev_priv;
        struct list_head *lru_list = &dev_priv->res_lru[res->func->res_type];
        struct ttm_validate_buffer val_buf;
        unsigned err_count = 0;

        if (!res->func->create)
                return 0;

        val_buf.bo = NULL;
        val_buf.num_shared = 0;
        if (res->guest_memory_bo)
                val_buf.bo = &res->guest_memory_bo->tbo;
        do {
                ret = vmw_resource_do_validate(res, &val_buf, dirtying);
                if (likely(ret != -EBUSY))
                        break;

                spin_lock(&dev_priv->resource_lock);
                if (list_empty(lru_list) || !res->func->may_evict) {
                        DRM_ERROR("Out of device device resources "
                                  "for %s.\n", res->func->type_name);
                        ret = -EBUSY;
                        spin_unlock(&dev_priv->resource_lock);
                        break;
                }

                evict_res = vmw_resource_reference
                        (list_first_entry(lru_list, struct vmw_resource,
                                          lru_head));
                list_del_init(&evict_res->lru_head);

                spin_unlock(&dev_priv->resource_lock);

                /* Trylock backup buffers with a NULL ticket. */
                ret = vmw_resource_do_evict(NULL, evict_res, intr);
                if (unlikely(ret != 0)) {
                        spin_lock(&dev_priv->resource_lock);
                        list_add_tail(&evict_res->lru_head, lru_list);
                        spin_unlock(&dev_priv->resource_lock);
                        if (ret == -ERESTARTSYS ||
                            ++err_count > VMW_RES_EVICT_ERR_COUNT) {
                                vmw_resource_unreference(&evict_res);
                                goto out_no_validate;
                        }
                }

                vmw_resource_unreference(&evict_res);
        } while (1);

        if (unlikely(ret != 0))
                goto out_no_validate;
        else if (!res->func->needs_guest_memory && res->guest_memory_bo) {
                WARN_ON_ONCE(vmw_resource_mob_attached(res));
                vmw_user_bo_unref(&res->guest_memory_bo);
        }

        return 0;

out_no_validate:
        return ret;
}


/**
 * vmw_resource_unbind_list
 *
 * @vbo: Pointer to the current backing MOB.
 *
 * Evicts the Guest Backed hardware resource if the backup
 * buffer is being moved out of MOB memory.
 * Note that this function will not race with the resource
 * validation code, since resource validation and eviction
 * both require the backup buffer to be reserved.
 */
void vmw_resource_unbind_list(struct vmw_bo *vbo)
{
        struct ttm_validate_buffer val_buf = {
                .bo = &vbo->tbo,
                .num_shared = 0
        };

        dma_resv_assert_held(vbo->tbo.base.resv);
        while (!RB_EMPTY_ROOT(&vbo->res_tree)) {
                struct rb_node *node = vbo->res_tree.rb_node;
                struct vmw_resource *res =
                        container_of(node, struct vmw_resource, mob_node);

                if (!WARN_ON_ONCE(!res->func->unbind))
                        (void) res->func->unbind(res, res->res_dirty, &val_buf);

                res->guest_memory_size = true;
                res->res_dirty = false;
                vmw_resource_mob_detach(res);
        }

        (void) ttm_bo_wait(&vbo->tbo, false, false);
}


/**
 * vmw_query_readback_all - Read back cached query states
 *
 * @dx_query_mob: Buffer containing the DX query MOB
 *
 * Read back cached states from the device if they exist.  This function
 * assumes binding_mutex is held.
 */
int vmw_query_readback_all(struct vmw_bo *dx_query_mob)
{
        struct vmw_resource *dx_query_ctx;
        struct vmw_private *dev_priv;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdDXReadbackAllQuery body;
        } *cmd;


        /* No query bound, so do nothing */
        if (!dx_query_mob || !dx_query_mob->dx_query_ctx)
                return 0;

        dx_query_ctx = dx_query_mob->dx_query_ctx;
        dev_priv     = dx_query_ctx->dev_priv;

        cmd = VMW_CMD_CTX_RESERVE(dev_priv, sizeof(*cmd), dx_query_ctx->id);
        if (unlikely(cmd == NULL))
                return -ENOMEM;

        cmd->header.id   = SVGA_3D_CMD_DX_READBACK_ALL_QUERY;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.cid    = dx_query_ctx->id;

        vmw_cmd_commit(dev_priv, sizeof(*cmd));

        /* Triggers a rebind the next time affected context is bound */
        dx_query_mob->dx_query_ctx = NULL;

        return 0;
}



/**
 * vmw_query_move_notify - Read back cached query states
 *
 * @bo: The TTM buffer object about to move.
 * @old_mem: The memory region @bo is moving from.
 * @new_mem: The memory region @bo is moving to.
 *
 * Called before the query MOB is swapped out to read back cached query
 * states from the device.
 */
void vmw_query_move_notify(struct ttm_buffer_object *bo,
                           struct ttm_resource *old_mem,
                           struct ttm_resource *new_mem)
{
        struct vmw_bo *dx_query_mob;
        struct ttm_device *bdev = bo->bdev;
        struct vmw_private *dev_priv = vmw_priv_from_ttm(bdev);

        mutex_lock(&dev_priv->binding_mutex);

        /* If BO is being moved from MOB to system memory */
        if (old_mem &&
            new_mem->mem_type == TTM_PL_SYSTEM &&
            old_mem->mem_type == VMW_PL_MOB) {
                struct vmw_fence_obj *fence;

                dx_query_mob = to_vmw_bo(&bo->base);
                if (!dx_query_mob || !dx_query_mob->dx_query_ctx) {
                        mutex_unlock(&dev_priv->binding_mutex);
                        return;
                }

                (void) vmw_query_readback_all(dx_query_mob);
                mutex_unlock(&dev_priv->binding_mutex);

                /* Create a fence and attach the BO to it */
                (void) vmw_execbuf_fence_commands(NULL, dev_priv, &fence, NULL);
                vmw_bo_fence_single(bo, fence);

                if (fence != NULL)
                        vmw_fence_obj_unreference(&fence);

                (void) ttm_bo_wait(bo, false, false);
        } else
                mutex_unlock(&dev_priv->binding_mutex);
}

/**
 * vmw_resource_needs_backup - Return whether a resource needs a backup buffer.
 *
 * @res:            The resource being queried.
 */
bool vmw_resource_needs_backup(const struct vmw_resource *res)
{
        return res->func->needs_guest_memory;
}

/**
 * vmw_resource_evict_type - Evict all resources of a specific type
 *
 * @dev_priv:       Pointer to a device private struct
 * @type:           The resource type to evict
 *
 * To avoid thrashing starvation or as part of the hibernation sequence,
 * try to evict all evictable resources of a specific type.
 */
static void vmw_resource_evict_type(struct vmw_private *dev_priv,
                                    enum vmw_res_type type)
{
        struct list_head *lru_list = &dev_priv->res_lru[type];
        struct vmw_resource *evict_res;
        unsigned err_count = 0;
        int ret;
        struct ww_acquire_ctx ticket;

        do {
                spin_lock(&dev_priv->resource_lock);

                if (list_empty(lru_list))
                        goto out_unlock;

                evict_res = vmw_resource_reference(
                        list_first_entry(lru_list, struct vmw_resource,
                                         lru_head));
                list_del_init(&evict_res->lru_head);
                spin_unlock(&dev_priv->resource_lock);

                /* Wait lock backup buffers with a ticket. */
                ret = vmw_resource_do_evict(&ticket, evict_res, false);
                if (unlikely(ret != 0)) {
                        spin_lock(&dev_priv->resource_lock);
                        list_add_tail(&evict_res->lru_head, lru_list);
                        spin_unlock(&dev_priv->resource_lock);
                        if (++err_count > VMW_RES_EVICT_ERR_COUNT) {
                                vmw_resource_unreference(&evict_res);
                                return;
                        }
                }

                vmw_resource_unreference(&evict_res);
        } while (1);

out_unlock:
        spin_unlock(&dev_priv->resource_lock);
}

/**
 * vmw_resource_evict_all - Evict all evictable resources
 *
 * @dev_priv:       Pointer to a device private struct
 *
 * To avoid thrashing starvation or as part of the hibernation sequence,
 * evict all evictable resources. In particular this means that all
 * guest-backed resources that are registered with the device are
 * evicted and the OTable becomes clean.
 */
void vmw_resource_evict_all(struct vmw_private *dev_priv)
{
        enum vmw_res_type type;

        mutex_lock(&dev_priv->cmdbuf_mutex);

        for (type = 0; type < vmw_res_max; ++type)
                vmw_resource_evict_type(dev_priv, type);

        mutex_unlock(&dev_priv->cmdbuf_mutex);
}

/*
 * vmw_resource_pin - Add a pin reference on a resource
 *
 * @res: The resource to add a pin reference on
 *
 * This function adds a pin reference, and if needed validates the resource.
 * Having a pin reference means that the resource can never be evicted, and
 * its id will never change as long as there is a pin reference.
 * This function returns 0 on success and a negative error code on failure.
 */
int vmw_resource_pin(struct vmw_resource *res, bool interruptible)
{
        struct ttm_operation_ctx ctx = { interruptible, false };
        struct vmw_private *dev_priv = res->dev_priv;
        int ret;

        mutex_lock(&dev_priv->cmdbuf_mutex);
        ret = vmw_resource_reserve(res, interruptible, false);
        if (ret)
                goto out_no_reserve;

        if (res->pin_count == 0) {
                struct vmw_bo *vbo = NULL;

                if (res->guest_memory_bo) {
                        vbo = res->guest_memory_bo;

                        ret = ttm_bo_reserve(&vbo->tbo, interruptible, false, NULL);
                        if (ret)
                                goto out_no_validate;
                        if (!vbo->tbo.pin_count) {
                                vmw_bo_placement_set(vbo,
                                                     res->func->domain,
                                                     res->func->busy_domain);
                                ret = ttm_bo_validate
                                        (&vbo->tbo,
                                         &vbo->placement,
                                         &ctx);
                                if (ret) {
                                        ttm_bo_unreserve(&vbo->tbo);
                                        goto out_no_validate;
                                }
                        }

                        /* Do we really need to pin the MOB as well? */
                        vmw_bo_pin_reserved(vbo, true);
                }
                ret = vmw_resource_validate(res, interruptible, true);
                if (vbo)
                        ttm_bo_unreserve(&vbo->tbo);
                if (ret)
                        goto out_no_validate;
        }
        res->pin_count++;

out_no_validate:
        vmw_resource_unreserve(res, false, false, false, NULL, 0UL);
out_no_reserve:
        mutex_unlock(&dev_priv->cmdbuf_mutex);

        return ret;
}

/**
 * vmw_resource_unpin - Remove a pin reference from a resource
 *
 * @res: The resource to remove a pin reference from
 *
 * Having a pin reference means that the resource can never be evicted, and
 * its id will never change as long as there is a pin reference.
 */
void vmw_resource_unpin(struct vmw_resource *res)
{
        struct vmw_private *dev_priv = res->dev_priv;
        int ret;

        mutex_lock(&dev_priv->cmdbuf_mutex);

        ret = vmw_resource_reserve(res, false, true);
        WARN_ON(ret);

        WARN_ON(res->pin_count == 0);
        if (--res->pin_count == 0 && res->guest_memory_bo) {
                struct vmw_bo *vbo = res->guest_memory_bo;

                (void) ttm_bo_reserve(&vbo->tbo, false, false, NULL);
                vmw_bo_pin_reserved(vbo, false);
                ttm_bo_unreserve(&vbo->tbo);
        }

        vmw_resource_unreserve(res, false, false, false, NULL, 0UL);

        mutex_unlock(&dev_priv->cmdbuf_mutex);
}

/**
 * vmw_res_type - Return the resource type
 *
 * @res: Pointer to the resource
 */
enum vmw_res_type vmw_res_type(const struct vmw_resource *res)
{
        return res->func->res_type;
}

/**
 * vmw_resource_dirty_update - Update a resource's dirty tracker with a
 * sequential range of touched backing store memory.
 * @res: The resource.
 * @start: The first page touched.
 * @end: The last page touched + 1.
 */
void vmw_resource_dirty_update(struct vmw_resource *res, pgoff_t start,
                               pgoff_t end)
{
        if (res->dirty)
                res->func->dirty_range_add(res, start << PAGE_SHIFT,
                                           end << PAGE_SHIFT);
}

int vmw_resource_clean(struct vmw_resource *res)
{
        int ret = 0;

        if (res->res_dirty) {
                if (!res->func->clean)
                        return -EINVAL;

                ret = res->func->clean(res);
                if (ret)
                        return ret;
                res->res_dirty = false;
        }
        return ret;
}

/**
 * vmw_resources_clean - Clean resources intersecting a mob range
 * @vbo: The mob buffer object
 * @start: The mob page offset starting the range
 * @end: The mob page offset ending the range
 * @num_prefault: Returns how many pages including the first have been
 * cleaned and are ok to prefault
 */
int vmw_resources_clean(struct vmw_bo *vbo, pgoff_t start,
                        pgoff_t end, pgoff_t *num_prefault)
{
        struct rb_node *cur = vbo->res_tree.rb_node;
        struct vmw_resource *found = NULL;
        unsigned long res_start = start << PAGE_SHIFT;
        unsigned long res_end = end << PAGE_SHIFT;
        unsigned long last_cleaned = 0;
        int ret;

        /*
         * Find the resource with lowest backup_offset that intersects the
         * range.
         */
        while (cur) {
                struct vmw_resource *cur_res =
                        container_of(cur, struct vmw_resource, mob_node);

                if (cur_res->guest_memory_offset >= res_end) {
                        cur = cur->rb_left;
                } else if (cur_res->guest_memory_offset + cur_res->guest_memory_size <=
                           res_start) {
                        cur = cur->rb_right;
                } else {
                        found = cur_res;
                        cur = cur->rb_left;
                        /* Continue to look for resources with lower offsets */
                }
        }

        /*
         * In order of increasing guest_memory_offset, clean dirty resources
         * intersecting the range.
         */
        while (found) {
                ret = vmw_resource_clean(found);
                if (ret)
                        return ret;
                last_cleaned = found->guest_memory_offset + found->guest_memory_size;
                cur = rb_next(&found->mob_node);
                if (!cur)
                        break;

                found = container_of(cur, struct vmw_resource, mob_node);
                if (found->guest_memory_offset >= res_end)
                        break;
        }

        /*
         * Set number of pages allowed prefaulting and fence the buffer object
         */
        *num_prefault = 1;
        if (last_cleaned > res_start) {
                struct ttm_buffer_object *bo = &vbo->tbo;

                *num_prefault = __KERNEL_DIV_ROUND_UP(last_cleaned - res_start,
                                                      PAGE_SIZE);
                vmw_bo_fence_single(bo, NULL);
        }

        return 0;
}