vmwgfx_fence.c

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/**************************************************************************
 *
 * Copyright © 2011 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.
 *
 **************************************************************************/

#include <drm/drmP.h>
#include "vmwgfx_drv.h"

#define VMW_FENCE_WRAP (1 << 31)

struct vmw_fence_manager {
    int num_fence_objects;
    struct vmw_private *dev_priv;
    spinlock_t lock;
    struct list_head fence_list;
    struct work_struct work;
    u32 user_fence_size;
    u32 fence_size;
    u32 event_fence_action_size;
    bool fifo_down;
    struct list_head cleanup_list;
    uint32_t pending_actions[VMW_ACTION_MAX];
    struct mutex goal_irq_mutex;
    bool goal_irq_on; /* Protected by @goal_irq_mutex */
    bool seqno_valid; /* Protected by @lock, and may not be set to true
                 without the @goal_irq_mutex held. */
};

struct vmw_user_fence {
    struct ttm_base_object base;
    struct vmw_fence_obj fence;
};

struct vmw_event_fence_action {
    struct vmw_fence_action action;
    struct list_head fpriv_head;

    struct drm_pending_event *event;
    struct vmw_fence_obj *fence;
    struct drm_device *dev;

    uint32_t *tv_sec;
    uint32_t *tv_usec;
};

static void vmw_fence_obj_destroy_locked(struct kref *kref)
{
    struct vmw_fence_obj *fence =
        container_of(kref, struct vmw_fence_obj, kref);

    struct vmw_fence_manager *fman = fence->fman;
    unsigned int num_fences;

    list_del_init(&fence->head);
    num_fences = --fman->num_fence_objects;
    spin_unlock_irq(&fman->lock);
    if (fence->destroy)
        fence->destroy(fence);
    else
        kfree(fence);

    spin_lock_irq(&fman->lock);
}


static void vmw_fence_work_func(struct work_struct *work)
{
    struct vmw_fence_manager *fman =
        container_of(work, struct vmw_fence_manager, work);
    struct list_head list;
    struct vmw_fence_action *action, *next_action;
    bool seqno_valid;

    do {
        INIT_LIST_HEAD(&list);
        mutex_lock(&fman->goal_irq_mutex);

        spin_lock_irq(&fman->lock);
        list_splice_init(&fman->cleanup_list, &list);
        seqno_valid = fman->seqno_valid;
        spin_unlock_irq(&fman->lock);

        if (!seqno_valid && fman->goal_irq_on) {
            fman->goal_irq_on = false;
            vmw_goal_waiter_remove(fman->dev_priv);
        }
        mutex_unlock(&fman->goal_irq_mutex);

        if (list_empty(&list))
            return;

        /*
         * At this point, only we should be able to manipulate the
         * list heads of the actions we have on the private list.
         * hence fman::lock not held.
         */

        list_for_each_entry_safe(action, next_action, &list, head) {
            list_del_init(&action->head);
            if (action->cleanup)
                action->cleanup(action);
        }
    } while (1);
}

struct vmw_fence_manager *vmw_fence_manager_init(struct vmw_private *dev_priv)
{
    struct vmw_fence_manager *fman = kzalloc(sizeof(*fman), GFP_KERNEL);

    if (unlikely(fman == NULL))
        return NULL;

    fman->dev_priv = dev_priv;
    spin_lock_init(&fman->lock);
    INIT_LIST_HEAD(&fman->fence_list);
    INIT_LIST_HEAD(&fman->cleanup_list);
    INIT_WORK(&fman->work, &vmw_fence_work_func);
    fman->fifo_down = true;
    fman->user_fence_size = ttm_round_pot(sizeof(struct vmw_user_fence));
    fman->fence_size = ttm_round_pot(sizeof(struct vmw_fence_obj));
    fman->event_fence_action_size =
        ttm_round_pot(sizeof(struct vmw_event_fence_action));
    mutex_init(&fman->goal_irq_mutex);

    return fman;
}

void vmw_fence_manager_takedown(struct vmw_fence_manager *fman)
{
    unsigned long irq_flags;
    bool lists_empty;

    (void) cancel_work_sync(&fman->work);

    spin_lock_irqsave(&fman->lock, irq_flags);
    lists_empty = list_empty(&fman->fence_list) &&
        list_empty(&fman->cleanup_list);
    spin_unlock_irqrestore(&fman->lock, irq_flags);

    BUG_ON(!lists_empty);
    kfree(fman);
}

static int vmw_fence_obj_init(struct vmw_fence_manager *fman,
                  struct vmw_fence_obj *fence,
                  u32 seqno,
                  uint32_t mask,
                  void (*destroy) (struct vmw_fence_obj *fence))
{
    unsigned long irq_flags;
    unsigned int num_fences;
    int ret = 0;

    fence->seqno = seqno;
    INIT_LIST_HEAD(&fence->seq_passed_actions);
    fence->fman = fman;
    fence->signaled = 0;
    fence->signal_mask = mask;
    kref_init(&fence->kref);
    fence->destroy = destroy;
    init_waitqueue_head(&fence->queue);

    spin_lock_irqsave(&fman->lock, irq_flags);
    if (unlikely(fman->fifo_down)) {
        ret = -EBUSY;
        goto out_unlock;
    }
    list_add_tail(&fence->head, &fman->fence_list);
    num_fences = ++fman->num_fence_objects;

out_unlock:
    spin_unlock_irqrestore(&fman->lock, irq_flags);
    return ret;

}

struct vmw_fence_obj *vmw_fence_obj_reference(struct vmw_fence_obj *fence)
{
    if (unlikely(fence == NULL))
        return NULL;

    kref_get(&fence->kref);
    return fence;
}

void vmw_fence_obj_unreference(struct vmw_fence_obj **fence_p)
{
    struct vmw_fence_obj *fence = *fence_p;
    struct vmw_fence_manager *fman;

    if (unlikely(fence == NULL))
        return;

    fman = fence->fman;
    *fence_p = NULL;
    spin_lock_irq(&fman->lock);
    BUG_ON(atomic_read(&fence->kref.refcount) == 0);
    kref_put(&fence->kref, vmw_fence_obj_destroy_locked);
    spin_unlock_irq(&fman->lock);
}

void vmw_fences_perform_actions(struct vmw_fence_manager *fman,
                struct list_head *list)
{
    struct vmw_fence_action *action, *next_action;

    list_for_each_entry_safe(action, next_action, list, head) {
        list_del_init(&action->head);
        fman->pending_actions[action->type]--;
        if (action->seq_passed != NULL)
            action->seq_passed(action);

        /*
         * Add the cleanup action to the cleanup list so that
         * it will be performed by a worker task.
         */

        list_add_tail(&action->head, &fman->cleanup_list);
    }
}

static bool vmw_fence_goal_new_locked(struct vmw_fence_manager *fman,
                      u32 passed_seqno)
{
    u32 goal_seqno;
    __le32 __iomem *fifo_mem;
    struct vmw_fence_obj *fence;

    if (likely(!fman->seqno_valid))
        return false;

    fifo_mem = fman->dev_priv->mmio_virt;
    goal_seqno = ioread32(fifo_mem + SVGA_FIFO_FENCE_GOAL);
    if (likely(passed_seqno - goal_seqno >= VMW_FENCE_WRAP))
        return false;

    fman->seqno_valid = false;
    list_for_each_entry(fence, &fman->fence_list, head) {
        if (!list_empty(&fence->seq_passed_actions)) {
            fman->seqno_valid = true;
            iowrite32(fence->seqno,
                  fifo_mem + SVGA_FIFO_FENCE_GOAL);
            break;
        }
    }

    return true;
}


static bool vmw_fence_goal_check_locked(struct vmw_fence_obj *fence)
{
    u32 goal_seqno;
    __le32 __iomem *fifo_mem;

    if (fence->signaled & DRM_VMW_FENCE_FLAG_EXEC)
        return false;

    fifo_mem = fence->fman->dev_priv->mmio_virt;
    goal_seqno = ioread32(fifo_mem + SVGA_FIFO_FENCE_GOAL);
    if (likely(fence->fman->seqno_valid &&
           goal_seqno - fence->seqno < VMW_FENCE_WRAP))
        return false;

    iowrite32(fence->seqno, fifo_mem + SVGA_FIFO_FENCE_GOAL);
    fence->fman->seqno_valid = true;

    return true;
}

void vmw_fences_update(struct vmw_fence_manager *fman)
{
    unsigned long flags;
    struct vmw_fence_obj *fence, *next_fence;
    struct list_head action_list;
    bool needs_rerun;
    uint32_t seqno, new_seqno;
    __le32 __iomem *fifo_mem = fman->dev_priv->mmio_virt;

    seqno = ioread32(fifo_mem + SVGA_FIFO_FENCE);
rerun:
    spin_lock_irqsave(&fman->lock, flags);
    list_for_each_entry_safe(fence, next_fence, &fman->fence_list, head) {
        if (seqno - fence->seqno < VMW_FENCE_WRAP) {
            list_del_init(&fence->head);
            fence->signaled |= DRM_VMW_FENCE_FLAG_EXEC;
            INIT_LIST_HEAD(&action_list);
            list_splice_init(&fence->seq_passed_actions,
                     &action_list);
            vmw_fences_perform_actions(fman, &action_list);
            wake_up_all(&fence->queue);
        } else
            break;
    }

    needs_rerun = vmw_fence_goal_new_locked(fman, seqno);

    if (!list_empty(&fman->cleanup_list))
        (void) schedule_work(&fman->work);
    spin_unlock_irqrestore(&fman->lock, flags);

    /*
     * Rerun if the fence goal seqno was updated, and the
     * hardware might have raced with that update, so that
     * we missed a fence_goal irq.
     */

    if (unlikely(needs_rerun)) {
        new_seqno = ioread32(fifo_mem + SVGA_FIFO_FENCE);
        if (new_seqno != seqno) {
            seqno = new_seqno;
            goto rerun;
        }
    }
}

bool vmw_fence_obj_signaled(struct vmw_fence_obj *fence,
                uint32_t flags)
{
    struct vmw_fence_manager *fman = fence->fman;
    unsigned long irq_flags;
    uint32_t signaled;

    spin_lock_irqsave(&fman->lock, irq_flags);
    signaled = fence->signaled;
    spin_unlock_irqrestore(&fman->lock, irq_flags);

    flags &= fence->signal_mask;
    if ((signaled & flags) == flags)
        return 1;

    if ((signaled & DRM_VMW_FENCE_FLAG_EXEC) == 0)
        vmw_fences_update(fman);

    spin_lock_irqsave(&fman->lock, irq_flags);
    signaled = fence->signaled;
    spin_unlock_irqrestore(&fman->lock, irq_flags);

    return ((signaled & flags) == flags);
}

int vmw_fence_obj_wait(struct vmw_fence_obj *fence,
               uint32_t flags, bool lazy,
               bool interruptible, unsigned long timeout)
{
    struct vmw_private *dev_priv = fence->fman->dev_priv;
    long ret;

    if (likely(vmw_fence_obj_signaled(fence, flags)))
        return 0;

    vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
    vmw_seqno_waiter_add(dev_priv);

    if (interruptible)
        ret = wait_event_interruptible_timeout
            (fence->queue,
             vmw_fence_obj_signaled(fence, flags),
             timeout);
    else
        ret = wait_event_timeout
            (fence->queue,
             vmw_fence_obj_signaled(fence, flags),
             timeout);

    vmw_seqno_waiter_remove(dev_priv);

    if (unlikely(ret == 0))
        ret = -EBUSY;
    else if (likely(ret > 0))
        ret = 0;

    return ret;
}

void vmw_fence_obj_flush(struct vmw_fence_obj *fence)
{
    struct vmw_private *dev_priv = fence->fman->dev_priv;

    vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
}

static void vmw_fence_destroy(struct vmw_fence_obj *fence)
{
    struct vmw_fence_manager *fman = fence->fman;

    kfree(fence);
    /*
     * Free kernel space accounting.
     */
    ttm_mem_global_free(vmw_mem_glob(fman->dev_priv),
                fman->fence_size);
}

int vmw_fence_create(struct vmw_fence_manager *fman,
             uint32_t seqno,
             uint32_t mask,
             struct vmw_fence_obj **p_fence)
{
    struct ttm_mem_global *mem_glob = vmw_mem_glob(fman->dev_priv);
    struct vmw_fence_obj *fence;
    int ret;

    ret = ttm_mem_global_alloc(mem_glob, fman->fence_size,
                   false, false);
    if (unlikely(ret != 0))
        return ret;

    fence = kzalloc(sizeof(*fence), GFP_KERNEL);
    if (unlikely(fence == NULL)) {
        ret = -ENOMEM;
        goto out_no_object;
    }

    ret = vmw_fence_obj_init(fman, fence, seqno, mask,
                 vmw_fence_destroy);
    if (unlikely(ret != 0))
        goto out_err_init;

    *p_fence = fence;
    return 0;

out_err_init:
    kfree(fence);
out_no_object:
    ttm_mem_global_free(mem_glob, fman->fence_size);
    return ret;
}


static void vmw_user_fence_destroy(struct vmw_fence_obj *fence)
{
    struct vmw_user_fence *ufence =
        container_of(fence, struct vmw_user_fence, fence);
    struct vmw_fence_manager *fman = fence->fman;

    kfree(ufence);
    /*
     * Free kernel space accounting.
     */
    ttm_mem_global_free(vmw_mem_glob(fman->dev_priv),
                fman->user_fence_size);
}

static void vmw_user_fence_base_release(struct ttm_base_object **p_base)
{
    struct ttm_base_object *base = *p_base;
    struct vmw_user_fence *ufence =
        container_of(base, struct vmw_user_fence, base);
    struct vmw_fence_obj *fence = &ufence->fence;

    *p_base = NULL;
    vmw_fence_obj_unreference(&fence);
}

int vmw_user_fence_create(struct drm_file *file_priv,
              struct vmw_fence_manager *fman,
              uint32_t seqno,
              uint32_t mask,
              struct vmw_fence_obj **p_fence,
              uint32_t *p_handle)
{
    struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
    struct vmw_user_fence *ufence;
    struct vmw_fence_obj *tmp;
    struct ttm_mem_global *mem_glob = vmw_mem_glob(fman->dev_priv);
    int ret;

    /*
     * Kernel memory space accounting, since this object may
     * be created by a user-space request.
     */

    ret = ttm_mem_global_alloc(mem_glob, fman->user_fence_size,
                   false, false);
    if (unlikely(ret != 0))
        return ret;

    ufence = kzalloc(sizeof(*ufence), GFP_KERNEL);
    if (unlikely(ufence == NULL)) {
        ret = -ENOMEM;
        goto out_no_object;
    }

    ret = vmw_fence_obj_init(fman, &ufence->fence, seqno,
                 mask, vmw_user_fence_destroy);
    if (unlikely(ret != 0)) {
        kfree(ufence);
        goto out_no_object;
    }

    /*
     * The base object holds a reference which is freed in
     * vmw_user_fence_base_release.
     */
    tmp = vmw_fence_obj_reference(&ufence->fence);
    ret = ttm_base_object_init(tfile, &ufence->base, false,
                   VMW_RES_FENCE,
                   &vmw_user_fence_base_release, NULL);


    if (unlikely(ret != 0)) {
        /*
         * Free the base object's reference
         */
        vmw_fence_obj_unreference(&tmp);
        goto out_err;
    }

    *p_fence = &ufence->fence;
    *p_handle = ufence->base.hash.key;

    return 0;
out_err:
    tmp = &ufence->fence;
    vmw_fence_obj_unreference(&tmp);
out_no_object:
    ttm_mem_global_free(mem_glob, fman->user_fence_size);
    return ret;
}


void vmw_fence_fifo_down(struct vmw_fence_manager *fman)
{
    unsigned long irq_flags;
    struct list_head action_list;
    int ret;

    /*
     * The list may be altered while we traverse it, so always
     * restart when we've released the fman->lock.
     */

    spin_lock_irqsave(&fman->lock, irq_flags);
    fman->fifo_down = true;
    while (!list_empty(&fman->fence_list)) {
        struct vmw_fence_obj *fence =
            list_entry(fman->fence_list.prev, struct vmw_fence_obj,
                   head);
        kref_get(&fence->kref);
        spin_unlock_irq(&fman->lock);

        ret = vmw_fence_obj_wait(fence, fence->signal_mask,
                     false, false,
                     VMW_FENCE_WAIT_TIMEOUT);

        if (unlikely(ret != 0)) {
            list_del_init(&fence->head);
            fence->signaled |= DRM_VMW_FENCE_FLAG_EXEC;
            INIT_LIST_HEAD(&action_list);
            list_splice_init(&fence->seq_passed_actions,
                     &action_list);
            vmw_fences_perform_actions(fman, &action_list);
            wake_up_all(&fence->queue);
        }

        spin_lock_irq(&fman->lock);

        BUG_ON(!list_empty(&fence->head));
        kref_put(&fence->kref, vmw_fence_obj_destroy_locked);
    }
    spin_unlock_irqrestore(&fman->lock, irq_flags);
}

void vmw_fence_fifo_up(struct vmw_fence_manager *fman)
{
    unsigned long irq_flags;

    spin_lock_irqsave(&fman->lock, irq_flags);
    fman->fifo_down = false;
    spin_unlock_irqrestore(&fman->lock, irq_flags);
}


int vmw_fence_obj_wait_ioctl(struct drm_device *dev, void *data,
                 struct drm_file *file_priv)
{
    struct drm_vmw_fence_wait_arg *arg =
        (struct drm_vmw_fence_wait_arg *)data;
    unsigned long timeout;
    struct ttm_base_object *base;
    struct vmw_fence_obj *fence;
    struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
    int ret;
    uint64_t wait_timeout = ((uint64_t)arg->timeout_us * HZ);

    /*
     * 64-bit division not present on 32-bit systems, so do an
     * approximation. (Divide by 1000000).
     */

    wait_timeout = (wait_timeout >> 20) + (wait_timeout >> 24) -
      (wait_timeout >> 26);

    if (!arg->cookie_valid) {
        arg->cookie_valid = 1;
        arg->kernel_cookie = jiffies + wait_timeout;
    }

    base = ttm_base_object_lookup(tfile, arg->handle);
    if (unlikely(base == NULL)) {
        printk(KERN_ERR "Wait invalid fence object handle "
               "0x%08lx.\n",
               (unsigned long)arg->handle);
        return -EINVAL;
    }

    fence = &(container_of(base, struct vmw_user_fence, base)->fence);

    timeout = jiffies;
    if (time_after_eq(timeout, (unsigned long)arg->kernel_cookie)) {
        ret = ((vmw_fence_obj_signaled(fence, arg->flags)) ?
               0 : -EBUSY);
        goto out;
    }

    timeout = (unsigned long)arg->kernel_cookie - timeout;

    ret = vmw_fence_obj_wait(fence, arg->flags, arg->lazy, true, timeout);

out:
    ttm_base_object_unref(&base);

    /*
     * Optionally unref the fence object.
     */

    if (ret == 0 && (arg->wait_options & DRM_VMW_WAIT_OPTION_UNREF))
        return ttm_ref_object_base_unref(tfile, arg->handle,
                         TTM_REF_USAGE);
    return ret;
}

int vmw_fence_obj_signaled_ioctl(struct drm_device *dev, void *data,
                 struct drm_file *file_priv)
{
    struct drm_vmw_fence_signaled_arg *arg =
        (struct drm_vmw_fence_signaled_arg *) data;
    struct ttm_base_object *base;
    struct vmw_fence_obj *fence;
    struct vmw_fence_manager *fman;
    struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
    struct vmw_private *dev_priv = vmw_priv(dev);

    base = ttm_base_object_lookup(tfile, arg->handle);
    if (unlikely(base == NULL)) {
        printk(KERN_ERR "Fence signaled invalid fence object handle "
               "0x%08lx.\n",
               (unsigned long)arg->handle);
        return -EINVAL;
    }

    fence = &(container_of(base, struct vmw_user_fence, base)->fence);
    fman = fence->fman;

    arg->signaled = vmw_fence_obj_signaled(fence, arg->flags);
    spin_lock_irq(&fman->lock);

    arg->signaled_flags = fence->signaled;
    arg->passed_seqno = dev_priv->last_read_seqno;
    spin_unlock_irq(&fman->lock);

    ttm_base_object_unref(&base);

    return 0;
}


int vmw_fence_obj_unref_ioctl(struct drm_device *dev, void *data,
                  struct drm_file *file_priv)
{
    struct drm_vmw_fence_arg *arg =
        (struct drm_vmw_fence_arg *) data;

    return ttm_ref_object_base_unref(vmw_fpriv(file_priv)->tfile,
                     arg->handle,
                     TTM_REF_USAGE);
}

void vmw_event_fence_fpriv_gone(struct vmw_fence_manager *fman,
                struct list_head *event_list)
{
    struct vmw_event_fence_action *eaction;
    struct drm_pending_event *event;
    unsigned long irq_flags;

    while (1) {
        spin_lock_irqsave(&fman->lock, irq_flags);
        if (list_empty(event_list))
            goto out_unlock;
        eaction = list_first_entry(event_list,
                       struct vmw_event_fence_action,
                       fpriv_head);
        list_del_init(&eaction->fpriv_head);
        event = eaction->event;
        eaction->event = NULL;
        spin_unlock_irqrestore(&fman->lock, irq_flags);
        event->destroy(event);
    }
out_unlock:
    spin_unlock_irqrestore(&fman->lock, irq_flags);
}


static void vmw_event_fence_action_seq_passed(struct vmw_fence_action *action)
{
    struct vmw_event_fence_action *eaction =
        container_of(action, struct vmw_event_fence_action, action);
    struct drm_device *dev = eaction->dev;
    struct drm_pending_event *event = eaction->event;
    struct drm_file *file_priv;
    unsigned long irq_flags;

    if (unlikely(event == NULL))
        return;

    file_priv = event->file_priv;
    spin_lock_irqsave(&dev->event_lock, irq_flags);

    if (likely(eaction->tv_sec != NULL)) {
        struct timeval tv;

        do_gettimeofday(&tv);
        *eaction->tv_sec = tv.tv_sec;
        *eaction->tv_usec = tv.tv_usec;
    }

    list_del_init(&eaction->fpriv_head);
    list_add_tail(&eaction->event->link, &file_priv->event_list);
    eaction->event = NULL;
    wake_up_all(&file_priv->event_wait);
    spin_unlock_irqrestore(&dev->event_lock, irq_flags);
}

static void vmw_event_fence_action_cleanup(struct vmw_fence_action *action)
{
    struct vmw_event_fence_action *eaction =
        container_of(action, struct vmw_event_fence_action, action);
    struct vmw_fence_manager *fman = eaction->fence->fman;
    unsigned long irq_flags;

    spin_lock_irqsave(&fman->lock, irq_flags);
    list_del(&eaction->fpriv_head);
    spin_unlock_irqrestore(&fman->lock, irq_flags);

    vmw_fence_obj_unreference(&eaction->fence);
    kfree(eaction);
}


void vmw_fence_obj_add_action(struct vmw_fence_obj *fence,
                  struct vmw_fence_action *action)
{
    struct vmw_fence_manager *fman = fence->fman;
    unsigned long irq_flags;
    bool run_update = false;

    mutex_lock(&fman->goal_irq_mutex);
    spin_lock_irqsave(&fman->lock, irq_flags);

    fman->pending_actions[action->type]++;
    if (fence->signaled & DRM_VMW_FENCE_FLAG_EXEC) {
        struct list_head action_list;

        INIT_LIST_HEAD(&action_list);
        list_add_tail(&action->head, &action_list);
        vmw_fences_perform_actions(fman, &action_list);
    } else {
        list_add_tail(&action->head, &fence->seq_passed_actions);

        /*
         * This function may set fman::seqno_valid, so it must
         * be run with the goal_irq_mutex held.
         */
        run_update = vmw_fence_goal_check_locked(fence);
    }

    spin_unlock_irqrestore(&fman->lock, irq_flags);

    if (run_update) {
        if (!fman->goal_irq_on) {
            fman->goal_irq_on = true;
            vmw_goal_waiter_add(fman->dev_priv);
        }
        vmw_fences_update(fman);
    }
    mutex_unlock(&fman->goal_irq_mutex);

}

int vmw_event_fence_action_queue(struct drm_file *file_priv,
                 struct vmw_fence_obj *fence,
                 struct drm_pending_event *event,
                 uint32_t *tv_sec,
                 uint32_t *tv_usec,
                 bool interruptible)
{
    struct vmw_event_fence_action *eaction;
    struct vmw_fence_manager *fman = fence->fman;
    struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
    unsigned long irq_flags;

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

    eaction->event = event;

    eaction->action.seq_passed = vmw_event_fence_action_seq_passed;
    eaction->action.cleanup = vmw_event_fence_action_cleanup;
    eaction->action.type = VMW_ACTION_EVENT;

    eaction->fence = vmw_fence_obj_reference(fence);
    eaction->dev = fman->dev_priv->dev;
    eaction->tv_sec = tv_sec;
    eaction->tv_usec = tv_usec;

    spin_lock_irqsave(&fman->lock, irq_flags);
    list_add_tail(&eaction->fpriv_head, &vmw_fp->fence_events);
    spin_unlock_irqrestore(&fman->lock, irq_flags);

    vmw_fence_obj_add_action(fence, &eaction->action);

    return 0;
}

struct vmw_event_fence_pending {
    struct drm_pending_event base;
    struct drm_vmw_event_fence event;
};

int vmw_event_fence_action_create(struct drm_file *file_priv,
                  struct vmw_fence_obj *fence,
                  uint32_t flags,
                  uint64_t user_data,
                  bool interruptible)
{
    struct vmw_event_fence_pending *event;
    struct drm_device *dev = fence->fman->dev_priv->dev;
    unsigned long irq_flags;
    int ret;

    spin_lock_irqsave(&dev->event_lock, irq_flags);

    ret = (file_priv->event_space < sizeof(event->event)) ? -EBUSY : 0;
    if (likely(ret == 0))
        file_priv->event_space -= sizeof(event->event);

    spin_unlock_irqrestore(&dev->event_lock, irq_flags);

    if (unlikely(ret != 0)) {
        DRM_ERROR("Failed to allocate event space for this file.\n");
        goto out_no_space;
    }


    event = kzalloc(sizeof(*event), GFP_KERNEL);
    if (unlikely(event == NULL)) {
        DRM_ERROR("Failed to allocate an event.\n");
        ret = -ENOMEM;
        goto out_no_event;
    }

    event->event.base.type = DRM_VMW_EVENT_FENCE_SIGNALED;
    event->event.base.length = sizeof(*event);
    event->event.user_data = user_data;

    event->base.event = &event->event.base;
    event->base.file_priv = file_priv;
    event->base.destroy = (void (*) (struct drm_pending_event *)) kfree;


    if (flags & DRM_VMW_FE_FLAG_REQ_TIME)
        ret = vmw_event_fence_action_queue(file_priv, fence,
                           &event->base,
                           &event->event.tv_sec,
                           &event->event.tv_usec,
                           interruptible);
    else
        ret = vmw_event_fence_action_queue(file_priv, fence,
                           &event->base,
                           NULL,
                           NULL,
                           interruptible);
    if (ret != 0)
        goto out_no_queue;

out_no_queue:
    event->base.destroy(&event->base);
out_no_event:
    spin_lock_irqsave(&dev->event_lock, irq_flags);
    file_priv->event_space += sizeof(*event);
    spin_unlock_irqrestore(&dev->event_lock, irq_flags);
out_no_space:
    return ret;
}

int vmw_fence_event_ioctl(struct drm_device *dev, void *data,
              struct drm_file *file_priv)
{
    struct vmw_private *dev_priv = vmw_priv(dev);
    struct drm_vmw_fence_event_arg *arg =
        (struct drm_vmw_fence_event_arg *) data;
    struct vmw_fence_obj *fence = NULL;
    struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
    struct drm_vmw_fence_rep __user *user_fence_rep =
        (struct drm_vmw_fence_rep __user *)(unsigned long)
        arg->fence_rep;
    uint32_t handle;
    int ret;

    /*
     * Look up an existing fence object,
     * and if user-space wants a new reference,
     * add one.
     */
    if (arg->handle) {
        struct ttm_base_object *base =
            ttm_base_object_lookup(vmw_fp->tfile, arg->handle);

        if (unlikely(base == NULL)) {
            DRM_ERROR("Fence event invalid fence object handle "
                  "0x%08lx.\n",
                  (unsigned long)arg->handle);
            return -EINVAL;
        }
        fence = &(container_of(base, struct vmw_user_fence,
                       base)->fence);
        (void) vmw_fence_obj_reference(fence);

        if (user_fence_rep != NULL) {
            bool existed;

            ret = ttm_ref_object_add(vmw_fp->tfile, base,
                         TTM_REF_USAGE, &existed);
            if (unlikely(ret != 0)) {
                DRM_ERROR("Failed to reference a fence "
                      "object.\n");
                goto out_no_ref_obj;
            }
            handle = base->hash.key;
        }
        ttm_base_object_unref(&base);
    }

    /*
     * Create a new fence object.
     */
    if (!fence) {
        ret = vmw_execbuf_fence_commands(file_priv, dev_priv,
                         &fence,
                         (user_fence_rep) ?
                         &handle : NULL);
        if (unlikely(ret != 0)) {
            DRM_ERROR("Fence event failed to create fence.\n");
            return ret;
        }
    }

    BUG_ON(fence == NULL);

    if (arg->flags & DRM_VMW_FE_FLAG_REQ_TIME)
        ret = vmw_event_fence_action_create(file_priv, fence,
                            arg->flags,
                            arg->user_data,
                            true);
    else
        ret = vmw_event_fence_action_create(file_priv, fence,
                            arg->flags,
                            arg->user_data,
                            true);

    if (unlikely(ret != 0)) {
        if (ret != -ERESTARTSYS)
            DRM_ERROR("Failed to attach event to fence.\n");
        goto out_no_create;
    }

    vmw_execbuf_copy_fence_user(dev_priv, vmw_fp, 0, user_fence_rep, fence,
                    handle);
    vmw_fence_obj_unreference(&fence);
    return 0;
out_no_create:
    if (user_fence_rep != NULL)
        ttm_ref_object_base_unref(vmw_fpriv(file_priv)->tfile,
                      handle, TTM_REF_USAGE);
out_no_ref_obj:
    vmw_fence_obj_unreference(&fence);
    return ret;
}