drivers/gpu/drm/virtio/virtgpu_fence.c

   1 /*
   2  * Copyright (C) 2015 Red Hat, Inc.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the
  14  * next paragraph) shall be included in all copies or substantial
  15  * portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  20  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #include <trace/events/dma_fence.h>
  27
  28 #include "virtgpu_drv.h"
  29
  30 #define to_virtio_gpu_fence(x) \
  31         container_of(x, struct virtio_gpu_fence, f)
  32
  33 static const char *virtio_gpu_get_driver_name(struct dma_fence *f)
  34 {
  35         return "virtio_gpu";
  36 }
  37
  38 static const char *virtio_gpu_get_timeline_name(struct dma_fence *f)
  39 {
  40         return "controlq";
  41 }
  42
  43 static bool virtio_gpu_fence_signaled(struct dma_fence *f)
  44 {
  45         /* leaked fence outside driver before completing
  46          * initialization with virtio_gpu_fence_emit.
  47          */
  48         WARN_ON_ONCE(f->seqno == 0);
  49         return false;
  50 }
  51
  52 static void virtio_gpu_fence_value_str(struct dma_fence *f, char *str, int size)
  53 {
  54         snprintf(str, size, "[%llu, %llu]", f->context, f->seqno);
  55 }
  56
  57 static void virtio_gpu_timeline_value_str(struct dma_fence *f, char *str,
  58                                           int size)
  59 {
  60         struct virtio_gpu_fence *fence = to_virtio_gpu_fence(f);
  61
  62         snprintf(str, size, "%llu",
  63                  (u64)atomic64_read(&fence->drv->last_fence_id));
  64 }
  65
  66 static const struct dma_fence_ops virtio_gpu_fence_ops = {
  67         .get_driver_name     = virtio_gpu_get_driver_name,
  68         .get_timeline_name   = virtio_gpu_get_timeline_name,
  69         .signaled            = virtio_gpu_fence_signaled,
  70         .fence_value_str     = virtio_gpu_fence_value_str,
  71         .timeline_value_str  = virtio_gpu_timeline_value_str,
  72 };
  73
  74 struct virtio_gpu_fence *virtio_gpu_fence_alloc(struct virtio_gpu_device *vgdev)
  75 {
  76         struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
  77         struct virtio_gpu_fence *fence = kzalloc(sizeof(struct virtio_gpu_fence),
  78                                                         GFP_KERNEL);
  79         if (!fence)
  80                 return fence;
  81
  82         fence->drv = drv;
  83
  84         /* This only partially initializes the fence because the seqno is
  85          * unknown yet.  The fence must not be used outside of the driver
  86          * until virtio_gpu_fence_emit is called.
  87          */
  88         dma_fence_init(&fence->f, &virtio_gpu_fence_ops, &drv->lock, drv->context,
  89                        0);
  90
  91         return fence;
  92 }
  93
  94 void virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
  95                           struct virtio_gpu_ctrl_hdr *cmd_hdr,
  96                           struct virtio_gpu_fence *fence)
  97 {
  98         struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
  99         unsigned long irq_flags;
 100
 101         spin_lock_irqsave(&drv->lock, irq_flags);
 102         fence->fence_id = fence->f.seqno = ++drv->current_fence_id;
 103         dma_fence_get(&fence->f);
 104         list_add_tail(&fence->node, &drv->fences);
 105         spin_unlock_irqrestore(&drv->lock, irq_flags);
 106
 107         trace_dma_fence_emit(&fence->f);
 108
 109         cmd_hdr->flags |= cpu_to_le32(VIRTIO_GPU_FLAG_FENCE);
 110         cmd_hdr->fence_id = cpu_to_le64(fence->fence_id);
 111 }
 112
 113 void virtio_gpu_fence_event_process(struct virtio_gpu_device *vgdev,
 114                                     u64 fence_id)
 115 {
 116         struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
 117         struct virtio_gpu_fence *signaled, *curr, *tmp;
 118         unsigned long irq_flags;
 119
 120         spin_lock_irqsave(&drv->lock, irq_flags);
 121         atomic64_set(&vgdev->fence_drv.last_fence_id, fence_id);
 122         list_for_each_entry_safe(curr, tmp, &drv->fences, node) {
 123                 if (fence_id != curr->fence_id)
 124                         continue;
 125
 126                 signaled = curr;
 127
 128                 /*
 129                  * Signal any fences with a strictly smaller sequence number
 130                  * than the current signaled fence.
 131                  */
 132                 list_for_each_entry_safe(curr, tmp, &drv->fences, node) {
 133                         /* dma-fence contexts must match */
 134                         if (signaled->f.context != curr->f.context)
 135                                 continue;
 136
 137                         if (!dma_fence_is_later(&signaled->f, &curr->f))
 138                                 continue;
 139
 140                         dma_fence_signal_locked(&curr->f);
 141                         list_del(&curr->node);
 142                         dma_fence_put(&curr->f);
 143                 }
 144
 145                 dma_fence_signal_locked(&signaled->f);
 146                 list_del(&signaled->node);
 147                 dma_fence_put(&signaled->f);
 148                 break;
 149         }
 150         spin_unlock_irqrestore(&drv->lock, irq_flags);
 151 }