Re: [RFC 1/5] drm/virtio: add virtio_gpu_alloc_fence()

Hi,

+struct virtio_gpu_fence *virtio_gpu_fence_alloc(struct virtio_gpu_device *vgdev) +{

• struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
• struct virtio_gpu_fence *fence;
• unsigned long irq_flags;
• fence = kmalloc(sizeof(struct virtio_gpu_fence), GFP_ATOMIC);
• if (!fence)

• return NULL;
  

• spin_lock_irqsave(&drv->lock, irq_flags);
• fence->drv = drv;
• fence->seq = ++drv->sync_seq;
• dma_fence_init(&fence->f, &virtio_fence_ops, &drv->lock,

•        drv->context, fence->seq);
  

• spin_unlock_irqrestore(&drv->lock, irq_flags);

seq assignment ...

• return fence;

+}

int virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev, struct virtio_gpu_ctrl_hdr *cmd_hdr,

• 	  struct virtio_gpu_fence **fence)
  

• 	  struct virtio_gpu_fence *fence)
  

{ struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv; unsigned long irq_flags;

• *fence = kmalloc(sizeof(struct virtio_gpu_fence), GFP_ATOMIC);
• if ((*fence) == NULL)

• return -ENOMEM;
  

• spin_lock_irqsave(&drv->lock, irq_flags);
• (*fence)->drv = drv;
• (*fence)->seq = ++drv->sync_seq;
• dma_fence_init(&(*fence)->f, &virtio_fence_ops, &drv->lock,

•        drv->context, (*fence)->seq);
  

... must stay here. Otherwise requests can be submitted to the virt queue with fence sequence numbers out of order.

cheers, Gerd