drm/vmwgfx: Implement a buffer object synccpu ioctl.
This ioctl enables inter-process synchronization of buffer objects,
which is needed for mesa Guest-Backed objects.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index b40978f..12e68e5 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -441,6 +441,21 @@
ttm_bo_unref(&bo);
}
+static void vmw_user_dmabuf_ref_obj_release(struct ttm_base_object *base,
+ enum ttm_ref_type ref_type)
+{
+ struct vmw_user_dma_buffer *user_bo;
+ user_bo = container_of(base, struct vmw_user_dma_buffer, prime.base);
+
+ switch (ref_type) {
+ case TTM_REF_SYNCCPU_WRITE:
+ ttm_bo_synccpu_write_release(&user_bo->dma.base);
+ break;
+ default:
+ BUG();
+ }
+}
+
/**
* vmw_user_dmabuf_alloc - Allocate a user dma buffer
*
@@ -484,7 +499,8 @@
&user_bo->prime,
shareable,
ttm_buffer_type,
- &vmw_user_dmabuf_release, NULL);
+ &vmw_user_dmabuf_release,
+ &vmw_user_dmabuf_ref_obj_release);
if (unlikely(ret != 0)) {
ttm_bo_unref(&tmp);
goto out_no_base_object;
@@ -517,6 +533,130 @@
vmw_user_bo->prime.base.shareable) ? 0 : -EPERM;
}
+/**
+ * vmw_user_dmabuf_synccpu_grab - Grab a struct vmw_user_dma_buffer for cpu
+ * access, idling previous GPU operations on the buffer and optionally
+ * blocking it for further command submissions.
+ *
+ * @user_bo: Pointer to the buffer object being grabbed for CPU access
+ * @tfile: Identifying the caller.
+ * @flags: Flags indicating how the grab should be performed.
+ *
+ * A blocking grab will be automatically released when @tfile is closed.
+ */
+static int vmw_user_dmabuf_synccpu_grab(struct vmw_user_dma_buffer *user_bo,
+ struct ttm_object_file *tfile,
+ uint32_t flags)
+{
+ struct ttm_buffer_object *bo = &user_bo->dma.base;
+ bool existed;
+ int ret;
+
+ if (flags & drm_vmw_synccpu_allow_cs) {
+ struct ttm_bo_device *bdev = bo->bdev;
+
+ spin_lock(&bdev->fence_lock);
+ ret = ttm_bo_wait(bo, false, true,
+ !!(flags & drm_vmw_synccpu_dontblock));
+ spin_unlock(&bdev->fence_lock);
+ return ret;
+ }
+
+ ret = ttm_bo_synccpu_write_grab
+ (bo, !!(flags & drm_vmw_synccpu_dontblock));
+ if (unlikely(ret != 0))
+ return ret;
+
+ ret = ttm_ref_object_add(tfile, &user_bo->prime.base,
+ TTM_REF_SYNCCPU_WRITE, &existed);
+ if (ret != 0 || existed)
+ ttm_bo_synccpu_write_release(&user_bo->dma.base);
+
+ return ret;
+}
+
+/**
+ * vmw_user_dmabuf_synccpu_release - Release a previous grab for CPU access,
+ * and unblock command submission on the buffer if blocked.
+ *
+ * @handle: Handle identifying the buffer object.
+ * @tfile: Identifying the caller.
+ * @flags: Flags indicating the type of release.
+ */
+static int vmw_user_dmabuf_synccpu_release(uint32_t handle,
+ struct ttm_object_file *tfile,
+ uint32_t flags)
+{
+ if (!(flags & drm_vmw_synccpu_allow_cs))
+ return ttm_ref_object_base_unref(tfile, handle,
+ TTM_REF_SYNCCPU_WRITE);
+
+ return 0;
+}
+
+/**
+ * vmw_user_dmabuf_synccpu_release - ioctl function implementing the synccpu
+ * functionality.
+ *
+ * @dev: Identifies the drm device.
+ * @data: Pointer to the ioctl argument.
+ * @file_priv: Identifies the caller.
+ *
+ * This function checks the ioctl arguments for validity and calls the
+ * relevant synccpu functions.
+ */
+int vmw_user_dmabuf_synccpu_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_vmw_synccpu_arg *arg =
+ (struct drm_vmw_synccpu_arg *) data;
+ struct vmw_dma_buffer *dma_buf;
+ struct vmw_user_dma_buffer *user_bo;
+ struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
+ int ret;
+
+ if ((arg->flags & (drm_vmw_synccpu_read | drm_vmw_synccpu_write)) == 0
+ || (arg->flags & ~(drm_vmw_synccpu_read | drm_vmw_synccpu_write |
+ drm_vmw_synccpu_dontblock |
+ drm_vmw_synccpu_allow_cs)) != 0) {
+ DRM_ERROR("Illegal synccpu flags.\n");
+ return -EINVAL;
+ }
+
+ switch (arg->op) {
+ case drm_vmw_synccpu_grab:
+ ret = vmw_user_dmabuf_lookup(tfile, arg->handle, &dma_buf);
+ if (unlikely(ret != 0))
+ return ret;
+
+ user_bo = container_of(dma_buf, struct vmw_user_dma_buffer,
+ dma);
+ ret = vmw_user_dmabuf_synccpu_grab(user_bo, tfile, arg->flags);
+ vmw_dmabuf_unreference(&dma_buf);
+ if (unlikely(ret != 0 && ret != -ERESTARTSYS &&
+ ret != -EBUSY)) {
+ DRM_ERROR("Failed synccpu grab on handle 0x%08x.\n",
+ (unsigned int) arg->handle);
+ return ret;
+ }
+ break;
+ case drm_vmw_synccpu_release:
+ ret = vmw_user_dmabuf_synccpu_release(arg->handle, tfile,
+ arg->flags);
+ if (unlikely(ret != 0)) {
+ DRM_ERROR("Failed synccpu release on handle 0x%08x.\n",
+ (unsigned int) arg->handle);
+ return ret;
+ }
+ break;
+ default:
+ DRM_ERROR("Invalid synccpu operation.\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
int vmw_dmabuf_alloc_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{