drm/syncobj: add timeline payload query ioctl v6

user mode can query timeline payload.
v2: check return value of copy_to_user
v3: handle querying entry by entry
v4: rebase on new chain container, simplify interface
v5: query last signaled timeline point, not last point.
v6: add unorder point check

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: Tobias Hector <Tobias.Hector@amd.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/295784/?series=58813&rev=1

drivers/gpu/drm/drm_internal.h

@@ -188,6 +188,8 @@ int drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
 			    struct drm_file *file_private);
 int drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
 			     struct drm_file *file_private);
+int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
+			    struct drm_file *file_private);
 
 /* drm_framebuffer.c */
 void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,

drivers/gpu/drm/drm_ioctl.c

@@ -694,6 +694,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
+		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, DRM_UNLOCKED),
 	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, DRM_UNLOCKED),
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER|DRM_UNLOCKED),

drivers/gpu/drm/drm_syncobj.c

@@ -1065,3 +1065,65 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
 
 	return ret;
 }
+
+int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
+			    struct drm_file *file_private)
+{
+	struct drm_syncobj_timeline_array *args = data;
+	struct drm_syncobj **syncobjs;
+	uint64_t __user *points = u64_to_user_ptr(args->points);
+	uint32_t i;
+	int ret;
+
+	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+		return -ENODEV;
+
+	if (args->pad != 0)
+		return -EINVAL;
+
+	if (args->count_handles == 0)
+		return -EINVAL;
+
+	ret = drm_syncobj_array_find(file_private,
+				     u64_to_user_ptr(args->handles),
+				     args->count_handles,
+				     &syncobjs);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < args->count_handles; i++) {
+		struct dma_fence_chain *chain;
+		struct dma_fence *fence;
+		uint64_t point;
+
+		fence = drm_syncobj_fence_get(syncobjs[i]);
+		chain = to_dma_fence_chain(fence);
+		if (chain) {
+			struct dma_fence *iter, *last_signaled = NULL;
+
+			dma_fence_chain_for_each(iter, fence) {
+				if (!iter)
+					break;
+				dma_fence_put(last_signaled);
+				last_signaled = dma_fence_get(iter);
+				if (!to_dma_fence_chain(last_signaled)->prev_seqno)
+					/* It is most likely that timeline has
+					 * unorder points. */
+					break;
+			}
+			point = dma_fence_is_signaled(last_signaled) ?
+				last_signaled->seqno :
+				to_dma_fence_chain(last_signaled)->prev_seqno;
+			dma_fence_put(last_signaled);
+		} else {
+			point = 0;
+		}
+		ret = copy_to_user(&points[i], &point, sizeof(uint64_t));
+		ret = ret ? -EFAULT : 0;
+		if (ret)
+			break;
+	}
+	drm_syncobj_array_free(syncobjs, args->count_handles);
+
+	return ret;
+}

include/uapi/drm/drm.h

@@ -767,6 +767,14 @@ struct drm_syncobj_array {
 	__u32 pad;
 };
 
+struct drm_syncobj_timeline_array {
+	__u64 handles;
+	__u64 points;
+	__u32 count_handles;
+	__u32 pad;
+};
+
+
 /* Query current scanout sequence number */
 struct drm_crtc_get_sequence {
 	__u32 crtc_id;		/* requested crtc_id */
@@ -924,6 +932,8 @@ extern "C" {
 #define DRM_IOCTL_MODE_REVOKE_LEASE	DRM_IOWR(0xC9, struct drm_mode_revoke_lease)
 
 #define DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT	DRM_IOWR(0xCA, struct drm_syncobj_timeline_wait)
+#define DRM_IOCTL_SYNCOBJ_QUERY		DRM_IOWR(0xCB, struct drm_syncobj_timeline_array)
+
 /**
  * Device specific ioctls should only be in their respective headers
  * The device specific ioctl range is from 0x40 to 0x9f.