drm/v3d: Create a CPU job extension to copy timestamp query to a buffer

A CPU job is a type of job that performs operations that requires CPU
intervention. A copy timestamp query job is a job that copy the complete
or partial result of a query to a buffer. As V3D doesn't provide any
mechanism to obtain a timestamp from the GPU, it is a job that needs
CPU intervention.

So, create a user extension for the CPU job that enables the creation
of a copy timestamp query job. This user extension will allow the creation
of a CPU job that copy the results of a timestamp query to a BO with the
possibility to indicate the timestamp availability with a availability bit.

Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231130164420.932823-17-mcanal@igalia.com

1 files changed, 45 insertions, 0 deletions

diff --git a/include/uapi/drm/v3d_drm.h b/include/uapi/drm/v3d_drm.h
index 930f8d07f088..f7defbf3d043 100644
--- a/include/uapi/drm/v3d_drm.h
+++ b/include/uapi/drm/v3d_drm.h
@@ -75,6 +75,7 @@ struct drm_v3d_extension {
 #define DRM_V3D_EXT_ID_CPU_INDIRECT_CSD		0x02
 #define DRM_V3D_EXT_ID_CPU_TIMESTAMP_QUERY		0x03
 #define DRM_V3D_EXT_ID_CPU_RESET_TIMESTAMP_QUERY	0x04
+#define DRM_V3D_EXT_ID_CPU_COPY_TIMESTAMP_QUERY	0x05
 	__u32 flags; /* mbz */
 };
 
@@ -451,6 +452,46 @@ struct drm_v3d_reset_timestamp_query {
 	__u32 count;
 };
 
+/**
+ * struct drm_v3d_copy_timestamp_query - ioctl extension for the CPU job to copy
+ * query results to a buffer
+ *
+ * When an extension DRM_V3D_EXT_ID_CPU_COPY_TIMESTAMP_QUERY is defined, it
+ * points to this extension to define a copy timestamp query submission. This
+ * CPU job will copy the timestamp queries results to a BO with the offset
+ * and stride defined in the extension.
+ */
+struct drm_v3d_copy_timestamp_query {
+	struct drm_v3d_extension base;
+
+	/* Define if should write to buffer using 64 or 32 bits */
+	__u8 do_64bit;
+
+	/* Define if it can write to buffer even if the query is not available */
+	__u8 do_partial;
+
+	/* Define if it should write availability bit to buffer */
+	__u8 availability_bit;
+
+	/* mbz */
+	__u8 pad;
+
+	/* Offset of the buffer in the BO */
+	__u32 offset;
+
+	/* Stride of the buffer in the BO */
+	__u32 stride;
+
+	/* Number of queries */
+	__u32 count;
+
+	/* Array of queries' offsets within the timestamp BO for their value */
+	__u64 offsets;
+
+	/* Array of timestamp's syncobjs to indicate its availability */
+	__u64 syncs;
+};
+
 struct drm_v3d_submit_cpu {
 	/* Pointer to a u32 array of the BOs that are referenced by the job.
 	 *
@@ -462,6 +503,10 @@ struct drm_v3d_submit_cpu {
 	 *
 	 * For DRM_V3D_EXT_ID_CPU_RESET_TIMESTAMP_QUERY, it must contain only
 	 * one BO, that contains the timestamp.
+	 *
+	 * For DRM_V3D_EXT_ID_CPU_COPY_TIMESTAMP_QUERY, it must contain two
+	 * BOs. The first is the BO where the timestamp queries will be written
+	 * to. The second is the BO that contains the timestamp.
 	 */
 	__u64 bo_handles;