drm/v3d: Create a CPU job extension for the timestamp query job

A CPU job is a type of job that performs operations that requires CPU
intervention. A timestamp query job is a job that calculates the
query timestamp and updates the query availability by signaling a
syncobj. 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 timestamp query job. This user extension will allow the creation of
a CPU job that performs the timestamp query calculation and updates the
timestamp BO with the proper value.

Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231130164420.932823-15-mcanal@igalia.com

1 files changed, 30 insertions, 0 deletions

diff --git a/include/uapi/drm/v3d_drm.h b/include/uapi/drm/v3d_drm.h
index 0c0f47782528..239801b5e117 100644
--- a/include/uapi/drm/v3d_drm.h
+++ b/include/uapi/drm/v3d_drm.h
@@ -73,6 +73,7 @@ struct drm_v3d_extension {
 	__u32 id;
 #define DRM_V3D_EXT_ID_MULTI_SYNC			0x01
 #define DRM_V3D_EXT_ID_CPU_INDIRECT_CSD		0x02
+#define DRM_V3D_EXT_ID_CPU_TIMESTAMP_QUERY		0x03
 	__u32 flags; /* mbz */
 };
 
@@ -400,11 +401,40 @@ struct drm_v3d_indirect_csd {
 	__u32 wg_uniform_offsets[3];
 };
 
+/**
+ * struct drm_v3d_timestamp_query - ioctl extension for the CPU job to calculate
+ * a timestamp query
+ *
+ * When an extension DRM_V3D_EXT_ID_TIMESTAMP_QUERY is defined, it points to
+ * this extension to define a timestamp query submission. This CPU job will
+ * calculate the timestamp query and update the query value within the
+ * timestamp BO. Moreover, it will signal the timestamp syncobj to indicate
+ * query availability.
+ */
+struct drm_v3d_timestamp_query {
+	struct drm_v3d_extension base;
+
+	/* Array of queries' offsets within the timestamp BO for their value */
+	__u64 offsets;
+
+	/* Array of timestamp's syncobjs to indicate its availability */
+	__u64 syncs;
+
+	/* Number of queries */
+	__u32 count;
+
+	/* mbz */
+	__u32 pad;
+};
+
 struct drm_v3d_submit_cpu {
 	/* Pointer to a u32 array of the BOs that are referenced by the job.
 	 *
 	 * For DRM_V3D_EXT_ID_CPU_INDIRECT_CSD, it must contain only one BO,
 	 * that contains the workgroup counts.
+	 *
+	 * For DRM_V3D_EXT_ID_TIMESTAMP_QUERY, it must contain only one BO,
+	 * that will contain the timestamp.
 	 */
 	__u64 bo_handles;