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

A CPU job is a type of job that performs operations that requires CPU
intervention. A reset timestamp job is a job that resets the timestamp
queries based on the value offset of the first query. 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 reset timestamp job. This user extension will allow the creation of
a CPU job that resets the timestamp value in the timestamp BO and resets
the availability syncobj.
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231130164420.932823-16-mcanal@igalia.com

drivers/gpu/drm/v3d/v3d_drv.h

@@ -319,6 +319,7 @@ struct v3d_csd_job {
 enum v3d_cpu_job_type {
 	V3D_CPU_JOB_TYPE_INDIRECT_CSD = 1,
 	V3D_CPU_JOB_TYPE_TIMESTAMP_QUERY,
+	V3D_CPU_JOB_TYPE_RESET_TIMESTAMP_QUERY,
 };
 
 struct v3d_timestamp_query {

drivers/gpu/drm/v3d/v3d_sched.c

@@ -342,9 +342,30 @@ v3d_timestamp_query(struct v3d_cpu_job *job)
 	v3d_put_bo_vaddr(bo);
 }
 
+static void
+v3d_reset_timestamp_queries(struct v3d_cpu_job *job)
+{
+	struct v3d_timestamp_query_info *timestamp_query = &job->timestamp_query;
+	struct v3d_timestamp_query *queries = timestamp_query->queries;
+	struct v3d_bo *bo = to_v3d_bo(job->base.bo[0]);
+	u8 *value_addr;
+
+	v3d_get_bo_vaddr(bo);
+
+	for (int i = 0; i < timestamp_query->count; i++) {
+		value_addr = ((u8 *)bo->vaddr) + queries[i].offset;
+		*((u64 *)value_addr) = 0;
+
+		drm_syncobj_replace_fence(queries[i].syncobj, NULL);
+	}
+
+	v3d_put_bo_vaddr(bo);
+}
+
 static const v3d_cpu_job_fn cpu_job_function[] = {
 	[V3D_CPU_JOB_TYPE_INDIRECT_CSD] = v3d_rewrite_csd_job_wg_counts_from_indirect,
 	[V3D_CPU_JOB_TYPE_TIMESTAMP_QUERY] = v3d_timestamp_query,
+	[V3D_CPU_JOB_TYPE_RESET_TIMESTAMP_QUERY] = v3d_reset_timestamp_queries,
 };
 
 static struct dma_fence *

drivers/gpu/drm/v3d/v3d_submit.c

@@ -491,6 +491,54 @@ v3d_get_cpu_timestamp_query_params(struct drm_file *file_priv,
 	return 0;
 }
 
+static int
+v3d_get_cpu_reset_timestamp_params(struct drm_file *file_priv,
+				   struct drm_v3d_extension __user *ext,
+				   struct v3d_cpu_job *job)
+{
+	u32 __user *syncs;
+	struct drm_v3d_reset_timestamp_query reset;
+
+	if (!job) {
+		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
+		return -EINVAL;
+	}
+
+	if (job->job_type) {
+		DRM_DEBUG("Two CPU job extensions were added to the same CPU job.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&reset, ext, sizeof(reset)))
+		return -EFAULT;
+
+	job->job_type = V3D_CPU_JOB_TYPE_RESET_TIMESTAMP_QUERY;
+
+	job->timestamp_query.queries = kvmalloc_array(reset.count,
+						      sizeof(struct v3d_timestamp_query),
+						      GFP_KERNEL);
+	if (!job->timestamp_query.queries)
+		return -ENOMEM;
+
+	syncs = u64_to_user_ptr(reset.syncs);
+
+	for (int i = 0; i < reset.count; i++) {
+		u32 sync;
+
+		job->timestamp_query.queries[i].offset = reset.offset + 8 * i;
+
+		if (copy_from_user(&sync, syncs++, sizeof(sync))) {
+			kvfree(job->timestamp_query.queries);
+			return -EFAULT;
+		}
+
+		job->timestamp_query.queries[i].syncobj = drm_syncobj_find(file_priv, sync);
+	}
+	job->timestamp_query.count = reset.count;
+
+	return 0;
+}
+
 /* Whenever userspace sets ioctl extensions, v3d_get_extensions parses data
  * according to the extension id (name).
  */
@@ -522,6 +570,9 @@ v3d_get_extensions(struct drm_file *file_priv,
 		case DRM_V3D_EXT_ID_CPU_TIMESTAMP_QUERY:
 			ret = v3d_get_cpu_timestamp_query_params(file_priv, user_ext, job);
 			break;
+		case DRM_V3D_EXT_ID_CPU_RESET_TIMESTAMP_QUERY:
+			ret = v3d_get_cpu_reset_timestamp_params(file_priv, user_ext, job);
+			break;
 		default:
 			DRM_DEBUG_DRIVER("Unknown extension id: %d\n", ext.id);
 			return -EINVAL;
@@ -899,6 +950,7 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data,
 static const unsigned int cpu_job_bo_handle_count[] = {
 	[V3D_CPU_JOB_TYPE_INDIRECT_CSD] = 1,
 	[V3D_CPU_JOB_TYPE_TIMESTAMP_QUERY] = 1,
+	[V3D_CPU_JOB_TYPE_RESET_TIMESTAMP_QUERY] = 1,
 };
 
 /**

include/uapi/drm/v3d_drm.h

@@ -74,6 +74,7 @@ struct drm_v3d_extension {
 #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
+#define DRM_V3D_EXT_ID_CPU_RESET_TIMESTAMP_QUERY	0x04
 	__u32 flags; /* mbz */
 };
 
@@ -427,6 +428,29 @@ struct drm_v3d_timestamp_query {
 	__u32 pad;
 };
 
+/**
+ * struct drm_v3d_reset_timestamp_query - ioctl extension for the CPU job to
+ * reset timestamp queries
+ *
+ * When an extension DRM_V3D_EXT_ID_CPU_RESET_TIMESTAMP_QUERY is defined, it
+ * points to this extension to define a reset timestamp submission. This CPU
+ * job will reset the timestamp queries based on value offset of the first
+ * query. Moreover, it will reset the timestamp syncobj to reset query
+ * availability.
+ */
+struct drm_v3d_reset_timestamp_query {
+	struct drm_v3d_extension base;
+
+	/* Array of timestamp's syncobjs to indicate its availability */
+	__u64 syncs;
+
+	/* Offset of the first query within the timestamp BO for its value */
+	__u32 offset;
+
+	/* Number of queries */
+	__u32 count;
+};
+
 struct drm_v3d_submit_cpu {
 	/* Pointer to a u32 array of the BOs that are referenced by the job.
 	 *
@@ -435,6 +459,9 @@ struct drm_v3d_submit_cpu {
 	 *
 	 * For DRM_V3D_EXT_ID_TIMESTAMP_QUERY, it must contain only one BO,
 	 * that will contain the timestamp.
+	 *
+	 * For DRM_V3D_EXT_ID_CPU_RESET_TIMESTAMP_QUERY, it must contain only
+	 * one BO, that contains the timestamp.
 	 */
 	__u64 bo_handles;