drm/v3d: Decouple job allocation from job initiation

We want to allow the IOCTLs to allocate the job without initiating it.
This will be useful for the CPU job submission IOCTL, as the CPU job has
the need to use information from the user extensions. Currently, the
user extensions are parsed before the job allocation, making it
impossible to fill the CPU job when parsing the user extensions.
Therefore, decouple the job allocation from the job initiation.
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231130164420.932823-8-mcanal@igalia.com

drivers/gpu/drm/v3d/v3d_submit.c

@@ -135,23 +135,27 @@ void v3d_job_put(struct v3d_job *job)
 	kref_put(&job->refcount, job->free);
 }
 
+static int
+v3d_job_allocate(void **container, size_t size)
+{
+	*container = kcalloc(1, size, GFP_KERNEL);
+	if (!*container) {
+		DRM_ERROR("Cannot allocate memory for V3D job.\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
 static int
 v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
-	     void **container, size_t size, void (*free)(struct kref *ref),
+	     struct v3d_job *job, void (*free)(struct kref *ref),
 	     u32 in_sync, struct v3d_submit_ext *se, enum v3d_queue queue)
 {
 	struct v3d_file_priv *v3d_priv = file_priv->driver_priv;
-	struct v3d_job *job;
 	bool has_multisync = se && (se->flags & DRM_V3D_EXT_ID_MULTI_SYNC);
 	int ret, i;
 
-	*container = kcalloc(1, size, GFP_KERNEL);
-	if (!*container) {
-		DRM_ERROR("Cannot allocate memory for v3d job.");
-		return -ENOMEM;
-	}
-
-	job = *container;
 	job->v3d = v3d;
 	job->free = free;
 	job->file = file_priv;
@@ -159,7 +163,7 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
 	ret = drm_sched_job_init(&job->base, &v3d_priv->sched_entity[queue],
 				 1, v3d_priv);
 	if (ret)
-		goto fail;
+		return ret;
 
 	if (has_multisync) {
 		if (se->in_sync_count && se->wait_stage == queue) {
@@ -194,10 +198,6 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
 
 fail_deps:
 	drm_sched_job_cleanup(&job->base);
-fail:
-	kfree(*container);
-	*container = NULL;
-
 	return ret;
 }
 
@@ -437,7 +437,11 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 		}
 	}
 
-	ret = v3d_job_init(v3d, file_priv, (void *)&render, sizeof(*render),
+	ret = v3d_job_allocate((void *)&render, sizeof(*render));
+	if (ret)
+		return ret;
+
+	ret = v3d_job_init(v3d, file_priv, &render->base,
 			   v3d_render_job_free, args->in_sync_rcl, &se, V3D_RENDER);
 	if (ret)
 		goto fail;
@@ -447,7 +451,11 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 	INIT_LIST_HEAD(&render->unref_list);
 
 	if (args->bcl_start != args->bcl_end) {
-		ret = v3d_job_init(v3d, file_priv, (void *)&bin, sizeof(*bin),
+		ret = v3d_job_allocate((void *)&bin, sizeof(*bin));
+		if (ret)
+			goto fail;
+
+		ret = v3d_job_init(v3d, file_priv, &bin->base,
 				   v3d_job_free, args->in_sync_bcl, &se, V3D_BIN);
 		if (ret)
 			goto fail;
@@ -461,7 +469,11 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 	}
 
 	if (args->flags & DRM_V3D_SUBMIT_CL_FLUSH_CACHE) {
-		ret = v3d_job_init(v3d, file_priv, (void *)&clean_job, sizeof(*clean_job),
+		ret = v3d_job_allocate((void *)&clean_job, sizeof(*clean_job));
+		if (ret)
+			goto fail;
+
+		ret = v3d_job_init(v3d, file_priv, clean_job,
 				   v3d_job_free, 0, NULL, V3D_CACHE_CLEAN);
 		if (ret)
 			goto fail;
@@ -580,7 +592,11 @@ v3d_submit_tfu_ioctl(struct drm_device *dev, void *data,
 		}
 	}
 
-	ret = v3d_job_init(v3d, file_priv, (void *)&job, sizeof(*job),
+	ret = v3d_job_allocate((void *)&job, sizeof(*job));
+	if (ret)
+		return ret;
+
+	ret = v3d_job_init(v3d, file_priv, &job->base,
 			   v3d_job_free, args->in_sync, &se, V3D_TFU);
 	if (ret)
 		goto fail;
@@ -683,12 +699,20 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data,
 		}
 	}
 
-	ret = v3d_job_init(v3d, file_priv, (void *)&job, sizeof(*job),
+	ret = v3d_job_allocate((void *)&job, sizeof(*job));
+	if (ret)
+		return ret;
+
+	ret = v3d_job_init(v3d, file_priv, &job->base,
 			   v3d_job_free, args->in_sync, &se, V3D_CSD);
 	if (ret)
 		goto fail;
 
-	ret = v3d_job_init(v3d, file_priv, (void *)&clean_job, sizeof(*clean_job),
+	ret = v3d_job_allocate((void *)&clean_job, sizeof(*clean_job));
+	if (ret)
+		goto fail;
+
+	ret = v3d_job_init(v3d, file_priv, clean_job,
 			   v3d_job_free, 0, NULL, V3D_CACHE_CLEAN);
 	if (ret)
 		goto fail;