drm/etnaviv: print offender task information on hangcheck recovery

Track the pid per submit, so we can print the name and cmdline of
the task which submitted the batch that caused the gpu to hang.
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_gem.h

@@ -96,6 +96,7 @@ struct etnaviv_gem_submit {
 	int out_fence_id;
 	struct list_head node; /* GPU active submit list */
 	struct etnaviv_cmdbuf cmdbuf;
+	struct pid *pid;       /* submitting process */
 	bool runtime_resumed;
 	u32 exec_state;
 	u32 flags;

drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c

@@ -399,6 +399,9 @@ static void submit_cleanup(struct kref *kref)
 		mutex_unlock(&submit->gpu->fence_lock);
 		dma_fence_put(submit->out_fence);
 	}
+
+	put_pid(submit->pid);
+
 	kfree(submit->pmrs);
 	kfree(submit);
 }
@@ -422,6 +425,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 	struct sync_file *sync_file = NULL;
 	struct ww_acquire_ctx ticket;
 	int out_fence_fd = -1;
+	struct pid *pid = get_pid(task_pid(current));
 	void *stream;
 	int ret;
 
@@ -519,6 +523,8 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 		goto err_submit_ww_acquire;
 	}
 
+	submit->pid = pid;
+
 	ret = etnaviv_cmdbuf_init(priv->cmdbuf_suballoc, &submit->cmdbuf,
 				  ALIGN(args->stream_size, 8) + 8);
 	if (ret)

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -1045,12 +1045,28 @@ int etnaviv_gpu_debugfs(struct etnaviv_gpu *gpu, struct seq_file *m)
 }
 #endif
 
-void etnaviv_gpu_recover_hang(struct etnaviv_gpu *gpu)
+void etnaviv_gpu_recover_hang(struct etnaviv_gem_submit *submit)
 {
+	struct etnaviv_gpu *gpu = submit->gpu;
+	char *comm = NULL, *cmd = NULL;
+	struct task_struct *task;
 	unsigned int i;
 
 	dev_err(gpu->dev, "recover hung GPU!\n");
 
+	task = get_pid_task(submit->pid, PIDTYPE_PID);
+	if (task) {
+		comm = kstrdup(task->comm, GFP_KERNEL);
+		cmd = kstrdup_quotable_cmdline(task, GFP_KERNEL);
+		put_task_struct(task);
+	}
+
+	if (comm && cmd)
+		dev_err(gpu->dev, "offending task: %s (%s)\n", comm, cmd);
+
+	kfree(cmd);
+	kfree(comm);
+
 	if (pm_runtime_get_sync(gpu->dev) < 0)
 		goto pm_put;
 

drivers/gpu/drm/etnaviv/etnaviv_gpu.h

@@ -168,7 +168,7 @@ bool etnaviv_fill_identity_from_hwdb(struct etnaviv_gpu *gpu);
 int etnaviv_gpu_debugfs(struct etnaviv_gpu *gpu, struct seq_file *m);
 #endif
 
-void etnaviv_gpu_recover_hang(struct etnaviv_gpu *gpu);
+void etnaviv_gpu_recover_hang(struct etnaviv_gem_submit *submit);
 void etnaviv_gpu_retire(struct etnaviv_gpu *gpu);
 int etnaviv_gpu_wait_fence_interruptible(struct etnaviv_gpu *gpu,
 	u32 fence, struct drm_etnaviv_timespec *timeout);

drivers/gpu/drm/etnaviv/etnaviv_sched.c

@@ -67,7 +67,7 @@ static enum drm_gpu_sched_stat etnaviv_sched_timedout_job(struct drm_sched_job
 
 	/* get the GPU back into the init state */
 	etnaviv_core_dump(submit);
-	etnaviv_gpu_recover_hang(gpu);
+	etnaviv_gpu_recover_hang(submit);
 
 	drm_sched_resubmit_jobs(&gpu->sched);