drm/lima: save process info for debug usage

When task fail, we can find its process with this information.
Tested-by: Andreas Baierl <ichgeh@imkreisrum.de>
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200222024210.18697-2-yuq825@gmail.com

drivers/gpu/drm/lima/lima_ctx.c

@@ -27,6 +27,9 @@ int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id)
 	if (err < 0)
 		goto err_out0;
 
+	ctx->pid = task_pid_nr(current);
+	get_task_comm(ctx->pname, current);
+
 	return 0;
 
 err_out0:

drivers/gpu/drm/lima/lima_ctx.h

@@ -5,6 +5,7 @@
 #define __LIMA_CTX_H__
 
 #include <linux/xarray.h>
+#include <linux/sched.h>
 
 #include "lima_device.h"
 
@@ -13,6 +14,10 @@ struct lima_ctx {
 	struct lima_device *dev;
 	struct lima_sched_context context[lima_pipe_num];
 	atomic_t guilty;
+
+	/* debug info */
+	char pname[TASK_COMM_LEN];
+	pid_t pid;
 };
 
 struct lima_ctx_mgr {