v4.19.13 snapshot.
diff --git a/tools/perf/ui/tui/helpline.c b/tools/perf/ui/tui/helpline.c
new file mode 100644
index 0000000..4ca799a
--- /dev/null
+++ b/tools/perf/ui/tui/helpline.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+
+#include "../../util/debug.h"
+#include "../helpline.h"
+#include "../ui.h"
+#include "../libslang.h"
+
+char ui_helpline__last_msg[1024];
+bool tui_helpline__set;
+
+static void tui_helpline__pop(void)
+{
+}
+
+static void tui_helpline__push(const char *msg)
+{
+ const size_t sz = sizeof(ui_helpline__current);
+
+ SLsmg_gotorc(SLtt_Screen_Rows - 1, 0);
+ SLsmg_set_color(0);
+ SLsmg_write_nstring((char *)msg, SLtt_Screen_Cols);
+ SLsmg_refresh();
+ strncpy(ui_helpline__current, msg, sz)[sz - 1] = '\0';
+}
+
+static int tui_helpline__show(const char *format, va_list ap)
+{
+ int ret;
+ static int backlog;
+
+ pthread_mutex_lock(&ui__lock);
+ ret = vscnprintf(ui_helpline__last_msg + backlog,
+ sizeof(ui_helpline__last_msg) - backlog, format, ap);
+ backlog += ret;
+
+ tui_helpline__set = true;
+
+ if (ui_helpline__last_msg[backlog - 1] == '\n') {
+ ui_helpline__puts(ui_helpline__last_msg);
+ SLsmg_refresh();
+ backlog = 0;
+ }
+ pthread_mutex_unlock(&ui__lock);
+
+ return ret;
+}
+
+struct ui_helpline tui_helpline_fns = {
+ .pop = tui_helpline__pop,
+ .push = tui_helpline__push,
+ .show = tui_helpline__show,
+};
+
+void ui_helpline__init(void)
+{
+ helpline_fns = &tui_helpline_fns;
+ ui_helpline__puts(" ");
+}