v4.19.13 snapshot.
diff --git a/tools/perf/util/perf_regs.c b/tools/perf/util/perf_regs.c
new file mode 100644
index 0000000..2acfcc5
--- /dev/null
+++ b/tools/perf/util/perf_regs.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include "perf_regs.h"
+#include "event.h"
+
+const struct sample_reg __weak sample_reg_masks[] = {
+ SMPL_REG_END
+};
+
+int __weak arch_sdt_arg_parse_op(char *old_op __maybe_unused,
+ char **new_op __maybe_unused)
+{
+ return SDT_ARG_SKIP;
+}
+
+#ifdef HAVE_PERF_REGS_SUPPORT
+int perf_reg_value(u64 *valp, struct regs_dump *regs, int id)
+{
+ int i, idx = 0;
+ u64 mask = regs->mask;
+
+ if (regs->cache_mask & (1ULL << id))
+ goto out;
+
+ if (!(mask & (1ULL << id)))
+ return -EINVAL;
+
+ for (i = 0; i < id; i++) {
+ if (mask & (1ULL << i))
+ idx++;
+ }
+
+ regs->cache_mask |= (1ULL << id);
+ regs->cache_regs[id] = regs->regs[idx];
+
+out:
+ *valp = regs->cache_regs[id];
+ return 0;
+}
+#endif