From e6caac717b4fc2b87cf93f67109884e768253e77 Mon Sep 17 00:00:00 2001
From: Colin Percival <cperciva@FreeBSD.org>
Date: Wed, 23 Jun 2021 22:21:23 -0700
Subject: [PATCH] libsa: Add tslog support for arm64

The original code only supported x86 and used rdtsc(); we now also
support arm64 and use the CNTVCT_EL0 special register.
---
 stand/libsa/tslog.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/stand/libsa/tslog.c b/stand/libsa/tslog.c
index 7ea18e0bb8f..c6164aab02a 100644
--- a/stand/libsa/tslog.c
+++ b/stand/libsa/tslog.c
@@ -29,7 +29,11 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/types.h>
 
+#if defined(__amd64__) || defined(__i386__)
 #include <machine/cpufunc.h>
+#elif defined(__aarch64__)
+#include <machine/armreg.h>
+#endif
 
 #include <stand.h>
 
@@ -60,6 +64,8 @@ tslog(const char * type, const char * f, const char * s)
 {
 #if defined(__amd64__) || defined(__i386__)
 	uint64_t tsc = rdtsc();
+#elif defined(__aarch64__)
+	uint64_t tsc = READ_SPECIALREG(cntvct_el0);
 #else
 	uint64_t tsc = 0;
 #endif