From 63a4e21dad12e61a8688757bb1d43b75f9e41c07 Mon Sep 17 00:00:00 2001
From: cheloha <cheloha@openbsd.org>
Date: Sat, 5 Nov 2022 16:23:02 +0000
Subject: [PATCH] powerpc64: TimeBase: add userspace timecounting support

Tested by gkoehler@.

ok gkoehler@
---
 lib/libc/arch/powerpc64/gen/usertc.c | 23 +++++++++++++++++++++--
 sys/arch/powerpc64/include/timetc.h  |  4 ++--
 sys/arch/powerpc64/powerpc64/clock.c |  3 ++-
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/lib/libc/arch/powerpc64/gen/usertc.c b/lib/libc/arch/powerpc64/gen/usertc.c
index 2ad6f973007..f0ff2df276f 100644
--- a/lib/libc/arch/powerpc64/gen/usertc.c
+++ b/lib/libc/arch/powerpc64/gen/usertc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: usertc.c,v 1.1 2020/07/11 16:21:29 kettenis Exp $	*/
+/*	$OpenBSD: usertc.c,v 1.2 2022/11/05 16:23:02 cheloha Exp $	*/
 /*
  * Copyright (c) 2020 Paul Irofti <paul@irofti.net>
  *
@@ -18,4 +18,23 @@
 #include <sys/types.h>
 #include <sys/timetc.h>
 
-int (*const _tc_get_timecount)(struct timekeep *, u_int *) = NULL;
+static u_int
+mftbl(void)
+{
+	uint64_t value;
+	__asm volatile ("mftb %0" : "=r"(value));
+	return value;
+}
+
+static int
+tc_get_timecount(struct timekeep *tk, u_int *tc)
+{
+	switch (tk->tk_user) {
+	case TC_TB:
+		*tc = mftbl();
+		return 0;
+	}
+	return -1;
+}
+
+int (*const _tc_get_timecount)(struct timekeep *, u_int *) = tc_get_timecount;
diff --git a/sys/arch/powerpc64/include/timetc.h b/sys/arch/powerpc64/include/timetc.h
index ec63af16d18..4567a49ada4 100644
--- a/sys/arch/powerpc64/include/timetc.h
+++ b/sys/arch/powerpc64/include/timetc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: timetc.h,v 1.1 2020/07/06 13:33:08 pirofti Exp $ */
+/*	$OpenBSD: timetc.h,v 1.2 2022/11/05 16:23:02 cheloha Exp $ */
 /*
  * Copyright (c) 2020 Paul Irofti <paul@irofti.net>
  *
@@ -18,6 +18,6 @@
 #ifndef _MACHINE_TIMETC_H_
 #define _MACHINE_TIMETC_H_
 
-#define	TC_LAST	0
+#define	TC_TB	1
 
 #endif	/* _MACHINE_TIMETC_H_ */
diff --git a/sys/arch/powerpc64/powerpc64/clock.c b/sys/arch/powerpc64/powerpc64/clock.c
index aef95e83dd8..20e81c62414 100644
--- a/sys/arch/powerpc64/powerpc64/clock.c
+++ b/sys/arch/powerpc64/powerpc64/clock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: clock.c,v 1.5 2022/08/11 17:15:21 cheloha Exp $	*/
+/*	$OpenBSD: clock.c,v 1.6 2022/11/05 16:23:02 cheloha Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -44,6 +44,7 @@ static struct timecounter tb_timecounter = {
 	.tc_name = "tb",
 	.tc_quality = 0,
 	.tc_priv = NULL,
+	.tc_user = TC_TB,
 };
 
 void	cpu_startclock(void);
-- 
2.20.1