From 706c56e4a9c40faaac5ad4fb91e9128eafe186ce Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Tue, 9 Apr 2013 17:55:39 +0000
Subject: [PATCH] Pass the segmented address of the counter, based on %fs, i.e.
 offset from the pcpu[0] to the counter base, instead of the linear address.

---
 sys/i386/include/counter.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/i386/include/counter.h b/sys/i386/include/counter.h
index f45d9535869..3e93b362114 100644
--- a/sys/i386/include/counter.h
+++ b/sys/i386/include/counter.h
@@ -46,6 +46,8 @@
 		critical_exit();			\
 } while (0)
 
+extern struct pcpu __pcpu[MAXCPU];
+
 static inline void
 counter_64_inc_8b(uint64_t *p, int64_t inc)
 {
@@ -61,7 +63,7 @@ counter_64_inc_8b(uint64_t *p, int64_t inc)
 	"cmpxchg8b %%fs:(%%esi)\n\t"
 	"jnz	1b"
 	:
-	: "S" (p), "D" (&inc)
+	: "S" ((char *)p - (char *)&__pcpu[0]), "D" (&inc)
 	: "memory", "cc", "eax", "edx", "ebx", "ecx");
 }