From 375074cc736ab1d89a708c0a8d7baa4a70d5d476 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@amacapital.net>
Date: Fri, 24 Oct 2014 15:58:07 -0700
Subject: x86: Clean up cr4 manipulation

CR4 manipulation was split, seemingly at random, between direct
(write_cr4) and using a helper (set/clear_in_cr4).  Unfortunately,
the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code,
which only a small subset of users actually wanted.

This patch replaces all cr4 access in functions that don't leave cr4
exactly the way they found it with new helpers cr4_set_bits,
cr4_clear_bits, and cr4_set_bits_and_update_boot.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/lguest/x86/core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

(limited to 'drivers')

diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index 922a1acbf652..6adfd7ba4c97 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -47,6 +47,7 @@
 #include <asm/lguest.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
+#include <asm/tlbflush.h>
 #include "../lg.h"
 
 static int cpu_had_pge;
@@ -452,9 +453,9 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
 static void adjust_pge(void *on)
 {
 	if (on)
-		write_cr4(read_cr4() | X86_CR4_PGE);
+		cr4_set_bits(X86_CR4_PGE);
 	else
-		write_cr4(read_cr4() & ~X86_CR4_PGE);
+		cr4_clear_bits(X86_CR4_PGE);
 }
 
 /*H:020
-- 
cgit v1.2.3-70-g09d2