[tip:x86/cpu] x86/CPU: Use correct macros for Cyrix calls

From: tip-bot for Matthew Whitehead
Date: Sat Sep 22 2018 - 05:58:47 EST


Commit-ID: 03b099bdcdf7125d4a63dc9ddeefdd454e05123d
Gitweb: https://git.kernel.org/tip/03b099bdcdf7125d4a63dc9ddeefdd454e05123d
Author: Matthew Whitehead <tedheadster@xxxxxxxxx>
AuthorDate: Fri, 21 Sep 2018 17:20:40 -0400
Committer: Borislav Petkov <bp@xxxxxxx>
CommitDate: Sat, 22 Sep 2018 11:46:56 +0200

x86/CPU: Use correct macros for Cyrix calls

There are comments in processor-cyrix.h advising you to _not_ make calls
using the deprecated macros in this style:

setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x80);

This is because it expands the macro into a non-functioning calling
sequence. The calling order must be:

outb(CX86_CCR2, 0x22);
inb(0x23);

>From the comments:

* When using the old macros a line like
* setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);
* gets expanded to:
* do {
* outb((CX86_CCR2), 0x22);
* outb((({
* outb((CX86_CCR2), 0x22);
* inb(0x23);
* }) | 0x88), 0x23);
* } while (0);

The new macros fix this problem, so use them instead.

Signed-off-by: Matthew Whitehead <tedheadster@xxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jia Zhang <qianyue.zj@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Philippe Ombredanne <pombredanne@xxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180921212041.13096-2-tedheadster@xxxxxxxxx
---
arch/x86/kernel/cpu/cyrix.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c
index 8949b7ae6d92..d12226f60168 100644
--- a/arch/x86/kernel/cpu/cyrix.c
+++ b/arch/x86/kernel/cpu/cyrix.c
@@ -437,7 +437,7 @@ static void cyrix_identify(struct cpuinfo_x86 *c)
/* enable MAPEN */
setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10);
/* enable cpuid */
- setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x80);
+ setCx86(CX86_CCR4, getCx86(CX86_CCR4) | 0x80);
/* disable MAPEN */
setCx86(CX86_CCR3, ccr3);
local_irq_restore(flags);