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| author | Matthew Whitehead <tedheadster@gmail.com> | 2018-09-21 17:20:40 -0400 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2018-09-22 11:46:56 +0200 |
| commit | 03b099bdcdf7125d4a63dc9ddeefdd454e05123d (patch) | |
| tree | b1e32e73a052a62bf47a72218b8b3e77e8fe6ede | |
| parent | 7876320f88802b22d4e2daf7eb027dd14175a0f8 (diff) | |
| download | lwn-03b099bdcdf7125d4a63dc9ddeefdd454e05123d.tar.gz lwn-03b099bdcdf7125d4a63dc9ddeefdd454e05123d.zip | |
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@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jia Zhang <qianyue.zj@alibaba-inc.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180921212041.13096-2-tedheadster@gmail.com
| -rw-r--r-- | arch/x86/kernel/cpu/cyrix.c | 2 |
1 files changed, 1 insertions, 1 deletions
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); |