linux/arch/x86/kernel/cpu/mcheck/p5.c
Andy Lutomirski 375074cc73 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>
2015-02-04 12:10:41 +01:00

74 lines
1.8 KiB
C

/*
* P5 specific Machine Check Exception Reporting
* (C) Copyright 2002 Alan Cox <alan@lxorguk.ukuu.org.uk>
*/
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/smp.h>
#include <asm/processor.h>
#include <asm/traps.h>
#include <asm/tlbflush.h>
#include <asm/mce.h>
#include <asm/msr.h>
/* By default disabled */
int mce_p5_enabled __read_mostly;
/* Machine check handler for Pentium class Intel CPUs: */
static void pentium_machine_check(struct pt_regs *regs, long error_code)
{
enum ctx_state prev_state;
u32 loaddr, hi, lotype;
prev_state = ist_enter(regs);
rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi);
rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi);
printk(KERN_EMERG
"CPU#%d: Machine Check Exception: 0x%8X (type 0x%8X).\n",
smp_processor_id(), loaddr, lotype);
if (lotype & (1<<5)) {
printk(KERN_EMERG
"CPU#%d: Possible thermal failure (CPU on fire ?).\n",
smp_processor_id());
}
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
ist_exit(regs, prev_state);
}
/* Set up machine check reporting for processors with Intel style MCE: */
void intel_p5_mcheck_init(struct cpuinfo_x86 *c)
{
u32 l, h;
/* Default P5 to off as its often misconnected: */
if (!mce_p5_enabled)
return;
/* Check for MCE support: */
if (!cpu_has(c, X86_FEATURE_MCE))
return;
machine_check_vector = pentium_machine_check;
/* Make sure the vector pointer is visible before we enable MCEs: */
wmb();
/* Read registers before enabling: */
rdmsr(MSR_IA32_P5_MC_ADDR, l, h);
rdmsr(MSR_IA32_P5_MC_TYPE, l, h);
printk(KERN_INFO
"Intel old style machine check architecture supported.\n");
/* Enable MCE: */
cr4_set_bits(X86_CR4_MCE);
printk(KERN_INFO
"Intel old style machine check reporting enabled on CPU#%d.\n",
smp_processor_id());
}