linux/arch/x86/kernel/cpu/mcheck/p5.c

70 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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)
{
u32 loaddr, hi, lotype;
ist_enter(regs);
rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi);
rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi);
pr_emerg("CPU#%d: Machine Check Exception: 0x%8X (type 0x%8X).\n",
smp_processor_id(), loaddr, lotype);
if (lotype & (1<<5)) {
pr_emerg("CPU#%d: Possible thermal failure (CPU on fire ?).\n",
smp_processor_id());
}
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
ist_exit(regs);
}
/* 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);
pr_info("Intel old style machine check architecture supported.\n");
/* Enable MCE: */
cr4_set_bits(X86_CR4_MCE);
pr_info("Intel old style machine check reporting enabled on CPU#%d.\n",
smp_processor_id());
}