arch/x86/kernel/cpu/mcheck/winchip.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * IDT Winchip specific Machine Check Exception Reporting
   4  * (C) Copyright 2002 Alan Cox <alan@lxorguk.ukuu.org.uk>
   5  */
   6 #include <linux/interrupt.h>
   7 #include <linux/kernel.h>
   8 #include <linux/types.h>
   9
  10 #include <asm/processor.h>
  11 #include <asm/traps.h>
  12 #include <asm/tlbflush.h>
  13 #include <asm/mce.h>
  14 #include <asm/msr.h>
  15
  16 /* Machine check handler for WinChip C6: */
  17 static void winchip_machine_check(struct pt_regs *regs, long error_code)
  18 {
  19         ist_enter(regs);
  20
  21         pr_emerg("CPU0: Machine Check Exception.\n");
  22         add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
  23
  24         ist_exit(regs);
  25 }
  26
  27 /* Set up machine check reporting on the Winchip C6 series */
  28 void winchip_mcheck_init(struct cpuinfo_x86 *c)
  29 {
  30         u32 lo, hi;
  31
  32         machine_check_vector = winchip_machine_check;
  33         /* Make sure the vector pointer is visible before we enable MCEs: */
  34         wmb();
  35
  36         rdmsr(MSR_IDT_FCR1, lo, hi);
  37         lo |= (1<<2);   /* Enable EIERRINT (int 18 MCE) */
  38         lo &= ~(1<<4);  /* Enable MCE */
  39         wrmsr(MSR_IDT_FCR1, lo, hi);
  40
  41         cr4_set_bits(X86_CR4_MCE);
  42
  43         pr_info("Winchip machine check reporting enabled on CPU#0.\n");
  44 }