xref: /openbmc/linux/arch/x86/kernel/cpu/mce/winchip.c (revision d2574c33)
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 #include "internal.h"
17 
18 /* Machine check handler for WinChip C6: */
19 static void winchip_machine_check(struct pt_regs *regs, long error_code)
20 {
21 	ist_enter(regs);
22 
23 	pr_emerg("CPU0: Machine Check Exception.\n");
24 	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
25 
26 	ist_exit(regs);
27 }
28 
29 /* Set up machine check reporting on the Winchip C6 series */
30 void winchip_mcheck_init(struct cpuinfo_x86 *c)
31 {
32 	u32 lo, hi;
33 
34 	machine_check_vector = winchip_machine_check;
35 	/* Make sure the vector pointer is visible before we enable MCEs: */
36 	wmb();
37 
38 	rdmsr(MSR_IDT_FCR1, lo, hi);
39 	lo |= (1<<2);	/* Enable EIERRINT (int 18 MCE) */
40 	lo &= ~(1<<4);	/* Enable MCE */
41 	wrmsr(MSR_IDT_FCR1, lo, hi);
42 
43 	cr4_set_bits(X86_CR4_MCE);
44 
45 	pr_info("Winchip machine check reporting enabled on CPU#0.\n");
46 }
47