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: */
winchip_machine_check(struct pt_regs * regs,long error_code)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 */
winchip_mcheck_init(struct cpuinfo_x86 * c)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 }
45