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 #include <linux/hardirq.h> 10 11 #include <asm/processor.h> 12 #include <asm/traps.h> 13 #include <asm/tlbflush.h> 14 #include <asm/mce.h> 15 #include <asm/msr.h> 16 17 #include "internal.h" 18 19 /* Machine check handler for WinChip C6: */ 20 static noinstr void winchip_machine_check(struct pt_regs *regs) 21 { 22 instrumentation_begin(); 23 pr_emerg("CPU0: Machine Check Exception.\n"); 24 add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); 25 instrumentation_end(); 26 } 27 28 /* Set up machine check reporting on the Winchip C6 series */ 29 void winchip_mcheck_init(struct cpuinfo_x86 *c) 30 { 31 u32 lo, hi; 32 33 machine_check_vector = winchip_machine_check; 34 /* Make sure the vector pointer is visible before we enable MCEs: */ 35 wmb(); 36 37 rdmsr(MSR_IDT_FCR1, lo, hi); 38 lo |= (1<<2); /* Enable EIERRINT (int 18 MCE) */ 39 lo &= ~(1<<4); /* Enable MCE */ 40 wrmsr(MSR_IDT_FCR1, lo, hi); 41 42 cr4_set_bits(X86_CR4_MCE); 43 44 pr_info("Winchip machine check reporting enabled on CPU#0.\n"); 45 } 46