1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * P5 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/smp.h> 10 #include <linux/hardirq.h> 11 12 #include <asm/processor.h> 13 #include <asm/traps.h> 14 #include <asm/tlbflush.h> 15 #include <asm/mce.h> 16 #include <asm/msr.h> 17 18 #include "internal.h" 19 20 /* By default disabled */ 21 int mce_p5_enabled __read_mostly; 22 23 /* Machine check handler for Pentium class Intel CPUs: */ 24 static noinstr void pentium_machine_check(struct pt_regs *regs) 25 { 26 u32 loaddr, hi, lotype; 27 28 instrumentation_begin(); 29 rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi); 30 rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi); 31 32 pr_emerg("CPU#%d: Machine Check Exception: 0x%8X (type 0x%8X).\n", 33 smp_processor_id(), loaddr, lotype); 34 35 if (lotype & (1<<5)) { 36 pr_emerg("CPU#%d: Possible thermal failure (CPU on fire ?).\n", 37 smp_processor_id()); 38 } 39 40 add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); 41 instrumentation_end(); 42 } 43 44 /* Set up machine check reporting for processors with Intel style MCE: */ 45 void intel_p5_mcheck_init(struct cpuinfo_x86 *c) 46 { 47 u32 l, h; 48 49 /* Default P5 to off as its often misconnected: */ 50 if (!mce_p5_enabled) 51 return; 52 53 /* Check for MCE support: */ 54 if (!cpu_has(c, X86_FEATURE_MCE)) 55 return; 56 57 machine_check_vector = pentium_machine_check; 58 /* Make sure the vector pointer is visible before we enable MCEs: */ 59 wmb(); 60 61 /* Read registers before enabling: */ 62 rdmsr(MSR_IA32_P5_MC_ADDR, l, h); 63 rdmsr(MSR_IA32_P5_MC_TYPE, l, h); 64 pr_info("Intel old style machine check architecture supported.\n"); 65 66 /* Enable MCE: */ 67 cr4_set_bits(X86_CR4_MCE); 68 pr_info("Intel old style machine check reporting enabled on CPU#%d.\n", 69 smp_processor_id()); 70 } 71