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1 /*
2  * P4 specific Machine Check Exception Reporting
3  */
4 
5 #include <linux/init.h>
6 #include <linux/types.h>
7 #include <linux/kernel.h>
8 #include <linux/interrupt.h>
9 #include <linux/smp.h>
10 
11 #include <asm/processor.h>
12 #include <asm/system.h>
13 #include <asm/msr.h>
14 #include <asm/apic.h>
15 
16 #include <asm/therm_throt.h>
17 
18 #include "mce.h"
19 
20 /* as supported by the P4/Xeon family */
21 struct intel_mce_extended_msrs {
22 	u32 eax;
23 	u32 ebx;
24 	u32 ecx;
25 	u32 edx;
26 	u32 esi;
27 	u32 edi;
28 	u32 ebp;
29 	u32 esp;
30 	u32 eflags;
31 	u32 eip;
32 	/* u32 *reserved[]; */
33 };
34 
35 static int mce_num_extended_msrs;
36 
37 
38 #ifdef CONFIG_X86_MCE_P4THERMAL
unexpected_thermal_interrupt(struct pt_regs * regs)39 static void unexpected_thermal_interrupt(struct pt_regs *regs)
40 {
41 	printk(KERN_ERR "CPU%d: Unexpected LVT TMR interrupt!\n",
42 			smp_processor_id());
43 	add_taint(TAINT_MACHINE_CHECK);
44 }
45 
46 /* P4/Xeon Thermal transition interrupt handler */
intel_thermal_interrupt(struct pt_regs * regs)47 static void intel_thermal_interrupt(struct pt_regs *regs)
48 {
49 	__u64 msr_val;
50 
51 	ack_APIC_irq();
52 
53 	rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
54 	therm_throt_process(msr_val & 0x1);
55 }
56 
57 /* Thermal interrupt handler for this CPU setup */
58 static void (*vendor_thermal_interrupt)(struct pt_regs *regs) = unexpected_thermal_interrupt;
59 
smp_thermal_interrupt(struct pt_regs * regs)60 void smp_thermal_interrupt(struct pt_regs *regs)
61 {
62 	irq_enter();
63 	vendor_thermal_interrupt(regs);
64 	__get_cpu_var(irq_stat).irq_thermal_count++;
65 	irq_exit();
66 }
67 
68 /* P4/Xeon Thermal regulation detect and init */
intel_init_thermal(struct cpuinfo_x86 * c)69 static void intel_init_thermal(struct cpuinfo_x86 *c)
70 {
71 	u32 l, h;
72 	unsigned int cpu = smp_processor_id();
73 
74 	/* Thermal monitoring */
75 	if (!cpu_has(c, X86_FEATURE_ACPI))
76 		return;	/* -ENODEV */
77 
78 	/* Clock modulation */
79 	if (!cpu_has(c, X86_FEATURE_ACC))
80 		return;	/* -ENODEV */
81 
82 	/* first check if its enabled already, in which case there might
83 	 * be some SMM goo which handles it, so we can't even put a handler
84 	 * since it might be delivered via SMI already -zwanem.
85 	 */
86 	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
87 	h = apic_read(APIC_LVTTHMR);
88 	if ((l & (1<<3)) && (h & APIC_DM_SMI)) {
89 		printk(KERN_DEBUG "CPU%d: Thermal monitoring handled by SMI\n",
90 				cpu);
91 		return; /* -EBUSY */
92 	}
93 
94 	/* check whether a vector already exists, temporarily masked? */
95 	if (h & APIC_VECTOR_MASK) {
96 		printk(KERN_DEBUG "CPU%d: Thermal LVT vector (%#x) already "
97 				"installed\n",
98 			cpu, (h & APIC_VECTOR_MASK));
99 		return; /* -EBUSY */
100 	}
101 
102 	/* The temperature transition interrupt handler setup */
103 	h = THERMAL_APIC_VECTOR;		/* our delivery vector */
104 	h |= (APIC_DM_FIXED | APIC_LVT_MASKED);	/* we'll mask till we're ready */
105 	apic_write(APIC_LVTTHMR, h);
106 
107 	rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
108 	wrmsr(MSR_IA32_THERM_INTERRUPT, l | 0x03 , h);
109 
110 	/* ok we're good to go... */
111 	vendor_thermal_interrupt = intel_thermal_interrupt;
112 
113 	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
114 	wrmsr(MSR_IA32_MISC_ENABLE, l | (1<<3), h);
115 
116 	l = apic_read(APIC_LVTTHMR);
117 	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
118 	printk(KERN_INFO "CPU%d: Thermal monitoring enabled\n", cpu);
119 
120 	/* enable thermal throttle processing */
121 	atomic_set(&therm_throt_en, 1);
122 	return;
123 }
124 #endif /* CONFIG_X86_MCE_P4THERMAL */
125 
126 
127 /* P4/Xeon Extended MCE MSR retrieval, return 0 if unsupported */
intel_get_extended_msrs(struct intel_mce_extended_msrs * r)128 static inline void intel_get_extended_msrs(struct intel_mce_extended_msrs *r)
129 {
130 	u32 h;
131 
132 	rdmsr(MSR_IA32_MCG_EAX, r->eax, h);
133 	rdmsr(MSR_IA32_MCG_EBX, r->ebx, h);
134 	rdmsr(MSR_IA32_MCG_ECX, r->ecx, h);
135 	rdmsr(MSR_IA32_MCG_EDX, r->edx, h);
136 	rdmsr(MSR_IA32_MCG_ESI, r->esi, h);
137 	rdmsr(MSR_IA32_MCG_EDI, r->edi, h);
138 	rdmsr(MSR_IA32_MCG_EBP, r->ebp, h);
139 	rdmsr(MSR_IA32_MCG_ESP, r->esp, h);
140 	rdmsr(MSR_IA32_MCG_EFLAGS, r->eflags, h);
141 	rdmsr(MSR_IA32_MCG_EIP, r->eip, h);
142 }
143 
intel_machine_check(struct pt_regs * regs,long error_code)144 static void intel_machine_check(struct pt_regs *regs, long error_code)
145 {
146 	int recover = 1;
147 	u32 alow, ahigh, high, low;
148 	u32 mcgstl, mcgsth;
149 	int i;
150 
151 	rdmsr(MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
152 	if (mcgstl & (1<<0))	/* Recoverable ? */
153 		recover = 0;
154 
155 	printk(KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
156 		smp_processor_id(), mcgsth, mcgstl);
157 
158 	if (mce_num_extended_msrs > 0) {
159 		struct intel_mce_extended_msrs dbg;
160 		intel_get_extended_msrs(&dbg);
161 		printk(KERN_DEBUG "CPU %d: EIP: %08x EFLAGS: %08x\n"
162 			"\teax: %08x ebx: %08x ecx: %08x edx: %08x\n"
163 			"\tesi: %08x edi: %08x ebp: %08x esp: %08x\n",
164 			smp_processor_id(), dbg.eip, dbg.eflags,
165 			dbg.eax, dbg.ebx, dbg.ecx, dbg.edx,
166 			dbg.esi, dbg.edi, dbg.ebp, dbg.esp);
167 	}
168 
169 	for (i = 0; i < nr_mce_banks; i++) {
170 		rdmsr(MSR_IA32_MC0_STATUS+i*4, low, high);
171 		if (high & (1<<31)) {
172 			char misc[20];
173 			char addr[24];
174 			misc[0] = addr[0] = '\0';
175 			if (high & (1<<29))
176 				recover |= 1;
177 			if (high & (1<<25))
178 				recover |= 2;
179 			high &= ~(1<<31);
180 			if (high & (1<<27)) {
181 				rdmsr(MSR_IA32_MC0_MISC+i*4, alow, ahigh);
182 				snprintf(misc, 20, "[%08x%08x]", ahigh, alow);
183 			}
184 			if (high & (1<<26)) {
185 				rdmsr(MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
186 				snprintf(addr, 24, " at %08x%08x", ahigh, alow);
187 			}
188 			printk(KERN_EMERG "CPU %d: Bank %d: %08x%08x%s%s\n",
189 				smp_processor_id(), i, high, low, misc, addr);
190 		}
191 	}
192 
193 	if (recover & 2)
194 		panic("CPU context corrupt");
195 	if (recover & 1)
196 		panic("Unable to continue");
197 
198 	printk(KERN_EMERG "Attempting to continue.\n");
199 	/*
200 	 * Do not clear the MSR_IA32_MCi_STATUS if the error is not
201 	 * recoverable/continuable.This will allow BIOS to look at the MSRs
202 	 * for errors if the OS could not log the error.
203 	 */
204 	for (i = 0; i < nr_mce_banks; i++) {
205 		u32 msr;
206 		msr = MSR_IA32_MC0_STATUS+i*4;
207 		rdmsr(msr, low, high);
208 		if (high&(1<<31)) {
209 			/* Clear it */
210 			wrmsr(msr, 0UL, 0UL);
211 			/* Serialize */
212 			wmb();
213 			add_taint(TAINT_MACHINE_CHECK);
214 		}
215 	}
216 	mcgstl &= ~(1<<2);
217 	wrmsr(MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
218 }
219 
220 
intel_p4_mcheck_init(struct cpuinfo_x86 * c)221 void intel_p4_mcheck_init(struct cpuinfo_x86 *c)
222 {
223 	u32 l, h;
224 	int i;
225 
226 	machine_check_vector = intel_machine_check;
227 	wmb();
228 
229 	printk(KERN_INFO "Intel machine check architecture supported.\n");
230 	rdmsr(MSR_IA32_MCG_CAP, l, h);
231 	if (l & (1<<8))	/* Control register present ? */
232 		wrmsr(MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff);
233 	nr_mce_banks = l & 0xff;
234 
235 	for (i = 0; i < nr_mce_banks; i++) {
236 		wrmsr(MSR_IA32_MC0_CTL+4*i, 0xffffffff, 0xffffffff);
237 		wrmsr(MSR_IA32_MC0_STATUS+4*i, 0x0, 0x0);
238 	}
239 
240 	set_in_cr4(X86_CR4_MCE);
241 	printk(KERN_INFO "Intel machine check reporting enabled on CPU#%d.\n",
242 		smp_processor_id());
243 
244 	/* Check for P4/Xeon extended MCE MSRs */
245 	rdmsr(MSR_IA32_MCG_CAP, l, h);
246 	if (l & (1<<9))	{/* MCG_EXT_P */
247 		mce_num_extended_msrs = (l >> 16) & 0xff;
248 		printk(KERN_INFO "CPU%d: Intel P4/Xeon Extended MCE MSRs (%d)"
249 				" available\n",
250 			smp_processor_id(), mce_num_extended_msrs);
251 
252 #ifdef CONFIG_X86_MCE_P4THERMAL
253 		/* Check for P4/Xeon Thermal monitor */
254 		intel_init_thermal(c);
255 #endif
256 	}
257 }
258