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-rw-r--r--arch/powerpc/kernel/mce.c352
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diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
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1/*
2 * Machine check exception handling.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright 2013 IBM Corporation
19 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
20 */
21
22#undef DEBUG
23#define pr_fmt(fmt) "mce: " fmt
24
25#include <linux/types.h>
26#include <linux/ptrace.h>
27#include <linux/percpu.h>
28#include <linux/export.h>
29#include <linux/irq_work.h>
30#include <asm/mce.h>
31
32static DEFINE_PER_CPU(int, mce_nest_count);
33static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);
34
35/* Queue for delayed MCE events. */
36static DEFINE_PER_CPU(int, mce_queue_count);
37static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);
38
39static void machine_check_process_queued_event(struct irq_work *work);
40struct irq_work mce_event_process_work = {
41 .func = machine_check_process_queued_event,
42};
43
44static void mce_set_error_info(struct machine_check_event *mce,
45 struct mce_error_info *mce_err)
46{
47 mce->error_type = mce_err->error_type;
48 switch (mce_err->error_type) {
49 case MCE_ERROR_TYPE_UE:
50 mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
51 break;
52 case MCE_ERROR_TYPE_SLB:
53 mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
54 break;
55 case MCE_ERROR_TYPE_ERAT:
56 mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
57 break;
58 case MCE_ERROR_TYPE_TLB:
59 mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
60 break;
61 case MCE_ERROR_TYPE_UNKNOWN:
62 default:
63 break;
64 }
65}
66
67/*
68 * Decode and save high level MCE information into per cpu buffer which
69 * is an array of machine_check_event structure.
70 */
71void save_mce_event(struct pt_regs *regs, long handled,
72 struct mce_error_info *mce_err,
73 uint64_t addr)
74{
75 uint64_t srr1;
76 int index = __get_cpu_var(mce_nest_count)++;
77 struct machine_check_event *mce = &__get_cpu_var(mce_event[index]);
78
79 /*
80 * Return if we don't have enough space to log mce event.
81 * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
82 * the check below will stop buffer overrun.
83 */
84 if (index >= MAX_MC_EVT)
85 return;
86
87 /* Populate generic machine check info */
88 mce->version = MCE_V1;
89 mce->srr0 = regs->nip;
90 mce->srr1 = regs->msr;
91 mce->gpr3 = regs->gpr[3];
92 mce->in_use = 1;
93
94 mce->initiator = MCE_INITIATOR_CPU;
95 if (handled)
96 mce->disposition = MCE_DISPOSITION_RECOVERED;
97 else
98 mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
99 mce->severity = MCE_SEV_ERROR_SYNC;
100
101 srr1 = regs->msr;
102
103 /*
104 * Populate the mce error_type and type-specific error_type.
105 */
106 mce_set_error_info(mce, mce_err);
107
108 if (!addr)
109 return;
110
111 if (mce->error_type == MCE_ERROR_TYPE_TLB) {
112 mce->u.tlb_error.effective_address_provided = true;
113 mce->u.tlb_error.effective_address = addr;
114 } else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
115 mce->u.slb_error.effective_address_provided = true;
116 mce->u.slb_error.effective_address = addr;
117 } else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
118 mce->u.erat_error.effective_address_provided = true;
119 mce->u.erat_error.effective_address = addr;
120 } else if (mce->error_type == MCE_ERROR_TYPE_UE) {
121 mce->u.ue_error.effective_address_provided = true;
122 mce->u.ue_error.effective_address = addr;
123 }
124 return;
125}
126
127/*
128 * get_mce_event:
129 * mce Pointer to machine_check_event structure to be filled.
130 * release Flag to indicate whether to free the event slot or not.
131 * 0 <= do not release the mce event. Caller will invoke
132 * release_mce_event() once event has been consumed.
133 * 1 <= release the slot.
134 *
135 * return 1 = success
136 * 0 = failure
137 *
138 * get_mce_event() will be called by platform specific machine check
139 * handle routine and in KVM.
140 * When we call get_mce_event(), we are still in interrupt context and
141 * preemption will not be scheduled until ret_from_expect() routine
142 * is called.
143 */
144int get_mce_event(struct machine_check_event *mce, bool release)
145{
146 int index = __get_cpu_var(mce_nest_count) - 1;
147 struct machine_check_event *mc_evt;
148 int ret = 0;
149
150 /* Sanity check */
151 if (index < 0)
152 return ret;
153
154 /* Check if we have MCE info to process. */
155 if (index < MAX_MC_EVT) {
156 mc_evt = &__get_cpu_var(mce_event[index]);
157 /* Copy the event structure and release the original */
158 if (mce)
159 *mce = *mc_evt;
160 if (release)
161 mc_evt->in_use = 0;
162 ret = 1;
163 }
164 /* Decrement the count to free the slot. */
165 if (release)
166 __get_cpu_var(mce_nest_count)--;
167
168 return ret;
169}
170
171void release_mce_event(void)
172{
173 get_mce_event(NULL, true);
174}
175
176/*
177 * Queue up the MCE event which then can be handled later.
178 */
179void machine_check_queue_event(void)
180{
181 int index;
182 struct machine_check_event evt;
183
184 if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
185 return;
186
187 index = __get_cpu_var(mce_queue_count)++;
188 /* If queue is full, just return for now. */
189 if (index >= MAX_MC_EVT) {
190 __get_cpu_var(mce_queue_count)--;
191 return;
192 }
193 __get_cpu_var(mce_event_queue[index]) = evt;
194
195 /* Queue irq work to process this event later. */
196 irq_work_queue(&mce_event_process_work);
197}
198
199/*
200 * process pending MCE event from the mce event queue. This function will be
201 * called during syscall exit.
202 */
203static void machine_check_process_queued_event(struct irq_work *work)
204{
205 int index;
206
207 /*
208 * For now just print it to console.
209 * TODO: log this error event to FSP or nvram.
210 */
211 while (__get_cpu_var(mce_queue_count) > 0) {
212 index = __get_cpu_var(mce_queue_count) - 1;
213 machine_check_print_event_info(
214 &__get_cpu_var(mce_event_queue[index]));
215 __get_cpu_var(mce_queue_count)--;
216 }
217}
218
219void machine_check_print_event_info(struct machine_check_event *evt)
220{
221 const char *level, *sevstr, *subtype;
222 static const char *mc_ue_types[] = {
223 "Indeterminate",
224 "Instruction fetch",
225 "Page table walk ifetch",
226 "Load/Store",
227 "Page table walk Load/Store",
228 };
229 static const char *mc_slb_types[] = {
230 "Indeterminate",
231 "Parity",
232 "Multihit",
233 };
234 static const char *mc_erat_types[] = {
235 "Indeterminate",
236 "Parity",
237 "Multihit",
238 };
239 static const char *mc_tlb_types[] = {
240 "Indeterminate",
241 "Parity",
242 "Multihit",
243 };
244
245 /* Print things out */
246 if (evt->version != MCE_V1) {
247 pr_err("Machine Check Exception, Unknown event version %d !\n",
248 evt->version);
249 return;
250 }
251 switch (evt->severity) {
252 case MCE_SEV_NO_ERROR:
253 level = KERN_INFO;
254 sevstr = "Harmless";
255 break;
256 case MCE_SEV_WARNING:
257 level = KERN_WARNING;
258 sevstr = "";
259 break;
260 case MCE_SEV_ERROR_SYNC:
261 level = KERN_ERR;
262 sevstr = "Severe";
263 break;
264 case MCE_SEV_FATAL:
265 default:
266 level = KERN_ERR;
267 sevstr = "Fatal";
268 break;
269 }
270
271 printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
272 evt->disposition == MCE_DISPOSITION_RECOVERED ?
273 "Recovered" : "[Not recovered");
274 printk("%s Initiator: %s\n", level,
275 evt->initiator == MCE_INITIATOR_CPU ? "CPU" : "Unknown");
276 switch (evt->error_type) {
277 case MCE_ERROR_TYPE_UE:
278 subtype = evt->u.ue_error.ue_error_type <
279 ARRAY_SIZE(mc_ue_types) ?
280 mc_ue_types[evt->u.ue_error.ue_error_type]
281 : "Unknown";
282 printk("%s Error type: UE [%s]\n", level, subtype);
283 if (evt->u.ue_error.effective_address_provided)
284 printk("%s Effective address: %016llx\n",
285 level, evt->u.ue_error.effective_address);
286 if (evt->u.ue_error.physical_address_provided)
287 printk("%s Physial address: %016llx\n",
288 level, evt->u.ue_error.physical_address);
289 break;
290 case MCE_ERROR_TYPE_SLB:
291 subtype = evt->u.slb_error.slb_error_type <
292 ARRAY_SIZE(mc_slb_types) ?
293 mc_slb_types[evt->u.slb_error.slb_error_type]
294 : "Unknown";
295 printk("%s Error type: SLB [%s]\n", level, subtype);
296 if (evt->u.slb_error.effective_address_provided)
297 printk("%s Effective address: %016llx\n",
298 level, evt->u.slb_error.effective_address);
299 break;
300 case MCE_ERROR_TYPE_ERAT:
301 subtype = evt->u.erat_error.erat_error_type <
302 ARRAY_SIZE(mc_erat_types) ?
303 mc_erat_types[evt->u.erat_error.erat_error_type]
304 : "Unknown";
305 printk("%s Error type: ERAT [%s]\n", level, subtype);
306 if (evt->u.erat_error.effective_address_provided)
307 printk("%s Effective address: %016llx\n",
308 level, evt->u.erat_error.effective_address);
309 break;
310 case MCE_ERROR_TYPE_TLB:
311 subtype = evt->u.tlb_error.tlb_error_type <
312 ARRAY_SIZE(mc_tlb_types) ?
313 mc_tlb_types[evt->u.tlb_error.tlb_error_type]
314 : "Unknown";
315 printk("%s Error type: TLB [%s]\n", level, subtype);
316 if (evt->u.tlb_error.effective_address_provided)
317 printk("%s Effective address: %016llx\n",
318 level, evt->u.tlb_error.effective_address);
319 break;
320 default:
321 case MCE_ERROR_TYPE_UNKNOWN:
322 printk("%s Error type: Unknown\n", level);
323 break;
324 }
325}
326
327uint64_t get_mce_fault_addr(struct machine_check_event *evt)
328{
329 switch (evt->error_type) {
330 case MCE_ERROR_TYPE_UE:
331 if (evt->u.ue_error.effective_address_provided)
332 return evt->u.ue_error.effective_address;
333 break;
334 case MCE_ERROR_TYPE_SLB:
335 if (evt->u.slb_error.effective_address_provided)
336 return evt->u.slb_error.effective_address;
337 break;
338 case MCE_ERROR_TYPE_ERAT:
339 if (evt->u.erat_error.effective_address_provided)
340 return evt->u.erat_error.effective_address;
341 break;
342 case MCE_ERROR_TYPE_TLB:
343 if (evt->u.tlb_error.effective_address_provided)
344 return evt->u.tlb_error.effective_address;
345 break;
346 default:
347 case MCE_ERROR_TYPE_UNKNOWN:
348 break;
349 }
350 return 0;
351}
352EXPORT_SYMBOL(get_mce_fault_addr);
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