1 /*
2 * Copyright (C) 2001 Dave Engebretsen IBM Corporation
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
19 #include <linux/sched.h>
20 #include <linux/interrupt.h>
21 #include <linux/irq.h>
22 #include <linux/of.h>
23 #include <linux/fs.h>
24 #include <linux/reboot.h>
25
26 #include <asm/machdep.h>
27 #include <asm/rtas.h>
28 #include <asm/firmware.h>
29
30 #include "pseries.h"
31
32 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
33 static DEFINE_SPINLOCK(ras_log_buf_lock);
34
35 static char global_mce_data_buf[RTAS_ERROR_LOG_MAX];
36 static DEFINE_PER_CPU(__u64, mce_data_buf);
37
38 static int ras_check_exception_token;
39
40 #define EPOW_SENSOR_TOKEN 9
41 #define EPOW_SENSOR_INDEX 0
42
43 /* EPOW events counter variable */
44 static int num_epow_events;
45
46 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id);
47 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
48 static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
49
50
51 /*
52 * Initialize handlers for the set of interrupts caused by hardware errors
53 * and power system events.
54 */
init_ras_IRQ(void)55 static int __init init_ras_IRQ(void)
56 {
57 struct device_node *np;
58
59 ras_check_exception_token = rtas_token("check-exception");
60
61 /* Internal Errors */
62 np = of_find_node_by_path("/event-sources/internal-errors");
63 if (np != NULL) {
64 request_event_sources_irqs(np, ras_error_interrupt,
65 "RAS_ERROR");
66 of_node_put(np);
67 }
68
69 /* Hotplug Events */
70 np = of_find_node_by_path("/event-sources/hot-plug-events");
71 if (np != NULL) {
72 request_event_sources_irqs(np, ras_hotplug_interrupt,
73 "RAS_HOTPLUG");
74 of_node_put(np);
75 }
76
77 /* EPOW Events */
78 np = of_find_node_by_path("/event-sources/epow-events");
79 if (np != NULL) {
80 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
81 of_node_put(np);
82 }
83
84 return 0;
85 }
86 machine_subsys_initcall(pseries, init_ras_IRQ);
87
88 #define EPOW_SHUTDOWN_NORMAL 1
89 #define EPOW_SHUTDOWN_ON_UPS 2
90 #define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS 3
91 #define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH 4
92
handle_system_shutdown(char event_modifier)93 static void handle_system_shutdown(char event_modifier)
94 {
95 switch (event_modifier) {
96 case EPOW_SHUTDOWN_NORMAL:
97 pr_emerg("Power off requested\n");
98 orderly_poweroff(true);
99 break;
100
101 case EPOW_SHUTDOWN_ON_UPS:
102 pr_emerg("Loss of system power detected. System is running on"
103 " UPS/battery. Check RTAS error log for details\n");
104 orderly_poweroff(true);
105 break;
106
107 case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
108 pr_emerg("Loss of system critical functions detected. Check"
109 " RTAS error log for details\n");
110 orderly_poweroff(true);
111 break;
112
113 case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
114 pr_emerg("High ambient temperature detected. Check RTAS"
115 " error log for details\n");
116 orderly_poweroff(true);
117 break;
118
119 default:
120 pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
121 event_modifier);
122 }
123 }
124
125 struct epow_errorlog {
126 unsigned char sensor_value;
127 unsigned char event_modifier;
128 unsigned char extended_modifier;
129 unsigned char reserved;
130 unsigned char platform_reason;
131 };
132
133 #define EPOW_RESET 0
134 #define EPOW_WARN_COOLING 1
135 #define EPOW_WARN_POWER 2
136 #define EPOW_SYSTEM_SHUTDOWN 3
137 #define EPOW_SYSTEM_HALT 4
138 #define EPOW_MAIN_ENCLOSURE 5
139 #define EPOW_POWER_OFF 7
140
rtas_parse_epow_errlog(struct rtas_error_log * log)141 static void rtas_parse_epow_errlog(struct rtas_error_log *log)
142 {
143 struct pseries_errorlog *pseries_log;
144 struct epow_errorlog *epow_log;
145 char action_code;
146 char modifier;
147
148 pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
149 if (pseries_log == NULL)
150 return;
151
152 epow_log = (struct epow_errorlog *)pseries_log->data;
153 action_code = epow_log->sensor_value & 0xF; /* bottom 4 bits */
154 modifier = epow_log->event_modifier & 0xF; /* bottom 4 bits */
155
156 switch (action_code) {
157 case EPOW_RESET:
158 if (num_epow_events) {
159 pr_info("Non critical power/cooling issue cleared\n");
160 num_epow_events--;
161 }
162 break;
163
164 case EPOW_WARN_COOLING:
165 pr_info("Non-critical cooling issue detected. Check RTAS error"
166 " log for details\n");
167 break;
168
169 case EPOW_WARN_POWER:
170 pr_info("Non-critical power issue detected. Check RTAS error"
171 " log for details\n");
172 break;
173
174 case EPOW_SYSTEM_SHUTDOWN:
175 handle_system_shutdown(epow_log->event_modifier);
176 break;
177
178 case EPOW_SYSTEM_HALT:
179 pr_emerg("Critical power/cooling issue detected. Check RTAS"
180 " error log for details. Powering off.\n");
181 orderly_poweroff(true);
182 break;
183
184 case EPOW_MAIN_ENCLOSURE:
185 case EPOW_POWER_OFF:
186 pr_emerg("System about to lose power. Check RTAS error log "
187 " for details. Powering off immediately.\n");
188 emergency_sync();
189 kernel_power_off();
190 break;
191
192 default:
193 pr_err("Unknown power/cooling event (action code = %d)\n",
194 action_code);
195 }
196
197 /* Increment epow events counter variable */
198 if (action_code != EPOW_RESET)
199 num_epow_events++;
200 }
201
ras_hotplug_interrupt(int irq,void * dev_id)202 static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id)
203 {
204 struct pseries_errorlog *pseries_log;
205 struct pseries_hp_errorlog *hp_elog;
206
207 spin_lock(&ras_log_buf_lock);
208
209 rtas_call(ras_check_exception_token, 6, 1, NULL,
210 RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq),
211 RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf),
212 rtas_get_error_log_max());
213
214 pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf,
215 PSERIES_ELOG_SECT_ID_HOTPLUG);
216 hp_elog = (struct pseries_hp_errorlog *)pseries_log->data;
217
218 /*
219 * Since PCI hotplug is not currently supported on pseries, put PCI
220 * hotplug events on the ras_log_buf to be handled by rtas_errd.
221 */
222 if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM ||
223 hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU)
224 queue_hotplug_event(hp_elog, NULL, NULL);
225 else
226 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
227
228 spin_unlock(&ras_log_buf_lock);
229 return IRQ_HANDLED;
230 }
231
232 /* Handle environmental and power warning (EPOW) interrupts. */
ras_epow_interrupt(int irq,void * dev_id)233 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
234 {
235 int status;
236 int state;
237 int critical;
238
239 status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX,
240 &state);
241
242 if (state > 3)
243 critical = 1; /* Time Critical */
244 else
245 critical = 0;
246
247 spin_lock(&ras_log_buf_lock);
248
249 status = rtas_call(ras_check_exception_token, 6, 1, NULL,
250 RTAS_VECTOR_EXTERNAL_INTERRUPT,
251 virq_to_hw(irq),
252 RTAS_EPOW_WARNING,
253 critical, __pa(&ras_log_buf),
254 rtas_get_error_log_max());
255
256 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
257
258 rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
259
260 spin_unlock(&ras_log_buf_lock);
261 return IRQ_HANDLED;
262 }
263
264 /*
265 * Handle hardware error interrupts.
266 *
267 * RTAS check-exception is called to collect data on the exception. If
268 * the error is deemed recoverable, we log a warning and return.
269 * For nonrecoverable errors, an error is logged and we stop all processing
270 * as quickly as possible in order to prevent propagation of the failure.
271 */
ras_error_interrupt(int irq,void * dev_id)272 static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
273 {
274 struct rtas_error_log *rtas_elog;
275 int status;
276 int fatal;
277
278 spin_lock(&ras_log_buf_lock);
279
280 status = rtas_call(ras_check_exception_token, 6, 1, NULL,
281 RTAS_VECTOR_EXTERNAL_INTERRUPT,
282 virq_to_hw(irq),
283 RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
284 __pa(&ras_log_buf),
285 rtas_get_error_log_max());
286
287 rtas_elog = (struct rtas_error_log *)ras_log_buf;
288
289 if (status == 0 &&
290 rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
291 fatal = 1;
292 else
293 fatal = 0;
294
295 /* format and print the extended information */
296 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
297
298 if (fatal) {
299 pr_emerg("Fatal hardware error detected. Check RTAS error"
300 " log for details. Powering off immediately\n");
301 emergency_sync();
302 kernel_power_off();
303 } else {
304 pr_err("Recoverable hardware error detected\n");
305 }
306
307 spin_unlock(&ras_log_buf_lock);
308 return IRQ_HANDLED;
309 }
310
311 /*
312 * Some versions of FWNMI place the buffer inside the 4kB page starting at
313 * 0x7000. Other versions place it inside the rtas buffer. We check both.
314 */
315 #define VALID_FWNMI_BUFFER(A) \
316 ((((A) >= 0x7000) && ((A) < 0x7ff0)) || \
317 (((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16))))
318
319 /*
320 * Get the error information for errors coming through the
321 * FWNMI vectors. The pt_regs' r3 will be updated to reflect
322 * the actual r3 if possible, and a ptr to the error log entry
323 * will be returned if found.
324 *
325 * If the RTAS error is not of the extended type, then we put it in a per
326 * cpu 64bit buffer. If it is the extended type we use global_mce_data_buf.
327 *
328 * The global_mce_data_buf does not have any locks or protection around it,
329 * if a second machine check comes in, or a system reset is done
330 * before we have logged the error, then we will get corruption in the
331 * error log. This is preferable over holding off on calling
332 * ibm,nmi-interlock which would result in us checkstopping if a
333 * second machine check did come in.
334 */
fwnmi_get_errinfo(struct pt_regs * regs)335 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
336 {
337 unsigned long *savep;
338 struct rtas_error_log *h, *errhdr = NULL;
339
340 /* Mask top two bits */
341 regs->gpr[3] &= ~(0x3UL << 62);
342
343 if (!VALID_FWNMI_BUFFER(regs->gpr[3])) {
344 printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
345 return NULL;
346 }
347
348 savep = __va(regs->gpr[3]);
349 regs->gpr[3] = savep[0]; /* restore original r3 */
350
351 /* If it isn't an extended log we can use the per cpu 64bit buffer */
352 h = (struct rtas_error_log *)&savep[1];
353 if (!rtas_error_extended(h)) {
354 memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64));
355 errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf);
356 } else {
357 int len, error_log_length;
358
359 error_log_length = 8 + rtas_error_extended_log_length(h);
360 len = max_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
361 memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
362 memcpy(global_mce_data_buf, h, len);
363 errhdr = (struct rtas_error_log *)global_mce_data_buf;
364 }
365
366 return errhdr;
367 }
368
369 /* Call this when done with the data returned by FWNMI_get_errinfo.
370 * It will release the saved data area for other CPUs in the
371 * partition to receive FWNMI errors.
372 */
fwnmi_release_errinfo(void)373 static void fwnmi_release_errinfo(void)
374 {
375 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL);
376 if (ret != 0)
377 printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
378 }
379
pSeries_system_reset_exception(struct pt_regs * regs)380 int pSeries_system_reset_exception(struct pt_regs *regs)
381 {
382 if (fwnmi_active) {
383 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs);
384 if (errhdr) {
385 /* XXX Should look at FWNMI information */
386 }
387 fwnmi_release_errinfo();
388 }
389 return 0; /* need to perform reset */
390 }
391
392 /*
393 * See if we can recover from a machine check exception.
394 * This is only called on power4 (or above) and only via
395 * the Firmware Non-Maskable Interrupts (fwnmi) handler
396 * which provides the error analysis for us.
397 *
398 * Return 1 if corrected (or delivered a signal).
399 * Return 0 if there is nothing we can do.
400 */
recover_mce(struct pt_regs * regs,struct rtas_error_log * err)401 static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err)
402 {
403 int recovered = 0;
404 int disposition = rtas_error_disposition(err);
405
406 if (!(regs->msr & MSR_RI)) {
407 /* If MSR_RI isn't set, we cannot recover */
408 recovered = 0;
409
410 } else if (disposition == RTAS_DISP_FULLY_RECOVERED) {
411 /* Platform corrected itself */
412 recovered = 1;
413
414 } else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
415 /* Platform corrected itself but could be degraded */
416 printk(KERN_ERR "MCE: limited recovery, system may "
417 "be degraded\n");
418 recovered = 1;
419
420 } else if (user_mode(regs) && !is_global_init(current) &&
421 rtas_error_severity(err) == RTAS_SEVERITY_ERROR_SYNC) {
422
423 /*
424 * If we received a synchronous error when in userspace
425 * kill the task. Firmware may report details of the fail
426 * asynchronously, so we can't rely on the target and type
427 * fields being valid here.
428 */
429 printk(KERN_ERR "MCE: uncorrectable error, killing task "
430 "%s:%d\n", current->comm, current->pid);
431
432 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
433 recovered = 1;
434 }
435
436 log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
437
438 return recovered;
439 }
440
441 /*
442 * Handle a machine check.
443 *
444 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
445 * should be present. If so the handler which called us tells us if the
446 * error was recovered (never true if RI=0).
447 *
448 * On hardware prior to Power 4 these exceptions were asynchronous which
449 * means we can't tell exactly where it occurred and so we can't recover.
450 */
pSeries_machine_check_exception(struct pt_regs * regs)451 int pSeries_machine_check_exception(struct pt_regs *regs)
452 {
453 struct rtas_error_log *errp;
454
455 if (fwnmi_active) {
456 errp = fwnmi_get_errinfo(regs);
457 fwnmi_release_errinfo();
458 if (errp && recover_mce(regs, errp))
459 return 1;
460 }
461
462 return 0;
463 }
464