summaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/pseries/ras.c
blob: 3b6647e574b6d0f3fbabd7780f176fbcfef7f4f5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
/*
 * Copyright (C) 2001 Dave Engebretsen IBM Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/fs.h>
#include <linux/reboot.h>

#include <asm/machdep.h>
#include <asm/rtas.h>
#include <asm/firmware.h>

#include "pseries.h"

static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
static DEFINE_SPINLOCK(ras_log_buf_lock);

static char global_mce_data_buf[RTAS_ERROR_LOG_MAX];
static DEFINE_PER_CPU(__u64, mce_data_buf);

static int ras_check_exception_token;

#define EPOW_SENSOR_TOKEN	9
#define EPOW_SENSOR_INDEX	0

static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
static irqreturn_t ras_error_interrupt(int irq, void *dev_id);


/*
 * Initialize handlers for the set of interrupts caused by hardware errors
 * and power system events.
 */
static int __init init_ras_IRQ(void)
{
	struct device_node *np;

	ras_check_exception_token = rtas_token("check-exception");

	/* Internal Errors */
	np = of_find_node_by_path("/event-sources/internal-errors");
	if (np != NULL) {
		request_event_sources_irqs(np, ras_error_interrupt,
					   "RAS_ERROR");
		of_node_put(np);
	}

	/* EPOW Events */
	np = of_find_node_by_path("/event-sources/epow-events");
	if (np != NULL) {
		request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
		of_node_put(np);
	}

	return 0;
}
machine_subsys_initcall(pseries, init_ras_IRQ);

#define EPOW_SHUTDOWN_NORMAL				1
#define EPOW_SHUTDOWN_ON_UPS				2
#define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS	3
#define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH	4

static void handle_system_shutdown(char event_modifier)
{
	switch (event_modifier) {
	case EPOW_SHUTDOWN_NORMAL:
		pr_emerg("Firmware initiated power off");
		orderly_poweroff(true);
		break;

	case EPOW_SHUTDOWN_ON_UPS:
		pr_emerg("Loss of power reported by firmware, system is "
			"running on UPS/battery");
		pr_emerg("Check RTAS error log for details");
		orderly_poweroff(true);
		break;

	case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
		pr_emerg("Loss of system critical functions reported by "
			"firmware");
		pr_emerg("Check RTAS error log for details");
		orderly_poweroff(true);
		break;

	case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
		pr_emerg("Ambient temperature too high reported by firmware");
		pr_emerg("Check RTAS error log for details");
		orderly_poweroff(true);
		break;

	default:
		pr_err("Unknown power/cooling shutdown event (modifier %d)",
			event_modifier);
	}
}

struct epow_errorlog {
	unsigned char sensor_value;
	unsigned char event_modifier;
	unsigned char extended_modifier;
	unsigned char reserved;
	unsigned char platform_reason;
};

#define EPOW_RESET			0
#define EPOW_WARN_COOLING		1
#define EPOW_WARN_POWER			2
#define EPOW_SYSTEM_SHUTDOWN		3
#define EPOW_SYSTEM_HALT		4
#define EPOW_MAIN_ENCLOSURE		5
#define EPOW_POWER_OFF			7

static void rtas_parse_epow_errlog(struct rtas_error_log *log)
{
	struct pseries_errorlog *pseries_log;
	struct epow_errorlog *epow_log;
	char action_code;
	char modifier;

	pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
	if (pseries_log == NULL)
		return;

	epow_log = (struct epow_errorlog *)pseries_log->data;
	action_code = epow_log->sensor_value & 0xF;	/* bottom 4 bits */
	modifier = epow_log->event_modifier & 0xF;	/* bottom 4 bits */

	switch (action_code) {
	case EPOW_RESET:
		pr_err("Non critical power or cooling issue cleared");
		break;

	case EPOW_WARN_COOLING:
		pr_err("Non critical cooling issue reported by firmware");
		pr_err("Check RTAS error log for details");
		break;

	case EPOW_WARN_POWER:
		pr_err("Non critical power issue reported by firmware");
		pr_err("Check RTAS error log for details");
		break;

	case EPOW_SYSTEM_SHUTDOWN:
		handle_system_shutdown(epow_log->event_modifier);
		break;

	case EPOW_SYSTEM_HALT:
		pr_emerg("Firmware initiated power off");
		orderly_poweroff(true);
		break;

	case EPOW_MAIN_ENCLOSURE:
	case EPOW_POWER_OFF:
		pr_emerg("Critical power/cooling issue reported by firmware");
		pr_emerg("Check RTAS error log for details");
		pr_emerg("Immediate power off");
		emergency_sync();
		kernel_power_off();
		break;

	default:
		pr_err("Unknown power/cooling event (action code %d)",
			action_code);
	}
}

/* Handle environmental and power warning (EPOW) interrupts. */
static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
{
	int status;
	int state;
	int critical;

	status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX,
				      &state);

	if (state > 3)
		critical = 1;		/* Time Critical */
	else
		critical = 0;

	spin_lock(&ras_log_buf_lock);

	status = rtas_call(ras_check_exception_token, 6, 1, NULL,
			   RTAS_VECTOR_EXTERNAL_INTERRUPT,
			   virq_to_hw(irq),
			   RTAS_EPOW_WARNING,
			   critical, __pa(&ras_log_buf),
				rtas_get_error_log_max());

	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);

	rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);

	spin_unlock(&ras_log_buf_lock);
	return IRQ_HANDLED;
}

/*
 * Handle hardware error interrupts.
 *
 * RTAS check-exception is called to collect data on the exception.  If
 * the error is deemed recoverable, we log a warning and return.
 * For nonrecoverable errors, an error is logged and we stop all processing
 * as quickly as possible in order to prevent propagation of the failure.
 */
static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
{
	struct rtas_error_log *rtas_elog;
	int status;
	int fatal;

	spin_lock(&ras_log_buf_lock);

	status = rtas_call(ras_check_exception_token, 6, 1, NULL,
			   RTAS_VECTOR_EXTERNAL_INTERRUPT,
			   virq_to_hw(irq),
			   RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
			   __pa(&ras_log_buf),
				rtas_get_error_log_max());

	rtas_elog = (struct rtas_error_log *)ras_log_buf;

	if (status == 0 &&
	    rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
		fatal = 1;
	else
		fatal = 0;

	/* format and print the extended information */
	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);

	if (fatal) {
		pr_emerg("Fatal hardware error reported by firmware");
		pr_emerg("Check RTAS error log for details");
		pr_emerg("Immediate power off");
		emergency_sync();
		kernel_power_off();
	} else {
		pr_err("Recoverable hardware error reported by firmware");
	}

	spin_unlock(&ras_log_buf_lock);
	return IRQ_HANDLED;
}

/*
 * Some versions of FWNMI place the buffer inside the 4kB page starting at
 * 0x7000. Other versions place it inside the rtas buffer. We check both.
 */
#define VALID_FWNMI_BUFFER(A) \
	((((A) >= 0x7000) && ((A) < 0x7ff0)) || \
	(((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16))))

/*
 * Get the error information for errors coming through the
 * FWNMI vectors.  The pt_regs' r3 will be updated to reflect
 * the actual r3 if possible, and a ptr to the error log entry
 * will be returned if found.
 *
 * If the RTAS error is not of the extended type, then we put it in a per
 * cpu 64bit buffer. If it is the extended type we use global_mce_data_buf.
 *
 * The global_mce_data_buf does not have any locks or protection around it,
 * if a second machine check comes in, or a system reset is done
 * before we have logged the error, then we will get corruption in the
 * error log.  This is preferable over holding off on calling
 * ibm,nmi-interlock which would result in us checkstopping if a
 * second machine check did come in.
 */
static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
{
	unsigned long *savep;
	struct rtas_error_log *h, *errhdr = NULL;

	/* Mask top two bits */
	regs->gpr[3] &= ~(0x3UL << 62);

	if (!VALID_FWNMI_BUFFER(regs->gpr[3])) {
		printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
		return NULL;
	}

	savep = __va(regs->gpr[3]);
	regs->gpr[3] = savep[0];	/* restore original r3 */

	/* If it isn't an extended log we can use the per cpu 64bit buffer */
	h = (struct rtas_error_log *)&savep[1];
	if (!rtas_error_extended(h)) {
		memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64));
		errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf);
	} else {
		int len, error_log_length;

		error_log_length = 8 + rtas_error_extended_log_length(h);
		len = max_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
		memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
		memcpy(global_mce_data_buf, h, len);
		errhdr = (struct rtas_error_log *)global_mce_data_buf;
	}

	return errhdr;
}

/* Call this when done with the data returned by FWNMI_get_errinfo.
 * It will release the saved data area for other CPUs in the
 * partition to receive FWNMI errors.
 */
static void fwnmi_release_errinfo(void)
{
	int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL);
	if (ret != 0)
		printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
}

int pSeries_system_reset_exception(struct pt_regs *regs)
{
	if (fwnmi_active) {
		struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs);
		if (errhdr) {
			/* XXX Should look at FWNMI information */
		}
		fwnmi_release_errinfo();
	}
	return 0; /* need to perform reset */
}

/*
 * See if we can recover from a machine check exception.
 * This is only called on power4 (or above) and only via
 * the Firmware Non-Maskable Interrupts (fwnmi) handler
 * which provides the error analysis for us.
 *
 * Return 1 if corrected (or delivered a signal).
 * Return 0 if there is nothing we can do.
 */
static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err)
{
	int recovered = 0;
	int disposition = rtas_error_disposition(err);

	if (!(regs->msr & MSR_RI)) {
		/* If MSR_RI isn't set, we cannot recover */
		recovered = 0;

	} else if (disposition == RTAS_DISP_FULLY_RECOVERED) {
		/* Platform corrected itself */
		recovered = 1;

	} else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
		/* Platform corrected itself but could be degraded */
		printk(KERN_ERR "MCE: limited recovery, system may "
		       "be degraded\n");
		recovered = 1;

	} else if (user_mode(regs) && !is_global_init(current) &&
		   rtas_error_severity(err) == RTAS_SEVERITY_ERROR_SYNC) {

		/*
		 * If we received a synchronous error when in userspace
		 * kill the task. Firmware may report details of the fail
		 * asynchronously, so we can't rely on the target and type
		 * fields being valid here.
		 */
		printk(KERN_ERR "MCE: uncorrectable error, killing task "
		       "%s:%d\n", current->comm, current->pid);

		_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
		recovered = 1;
	}

	log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);

	return recovered;
}

/*
 * Handle a machine check.
 *
 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
 * should be present.  If so the handler which called us tells us if the
 * error was recovered (never true if RI=0).
 *
 * On hardware prior to Power 4 these exceptions were asynchronous which
 * means we can't tell exactly where it occurred and so we can't recover.
 */
int pSeries_machine_check_exception(struct pt_regs *regs)
{
	struct rtas_error_log *errp;

	if (fwnmi_active) {
		errp = fwnmi_get_errinfo(regs);
		fwnmi_release_errinfo();
		if (errp && recover_mce(regs, errp))
			return 1;
	}

	return 0;
}