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kmemtrace: SLOB hooks.
[linux-2.6/kmemtrace.git] / drivers / s390 / s390mach.c
blob5bfbe76598303be074518a4597f83305202960a8
1 /*
2 * drivers/s390/s390mach.c
3 * S/390 machine check handler
4 *
5 * S390 version
6 * Copyright (C) 2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
7 * Author(s): Ingo Adlung (adlung@de.ibm.com)
8 * Martin Schwidefsky (schwidefsky@de.ibm.com)
9 */
10
11 #include <linux/init.h>
12 #include <linux/sched.h>
13 #include <linux/errno.h>
14 #include <linux/workqueue.h>
15 #include <linux/time.h>
16 #include <linux/device.h>
17 #include <linux/kthread.h>
18 #include <asm/etr.h>
19 #include <asm/lowcore.h>
20 #include <asm/cio.h>
21 #include "cio/cio.h"
22 #include "cio/chsc.h"
23 #include "cio/css.h"
24 #include "cio/chp.h"
25 #include "s390mach.h"
26
27 static struct semaphore m_sem;
28
29 static NORET_TYPE void
30 s390_handle_damage(char *msg)
31 {
32 #ifdef CONFIG_SMP
33 smp_send_stop();
34 #endif
35 disabled_wait((unsigned long) __builtin_return_address(0));
36 for(;;);
37 }
38
39 /*
40 * Retrieve CRWs and call function to handle event.
41 *
42 * Note : we currently process CRWs for io and chsc subchannels only
43 */
44 static int
45 s390_collect_crw_info(void *param)
46 {
47 struct crw crw[2];
48 int ccode;
49 struct semaphore *sem;
50 unsigned int chain;
51 int ignore;
52
53 sem = (struct semaphore *)param;
54 repeat:
55 ignore = down_interruptible(sem);
56 chain = 0;
57 while (1) {
58 if (unlikely(chain > 1)) {
59 struct crw tmp_crw;
60
61 printk(KERN_WARNING"%s: Code does not support more "
62 "than two chained crws; please report to "
63 "linux390@de.ibm.com!\n", __func__);
64 ccode = stcrw(&tmp_crw);
65 printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
66 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
67 __func__, tmp_crw.slct, tmp_crw.oflw,
68 tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
69 tmp_crw.erc, tmp_crw.rsid);
70 printk(KERN_WARNING"%s: This was crw number %x in the "
71 "chain\n", __func__, chain);
72 if (ccode != 0)
73 break;
74 chain = tmp_crw.chn ? chain + 1 : 0;
75 continue;
76 }
77 ccode = stcrw(&crw[chain]);
78 if (ccode != 0)
79 break;
80 printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
81 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
82 crw[chain].slct, crw[chain].oflw, crw[chain].chn,
83 crw[chain].rsc, crw[chain].anc, crw[chain].erc,
84 crw[chain].rsid);
85 /* Check for overflows. */
86 if (crw[chain].oflw) {
87 pr_debug("%s: crw overflow detected!\n", __func__);
88 css_schedule_eval_all();
89 chain = 0;
90 continue;
91 }
92 switch (crw[chain].rsc) {
93 case CRW_RSC_SCH:
94 if (crw[0].chn && !chain)
95 break;
96 pr_debug("source is subchannel %04X\n", crw[0].rsid);
97 css_process_crw(crw[0].rsid, chain ? crw[1].rsid : 0);
98 break;
99 case CRW_RSC_MONITOR:
100 pr_debug("source is monitoring facility\n");
101 break;
102 case CRW_RSC_CPATH:
103 pr_debug("source is channel path %02X\n", crw[0].rsid);
104 /*
105 * Check for solicited machine checks. These are
106 * created by reset channel path and need not be
107 * reported to the common I/O layer.
108 */
109 if (crw[chain].slct) {
110 pr_debug("solicited machine check for "
111 "channel path %02X\n", crw[0].rsid);
112 break;
113 }
114 switch (crw[0].erc) {
115 case CRW_ERC_IPARM: /* Path has come. */
116 chp_process_crw(crw[0].rsid, 1);
117 break;
118 case CRW_ERC_PERRI: /* Path has gone. */
119 case CRW_ERC_PERRN:
120 chp_process_crw(crw[0].rsid, 0);
121 break;
122 default:
123 pr_debug("Don't know how to handle erc=%x\n",
124 crw[0].erc);
125 }
126 break;
127 case CRW_RSC_CONFIG:
128 pr_debug("source is configuration-alert facility\n");
129 break;
130 case CRW_RSC_CSS:
131 pr_debug("source is channel subsystem\n");
132 chsc_process_crw();
133 break;
134 default:
135 pr_debug("unknown source\n");
136 break;
137 }
138 /* chain is always 0 or 1 here. */
139 chain = crw[chain].chn ? chain + 1 : 0;
140 }
141 goto repeat;
142 return 0;
143 }
144
145 struct mcck_struct {
146 int kill_task;
147 int channel_report;
148 int warning;
149 unsigned long long mcck_code;
150 };
151
152 static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
153
154 /*
155 * Main machine check handler function. Will be called with interrupts enabled
156 * or disabled and machine checks enabled or disabled.
157 */
158 void
159 s390_handle_mcck(void)
160 {
161 unsigned long flags;
162 struct mcck_struct mcck;
163
164 /*
165 * Disable machine checks and get the current state of accumulated
166 * machine checks. Afterwards delete the old state and enable machine
167 * checks again.
168 */
169 local_irq_save(flags);
170 local_mcck_disable();
171 mcck = __get_cpu_var(cpu_mcck);
172 memset(&__get_cpu_var(cpu_mcck), 0, sizeof(struct mcck_struct));
173 clear_thread_flag(TIF_MCCK_PENDING);
174 local_mcck_enable();
175 local_irq_restore(flags);
176
177 if (mcck.channel_report)
178 up(&m_sem);
179
180 #ifdef CONFIG_MACHCHK_WARNING
181 /*
182 * The warning may remain for a prolonged period on the bare iron.
183 * (actually till the machine is powered off, or until the problem is gone)
184 * So we just stop listening for the WARNING MCH and prevent continuously
185 * being interrupted. One caveat is however, that we must do this per
186 * processor and cannot use the smp version of ctl_clear_bit().
187 * On VM we only get one interrupt per virtally presented machinecheck.
188 * Though one suffices, we may get one interrupt per (virtual) processor.
189 */
190 if (mcck.warning) { /* WARNING pending ? */
191 static int mchchk_wng_posted = 0;
192 /*
193 * Use single machine clear, as we cannot handle smp right now
194 */
195 __ctl_clear_bit(14, 24); /* Disable WARNING MCH */
196 if (xchg(&mchchk_wng_posted, 1) == 0)
197 kill_cad_pid(SIGPWR, 1);
198 }
199 #endif
200
201 if (mcck.kill_task) {
202 local_irq_enable();
203 printk(KERN_EMERG "mcck: Terminating task because of machine "
204 "malfunction (code 0x%016llx).\n", mcck.mcck_code);
205 printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
206 current->comm, current->pid);
207 do_exit(SIGSEGV);
208 }
209 }
210 EXPORT_SYMBOL_GPL(s390_handle_mcck);
211
212 /*
213 * returns 0 if all registers could be validated
214 * returns 1 otherwise
215 */
216 static int
217 s390_revalidate_registers(struct mci *mci)
218 {
219 int kill_task;
220 u64 tmpclock;
221 u64 zero;
222 void *fpt_save_area, *fpt_creg_save_area;
223
224 kill_task = 0;
225 zero = 0;
226 /* General purpose registers */
227 if (!mci->gr)
228 /*
229 * General purpose registers couldn't be restored and have
230 * unknown contents. Process needs to be terminated.
231 */
232 kill_task = 1;
233
234 /* Revalidate floating point registers */
235 if (!mci->fp)
236 /*
237 * Floating point registers can't be restored and
238 * therefore the process needs to be terminated.
239 */
240 kill_task = 1;
241
242 #ifndef CONFIG_64BIT
243 asm volatile(
244 " ld 0,0(%0)\n"
245 " ld 2,8(%0)\n"
246 " ld 4,16(%0)\n"
247 " ld 6,24(%0)"
248 : : "a" (&S390_lowcore.floating_pt_save_area));
249 #endif
250
251 if (MACHINE_HAS_IEEE) {
252 #ifdef CONFIG_64BIT
253 fpt_save_area = &S390_lowcore.floating_pt_save_area;
254 fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
255 #else
256 fpt_save_area = (void *) S390_lowcore.extended_save_area_addr;
257 fpt_creg_save_area = fpt_save_area+128;
258 #endif
259 /* Floating point control register */
260 if (!mci->fc) {
261 /*
262 * Floating point control register can't be restored.
263 * Task will be terminated.
264 */
265 asm volatile("lfpc 0(%0)" : : "a" (&zero), "m" (zero));
266 kill_task = 1;
267
268 } else
269 asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area));
270
271 asm volatile(
272 " ld 0,0(%0)\n"
273 " ld 1,8(%0)\n"
274 " ld 2,16(%0)\n"
275 " ld 3,24(%0)\n"
276 " ld 4,32(%0)\n"
277 " ld 5,40(%0)\n"
278 " ld 6,48(%0)\n"
279 " ld 7,56(%0)\n"
280 " ld 8,64(%0)\n"
281 " ld 9,72(%0)\n"
282 " ld 10,80(%0)\n"
283 " ld 11,88(%0)\n"
284 " ld 12,96(%0)\n"
285 " ld 13,104(%0)\n"
286 " ld 14,112(%0)\n"
287 " ld 15,120(%0)\n"
288 : : "a" (fpt_save_area));
289 }
290
291 /* Revalidate access registers */
292 asm volatile(
293 " lam 0,15,0(%0)"
294 : : "a" (&S390_lowcore.access_regs_save_area));
295 if (!mci->ar)
296 /*
297 * Access registers have unknown contents.
298 * Terminating task.
299 */
300 kill_task = 1;
301
302 /* Revalidate control registers */
303 if (!mci->cr)
304 /*
305 * Control registers have unknown contents.
306 * Can't recover and therefore stopping machine.
307 */
308 s390_handle_damage("invalid control registers.");
309 else
310 #ifdef CONFIG_64BIT
311 asm volatile(
312 " lctlg 0,15,0(%0)"
313 : : "a" (&S390_lowcore.cregs_save_area));
314 #else
315 asm volatile(
316 " lctl 0,15,0(%0)"
317 : : "a" (&S390_lowcore.cregs_save_area));
318 #endif
319
320 /*
321 * We don't even try to revalidate the TOD register, since we simply
322 * can't write something sensible into that register.
323 */
324
325 #ifdef CONFIG_64BIT
326 /*
327 * See if we can revalidate the TOD programmable register with its
328 * old contents (should be zero) otherwise set it to zero.
329 */
330 if (!mci->pr)
331 asm volatile(
332 " sr 0,0\n"
333 " sckpf"
334 : : : "0", "cc");
335 else
336 asm volatile(
337 " l 0,0(%0)\n"
338 " sckpf"
339 : : "a" (&S390_lowcore.tod_progreg_save_area)
340 : "0", "cc");
341 #endif
342
343 /* Revalidate clock comparator register */
344 asm volatile(
345 " stck 0(%1)\n"
346 " sckc 0(%1)"
347 : "=m" (tmpclock) : "a" (&(tmpclock)) : "cc", "memory");
348
349 /* Check if old PSW is valid */
350 if (!mci->wp)
351 /*
352 * Can't tell if we come from user or kernel mode
353 * -> stopping machine.
354 */
355 s390_handle_damage("old psw invalid.");
356
357 if (!mci->ms || !mci->pm || !mci->ia)
358 kill_task = 1;
359
360 return kill_task;
361 }
362
363 #define MAX_IPD_COUNT 29
364 #define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
365
366 /*
367 * machine check handler.
368 */
369 void
370 s390_do_machine_check(struct pt_regs *regs)
371 {
372 static DEFINE_SPINLOCK(ipd_lock);
373 static unsigned long long last_ipd;
374 static int ipd_count;
375 unsigned long long tmp;
376 struct mci *mci;
377 struct mcck_struct *mcck;
378 int umode;
379
380 lockdep_off();
381
382 mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
383 mcck = &__get_cpu_var(cpu_mcck);
384 umode = user_mode(regs);
385
386 if (mci->sd)
387 /* System damage -> stopping machine */
388 s390_handle_damage("received system damage machine check.");
389
390 if (mci->pd) {
391 if (mci->b) {
392 /* Processing backup -> verify if we can survive this */
393 u64 z_mcic, o_mcic, t_mcic;
394 #ifdef CONFIG_64BIT
395 z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
396 o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
397 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
398 1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
399 1ULL<<16);
400 #else
401 z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<57 | 1ULL<<50 |
402 1ULL<<29);
403 o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
404 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
405 1ULL<<30 | 1ULL<<20 | 1ULL<<17 | 1ULL<<16);
406 #endif
407 t_mcic = *(u64 *)mci;
408
409 if (((t_mcic & z_mcic) != 0) ||
410 ((t_mcic & o_mcic) != o_mcic)) {
411 s390_handle_damage("processing backup machine "
412 "check with damage.");
413 }
414
415 /*
416 * Nullifying exigent condition, therefore we might
417 * retry this instruction.
418 */
419
420 spin_lock(&ipd_lock);
421
422 tmp = get_clock();
423
424 if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
425 ipd_count++;
426 else
427 ipd_count = 1;
428
429 last_ipd = tmp;
430
431 if (ipd_count == MAX_IPD_COUNT)
432 s390_handle_damage("too many ipd retries.");
433
434 spin_unlock(&ipd_lock);
435 }
436 else {
437 /* Processing damage -> stopping machine */
438 s390_handle_damage("received instruction processing "
439 "damage machine check.");
440 }
441 }
442 if (s390_revalidate_registers(mci)) {
443 if (umode) {
444 /*
445 * Couldn't restore all register contents while in
446 * user mode -> mark task for termination.
447 */
448 mcck->kill_task = 1;
449 mcck->mcck_code = *(unsigned long long *) mci;
450 set_thread_flag(TIF_MCCK_PENDING);
451 }
452 else
453 /*
454 * Couldn't restore all register contents while in
455 * kernel mode -> stopping machine.
456 */
457 s390_handle_damage("unable to revalidate registers.");
458 }
459
460 if (mci->cd) {
461 /* Timing facility damage */
462 s390_handle_damage("TOD clock damaged");
463 }
464
465 if (mci->ed && mci->ec) {
466 /* External damage */
467 if (S390_lowcore.external_damage_code & (1U << ED_ETR_SYNC))
468 etr_sync_check();
469 if (S390_lowcore.external_damage_code & (1U << ED_ETR_SWITCH))
470 etr_switch_to_local();
471 }
472
473 if (mci->se)
474 /* Storage error uncorrected */
475 s390_handle_damage("received storage error uncorrected "
476 "machine check.");
477
478 if (mci->ke)
479 /* Storage key-error uncorrected */
480 s390_handle_damage("received storage key-error uncorrected "
481 "machine check.");
482
483 if (mci->ds && mci->fa)
484 /* Storage degradation */
485 s390_handle_damage("received storage degradation machine "
486 "check.");
487
488 if (mci->cp) {
489 /* Channel report word pending */
490 mcck->channel_report = 1;
491 set_thread_flag(TIF_MCCK_PENDING);
492 }
493
494 if (mci->w) {
495 /* Warning pending */
496 mcck->warning = 1;
497 set_thread_flag(TIF_MCCK_PENDING);
498 }
499 lockdep_on();
500 }
501
502 /*
503 * s390_init_machine_check
504 *
505 * initialize machine check handling
506 */
507 static int
508 machine_check_init(void)
509 {
510 init_MUTEX_LOCKED(&m_sem);
511 ctl_set_bit(14, 25); /* enable external damage MCH */
512 ctl_set_bit(14, 27); /* enable system recovery MCH */
513 #ifdef CONFIG_MACHCHK_WARNING
514 ctl_set_bit(14, 24); /* enable warning MCH */
515 #endif
516 return 0;
517 }
518
519 /*
520 * Initialize the machine check handler really early to be able to
521 * catch all machine checks that happen during boot
522 */
523 arch_initcall(machine_check_init);
524
525 /*
526 * Machine checks for the channel subsystem must be enabled
527 * after the channel subsystem is initialized
528 */
529 static int __init
530 machine_check_crw_init (void)
531 {
532 struct task_struct *task;
533
534 task = kthread_run(s390_collect_crw_info, &m_sem, "kmcheck");
535 if (IS_ERR(task))
536 return PTR_ERR(task);
537 ctl_set_bit(14, 28); /* enable channel report MCH */
538 return 0;
539 }
540
541 device_initcall (machine_check_crw_init);
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