2 * drivers/s390/s390mach.c
3 * S/390 machine check handler
5 * Copyright IBM Corp. 2000,2008
6 * Author(s): Ingo Adlung (adlung@de.ibm.com)
7 * Martin Schwidefsky (schwidefsky@de.ibm.com)
8 * Cornelia Huck <cornelia.huck@de.ibm.com>
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>
19 #include <asm/lowcore.h>
24 static struct semaphore m_sem
;
26 static NORET_TYPE
void
27 s390_handle_damage(char *msg
)
32 disabled_wait((unsigned long) __builtin_return_address(0));
36 static crw_handler_t crw_handlers
[NR_RSCS
];
39 * s390_register_crw_handler() - register a channel report word handler
40 * @rsc: reporting source code to handle
41 * @handler: handler to be registered
43 * Returns %0 on success and a negative error value otherwise.
45 int s390_register_crw_handler(int rsc
, crw_handler_t handler
)
47 if ((rsc
< 0) || (rsc
>= NR_RSCS
))
49 if (!cmpxchg(&crw_handlers
[rsc
], NULL
, handler
))
55 * s390_unregister_crw_handler() - unregister a channel report word handler
56 * @rsc: reporting source code to handle
58 void s390_unregister_crw_handler(int rsc
)
60 if ((rsc
< 0) || (rsc
>= NR_RSCS
))
62 xchg(&crw_handlers
[rsc
], NULL
);
67 * Retrieve CRWs and call function to handle event.
69 static int s390_collect_crw_info(void *param
)
73 struct semaphore
*sem
;
77 sem
= (struct semaphore
*)param
;
79 ignore
= down_interruptible(sem
);
82 if (unlikely(chain
> 1)) {
85 printk(KERN_WARNING
"%s: Code does not support more "
86 "than two chained crws; please report to "
87 "linux390@de.ibm.com!\n", __func__
);
88 ccode
= stcrw(&tmp_crw
);
89 printk(KERN_WARNING
"%s: crw reports slct=%d, oflw=%d, "
90 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
91 __func__
, tmp_crw
.slct
, tmp_crw
.oflw
,
92 tmp_crw
.chn
, tmp_crw
.rsc
, tmp_crw
.anc
,
93 tmp_crw
.erc
, tmp_crw
.rsid
);
94 printk(KERN_WARNING
"%s: This was crw number %x in the "
95 "chain\n", __func__
, chain
);
98 chain
= tmp_crw
.chn
? chain
+ 1 : 0;
101 ccode
= stcrw(&crw
[chain
]);
104 printk(KERN_DEBUG
"crw_info : CRW reports slct=%d, oflw=%d, "
105 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
106 crw
[chain
].slct
, crw
[chain
].oflw
, crw
[chain
].chn
,
107 crw
[chain
].rsc
, crw
[chain
].anc
, crw
[chain
].erc
,
109 /* Check for overflows. */
110 if (crw
[chain
].oflw
) {
113 pr_debug("%s: crw overflow detected!\n", __func__
);
114 for (i
= 0; i
< NR_RSCS
; i
++) {
116 crw_handlers
[i
](NULL
, NULL
, 1);
121 if (crw
[0].chn
&& !chain
) {
125 if (crw_handlers
[crw
[chain
].rsc
])
126 crw_handlers
[crw
[chain
].rsc
](&crw
[0],
127 chain
? &crw
[1] : NULL
,
129 /* chain is always 0 or 1 here. */
130 chain
= crw
[chain
].chn
? chain
+ 1 : 0;
140 unsigned long long mcck_code
;
143 static DEFINE_PER_CPU(struct mcck_struct
, cpu_mcck
);
146 * Main machine check handler function. Will be called with interrupts enabled
147 * or disabled and machine checks enabled or disabled.
150 s390_handle_mcck(void)
153 struct mcck_struct mcck
;
156 * Disable machine checks and get the current state of accumulated
157 * machine checks. Afterwards delete the old state and enable machine
160 local_irq_save(flags
);
161 local_mcck_disable();
162 mcck
= __get_cpu_var(cpu_mcck
);
163 memset(&__get_cpu_var(cpu_mcck
), 0, sizeof(struct mcck_struct
));
164 clear_thread_flag(TIF_MCCK_PENDING
);
166 local_irq_restore(flags
);
168 if (mcck
.channel_report
)
171 #ifdef CONFIG_MACHCHK_WARNING
173 * The warning may remain for a prolonged period on the bare iron.
174 * (actually till the machine is powered off, or until the problem is gone)
175 * So we just stop listening for the WARNING MCH and prevent continuously
176 * being interrupted. One caveat is however, that we must do this per
177 * processor and cannot use the smp version of ctl_clear_bit().
178 * On VM we only get one interrupt per virtally presented machinecheck.
179 * Though one suffices, we may get one interrupt per (virtual) processor.
181 if (mcck
.warning
) { /* WARNING pending ? */
182 static int mchchk_wng_posted
= 0;
184 * Use single machine clear, as we cannot handle smp right now
186 __ctl_clear_bit(14, 24); /* Disable WARNING MCH */
187 if (xchg(&mchchk_wng_posted
, 1) == 0)
188 kill_cad_pid(SIGPWR
, 1);
192 if (mcck
.kill_task
) {
194 printk(KERN_EMERG
"mcck: Terminating task because of machine "
195 "malfunction (code 0x%016llx).\n", mcck
.mcck_code
);
196 printk(KERN_EMERG
"mcck: task: %s, pid: %d.\n",
197 current
->comm
, current
->pid
);
201 EXPORT_SYMBOL_GPL(s390_handle_mcck
);
204 * returns 0 if all registers could be validated
205 * returns 1 otherwise
208 s390_revalidate_registers(struct mci
*mci
)
213 void *fpt_save_area
, *fpt_creg_save_area
;
217 /* General purpose registers */
220 * General purpose registers couldn't be restored and have
221 * unknown contents. Process needs to be terminated.
225 /* Revalidate floating point registers */
228 * Floating point registers can't be restored and
229 * therefore the process needs to be terminated.
239 : : "a" (&S390_lowcore
.floating_pt_save_area
));
242 if (MACHINE_HAS_IEEE
) {
244 fpt_save_area
= &S390_lowcore
.floating_pt_save_area
;
245 fpt_creg_save_area
= &S390_lowcore
.fpt_creg_save_area
;
247 fpt_save_area
= (void *) S390_lowcore
.extended_save_area_addr
;
248 fpt_creg_save_area
= fpt_save_area
+128;
250 /* Floating point control register */
253 * Floating point control register can't be restored.
254 * Task will be terminated.
256 asm volatile("lfpc 0(%0)" : : "a" (&zero
), "m" (zero
));
260 asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area
));
279 : : "a" (fpt_save_area
));
282 /* Revalidate access registers */
285 : : "a" (&S390_lowcore
.access_regs_save_area
));
288 * Access registers have unknown contents.
293 /* Revalidate control registers */
296 * Control registers have unknown contents.
297 * Can't recover and therefore stopping machine.
299 s390_handle_damage("invalid control registers.");
304 : : "a" (&S390_lowcore
.cregs_save_area
));
308 : : "a" (&S390_lowcore
.cregs_save_area
));
312 * We don't even try to revalidate the TOD register, since we simply
313 * can't write something sensible into that register.
318 * See if we can revalidate the TOD programmable register with its
319 * old contents (should be zero) otherwise set it to zero.
330 : : "a" (&S390_lowcore
.tod_progreg_save_area
)
334 /* Revalidate clock comparator register */
338 : "=m" (tmpclock
) : "a" (&(tmpclock
)) : "cc", "memory");
340 /* Check if old PSW is valid */
343 * Can't tell if we come from user or kernel mode
344 * -> stopping machine.
346 s390_handle_damage("old psw invalid.");
348 if (!mci
->ms
|| !mci
->pm
|| !mci
->ia
)
354 #define MAX_IPD_COUNT 29
355 #define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
358 * machine check handler.
360 void notrace
s390_do_machine_check(struct pt_regs
*regs
)
362 static DEFINE_SPINLOCK(ipd_lock
);
363 static unsigned long long last_ipd
;
364 static int ipd_count
;
365 unsigned long long tmp
;
367 struct mcck_struct
*mcck
;
374 mci
= (struct mci
*) &S390_lowcore
.mcck_interruption_code
;
375 mcck
= &__get_cpu_var(cpu_mcck
);
376 umode
= user_mode(regs
);
379 /* System damage -> stopping machine */
380 s390_handle_damage("received system damage machine check.");
384 /* Processing backup -> verify if we can survive this */
385 u64 z_mcic
, o_mcic
, t_mcic
;
387 z_mcic
= (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
388 o_mcic
= (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
389 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
390 1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
393 z_mcic
= (1ULL<<63 | 1ULL<<59 | 1ULL<<57 | 1ULL<<50 |
395 o_mcic
= (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
396 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
397 1ULL<<30 | 1ULL<<20 | 1ULL<<17 | 1ULL<<16);
399 t_mcic
= *(u64
*)mci
;
401 if (((t_mcic
& z_mcic
) != 0) ||
402 ((t_mcic
& o_mcic
) != o_mcic
)) {
403 s390_handle_damage("processing backup machine "
404 "check with damage.");
408 * Nullifying exigent condition, therefore we might
409 * retry this instruction.
412 spin_lock(&ipd_lock
);
416 if (((tmp
- last_ipd
) >> 12) < MAX_IPD_TIME
)
423 if (ipd_count
== MAX_IPD_COUNT
)
424 s390_handle_damage("too many ipd retries.");
426 spin_unlock(&ipd_lock
);
429 /* Processing damage -> stopping machine */
430 s390_handle_damage("received instruction processing "
431 "damage machine check.");
434 if (s390_revalidate_registers(mci
)) {
437 * Couldn't restore all register contents while in
438 * user mode -> mark task for termination.
441 mcck
->mcck_code
= *(unsigned long long *) mci
;
442 set_thread_flag(TIF_MCCK_PENDING
);
446 * Couldn't restore all register contents while in
447 * kernel mode -> stopping machine.
449 s390_handle_damage("unable to revalidate registers.");
453 /* Timing facility damage */
454 s390_handle_damage("TOD clock damaged");
457 if (mci
->ed
&& mci
->ec
) {
458 /* External damage */
459 if (S390_lowcore
.external_damage_code
& (1U << ED_ETR_SYNC
))
461 if (S390_lowcore
.external_damage_code
& (1U << ED_ETR_SWITCH
))
462 etr_switch_to_local();
463 if (S390_lowcore
.external_damage_code
& (1U << ED_STP_SYNC
))
465 if (S390_lowcore
.external_damage_code
& (1U << ED_STP_ISLAND
))
470 /* Storage error uncorrected */
471 s390_handle_damage("received storage error uncorrected "
475 /* Storage key-error uncorrected */
476 s390_handle_damage("received storage key-error uncorrected "
479 if (mci
->ds
&& mci
->fa
)
480 /* Storage degradation */
481 s390_handle_damage("received storage degradation machine "
485 /* Channel report word pending */
486 mcck
->channel_report
= 1;
487 set_thread_flag(TIF_MCCK_PENDING
);
491 /* Warning pending */
493 set_thread_flag(TIF_MCCK_PENDING
);
499 * s390_init_machine_check
501 * initialize machine check handling
504 machine_check_init(void)
506 init_MUTEX_LOCKED(&m_sem
);
507 ctl_set_bit(14, 25); /* enable external damage MCH */
508 ctl_set_bit(14, 27); /* enable system recovery MCH */
509 #ifdef CONFIG_MACHCHK_WARNING
510 ctl_set_bit(14, 24); /* enable warning MCH */
516 * Initialize the machine check handler really early to be able to
517 * catch all machine checks that happen during boot
519 arch_initcall(machine_check_init
);
522 * Machine checks for the channel subsystem must be enabled
523 * after the channel subsystem is initialized
526 machine_check_crw_init (void)
528 struct task_struct
*task
;
530 task
= kthread_run(s390_collect_crw_info
, &m_sem
, "kmcheck");
532 return PTR_ERR(task
);
533 ctl_set_bit(14, 28); /* enable channel report MCH */
537 device_initcall (machine_check_crw_init
);