2 * Machine check handler
4 * Copyright IBM Corp. 2000,2009
5 * Author(s): Ingo Adlung <adlung@de.ibm.com>,
6 * Martin Schwidefsky <schwidefsky@de.ibm.com>,
7 * Cornelia Huck <cornelia.huck@de.ibm.com>,
8 * Heiko Carstens <heiko.carstens@de.ibm.com>,
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/hardirq.h>
14 #include <linux/time.h>
15 #include <linux/module.h>
16 #include <asm/lowcore.h>
19 #include <asm/cputime.h>
27 unsigned long long mcck_code
;
30 static DEFINE_PER_CPU(struct mcck_struct
, cpu_mcck
);
32 static NORET_TYPE
void s390_handle_damage(char *msg
)
35 disabled_wait((unsigned long) __builtin_return_address(0));
40 * Main machine check handler function. Will be called with interrupts enabled
41 * or disabled and machine checks enabled or disabled.
43 void s390_handle_mcck(void)
46 struct mcck_struct mcck
;
49 * Disable machine checks and get the current state of accumulated
50 * machine checks. Afterwards delete the old state and enable machine
53 local_irq_save(flags
);
55 mcck
= __get_cpu_var(cpu_mcck
);
56 memset(&__get_cpu_var(cpu_mcck
), 0, sizeof(struct mcck_struct
));
57 clear_thread_flag(TIF_MCCK_PENDING
);
59 local_irq_restore(flags
);
61 if (mcck
.channel_report
)
62 crw_handle_channel_report();
64 * A warning may remain for a prolonged period on the bare iron.
65 * (actually until the machine is powered off, or the problem is gone)
66 * So we just stop listening for the WARNING MCH and avoid continuously
67 * being interrupted. One caveat is however, that we must do this per
68 * processor and cannot use the smp version of ctl_clear_bit().
69 * On VM we only get one interrupt per virtally presented machinecheck.
70 * Though one suffices, we may get one interrupt per (virtual) cpu.
72 if (mcck
.warning
) { /* WARNING pending ? */
73 static int mchchk_wng_posted
= 0;
75 /* Use single cpu clear, as we cannot handle smp here. */
76 __ctl_clear_bit(14, 24); /* Disable WARNING MCH */
77 if (xchg(&mchchk_wng_posted
, 1) == 0)
78 kill_cad_pid(SIGPWR
, 1);
82 printk(KERN_EMERG
"mcck: Terminating task because of machine "
83 "malfunction (code 0x%016llx).\n", mcck
.mcck_code
);
84 printk(KERN_EMERG
"mcck: task: %s, pid: %d.\n",
85 current
->comm
, current
->pid
);
89 EXPORT_SYMBOL_GPL(s390_handle_mcck
);
92 * returns 0 if all registers could be validated
95 static int notrace
s390_revalidate_registers(struct mci
*mci
)
99 void *fpt_save_area
, *fpt_creg_save_area
;
106 * General purpose registers couldn't be restored and have
107 * unknown contents. Process needs to be terminated.
113 * Floating point registers can't be restored and
114 * therefore the process needs to be terminated.
124 : : "a" (&S390_lowcore
.floating_pt_save_area
));
127 if (MACHINE_HAS_IEEE
) {
129 fpt_save_area
= &S390_lowcore
.floating_pt_save_area
;
130 fpt_creg_save_area
= &S390_lowcore
.fpt_creg_save_area
;
132 fpt_save_area
= (void *) S390_lowcore
.extended_save_area_addr
;
133 fpt_creg_save_area
= fpt_save_area
+ 128;
137 * Floating point control register can't be restored.
138 * Task will be terminated.
140 asm volatile("lfpc 0(%0)" : : "a" (&zero
), "m" (zero
));
144 asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area
));
163 : : "a" (fpt_save_area
));
165 /* Revalidate access registers */
168 : : "a" (&S390_lowcore
.access_regs_save_area
));
171 * Access registers have unknown contents.
176 /* Revalidate control registers */
179 * Control registers have unknown contents.
180 * Can't recover and therefore stopping machine.
182 s390_handle_damage("invalid control registers.");
187 : : "a" (&S390_lowcore
.cregs_save_area
));
191 : : "a" (&S390_lowcore
.cregs_save_area
));
195 * We don't even try to revalidate the TOD register, since we simply
196 * can't write something sensible into that register.
200 * See if we can revalidate the TOD programmable register with its
201 * old contents (should be zero) otherwise set it to zero.
212 : : "a" (&S390_lowcore
.tod_progreg_save_area
)
215 /* Revalidate clock comparator register */
216 if (S390_lowcore
.clock_comparator
== -1)
217 set_clock_comparator(S390_lowcore
.mcck_clock
);
219 set_clock_comparator(S390_lowcore
.clock_comparator
);
220 /* Check if old PSW is valid */
223 * Can't tell if we come from user or kernel mode
224 * -> stopping machine.
226 s390_handle_damage("old psw invalid.");
228 if (!mci
->ms
|| !mci
->pm
|| !mci
->ia
)
234 #define MAX_IPD_COUNT 29
235 #define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
237 #define ED_STP_ISLAND 6 /* External damage STP island check */
238 #define ED_STP_SYNC 7 /* External damage STP sync check */
239 #define ED_ETR_SYNC 12 /* External damage ETR sync check */
240 #define ED_ETR_SWITCH 13 /* External damage ETR switch to local */
243 * machine check handler.
245 void notrace
s390_do_machine_check(struct pt_regs
*regs
)
247 static int ipd_count
;
248 static DEFINE_SPINLOCK(ipd_lock
);
249 static unsigned long long last_ipd
;
250 struct mcck_struct
*mcck
;
251 unsigned long long tmp
;
256 s390_idle_check(regs
, S390_lowcore
.mcck_clock
,
257 S390_lowcore
.mcck_enter_timer
);
259 mci
= (struct mci
*) &S390_lowcore
.mcck_interruption_code
;
260 mcck
= &__get_cpu_var(cpu_mcck
);
261 umode
= user_mode(regs
);
264 /* System damage -> stopping machine */
265 s390_handle_damage("received system damage machine check.");
269 /* Processing backup -> verify if we can survive this */
270 u64 z_mcic
, o_mcic
, t_mcic
;
272 z_mcic
= (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
273 o_mcic
= (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
274 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
275 1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
278 z_mcic
= (1ULL<<63 | 1ULL<<59 | 1ULL<<57 | 1ULL<<50 |
280 o_mcic
= (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
281 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
282 1ULL<<30 | 1ULL<<20 | 1ULL<<17 | 1ULL<<16);
284 t_mcic
= *(u64
*)mci
;
286 if (((t_mcic
& z_mcic
) != 0) ||
287 ((t_mcic
& o_mcic
) != o_mcic
)) {
288 s390_handle_damage("processing backup machine "
289 "check with damage.");
293 * Nullifying exigent condition, therefore we might
294 * retry this instruction.
296 spin_lock(&ipd_lock
);
298 if (((tmp
- last_ipd
) >> 12) < MAX_IPD_TIME
)
303 if (ipd_count
== MAX_IPD_COUNT
)
304 s390_handle_damage("too many ipd retries.");
305 spin_unlock(&ipd_lock
);
307 /* Processing damage -> stopping machine */
308 s390_handle_damage("received instruction processing "
309 "damage machine check.");
312 if (s390_revalidate_registers(mci
)) {
315 * Couldn't restore all register contents while in
316 * user mode -> mark task for termination.
319 mcck
->mcck_code
= *(unsigned long long *) mci
;
320 set_thread_flag(TIF_MCCK_PENDING
);
323 * Couldn't restore all register contents while in
324 * kernel mode -> stopping machine.
326 s390_handle_damage("unable to revalidate registers.");
330 /* Timing facility damage */
331 s390_handle_damage("TOD clock damaged");
333 if (mci
->ed
&& mci
->ec
) {
334 /* External damage */
335 if (S390_lowcore
.external_damage_code
& (1U << ED_ETR_SYNC
))
337 if (S390_lowcore
.external_damage_code
& (1U << ED_ETR_SWITCH
))
338 etr_switch_to_local();
339 if (S390_lowcore
.external_damage_code
& (1U << ED_STP_SYNC
))
341 if (S390_lowcore
.external_damage_code
& (1U << ED_STP_ISLAND
))
345 /* Storage error uncorrected */
346 s390_handle_damage("received storage error uncorrected "
349 /* Storage key-error uncorrected */
350 s390_handle_damage("received storage key-error uncorrected "
352 if (mci
->ds
&& mci
->fa
)
353 /* Storage degradation */
354 s390_handle_damage("received storage degradation machine "
357 /* Channel report word pending */
358 mcck
->channel_report
= 1;
359 set_thread_flag(TIF_MCCK_PENDING
);
362 /* Warning pending */
364 set_thread_flag(TIF_MCCK_PENDING
);
369 static int __init
machine_check_init(void)
371 ctl_set_bit(14, 25); /* enable external damage MCH */
372 ctl_set_bit(14, 27); /* enable system recovery MCH */
373 ctl_set_bit(14, 24); /* enable warning MCH */
376 arch_initcall(machine_check_init
);
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