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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Heiko Carstensf5daba12009-03-26 15:24:01 +01002 * Machine check handler
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
Heiko Carstensf5daba12009-03-26 15:24:01 +01004 * 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>,
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 */
10
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/errno.h>
Heiko Carstens022e4fc2006-05-01 12:16:14 -070013#include <linux/time.h>
Heiko Carstensf5daba12009-03-26 15:24:01 +010014#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <asm/lowcore.h>
Heiko Carstensf5daba12009-03-26 15:24:01 +010016#include <asm/smp.h>
17#include <asm/etr.h>
Martin Schwidefsky9cfb9b32008-12-31 15:11:41 +010018#include <asm/cpu.h>
Heiko Carstensf5daba12009-03-26 15:24:01 +010019#include <asm/nmi.h>
20#include <asm/crw.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
Heiko Carstens77fa2242005-06-25 14:55:30 -070022struct mcck_struct {
23 int kill_task;
24 int channel_report;
25 int warning;
26 unsigned long long mcck_code;
27};
28
29static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
30
Heiko Carstensf5daba12009-03-26 15:24:01 +010031static NORET_TYPE void s390_handle_damage(char *msg)
32{
33 smp_send_stop();
34 disabled_wait((unsigned long) __builtin_return_address(0));
35 while (1);
36}
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038/*
Heiko Carstens77fa2242005-06-25 14:55:30 -070039 * Main machine check handler function. Will be called with interrupts enabled
40 * or disabled and machine checks enabled or disabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 */
Heiko Carstensf5daba12009-03-26 15:24:01 +010042void s390_handle_mcck(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070043{
Heiko Carstens77fa2242005-06-25 14:55:30 -070044 unsigned long flags;
45 struct mcck_struct mcck;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Heiko Carstens77fa2242005-06-25 14:55:30 -070047 /*
48 * Disable machine checks and get the current state of accumulated
49 * machine checks. Afterwards delete the old state and enable machine
50 * checks again.
51 */
52 local_irq_save(flags);
53 local_mcck_disable();
54 mcck = __get_cpu_var(cpu_mcck);
55 memset(&__get_cpu_var(cpu_mcck), 0, sizeof(struct mcck_struct));
56 clear_thread_flag(TIF_MCCK_PENDING);
57 local_mcck_enable();
58 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
Heiko Carstens77fa2242005-06-25 14:55:30 -070060 if (mcck.channel_report)
Heiko Carstensf5daba12009-03-26 15:24:01 +010061 crw_handle_channel_report();
Heiko Carstens7b886412009-03-26 15:24:02 +010062 /*
63 * A warning may remain for a prolonged period on the bare iron.
64 * (actually until the machine is powered off, or the problem is gone)
65 * So we just stop listening for the WARNING MCH and avoid continuously
66 * being interrupted. One caveat is however, that we must do this per
67 * processor and cannot use the smp version of ctl_clear_bit().
68 * On VM we only get one interrupt per virtally presented machinecheck.
69 * Though one suffices, we may get one interrupt per (virtual) cpu.
70 */
Heiko Carstens77fa2242005-06-25 14:55:30 -070071 if (mcck.warning) { /* WARNING pending ? */
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 static int mchchk_wng_posted = 0;
Heiko Carstens7b886412009-03-26 15:24:02 +010073
74 /* Use single cpu clear, as we cannot handle smp here. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 __ctl_clear_bit(14, 24); /* Disable WARNING MCH */
76 if (xchg(&mchchk_wng_posted, 1) == 0)
Cedric Le Goater9ec52092006-10-02 02:19:00 -070077 kill_cad_pid(SIGPWR, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 }
Heiko Carstens77fa2242005-06-25 14:55:30 -070079 if (mcck.kill_task) {
80 local_irq_enable();
81 printk(KERN_EMERG "mcck: Terminating task because of machine "
82 "malfunction (code 0x%016llx).\n", mcck.mcck_code);
83 printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
84 current->comm, current->pid);
85 do_exit(SIGSEGV);
86 }
87}
Christian Borntraeger71cde582008-05-21 13:37:34 +020088EXPORT_SYMBOL_GPL(s390_handle_mcck);
Heiko Carstens77fa2242005-06-25 14:55:30 -070089
90/*
91 * returns 0 if all registers could be validated
92 * returns 1 otherwise
93 */
Heiko Carstensf5daba12009-03-26 15:24:01 +010094static int notrace s390_revalidate_registers(struct mci *mci)
Heiko Carstens77fa2242005-06-25 14:55:30 -070095{
96 int kill_task;
97 u64 tmpclock;
98 u64 zero;
99 void *fpt_save_area, *fpt_creg_save_area;
100
101 kill_task = 0;
102 zero = 0;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100103
104 if (!mci->gr) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700105 /*
106 * General purpose registers couldn't be restored and have
107 * unknown contents. Process needs to be terminated.
108 */
109 kill_task = 1;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100110 }
111 if (!mci->fp) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700112 /*
113 * Floating point registers can't be restored and
114 * therefore the process needs to be terminated.
115 */
116 kill_task = 1;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100117 }
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800118#ifndef CONFIG_64BIT
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200119 asm volatile(
120 " ld 0,0(%0)\n"
121 " ld 2,8(%0)\n"
122 " ld 4,16(%0)\n"
123 " ld 6,24(%0)"
124 : : "a" (&S390_lowcore.floating_pt_save_area));
Heiko Carstens77fa2242005-06-25 14:55:30 -0700125#endif
126
127 if (MACHINE_HAS_IEEE) {
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800128#ifdef CONFIG_64BIT
Heiko Carstens77fa2242005-06-25 14:55:30 -0700129 fpt_save_area = &S390_lowcore.floating_pt_save_area;
130 fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
131#else
132 fpt_save_area = (void *) S390_lowcore.extended_save_area_addr;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100133 fpt_creg_save_area = fpt_save_area + 128;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700134#endif
Heiko Carstens77fa2242005-06-25 14:55:30 -0700135 if (!mci->fc) {
136 /*
137 * Floating point control register can't be restored.
138 * Task will be terminated.
139 */
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200140 asm volatile("lfpc 0(%0)" : : "a" (&zero), "m" (zero));
Heiko Carstens77fa2242005-06-25 14:55:30 -0700141 kill_task = 1;
142
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200143 } else
144 asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area));
Heiko Carstens77fa2242005-06-25 14:55:30 -0700145
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200146 asm volatile(
147 " ld 0,0(%0)\n"
148 " ld 1,8(%0)\n"
149 " ld 2,16(%0)\n"
150 " ld 3,24(%0)\n"
151 " ld 4,32(%0)\n"
152 " ld 5,40(%0)\n"
153 " ld 6,48(%0)\n"
154 " ld 7,56(%0)\n"
155 " ld 8,64(%0)\n"
156 " ld 9,72(%0)\n"
157 " ld 10,80(%0)\n"
158 " ld 11,88(%0)\n"
159 " ld 12,96(%0)\n"
160 " ld 13,104(%0)\n"
161 " ld 14,112(%0)\n"
162 " ld 15,120(%0)\n"
163 : : "a" (fpt_save_area));
Heiko Carstens77fa2242005-06-25 14:55:30 -0700164 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700165 /* Revalidate access registers */
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200166 asm volatile(
167 " lam 0,15,0(%0)"
168 : : "a" (&S390_lowcore.access_regs_save_area));
Heiko Carstensf5daba12009-03-26 15:24:01 +0100169 if (!mci->ar) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700170 /*
171 * Access registers have unknown contents.
172 * Terminating task.
173 */
174 kill_task = 1;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100175 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700176 /* Revalidate control registers */
Heiko Carstensf5daba12009-03-26 15:24:01 +0100177 if (!mci->cr) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700178 /*
179 * Control registers have unknown contents.
180 * Can't recover and therefore stopping machine.
181 */
182 s390_handle_damage("invalid control registers.");
Heiko Carstensf5daba12009-03-26 15:24:01 +0100183 } else {
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800184#ifdef CONFIG_64BIT
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200185 asm volatile(
186 " lctlg 0,15,0(%0)"
187 : : "a" (&S390_lowcore.cregs_save_area));
Heiko Carstens77fa2242005-06-25 14:55:30 -0700188#else
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200189 asm volatile(
190 " lctl 0,15,0(%0)"
191 : : "a" (&S390_lowcore.cregs_save_area));
Heiko Carstens77fa2242005-06-25 14:55:30 -0700192#endif
Heiko Carstensf5daba12009-03-26 15:24:01 +0100193 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700194 /*
195 * We don't even try to revalidate the TOD register, since we simply
196 * can't write something sensible into that register.
197 */
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800198#ifdef CONFIG_64BIT
Heiko Carstens77fa2242005-06-25 14:55:30 -0700199 /*
200 * See if we can revalidate the TOD programmable register with its
201 * old contents (should be zero) otherwise set it to zero.
202 */
203 if (!mci->pr)
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200204 asm volatile(
205 " sr 0,0\n"
206 " sckpf"
207 : : : "0", "cc");
Heiko Carstens77fa2242005-06-25 14:55:30 -0700208 else
209 asm volatile(
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200210 " l 0,0(%0)\n"
211 " sckpf"
212 : : "a" (&S390_lowcore.tod_progreg_save_area)
213 : "0", "cc");
Heiko Carstens77fa2242005-06-25 14:55:30 -0700214#endif
Heiko Carstens77fa2242005-06-25 14:55:30 -0700215 /* Revalidate clock comparator register */
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200216 asm volatile(
217 " stck 0(%1)\n"
218 " sckc 0(%1)"
219 : "=m" (tmpclock) : "a" (&(tmpclock)) : "cc", "memory");
Heiko Carstens77fa2242005-06-25 14:55:30 -0700220
221 /* Check if old PSW is valid */
222 if (!mci->wp)
223 /*
224 * Can't tell if we come from user or kernel mode
225 * -> stopping machine.
226 */
227 s390_handle_damage("old psw invalid.");
228
229 if (!mci->ms || !mci->pm || !mci->ia)
230 kill_task = 1;
231
232 return kill_task;
233}
234
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700235#define MAX_IPD_COUNT 29
Heiko Carstens022e4fc2006-05-01 12:16:14 -0700236#define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700237
Heiko Carstensf5daba12009-03-26 15:24:01 +0100238#define ED_STP_ISLAND 6 /* External damage STP island check */
239#define ED_STP_SYNC 7 /* External damage STP sync check */
240#define ED_ETR_SYNC 12 /* External damage ETR sync check */
241#define ED_ETR_SWITCH 13 /* External damage ETR switch to local */
242
Heiko Carstens77fa2242005-06-25 14:55:30 -0700243/*
244 * machine check handler.
245 */
Heiko Carstenscc54c1e2009-03-26 15:23:59 +0100246void notrace s390_do_machine_check(struct pt_regs *regs)
Heiko Carstens77fa2242005-06-25 14:55:30 -0700247{
Heiko Carstensf5daba12009-03-26 15:24:01 +0100248 static int ipd_count;
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700249 static DEFINE_SPINLOCK(ipd_lock);
250 static unsigned long long last_ipd;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100251 struct mcck_struct *mcck;
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700252 unsigned long long tmp;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700253 struct mci *mci;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700254 int umode;
255
Heiko Carstens8e9ccae2006-07-03 00:25:00 -0700256 lockdep_off();
Martin Schwidefsky9cfb9b32008-12-31 15:11:41 +0100257 s390_idle_check();
258
Heiko Carstens77fa2242005-06-25 14:55:30 -0700259 mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
260 mcck = &__get_cpu_var(cpu_mcck);
261 umode = user_mode(regs);
262
Heiko Carstensf5daba12009-03-26 15:24:01 +0100263 if (mci->sd) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700264 /* System damage -> stopping machine */
265 s390_handle_damage("received system damage machine check.");
Heiko Carstensf5daba12009-03-26 15:24:01 +0100266 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700267 if (mci->pd) {
268 if (mci->b) {
269 /* Processing backup -> verify if we can survive this */
270 u64 z_mcic, o_mcic, t_mcic;
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800271#ifdef CONFIG_64BIT
Heiko Carstens77fa2242005-06-25 14:55:30 -0700272 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 |
276 1ULL<<16);
277#else
278 z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<57 | 1ULL<<50 |
279 1ULL<<29);
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);
283#endif
284 t_mcic = *(u64 *)mci;
285
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.");
290 }
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700291
292 /*
293 * Nullifying exigent condition, therefore we might
294 * retry this instruction.
295 */
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700296 spin_lock(&ipd_lock);
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700297 tmp = get_clock();
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700298 if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
299 ipd_count++;
300 else
301 ipd_count = 1;
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700302 last_ipd = tmp;
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700303 if (ipd_count == MAX_IPD_COUNT)
304 s390_handle_damage("too many ipd retries.");
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700305 spin_unlock(&ipd_lock);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100306 } else {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700307 /* Processing damage -> stopping machine */
308 s390_handle_damage("received instruction processing "
309 "damage machine check.");
310 }
311 }
312 if (s390_revalidate_registers(mci)) {
313 if (umode) {
314 /*
315 * Couldn't restore all register contents while in
316 * user mode -> mark task for termination.
317 */
318 mcck->kill_task = 1;
319 mcck->mcck_code = *(unsigned long long *) mci;
320 set_thread_flag(TIF_MCCK_PENDING);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100321 } else {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700322 /*
323 * Couldn't restore all register contents while in
324 * kernel mode -> stopping machine.
325 */
326 s390_handle_damage("unable to revalidate registers.");
Heiko Carstensf5daba12009-03-26 15:24:01 +0100327 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700328 }
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100329 if (mci->cd) {
330 /* Timing facility damage */
331 s390_handle_damage("TOD clock damaged");
332 }
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100333 if (mci->ed && mci->ec) {
334 /* External damage */
335 if (S390_lowcore.external_damage_code & (1U << ED_ETR_SYNC))
336 etr_sync_check();
337 if (S390_lowcore.external_damage_code & (1U << ED_ETR_SWITCH))
338 etr_switch_to_local();
Martin Schwidefskyd2fec592008-07-14 09:58:56 +0200339 if (S390_lowcore.external_damage_code & (1U << ED_STP_SYNC))
340 stp_sync_check();
341 if (S390_lowcore.external_damage_code & (1U << ED_STP_ISLAND))
342 stp_island_check();
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100343 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700344 if (mci->se)
345 /* Storage error uncorrected */
346 s390_handle_damage("received storage error uncorrected "
347 "machine check.");
Heiko Carstens77fa2242005-06-25 14:55:30 -0700348 if (mci->ke)
349 /* Storage key-error uncorrected */
350 s390_handle_damage("received storage key-error uncorrected "
351 "machine check.");
Heiko Carstens77fa2242005-06-25 14:55:30 -0700352 if (mci->ds && mci->fa)
353 /* Storage degradation */
354 s390_handle_damage("received storage degradation machine "
355 "check.");
Heiko Carstens77fa2242005-06-25 14:55:30 -0700356 if (mci->cp) {
357 /* Channel report word pending */
358 mcck->channel_report = 1;
359 set_thread_flag(TIF_MCCK_PENDING);
360 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700361 if (mci->w) {
362 /* Warning pending */
363 mcck->warning = 1;
364 set_thread_flag(TIF_MCCK_PENDING);
365 }
Heiko Carstens8e9ccae2006-07-03 00:25:00 -0700366 lockdep_on();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367}
368
Heiko Carstensf5daba12009-03-26 15:24:01 +0100369static int __init machine_check_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370{
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100371 ctl_set_bit(14, 25); /* enable external damage MCH */
Heiko Carstensf5daba12009-03-26 15:24:01 +0100372 ctl_set_bit(14, 27); /* enable system recovery MCH */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 ctl_set_bit(14, 24); /* enable warning MCH */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 return 0;
375}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376arch_initcall(machine_check_init);