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authorHeiko Carstens <heiko.carstens@de.ibm.com>2009-03-26 10:24:01 -0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2009-03-26 10:24:10 -0400
commitf5daba1d4116d964435ddd99f32b6c80448a496b (patch)
tree0c4ace40971e9cc455b556a3d5691b64a24044b5 /arch/s390/kernel/nmi.c
parent70193af9188113c9b4ff3dde1aed9f9c8f7c4f93 (diff)
[S390] split/move machine check handler code
Split machine check handler code and move it to cio and kernel code where it belongs to. No functional change. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/nmi.c')
-rw-r--r--arch/s390/kernel/nmi.c383
1 files changed, 383 insertions, 0 deletions
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
new file mode 100644
index 000000000000..8d50eaf76a60
--- /dev/null
+++ b/arch/s390/kernel/nmi.c
@@ -0,0 +1,383 @@
1/*
2 * Machine check handler
3 *
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>,
9 */
10
11#include <linux/init.h>
12#include <linux/errno.h>
13#include <linux/time.h>
14#include <linux/module.h>
15#include <asm/lowcore.h>
16#include <asm/smp.h>
17#include <asm/etr.h>
18#include <asm/cpu.h>
19#include <asm/nmi.h>
20#include <asm/crw.h>
21
22struct 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
31static 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
38/*
39 * Main machine check handler function. Will be called with interrupts enabled
40 * or disabled and machine checks enabled or disabled.
41 */
42void s390_handle_mcck(void)
43{
44 unsigned long flags;
45 struct mcck_struct mcck;
46
47 /*
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);
59
60 if (mcck.channel_report)
61 crw_handle_channel_report();
62
63#ifdef CONFIG_MACHCHK_WARNING
64/*
65 * The warning may remain for a prolonged period on the bare iron.
66 * (actually till the machine is powered off, or until the problem is gone)
67 * So we just stop listening for the WARNING MCH and prevent continuously
68 * being interrupted. One caveat is however, that we must do this per
69 * processor and cannot use the smp version of ctl_clear_bit().
70 * On VM we only get one interrupt per virtally presented machinecheck.
71 * Though one suffices, we may get one interrupt per (virtual) processor.
72 */
73 if (mcck.warning) { /* WARNING pending ? */
74 static int mchchk_wng_posted = 0;
75 /*
76 * Use single machine clear, as we cannot handle smp right now
77 */
78 __ctl_clear_bit(14, 24); /* Disable WARNING MCH */
79 if (xchg(&mchchk_wng_posted, 1) == 0)
80 kill_cad_pid(SIGPWR, 1);
81 }
82#endif
83
84 if (mcck.kill_task) {
85 local_irq_enable();
86 printk(KERN_EMERG "mcck: Terminating task because of machine "
87 "malfunction (code 0x%016llx).\n", mcck.mcck_code);
88 printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
89 current->comm, current->pid);
90 do_exit(SIGSEGV);
91 }
92}
93EXPORT_SYMBOL_GPL(s390_handle_mcck);
94
95/*
96 * returns 0 if all registers could be validated
97 * returns 1 otherwise
98 */
99static int notrace s390_revalidate_registers(struct mci *mci)
100{
101 int kill_task;
102 u64 tmpclock;
103 u64 zero;
104 void *fpt_save_area, *fpt_creg_save_area;
105
106 kill_task = 0;
107 zero = 0;
108
109 if (!mci->gr) {
110 /*
111 * General purpose registers couldn't be restored and have
112 * unknown contents. Process needs to be terminated.
113 */
114 kill_task = 1;
115 }
116 if (!mci->fp) {
117 /*
118 * Floating point registers can't be restored and
119 * therefore the process needs to be terminated.
120 */
121 kill_task = 1;
122 }
123#ifndef CONFIG_64BIT
124 asm volatile(
125 " ld 0,0(%0)\n"
126 " ld 2,8(%0)\n"
127 " ld 4,16(%0)\n"
128 " ld 6,24(%0)"
129 : : "a" (&S390_lowcore.floating_pt_save_area));
130#endif
131
132 if (MACHINE_HAS_IEEE) {
133#ifdef CONFIG_64BIT
134 fpt_save_area = &S390_lowcore.floating_pt_save_area;
135 fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
136#else
137 fpt_save_area = (void *) S390_lowcore.extended_save_area_addr;
138 fpt_creg_save_area = fpt_save_area + 128;
139#endif
140 if (!mci->fc) {
141 /*
142 * Floating point control register can't be restored.
143 * Task will be terminated.
144 */
145 asm volatile("lfpc 0(%0)" : : "a" (&zero), "m" (zero));
146 kill_task = 1;
147
148 } else
149 asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area));
150
151 asm volatile(
152 " ld 0,0(%0)\n"
153 " ld 1,8(%0)\n"
154 " ld 2,16(%0)\n"
155 " ld 3,24(%0)\n"
156 " ld 4,32(%0)\n"
157 " ld 5,40(%0)\n"
158 " ld 6,48(%0)\n"
159 " ld 7,56(%0)\n"
160 " ld 8,64(%0)\n"
161 " ld 9,72(%0)\n"
162 " ld 10,80(%0)\n"
163 " ld 11,88(%0)\n"
164 " ld 12,96(%0)\n"
165 " ld 13,104(%0)\n"
166 " ld 14,112(%0)\n"
167 " ld 15,120(%0)\n"
168 : : "a" (fpt_save_area));
169 }
170 /* Revalidate access registers */
171 asm volatile(
172 " lam 0,15,0(%0)"
173 : : "a" (&S390_lowcore.access_regs_save_area));
174 if (!mci->ar) {
175 /*
176 * Access registers have unknown contents.
177 * Terminating task.
178 */
179 kill_task = 1;
180 }
181 /* Revalidate control registers */
182 if (!mci->cr) {
183 /*
184 * Control registers have unknown contents.
185 * Can't recover and therefore stopping machine.
186 */
187 s390_handle_damage("invalid control registers.");
188 } else {
189#ifdef CONFIG_64BIT
190 asm volatile(
191 " lctlg 0,15,0(%0)"
192 : : "a" (&S390_lowcore.cregs_save_area));
193#else
194 asm volatile(
195 " lctl 0,15,0(%0)"
196 : : "a" (&S390_lowcore.cregs_save_area));
197#endif
198 }
199 /*
200 * We don't even try to revalidate the TOD register, since we simply
201 * can't write something sensible into that register.
202 */
203#ifdef CONFIG_64BIT
204 /*
205 * See if we can revalidate the TOD programmable register with its
206 * old contents (should be zero) otherwise set it to zero.
207 */
208 if (!mci->pr)
209 asm volatile(
210 " sr 0,0\n"
211 " sckpf"
212 : : : "0", "cc");
213 else
214 asm volatile(
215 " l 0,0(%0)\n"
216 " sckpf"
217 : : "a" (&S390_lowcore.tod_progreg_save_area)
218 : "0", "cc");
219#endif
220 /* Revalidate clock comparator register */
221 asm volatile(
222 " stck 0(%1)\n"
223 " sckc 0(%1)"
224 : "=m" (tmpclock) : "a" (&(tmpclock)) : "cc", "memory");
225
226 /* Check if old PSW is valid */
227 if (!mci->wp)
228 /*
229 * Can't tell if we come from user or kernel mode
230 * -> stopping machine.
231 */
232 s390_handle_damage("old psw invalid.");
233
234 if (!mci->ms || !mci->pm || !mci->ia)
235 kill_task = 1;
236
237 return kill_task;
238}
239
240#define MAX_IPD_COUNT 29
241#define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
242
243#define ED_STP_ISLAND 6 /* External damage STP island check */
244#define ED_STP_SYNC 7 /* External damage STP sync check */
245#define ED_ETR_SYNC 12 /* External damage ETR sync check */
246#define ED_ETR_SWITCH 13 /* External damage ETR switch to local */
247
248/*
249 * machine check handler.
250 */
251void notrace s390_do_machine_check(struct pt_regs *regs)
252{
253 static int ipd_count;
254 static DEFINE_SPINLOCK(ipd_lock);
255 static unsigned long long last_ipd;
256 struct mcck_struct *mcck;
257 unsigned long long tmp;
258 struct mci *mci;
259 int umode;
260
261 lockdep_off();
262 s390_idle_check();
263
264 mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
265 mcck = &__get_cpu_var(cpu_mcck);
266 umode = user_mode(regs);
267
268 if (mci->sd) {
269 /* System damage -> stopping machine */
270 s390_handle_damage("received system damage machine check.");
271 }
272 if (mci->pd) {
273 if (mci->b) {
274 /* Processing backup -> verify if we can survive this */
275 u64 z_mcic, o_mcic, t_mcic;
276#ifdef CONFIG_64BIT
277 z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
278 o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
279 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
280 1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
281 1ULL<<16);
282#else
283 z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<57 | 1ULL<<50 |
284 1ULL<<29);
285 o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
286 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
287 1ULL<<30 | 1ULL<<20 | 1ULL<<17 | 1ULL<<16);
288#endif
289 t_mcic = *(u64 *)mci;
290
291 if (((t_mcic & z_mcic) != 0) ||
292 ((t_mcic & o_mcic) != o_mcic)) {
293 s390_handle_damage("processing backup machine "
294 "check with damage.");
295 }
296
297 /*
298 * Nullifying exigent condition, therefore we might
299 * retry this instruction.
300 */
301 spin_lock(&ipd_lock);
302 tmp = get_clock();
303 if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
304 ipd_count++;
305 else
306 ipd_count = 1;
307 last_ipd = tmp;
308 if (ipd_count == MAX_IPD_COUNT)
309 s390_handle_damage("too many ipd retries.");
310 spin_unlock(&ipd_lock);
311 } else {
312 /* Processing damage -> stopping machine */
313 s390_handle_damage("received instruction processing "
314 "damage machine check.");
315 }
316 }
317 if (s390_revalidate_registers(mci)) {
318 if (umode) {
319 /*
320 * Couldn't restore all register contents while in
321 * user mode -> mark task for termination.
322 */
323 mcck->kill_task = 1;
324 mcck->mcck_code = *(unsigned long long *) mci;
325 set_thread_flag(TIF_MCCK_PENDING);
326 } else {
327 /*
328 * Couldn't restore all register contents while in
329 * kernel mode -> stopping machine.
330 */
331 s390_handle_damage("unable to revalidate registers.");
332 }
333 }
334 if (mci->cd) {
335 /* Timing facility damage */
336 s390_handle_damage("TOD clock damaged");
337 }
338 if (mci->ed && mci->ec) {
339 /* External damage */
340 if (S390_lowcore.external_damage_code & (1U << ED_ETR_SYNC))
341 etr_sync_check();
342 if (S390_lowcore.external_damage_code & (1U << ED_ETR_SWITCH))
343 etr_switch_to_local();
344 if (S390_lowcore.external_damage_code & (1U << ED_STP_SYNC))
345 stp_sync_check();
346 if (S390_lowcore.external_damage_code & (1U << ED_STP_ISLAND))
347 stp_island_check();
348 }
349 if (mci->se)
350 /* Storage error uncorrected */
351 s390_handle_damage("received storage error uncorrected "
352 "machine check.");
353 if (mci->ke)
354 /* Storage key-error uncorrected */
355 s390_handle_damage("received storage key-error uncorrected "
356 "machine check.");
357 if (mci->ds && mci->fa)
358 /* Storage degradation */
359 s390_handle_damage("received storage degradation machine "
360 "check.");
361 if (mci->cp) {
362 /* Channel report word pending */
363 mcck->channel_report = 1;
364 set_thread_flag(TIF_MCCK_PENDING);
365 }
366 if (mci->w) {
367 /* Warning pending */
368 mcck->warning = 1;
369 set_thread_flag(TIF_MCCK_PENDING);
370 }
371 lockdep_on();
372}
373
374static int __init machine_check_init(void)
375{
376 ctl_set_bit(14, 25); /* enable external damage MCH */
377 ctl_set_bit(14, 27); /* enable system recovery MCH */
378#ifdef CONFIG_MACHCHK_WARNING
379 ctl_set_bit(14, 24); /* enable warning MCH */
380#endif
381 return 0;
382}
383arch_initcall(machine_check_init);