Merge remote-tracking branch 'omap_dss2/for-next'
[deliverable/linux.git] / arch / s390 / kernel / nmi.c
CommitLineData
1da177e4 1/*
f5daba1d 2 * Machine check handler
1da177e4 3 *
a53c8fab 4 * Copyright IBM Corp. 2000, 2009
f5daba1d
HC
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>,
1da177e4
LT
9 */
10
052ff461 11#include <linux/kernel_stat.h>
1da177e4 12#include <linux/init.h>
1da177e4 13#include <linux/errno.h>
81f64b87 14#include <linux/hardirq.h>
022e4fc0 15#include <linux/time.h>
f5daba1d 16#include <linux/module.h>
1da177e4 17#include <asm/lowcore.h>
f5daba1d 18#include <asm/smp.h>
fd5ada04 19#include <asm/stp.h>
76d4e00a 20#include <asm/cputime.h>
f5daba1d
HC
21#include <asm/nmi.h>
22#include <asm/crw.h>
80703617 23#include <asm/switch_to.h>
cad49cfc 24#include <asm/ctl_reg.h>
1da177e4 25
77fa2245 26struct mcck_struct {
36324963
HC
27 unsigned int kill_task : 1;
28 unsigned int channel_report : 1;
29 unsigned int warning : 1;
29b0a825 30 unsigned int stp_queue : 1;
dc6e1555 31 unsigned long mcck_code;
77fa2245
HC
32};
33
34static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
35
3d68286a 36static void s390_handle_damage(void)
f5daba1d
HC
37{
38 smp_send_stop();
39 disabled_wait((unsigned long) __builtin_return_address(0));
40 while (1);
41}
42
1da177e4 43/*
77fa2245
HC
44 * Main machine check handler function. Will be called with interrupts enabled
45 * or disabled and machine checks enabled or disabled.
1da177e4 46 */
f5daba1d 47void s390_handle_mcck(void)
1da177e4 48{
77fa2245
HC
49 unsigned long flags;
50 struct mcck_struct mcck;
1da177e4 51
77fa2245
HC
52 /*
53 * Disable machine checks and get the current state of accumulated
54 * machine checks. Afterwards delete the old state and enable machine
55 * checks again.
56 */
57 local_irq_save(flags);
58 local_mcck_disable();
2cb4a182
SO
59 mcck = *this_cpu_ptr(&cpu_mcck);
60 memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(mcck));
d3a73acb 61 clear_cpu_flag(CIF_MCCK_PENDING);
77fa2245
HC
62 local_mcck_enable();
63 local_irq_restore(flags);
1da177e4 64
77fa2245 65 if (mcck.channel_report)
f5daba1d 66 crw_handle_channel_report();
7b886416
HC
67 /*
68 * A warning may remain for a prolonged period on the bare iron.
69 * (actually until the machine is powered off, or the problem is gone)
70 * So we just stop listening for the WARNING MCH and avoid continuously
71 * being interrupted. One caveat is however, that we must do this per
72 * processor and cannot use the smp version of ctl_clear_bit().
73 * On VM we only get one interrupt per virtally presented machinecheck.
74 * Though one suffices, we may get one interrupt per (virtual) cpu.
75 */
77fa2245 76 if (mcck.warning) { /* WARNING pending ? */
1da177e4 77 static int mchchk_wng_posted = 0;
7b886416
HC
78
79 /* Use single cpu clear, as we cannot handle smp here. */
1da177e4
LT
80 __ctl_clear_bit(14, 24); /* Disable WARNING MCH */
81 if (xchg(&mchchk_wng_posted, 1) == 0)
9ec52099 82 kill_cad_pid(SIGPWR, 1);
1da177e4 83 }
29b0a825
HC
84 if (mcck.stp_queue)
85 stp_queue_work();
77fa2245
HC
86 if (mcck.kill_task) {
87 local_irq_enable();
88 printk(KERN_EMERG "mcck: Terminating task because of machine "
dc6e1555 89 "malfunction (code 0x%016lx).\n", mcck.mcck_code);
77fa2245
HC
90 printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
91 current->comm, current->pid);
92 do_exit(SIGSEGV);
93 }
94}
71cde587 95EXPORT_SYMBOL_GPL(s390_handle_mcck);
77fa2245
HC
96
97/*
98 * returns 0 if all registers could be validated
99 * returns 1 otherwise
100 */
8f149ea6 101static int notrace s390_validate_registers(union mci mci, int umode)
77fa2245
HC
102{
103 int kill_task;
77fa2245
HC
104 u64 zero;
105 void *fpt_save_area, *fpt_creg_save_area;
106
107 kill_task = 0;
108 zero = 0;
f5daba1d 109
dc6e1555 110 if (!mci.gr) {
77fa2245
HC
111 /*
112 * General purpose registers couldn't be restored and have
8f149ea6 113 * unknown contents. Stop system or terminate process.
77fa2245 114 */
8f149ea6
MS
115 if (!umode)
116 s390_handle_damage();
77fa2245 117 kill_task = 1;
f5daba1d 118 }
dc6e1555 119 if (!mci.fp) {
77fa2245 120 /*
8f149ea6
MS
121 * Floating point registers can't be restored. If the
122 * kernel currently uses floating point registers the
123 * system is stopped. If the process has its floating
124 * pointer registers loaded it is terminated.
125 * Otherwise just revalidate the registers.
77fa2245 126 */
8f149ea6
MS
127 if (S390_lowcore.fpu_flags & KERNEL_VXR_V0V7)
128 s390_handle_damage();
129 if (!test_cpu_flag(CIF_FPU))
130 kill_task = 1;
f5daba1d 131 }
5a79859a
HC
132 fpt_save_area = &S390_lowcore.floating_pt_save_area;
133 fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
dc6e1555 134 if (!mci.fc) {
5a79859a
HC
135 /*
136 * Floating point control register can't be restored.
8f149ea6
MS
137 * If the kernel currently uses the floating pointer
138 * registers and needs the FPC register the system is
139 * stopped. If the process has its floating pointer
140 * registers loaded it is terminated. Otherwiese the
141 * FPC is just revalidated.
5a79859a 142 */
8f149ea6
MS
143 if (S390_lowcore.fpu_flags & KERNEL_FPC)
144 s390_handle_damage();
5a79859a 145 asm volatile("lfpc 0(%0)" : : "a" (&zero), "m" (zero));
8f149ea6
MS
146 if (!test_cpu_flag(CIF_FPU))
147 kill_task = 1;
5a79859a
HC
148 } else
149 asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area));
150
cad49cfc 151 if (!MACHINE_HAS_VX) {
975be635 152 /* Validate floating point registers */
cad49cfc
HC
153 asm volatile(
154 " ld 0,0(%0)\n"
155 " ld 1,8(%0)\n"
156 " ld 2,16(%0)\n"
157 " ld 3,24(%0)\n"
158 " ld 4,32(%0)\n"
159 " ld 5,40(%0)\n"
160 " ld 6,48(%0)\n"
161 " ld 7,56(%0)\n"
162 " ld 8,64(%0)\n"
163 " ld 9,72(%0)\n"
164 " ld 10,80(%0)\n"
165 " ld 11,88(%0)\n"
166 " ld 12,96(%0)\n"
167 " ld 13,104(%0)\n"
168 " ld 14,112(%0)\n"
169 " ld 15,120(%0)\n"
170 : : "a" (fpt_save_area));
171 } else {
975be635 172 /* Validate vector registers */
cad49cfc
HC
173 union ctlreg0 cr0;
174
dc6e1555 175 if (!mci.vr) {
80703617 176 /*
8f149ea6
MS
177 * Vector registers can't be restored. If the kernel
178 * currently uses vector registers the system is
179 * stopped. If the process has its vector registers
180 * loaded it is terminated. Otherwise just revalidate
181 * the registers.
80703617 182 */
8f149ea6
MS
183 if (S390_lowcore.fpu_flags & KERNEL_VXR)
184 s390_handle_damage();
185 if (!test_cpu_flag(CIF_FPU))
186 kill_task = 1;
80703617 187 }
cad49cfc
HC
188 cr0.val = S390_lowcore.cregs_save_area[0];
189 cr0.afp = cr0.vx = 1;
190 __ctl_load(cr0.val, 0, 0);
9977e886
HB
191 asm volatile(
192 " la 1,%0\n"
193 " .word 0xe70f,0x1000,0x0036\n" /* vlm 0,15,0(1) */
194 " .word 0xe70f,0x1100,0x0c36\n" /* vlm 16,31,256(1) */
195 : : "Q" (*(struct vx_array *)
196 &S390_lowcore.vector_save_area) : "1");
cad49cfc 197 __ctl_load(S390_lowcore.cregs_save_area[0], 0, 0);
80703617 198 }
975be635 199 /* Validate access registers */
94c12cc7
MS
200 asm volatile(
201 " lam 0,15,0(%0)"
202 : : "a" (&S390_lowcore.access_regs_save_area));
dc6e1555 203 if (!mci.ar) {
77fa2245
HC
204 /*
205 * Access registers have unknown contents.
206 * Terminating task.
207 */
208 kill_task = 1;
f5daba1d 209 }
975be635 210 /* Validate control registers */
dc6e1555 211 if (!mci.cr) {
77fa2245
HC
212 /*
213 * Control registers have unknown contents.
214 * Can't recover and therefore stopping machine.
215 */
3d68286a 216 s390_handle_damage();
f5daba1d 217 } else {
94c12cc7
MS
218 asm volatile(
219 " lctlg 0,15,0(%0)"
220 : : "a" (&S390_lowcore.cregs_save_area));
f5daba1d 221 }
77fa2245 222 /*
975be635 223 * We don't even try to validate the TOD register, since we simply
77fa2245
HC
224 * can't write something sensible into that register.
225 */
77fa2245 226 /*
975be635 227 * See if we can validate the TOD programmable register with its
77fa2245
HC
228 * old contents (should be zero) otherwise set it to zero.
229 */
dc6e1555 230 if (!mci.pr)
94c12cc7
MS
231 asm volatile(
232 " sr 0,0\n"
233 " sckpf"
234 : : : "0", "cc");
77fa2245
HC
235 else
236 asm volatile(
94c12cc7
MS
237 " l 0,0(%0)\n"
238 " sckpf"
239 : : "a" (&S390_lowcore.tod_progreg_save_area)
240 : "0", "cc");
975be635 241 /* Validate clock comparator register */
b6bed093 242 set_clock_comparator(S390_lowcore.clock_comparator);
77fa2245 243 /* Check if old PSW is valid */
dc6e1555 244 if (!mci.wp)
77fa2245
HC
245 /*
246 * Can't tell if we come from user or kernel mode
247 * -> stopping machine.
248 */
3d68286a 249 s390_handle_damage();
77fa2245 250
dc6e1555 251 if (!mci.ms || !mci.pm || !mci.ia)
77fa2245
HC
252 kill_task = 1;
253
254 return kill_task;
255}
256
b73d40c6 257#define MAX_IPD_COUNT 29
022e4fc0 258#define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
b73d40c6 259
f5daba1d
HC
260#define ED_STP_ISLAND 6 /* External damage STP island check */
261#define ED_STP_SYNC 7 /* External damage STP sync check */
f5daba1d 262
77fa2245
HC
263/*
264 * machine check handler.
265 */
cc54c1e6 266void notrace s390_do_machine_check(struct pt_regs *regs)
77fa2245 267{
f5daba1d 268 static int ipd_count;
b73d40c6
HC
269 static DEFINE_SPINLOCK(ipd_lock);
270 static unsigned long long last_ipd;
f5daba1d 271 struct mcck_struct *mcck;
b73d40c6 272 unsigned long long tmp;
dc6e1555 273 union mci mci;
77fa2245 274
81f64b87 275 nmi_enter();
420f42ec 276 inc_irq_stat(NMI_NMI);
dc6e1555 277 mci.val = S390_lowcore.mcck_interruption_code;
eb7e7d76 278 mcck = this_cpu_ptr(&cpu_mcck);
77fa2245 279
dc6e1555 280 if (mci.sd) {
77fa2245 281 /* System damage -> stopping machine */
3d68286a 282 s390_handle_damage();
f5daba1d 283 }
dc6e1555
HC
284 if (mci.pd) {
285 if (mci.b) {
77fa2245
HC
286 /* Processing backup -> verify if we can survive this */
287 u64 z_mcic, o_mcic, t_mcic;
77fa2245
HC
288 z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
289 o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
290 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
291 1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
292 1ULL<<16);
dc6e1555 293 t_mcic = mci.val;
77fa2245
HC
294
295 if (((t_mcic & z_mcic) != 0) ||
296 ((t_mcic & o_mcic) != o_mcic)) {
3d68286a 297 s390_handle_damage();
77fa2245 298 }
b73d40c6
HC
299
300 /*
301 * Nullifying exigent condition, therefore we might
302 * retry this instruction.
303 */
b73d40c6 304 spin_lock(&ipd_lock);
1aae0560 305 tmp = get_tod_clock();
b73d40c6
HC
306 if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
307 ipd_count++;
308 else
309 ipd_count = 1;
b73d40c6 310 last_ipd = tmp;
b73d40c6 311 if (ipd_count == MAX_IPD_COUNT)
3d68286a 312 s390_handle_damage();
b73d40c6 313 spin_unlock(&ipd_lock);
f5daba1d 314 } else {
77fa2245 315 /* Processing damage -> stopping machine */
3d68286a 316 s390_handle_damage();
77fa2245
HC
317 }
318 }
8f149ea6
MS
319 if (s390_validate_registers(mci, user_mode(regs))) {
320 /*
321 * Couldn't restore all register contents for the
322 * user space process -> mark task for termination.
323 */
324 mcck->kill_task = 1;
325 mcck->mcck_code = mci.val;
326 set_cpu_flag(CIF_MCCK_PENDING);
77fa2245 327 }
dc6e1555 328 if (mci.cd) {
d54853ef 329 /* Timing facility damage */
3d68286a 330 s390_handle_damage();
d54853ef 331 }
dc6e1555 332 if (mci.ed && mci.ec) {
d54853ef 333 /* External damage */
d2fec595 334 if (S390_lowcore.external_damage_code & (1U << ED_STP_SYNC))
29b0a825 335 mcck->stp_queue |= stp_sync_check();
d2fec595 336 if (S390_lowcore.external_damage_code & (1U << ED_STP_ISLAND))
29b0a825 337 mcck->stp_queue |= stp_island_check();
fd5ada04 338 if (mcck->stp_queue)
29b0a825 339 set_cpu_flag(CIF_MCCK_PENDING);
d54853ef 340 }
dc6e1555 341 if (mci.se)
77fa2245 342 /* Storage error uncorrected */
3d68286a 343 s390_handle_damage();
dc6e1555 344 if (mci.ke)
77fa2245 345 /* Storage key-error uncorrected */
3d68286a 346 s390_handle_damage();
dc6e1555 347 if (mci.ds && mci.fa)
77fa2245 348 /* Storage degradation */
3d68286a 349 s390_handle_damage();
dc6e1555 350 if (mci.cp) {
77fa2245
HC
351 /* Channel report word pending */
352 mcck->channel_report = 1;
d3a73acb 353 set_cpu_flag(CIF_MCCK_PENDING);
77fa2245 354 }
dc6e1555 355 if (mci.w) {
77fa2245
HC
356 /* Warning pending */
357 mcck->warning = 1;
d3a73acb 358 set_cpu_flag(CIF_MCCK_PENDING);
77fa2245 359 }
81f64b87 360 nmi_exit();
1da177e4
LT
361}
362
f5daba1d 363static int __init machine_check_init(void)
1da177e4 364{
d54853ef 365 ctl_set_bit(14, 25); /* enable external damage MCH */
f5daba1d 366 ctl_set_bit(14, 27); /* enable system recovery MCH */
1da177e4 367 ctl_set_bit(14, 24); /* enable warning MCH */
1da177e4
LT
368 return 0;
369}
24d05ff8 370early_initcall(machine_check_init);
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