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Greg Kroah-Hartmana17ae4c2017-11-24 15:00:32 +01001// SPDX-License-Identifier: GPL-2.0
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
Heiko Carstensf5daba12009-03-26 15:24:01 +01003 * Machine check handler
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Heiko Carstensa53c8fa2012-07-20 11:15:04 +02005 * Copyright IBM Corp. 2000, 2009
Heiko Carstensf5daba12009-03-26 15:24:01 +01006 * Author(s): Ingo Adlung <adlung@de.ibm.com>,
7 * Martin Schwidefsky <schwidefsky@de.ibm.com>,
8 * Cornelia Huck <cornelia.huck@de.ibm.com>,
9 * Heiko Carstens <heiko.carstens@de.ibm.com>,
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 */
11
Heiko Carstens052ff462011-01-05 12:47:28 +010012#include <linux/kernel_stat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/errno.h>
Heiko Carstens81f64b82009-04-14 15:36:18 +020015#include <linux/hardirq.h>
Martin Schwidefsky6c815112017-10-12 13:24:47 +020016#include <linux/log2.h>
Martin Schwidefsky00a8f882017-09-15 16:24:31 +020017#include <linux/kprobes.h>
Randy Dunlap514c6032018-04-05 16:25:34 -070018#include <linux/kmemleak.h>
Heiko Carstens022e4fc2006-05-01 12:16:14 -070019#include <linux/time.h>
Ingo Molnar3f07c012017-02-08 18:51:30 +010020#include <linux/module.h>
21#include <linux/sched/signal.h>
22
Paul Gortmaker3994a522017-02-09 15:20:23 -050023#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/lowcore.h>
Heiko Carstensf5daba12009-03-26 15:24:01 +010025#include <asm/smp.h>
Martin Schwidefskyfd5ada02016-05-31 15:06:51 +020026#include <asm/stp.h>
Martin Schwidefsky76d4e002009-06-12 10:26:21 +020027#include <asm/cputime.h>
Heiko Carstensf5daba12009-03-26 15:24:01 +010028#include <asm/nmi.h>
29#include <asm/crw.h>
Martin Schwidefsky80703612014-10-06 17:53:53 +020030#include <asm/switch_to.h>
Heiko Carstenscad49cf2015-07-07 08:40:49 +020031#include <asm/ctl_reg.h>
QingFeng Haoc9295002017-06-07 11:30:42 +020032#include <asm/asm-offsets.h>
QingFeng Haoda72ca42017-06-07 11:41:19 +020033#include <linux/kvm_host.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Heiko Carstens77fa2242005-06-25 14:55:30 -070035struct mcck_struct {
Heiko Carstens36324962015-10-12 13:04:12 +020036 unsigned int kill_task : 1;
37 unsigned int channel_report : 1;
38 unsigned int warning : 1;
Heiko Carstens29b0a822015-10-09 13:48:03 +020039 unsigned int stp_queue : 1;
Heiko Carstensdc6e1552015-10-12 13:00:39 +020040 unsigned long mcck_code;
Heiko Carstens77fa2242005-06-25 14:55:30 -070041};
42
43static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
Martin Schwidefsky6c815112017-10-12 13:24:47 +020044static struct kmem_cache *mcesa_cache;
45static unsigned long mcesa_origin_lc;
46
47static inline int nmi_needs_mcesa(void)
48{
49 return MACHINE_HAS_VX || MACHINE_HAS_GS;
50}
51
52static inline unsigned long nmi_get_mcesa_size(void)
53{
54 if (MACHINE_HAS_GS)
55 return MCESA_MAX_SIZE;
56 return MCESA_MIN_SIZE;
57}
58
59/*
60 * The initial machine check extended save area for the boot CPU.
61 * It will be replaced by nmi_init() with an allocated structure.
62 * The structure is required for machine check happening early in
63 * the boot process.
64 */
65static struct mcesa boot_mcesa __initdata __aligned(MCESA_MAX_SIZE);
66
67void __init nmi_alloc_boot_cpu(struct lowcore *lc)
68{
69 if (!nmi_needs_mcesa())
70 return;
71 lc->mcesad = (unsigned long) &boot_mcesa;
72 if (MACHINE_HAS_GS)
73 lc->mcesad |= ilog2(MCESA_MAX_SIZE);
74}
75
76static int __init nmi_init(void)
77{
78 unsigned long origin, cr0, size;
79
80 if (!nmi_needs_mcesa())
81 return 0;
82 size = nmi_get_mcesa_size();
83 if (size > MCESA_MIN_SIZE)
84 mcesa_origin_lc = ilog2(size);
85 /* create slab cache for the machine-check-extended-save-areas */
86 mcesa_cache = kmem_cache_create("nmi_save_areas", size, size, 0, NULL);
87 if (!mcesa_cache)
88 panic("Couldn't create nmi save area cache");
89 origin = (unsigned long) kmem_cache_alloc(mcesa_cache, GFP_KERNEL);
90 if (!origin)
91 panic("Couldn't allocate nmi save area");
92 /* The pointer is stored with mcesa_bits ORed in */
93 kmemleak_not_leak((void *) origin);
94 __ctl_store(cr0, 0, 0);
95 __ctl_clear_bit(0, 28); /* disable lowcore protection */
96 /* Replace boot_mcesa on the boot CPU */
97 S390_lowcore.mcesad = origin | mcesa_origin_lc;
98 __ctl_load(cr0, 0, 0);
99 return 0;
100}
101early_initcall(nmi_init);
102
103int nmi_alloc_per_cpu(struct lowcore *lc)
104{
105 unsigned long origin;
106
107 if (!nmi_needs_mcesa())
108 return 0;
109 origin = (unsigned long) kmem_cache_alloc(mcesa_cache, GFP_KERNEL);
110 if (!origin)
111 return -ENOMEM;
112 /* The pointer is stored with mcesa_bits ORed in */
113 kmemleak_not_leak((void *) origin);
114 lc->mcesad = origin | mcesa_origin_lc;
115 return 0;
116}
117
118void nmi_free_per_cpu(struct lowcore *lc)
119{
120 if (!nmi_needs_mcesa())
121 return;
122 kmem_cache_free(mcesa_cache, (void *)(lc->mcesad & MCESA_ORIGIN_MASK));
123}
Heiko Carstens77fa2242005-06-25 14:55:30 -0700124
Martin Schwidefsky00a8f882017-09-15 16:24:31 +0200125static notrace void s390_handle_damage(void)
Heiko Carstensf5daba12009-03-26 15:24:01 +0100126{
Martin Schwidefsky00a8f882017-09-15 16:24:31 +0200127 smp_emergency_stop();
Martin Schwidefsky98587c22019-04-30 12:33:45 +0200128 disabled_wait();
Heiko Carstensf5daba12009-03-26 15:24:01 +0100129 while (1);
130}
Martin Schwidefsky00a8f882017-09-15 16:24:31 +0200131NOKPROBE_SYMBOL(s390_handle_damage);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133/*
Heiko Carstens77fa2242005-06-25 14:55:30 -0700134 * Main machine check handler function. Will be called with interrupts enabled
135 * or disabled and machine checks enabled or disabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 */
Heiko Carstensf5daba12009-03-26 15:24:01 +0100137void s390_handle_mcck(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138{
Heiko Carstens77fa2242005-06-25 14:55:30 -0700139 unsigned long flags;
140 struct mcck_struct mcck;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
Heiko Carstens77fa2242005-06-25 14:55:30 -0700142 /*
143 * Disable machine checks and get the current state of accumulated
144 * machine checks. Afterwards delete the old state and enable machine
145 * checks again.
146 */
147 local_irq_save(flags);
148 local_mcck_disable();
Sebastian Ott2cb4a182014-11-28 15:40:57 +0100149 mcck = *this_cpu_ptr(&cpu_mcck);
150 memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(mcck));
Heiko Carstens77fa2242005-06-25 14:55:30 -0700151 local_mcck_enable();
152 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Heiko Carstens77fa2242005-06-25 14:55:30 -0700154 if (mcck.channel_report)
Heiko Carstensf5daba12009-03-26 15:24:01 +0100155 crw_handle_channel_report();
Heiko Carstens7b886412009-03-26 15:24:02 +0100156 /*
157 * A warning may remain for a prolonged period on the bare iron.
158 * (actually until the machine is powered off, or the problem is gone)
159 * So we just stop listening for the WARNING MCH and avoid continuously
160 * being interrupted. One caveat is however, that we must do this per
161 * processor and cannot use the smp version of ctl_clear_bit().
162 * On VM we only get one interrupt per virtally presented machinecheck.
163 * Though one suffices, we may get one interrupt per (virtual) cpu.
164 */
Heiko Carstens77fa2242005-06-25 14:55:30 -0700165 if (mcck.warning) { /* WARNING pending ? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 static int mchchk_wng_posted = 0;
Heiko Carstens7b886412009-03-26 15:24:02 +0100167
168 /* Use single cpu clear, as we cannot handle smp here. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 __ctl_clear_bit(14, 24); /* Disable WARNING MCH */
170 if (xchg(&mchchk_wng_posted, 1) == 0)
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700171 kill_cad_pid(SIGPWR, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 }
Heiko Carstens29b0a822015-10-09 13:48:03 +0200173 if (mcck.stp_queue)
174 stp_queue_work();
Heiko Carstens77fa2242005-06-25 14:55:30 -0700175 if (mcck.kill_task) {
176 local_irq_enable();
177 printk(KERN_EMERG "mcck: Terminating task because of machine "
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200178 "malfunction (code 0x%016lx).\n", mcck.mcck_code);
Heiko Carstens77fa2242005-06-25 14:55:30 -0700179 printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
180 current->comm, current->pid);
181 do_exit(SIGSEGV);
182 }
183}
Christian Borntraeger71cde582008-05-21 13:37:34 +0200184EXPORT_SYMBOL_GPL(s390_handle_mcck);
Heiko Carstens77fa2242005-06-25 14:55:30 -0700185
186/*
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200187 * returns 0 if all required registers are available
Heiko Carstens77fa2242005-06-25 14:55:30 -0700188 * returns 1 otherwise
189 */
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200190static int notrace s390_check_registers(union mci mci, int umode)
Heiko Carstens77fa2242005-06-25 14:55:30 -0700191{
Martin Schwidefskyad3bc0a2017-10-12 13:24:45 +0200192 union ctlreg2 cr2;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700193 int kill_task;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700194
195 kill_task = 0;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100196
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200197 if (!mci.gr) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700198 /*
199 * General purpose registers couldn't be restored and have
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200200 * unknown contents. Stop system or terminate process.
Heiko Carstens77fa2242005-06-25 14:55:30 -0700201 */
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200202 if (!umode)
203 s390_handle_damage();
Heiko Carstens77fa2242005-06-25 14:55:30 -0700204 kill_task = 1;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100205 }
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200206 /* Check control registers */
Heiko Carstens70e28aa2017-02-21 10:51:55 +0100207 if (!mci.cr) {
208 /*
209 * Control registers have unknown contents.
210 * Can't recover and therefore stopping machine.
211 */
212 s390_handle_damage();
Heiko Carstens70e28aa2017-02-21 10:51:55 +0100213 }
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200214 if (!mci.fp) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700215 /*
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200216 * Floating point registers can't be restored. If the
217 * kernel currently uses floating point registers the
218 * system is stopped. If the process has its floating
219 * pointer registers loaded it is terminated.
Heiko Carstens77fa2242005-06-25 14:55:30 -0700220 */
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200221 if (S390_lowcore.fpu_flags & KERNEL_VXR_V0V7)
222 s390_handle_damage();
223 if (!test_cpu_flag(CIF_FPU))
224 kill_task = 1;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100225 }
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200226 if (!mci.fc) {
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100227 /*
228 * Floating point control register can't be restored.
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200229 * If the kernel currently uses the floating pointer
230 * registers and needs the FPC register the system is
231 * stopped. If the process has its floating pointer
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200232 * registers loaded it is terminated.
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100233 */
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200234 if (S390_lowcore.fpu_flags & KERNEL_FPC)
235 s390_handle_damage();
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200236 if (!test_cpu_flag(CIF_FPU))
237 kill_task = 1;
Heiko Carstens86fa7082016-12-13 12:42:07 +0100238 }
Heiko Carstens5a79859a2015-02-12 13:08:27 +0100239
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200240 if (MACHINE_HAS_VX) {
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200241 if (!mci.vr) {
Martin Schwidefsky80703612014-10-06 17:53:53 +0200242 /*
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200243 * Vector registers can't be restored. If the kernel
244 * currently uses vector registers the system is
245 * stopped. If the process has its vector registers
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200246 * loaded it is terminated.
Martin Schwidefsky80703612014-10-06 17:53:53 +0200247 */
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200248 if (S390_lowcore.fpu_flags & KERNEL_VXR)
249 s390_handle_damage();
250 if (!test_cpu_flag(CIF_FPU))
251 kill_task = 1;
Martin Schwidefsky80703612014-10-06 17:53:53 +0200252 }
Martin Schwidefsky80703612014-10-06 17:53:53 +0200253 }
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200254 /* Check if access registers are valid */
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200255 if (!mci.ar) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700256 /*
257 * Access registers have unknown contents.
258 * Terminating task.
259 */
260 kill_task = 1;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100261 }
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200262 /* Check guarded storage registers */
Martin Schwidefskyad3bc0a2017-10-12 13:24:45 +0200263 cr2.val = S390_lowcore.cregs_save_area[2];
264 if (cr2.gse) {
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200265 if (!mci.gs) {
Martin Schwidefsky916cda12016-01-26 14:10:34 +0100266 /*
267 * Guarded storage register can't be restored and
268 * the current processes uses guarded storage.
269 * It has to be terminated.
270 */
271 kill_task = 1;
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200272 }
Martin Schwidefsky916cda12016-01-26 14:10:34 +0100273 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700274 /* Check if old PSW is valid */
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200275 if (!mci.wp) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700276 /*
277 * Can't tell if we come from user or kernel mode
278 * -> stopping machine.
279 */
Heiko Carstens3d682862015-10-12 12:39:09 +0200280 s390_handle_damage();
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200281 }
282 /* Check for invalid kernel instruction address */
283 if (!mci.ia && !umode) {
284 /*
285 * The instruction address got lost while running
286 * in the kernel -> stopping machine.
287 */
288 s390_handle_damage();
289 }
Heiko Carstens77fa2242005-06-25 14:55:30 -0700290
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200291 if (!mci.ms || !mci.pm || !mci.ia)
Heiko Carstens77fa2242005-06-25 14:55:30 -0700292 kill_task = 1;
293
294 return kill_task;
295}
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200296NOKPROBE_SYMBOL(s390_check_registers);
Heiko Carstens77fa2242005-06-25 14:55:30 -0700297
QingFeng Haoda72ca42017-06-07 11:41:19 +0200298/*
299 * Backup the guest's machine check info to its description block
300 */
301static void notrace s390_backup_mcck_info(struct pt_regs *regs)
302{
303 struct mcck_volatile_info *mcck_backup;
304 struct sie_page *sie_page;
305
306 /* r14 contains the sie block, which was set in sie64a */
307 struct kvm_s390_sie_block *sie_block =
308 (struct kvm_s390_sie_block *) regs->gprs[14];
309
310 if (sie_block == NULL)
311 /* Something's seriously wrong, stop system. */
312 s390_handle_damage();
313
314 sie_page = container_of(sie_block, struct sie_page, sie_block);
315 mcck_backup = &sie_page->mcck_info;
316 mcck_backup->mcic = S390_lowcore.mcck_interruption_code &
317 ~(MCCK_CODE_CP | MCCK_CODE_EXT_DAMAGE);
318 mcck_backup->ext_damage_code = S390_lowcore.external_damage_code;
319 mcck_backup->failing_storage_address
320 = S390_lowcore.failing_storage_address;
321}
Martin Schwidefsky00a8f882017-09-15 16:24:31 +0200322NOKPROBE_SYMBOL(s390_backup_mcck_info);
QingFeng Haoda72ca42017-06-07 11:41:19 +0200323
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700324#define MAX_IPD_COUNT 29
Heiko Carstens022e4fc2006-05-01 12:16:14 -0700325#define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700326
Heiko Carstensf5daba12009-03-26 15:24:01 +0100327#define ED_STP_ISLAND 6 /* External damage STP island check */
328#define ED_STP_SYNC 7 /* External damage STP sync check */
Heiko Carstensf5daba12009-03-26 15:24:01 +0100329
QingFeng Haoc9295002017-06-07 11:30:42 +0200330#define MCCK_CODE_NO_GUEST (MCCK_CODE_CP | MCCK_CODE_EXT_DAMAGE)
331
Heiko Carstens77fa2242005-06-25 14:55:30 -0700332/*
333 * machine check handler.
334 */
Sven Schnelle0b0ed652020-02-20 12:09:36 +0100335int notrace s390_do_machine_check(struct pt_regs *regs)
Heiko Carstens77fa2242005-06-25 14:55:30 -0700336{
Heiko Carstensf5daba12009-03-26 15:24:01 +0100337 static int ipd_count;
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700338 static DEFINE_SPINLOCK(ipd_lock);
339 static unsigned long long last_ipd;
Heiko Carstensf5daba12009-03-26 15:24:01 +0100340 struct mcck_struct *mcck;
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700341 unsigned long long tmp;
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200342 union mci mci;
QingFeng Haoc9295002017-06-07 11:30:42 +0200343 unsigned long mcck_dam_code;
Sven Schnelle0b0ed652020-02-20 12:09:36 +0100344 int mcck_pending = 0;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700345
Heiko Carstens81f64b82009-04-14 15:36:18 +0200346 nmi_enter();
Heiko Carstens420f42e2013-01-02 15:18:18 +0100347 inc_irq_stat(NMI_NMI);
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200348 mci.val = S390_lowcore.mcck_interruption_code;
Christoph Lametereb7e7d72014-08-17 12:30:45 -0500349 mcck = this_cpu_ptr(&cpu_mcck);
Heiko Carstens77fa2242005-06-25 14:55:30 -0700350
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200351 if (mci.sd) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700352 /* System damage -> stopping machine */
Heiko Carstens3d682862015-10-12 12:39:09 +0200353 s390_handle_damage();
Heiko Carstensf5daba12009-03-26 15:24:01 +0100354 }
QingFeng Haoc9295002017-06-07 11:30:42 +0200355
356 /*
357 * Reinject the instruction processing damages' machine checks
358 * including Delayed Access Exception into the guest
359 * instead of damaging the host if they happen in the guest.
360 */
361 if (mci.pd && !test_cpu_flag(CIF_MCCK_GUEST)) {
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200362 if (mci.b) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700363 /* Processing backup -> verify if we can survive this */
364 u64 z_mcic, o_mcic, t_mcic;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700365 z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
366 o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
367 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
368 1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
369 1ULL<<16);
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200370 t_mcic = mci.val;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700371
372 if (((t_mcic & z_mcic) != 0) ||
373 ((t_mcic & o_mcic) != o_mcic)) {
Heiko Carstens3d682862015-10-12 12:39:09 +0200374 s390_handle_damage();
Heiko Carstens77fa2242005-06-25 14:55:30 -0700375 }
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700376
377 /*
378 * Nullifying exigent condition, therefore we might
379 * retry this instruction.
380 */
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700381 spin_lock(&ipd_lock);
Heiko Carstens1aae0562013-01-30 09:49:40 +0100382 tmp = get_tod_clock();
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700383 if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
384 ipd_count++;
385 else
386 ipd_count = 1;
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700387 last_ipd = tmp;
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700388 if (ipd_count == MAX_IPD_COUNT)
Heiko Carstens3d682862015-10-12 12:39:09 +0200389 s390_handle_damage();
Heiko Carstensb73d40c2006-04-27 18:40:23 -0700390 spin_unlock(&ipd_lock);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100391 } else {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700392 /* Processing damage -> stopping machine */
Heiko Carstens3d682862015-10-12 12:39:09 +0200393 s390_handle_damage();
Heiko Carstens77fa2242005-06-25 14:55:30 -0700394 }
395 }
Martin Schwidefsky3037a522017-10-12 13:24:48 +0200396 if (s390_check_registers(mci, user_mode(regs))) {
Martin Schwidefsky8f149ea2016-08-22 14:40:06 +0200397 /*
398 * Couldn't restore all register contents for the
399 * user space process -> mark task for termination.
400 */
401 mcck->kill_task = 1;
402 mcck->mcck_code = mci.val;
Sven Schnelle0b0ed652020-02-20 12:09:36 +0100403 mcck_pending = 1;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700404 }
QingFeng Haoda72ca42017-06-07 11:41:19 +0200405
406 /*
407 * Backup the machine check's info if it happens when the guest
408 * is running.
409 */
410 if (test_cpu_flag(CIF_MCCK_GUEST))
411 s390_backup_mcck_info(regs);
412
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200413 if (mci.cd) {
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100414 /* Timing facility damage */
Heiko Carstens3d682862015-10-12 12:39:09 +0200415 s390_handle_damage();
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100416 }
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200417 if (mci.ed && mci.ec) {
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100418 /* External damage */
Martin Schwidefskyd2fec592008-07-14 09:58:56 +0200419 if (S390_lowcore.external_damage_code & (1U << ED_STP_SYNC))
Heiko Carstens29b0a822015-10-09 13:48:03 +0200420 mcck->stp_queue |= stp_sync_check();
Martin Schwidefskyd2fec592008-07-14 09:58:56 +0200421 if (S390_lowcore.external_damage_code & (1U << ED_STP_ISLAND))
Heiko Carstens29b0a822015-10-09 13:48:03 +0200422 mcck->stp_queue |= stp_island_check();
Sven Schnelle0b0ed652020-02-20 12:09:36 +0100423 mcck_pending = 1;
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100424 }
QingFeng Haoc9295002017-06-07 11:30:42 +0200425
426 /*
427 * Reinject storage related machine checks into the guest if they
428 * happen when the guest is running.
429 */
430 if (!test_cpu_flag(CIF_MCCK_GUEST)) {
431 if (mci.se)
432 /* Storage error uncorrected */
433 s390_handle_damage();
434 if (mci.ke)
435 /* Storage key-error uncorrected */
436 s390_handle_damage();
437 if (mci.ds && mci.fa)
438 /* Storage degradation */
439 s390_handle_damage();
440 }
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200441 if (mci.cp) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700442 /* Channel report word pending */
443 mcck->channel_report = 1;
Sven Schnelle0b0ed652020-02-20 12:09:36 +0100444 mcck_pending = 1;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700445 }
Heiko Carstensdc6e1552015-10-12 13:00:39 +0200446 if (mci.w) {
Heiko Carstens77fa2242005-06-25 14:55:30 -0700447 /* Warning pending */
448 mcck->warning = 1;
Sven Schnelle0b0ed652020-02-20 12:09:36 +0100449 mcck_pending = 1;
Heiko Carstens77fa2242005-06-25 14:55:30 -0700450 }
QingFeng Haoc9295002017-06-07 11:30:42 +0200451
452 /*
453 * If there are only Channel Report Pending and External Damage
454 * machine checks, they will not be reinjected into the guest
455 * because they refer to host conditions only.
456 */
457 mcck_dam_code = (mci.val & MCIC_SUBCLASS_MASK);
458 if (test_cpu_flag(CIF_MCCK_GUEST) &&
459 (mcck_dam_code & MCCK_CODE_NO_GUEST) != mcck_dam_code) {
460 /* Set exit reason code for host's later handling */
461 *((long *)(regs->gprs[15] + __SF_SIE_REASON)) = -EINTR;
462 }
463 clear_cpu_flag(CIF_MCCK_GUEST);
Sven Schnelle0b0ed652020-02-20 12:09:36 +0100464
465 if (user_mode(regs) && mcck_pending) {
466 nmi_exit();
467 return 1;
468 }
469
470 if (mcck_pending)
471 schedule_mcck_handler();
472
Heiko Carstens81f64b82009-04-14 15:36:18 +0200473 nmi_exit();
Sven Schnelle0b0ed652020-02-20 12:09:36 +0100474 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475}
Martin Schwidefsky00a8f882017-09-15 16:24:31 +0200476NOKPROBE_SYMBOL(s390_do_machine_check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477
Heiko Carstensf5daba12009-03-26 15:24:01 +0100478static int __init machine_check_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479{
Martin Schwidefskyd54853e2007-02-05 21:18:19 +0100480 ctl_set_bit(14, 25); /* enable external damage MCH */
Heiko Carstensf5daba12009-03-26 15:24:01 +0100481 ctl_set_bit(14, 27); /* enable system recovery MCH */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 ctl_set_bit(14, 24); /* enable warning MCH */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 return 0;
484}
Heiko Carstens24d05ff2015-08-17 08:09:17 +0200485early_initcall(machine_check_init);