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Linux/arch/powerpc/kernel/mce.c

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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  * Machine check exception handling.
  4  *
  5  * Copyright 2013 IBM Corporation
  6  * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
  7  */
  8 
  9 #undef DEBUG
 10 #define pr_fmt(fmt) "mce: " fmt
 11 
 12 #include <linux/hardirq.h>
 13 #include <linux/types.h>
 14 #include <linux/ptrace.h>
 15 #include <linux/percpu.h>
 16 #include <linux/export.h>
 17 #include <linux/irq_work.h>
 18 #include <linux/extable.h>
 19 #include <linux/ftrace.h>
 20 #include <linux/memblock.h>
 21 #include <linux/of.h>
 22 
 23 #include <asm/interrupt.h>
 24 #include <asm/machdep.h>
 25 #include <asm/mce.h>
 26 #include <asm/nmi.h>
 27 
 28 #include "setup.h"
 29 
 30 static void machine_check_ue_event(struct machine_check_event *evt);
 31 static void machine_process_ue_event(struct work_struct *work);
 32 
 33 static DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
 34 
 35 static BLOCKING_NOTIFIER_HEAD(mce_notifier_list);
 36 
 37 int mce_register_notifier(struct notifier_block *nb)
 38 {
 39         return blocking_notifier_chain_register(&mce_notifier_list, nb);
 40 }
 41 EXPORT_SYMBOL_GPL(mce_register_notifier);
 42 
 43 int mce_unregister_notifier(struct notifier_block *nb)
 44 {
 45         return blocking_notifier_chain_unregister(&mce_notifier_list, nb);
 46 }
 47 EXPORT_SYMBOL_GPL(mce_unregister_notifier);
 48 
 49 static void mce_set_error_info(struct machine_check_event *mce,
 50                                struct mce_error_info *mce_err)
 51 {
 52         mce->error_type = mce_err->error_type;
 53         switch (mce_err->error_type) {
 54         case MCE_ERROR_TYPE_UE:
 55                 mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
 56                 break;
 57         case MCE_ERROR_TYPE_SLB:
 58                 mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
 59                 break;
 60         case MCE_ERROR_TYPE_ERAT:
 61                 mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
 62                 break;
 63         case MCE_ERROR_TYPE_TLB:
 64                 mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
 65                 break;
 66         case MCE_ERROR_TYPE_USER:
 67                 mce->u.user_error.user_error_type = mce_err->u.user_error_type;
 68                 break;
 69         case MCE_ERROR_TYPE_RA:
 70                 mce->u.ra_error.ra_error_type = mce_err->u.ra_error_type;
 71                 break;
 72         case MCE_ERROR_TYPE_LINK:
 73                 mce->u.link_error.link_error_type = mce_err->u.link_error_type;
 74                 break;
 75         case MCE_ERROR_TYPE_UNKNOWN:
 76         default:
 77                 break;
 78         }
 79 }
 80 
 81 void mce_irq_work_queue(void)
 82 {
 83         /* Raise decrementer interrupt */
 84         arch_irq_work_raise();
 85         set_mce_pending_irq_work();
 86 }
 87 
 88 /*
 89  * Decode and save high level MCE information into per cpu buffer which
 90  * is an array of machine_check_event structure.
 91  */
 92 void save_mce_event(struct pt_regs *regs, long handled,
 93                     struct mce_error_info *mce_err,
 94                     uint64_t nip, uint64_t addr, uint64_t phys_addr)
 95 {
 96         int index = local_paca->mce_info->mce_nest_count++;
 97         struct machine_check_event *mce;
 98 
 99         mce = &local_paca->mce_info->mce_event[index];
100         /*
101          * Return if we don't have enough space to log mce event.
102          * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
103          * the check below will stop buffer overrun.
104          */
105         if (index >= MAX_MC_EVT)
106                 return;
107 
108         /* Populate generic machine check info */
109         mce->version = MCE_V1;
110         mce->srr0 = nip;
111         mce->srr1 = regs->msr;
112         mce->gpr3 = regs->gpr[3];
113         mce->in_use = 1;
114         mce->cpu = get_paca()->paca_index;
115 
116         /* Mark it recovered if we have handled it and MSR(RI=1). */
117         if (handled && (regs->msr & MSR_RI))
118                 mce->disposition = MCE_DISPOSITION_RECOVERED;
119         else
120                 mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
121 
122         mce->initiator = mce_err->initiator;
123         mce->severity = mce_err->severity;
124         mce->sync_error = mce_err->sync_error;
125         mce->error_class = mce_err->error_class;
126 
127         /*
128          * Populate the mce error_type and type-specific error_type.
129          */
130         mce_set_error_info(mce, mce_err);
131         if (mce->error_type == MCE_ERROR_TYPE_UE)
132                 mce->u.ue_error.ignore_event = mce_err->ignore_event;
133 
134         /*
135          * Raise irq work, So that we don't miss to log the error for
136          * unrecoverable errors.
137          */
138         if (mce->disposition == MCE_DISPOSITION_NOT_RECOVERED)
139                 mce_irq_work_queue();
140 
141         if (!addr)
142                 return;
143 
144         if (mce->error_type == MCE_ERROR_TYPE_TLB) {
145                 mce->u.tlb_error.effective_address_provided = true;
146                 mce->u.tlb_error.effective_address = addr;
147         } else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
148                 mce->u.slb_error.effective_address_provided = true;
149                 mce->u.slb_error.effective_address = addr;
150         } else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
151                 mce->u.erat_error.effective_address_provided = true;
152                 mce->u.erat_error.effective_address = addr;
153         } else if (mce->error_type == MCE_ERROR_TYPE_USER) {
154                 mce->u.user_error.effective_address_provided = true;
155                 mce->u.user_error.effective_address = addr;
156         } else if (mce->error_type == MCE_ERROR_TYPE_RA) {
157                 mce->u.ra_error.effective_address_provided = true;
158                 mce->u.ra_error.effective_address = addr;
159         } else if (mce->error_type == MCE_ERROR_TYPE_LINK) {
160                 mce->u.link_error.effective_address_provided = true;
161                 mce->u.link_error.effective_address = addr;
162         } else if (mce->error_type == MCE_ERROR_TYPE_UE) {
163                 mce->u.ue_error.effective_address_provided = true;
164                 mce->u.ue_error.effective_address = addr;
165                 if (phys_addr != ULONG_MAX) {
166                         mce->u.ue_error.physical_address_provided = true;
167                         mce->u.ue_error.physical_address = phys_addr;
168                         machine_check_ue_event(mce);
169                 }
170         }
171         return;
172 }
173 
174 /*
175  * get_mce_event:
176  *      mce     Pointer to machine_check_event structure to be filled.
177  *      release Flag to indicate whether to free the event slot or not.
178  *              0 <= do not release the mce event. Caller will invoke
179  *                   release_mce_event() once event has been consumed.
180  *              1 <= release the slot.
181  *
182  *      return  1 = success
183  *              0 = failure
184  *
185  * get_mce_event() will be called by platform specific machine check
186  * handle routine and in KVM.
187  * When we call get_mce_event(), we are still in interrupt context and
188  * preemption will not be scheduled until ret_from_expect() routine
189  * is called.
190  */
191 int get_mce_event(struct machine_check_event *mce, bool release)
192 {
193         int index = local_paca->mce_info->mce_nest_count - 1;
194         struct machine_check_event *mc_evt;
195         int ret = 0;
196 
197         /* Sanity check */
198         if (index < 0)
199                 return ret;
200 
201         /* Check if we have MCE info to process. */
202         if (index < MAX_MC_EVT) {
203                 mc_evt = &local_paca->mce_info->mce_event[index];
204                 /* Copy the event structure and release the original */
205                 if (mce)
206                         *mce = *mc_evt;
207                 if (release)
208                         mc_evt->in_use = 0;
209                 ret = 1;
210         }
211         /* Decrement the count to free the slot. */
212         if (release)
213                 local_paca->mce_info->mce_nest_count--;
214 
215         return ret;
216 }
217 
218 void release_mce_event(void)
219 {
220         get_mce_event(NULL, true);
221 }
222 
223 static void machine_check_ue_work(void)
224 {
225         schedule_work(&mce_ue_event_work);
226 }
227 
228 /*
229  * Queue up the MCE event which then can be handled later.
230  */
231 static void machine_check_ue_event(struct machine_check_event *evt)
232 {
233         int index;
234 
235         index = local_paca->mce_info->mce_ue_count++;
236         /* If queue is full, just return for now. */
237         if (index >= MAX_MC_EVT) {
238                 local_paca->mce_info->mce_ue_count--;
239                 return;
240         }
241         memcpy(&local_paca->mce_info->mce_ue_event_queue[index],
242                evt, sizeof(*evt));
243 }
244 
245 /*
246  * Queue up the MCE event which then can be handled later.
247  */
248 void machine_check_queue_event(void)
249 {
250         int index;
251         struct machine_check_event evt;
252 
253         if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
254                 return;
255 
256         index = local_paca->mce_info->mce_queue_count++;
257         /* If queue is full, just return for now. */
258         if (index >= MAX_MC_EVT) {
259                 local_paca->mce_info->mce_queue_count--;
260                 return;
261         }
262         memcpy(&local_paca->mce_info->mce_event_queue[index],
263                &evt, sizeof(evt));
264 
265         mce_irq_work_queue();
266 }
267 
268 void mce_common_process_ue(struct pt_regs *regs,
269                            struct mce_error_info *mce_err)
270 {
271         const struct exception_table_entry *entry;
272 
273         entry = search_kernel_exception_table(regs->nip);
274         if (entry) {
275                 mce_err->ignore_event = true;
276                 regs_set_return_ip(regs, extable_fixup(entry));
277         }
278 }
279 
280 /*
281  * process pending MCE event from the mce event queue. This function will be
282  * called during syscall exit.
283  */
284 static void machine_process_ue_event(struct work_struct *work)
285 {
286         int index;
287         struct machine_check_event *evt;
288 
289         while (local_paca->mce_info->mce_ue_count > 0) {
290                 index = local_paca->mce_info->mce_ue_count - 1;
291                 evt = &local_paca->mce_info->mce_ue_event_queue[index];
292                 blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
293 #ifdef CONFIG_MEMORY_FAILURE
294                 /*
295                  * This should probably queued elsewhere, but
296                  * oh! well
297                  *
298                  * Don't report this machine check because the caller has a
299                  * asked us to ignore the event, it has a fixup handler which
300                  * will do the appropriate error handling and reporting.
301                  */
302                 if (evt->error_type == MCE_ERROR_TYPE_UE) {
303                         if (evt->u.ue_error.ignore_event) {
304                                 local_paca->mce_info->mce_ue_count--;
305                                 continue;
306                         }
307 
308                         if (evt->u.ue_error.physical_address_provided) {
309                                 unsigned long pfn;
310 
311                                 pfn = evt->u.ue_error.physical_address >>
312                                         PAGE_SHIFT;
313                                 memory_failure(pfn, 0);
314                         } else
315                                 pr_warn("Failed to identify bad address from "
316                                         "where the uncorrectable error (UE) "
317                                         "was generated\n");
318                 }
319 #endif
320                 local_paca->mce_info->mce_ue_count--;
321         }
322 }
323 /*
324  * process pending MCE event from the mce event queue. This function will be
325  * called during syscall exit.
326  */
327 static void machine_check_process_queued_event(void)
328 {
329         int index;
330         struct machine_check_event *evt;
331 
332         add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
333 
334         /*
335          * For now just print it to console.
336          * TODO: log this error event to FSP or nvram.
337          */
338         while (local_paca->mce_info->mce_queue_count > 0) {
339                 index = local_paca->mce_info->mce_queue_count - 1;
340                 evt = &local_paca->mce_info->mce_event_queue[index];
341 
342                 if (evt->error_type == MCE_ERROR_TYPE_UE &&
343                     evt->u.ue_error.ignore_event) {
344                         local_paca->mce_info->mce_queue_count--;
345                         continue;
346                 }
347                 machine_check_print_event_info(evt, false, false);
348                 local_paca->mce_info->mce_queue_count--;
349         }
350 }
351 
352 void set_mce_pending_irq_work(void)
353 {
354         local_paca->mce_pending_irq_work = 1;
355 }
356 
357 void clear_mce_pending_irq_work(void)
358 {
359         local_paca->mce_pending_irq_work = 0;
360 }
361 
362 void mce_run_irq_context_handlers(void)
363 {
364         if (unlikely(local_paca->mce_pending_irq_work)) {
365                 if (ppc_md.machine_check_log_err)
366                         ppc_md.machine_check_log_err();
367                 machine_check_process_queued_event();
368                 machine_check_ue_work();
369                 clear_mce_pending_irq_work();
370         }
371 }
372 
373 void machine_check_print_event_info(struct machine_check_event *evt,
374                                     bool user_mode, bool in_guest)
375 {
376         const char *level, *sevstr, *subtype, *err_type, *initiator;
377         uint64_t ea = 0, pa = 0;
378         int n = 0;
379         char dar_str[50];
380         char pa_str[50];
381         static const char *mc_ue_types[] = {
382                 "Indeterminate",
383                 "Instruction fetch",
384                 "Page table walk ifetch",
385                 "Load/Store",
386                 "Page table walk Load/Store",
387         };
388         static const char *mc_slb_types[] = {
389                 "Indeterminate",
390                 "Parity",
391                 "Multihit",
392         };
393         static const char *mc_erat_types[] = {
394                 "Indeterminate",
395                 "Parity",
396                 "Multihit",
397         };
398         static const char *mc_tlb_types[] = {
399                 "Indeterminate",
400                 "Parity",
401                 "Multihit",
402         };
403         static const char *mc_user_types[] = {
404                 "Indeterminate",
405                 "tlbie(l) invalid",
406                 "scv invalid",
407         };
408         static const char *mc_ra_types[] = {
409                 "Indeterminate",
410                 "Instruction fetch (bad)",
411                 "Instruction fetch (foreign/control memory)",
412                 "Page table walk ifetch (bad)",
413                 "Page table walk ifetch (foreign/control memory)",
414                 "Load (bad)",
415                 "Store (bad)",
416                 "Page table walk Load/Store (bad)",
417                 "Page table walk Load/Store (foreign/control memory)",
418                 "Load/Store (foreign/control memory)",
419         };
420         static const char *mc_link_types[] = {
421                 "Indeterminate",
422                 "Instruction fetch (timeout)",
423                 "Page table walk ifetch (timeout)",
424                 "Load (timeout)",
425                 "Store (timeout)",
426                 "Page table walk Load/Store (timeout)",
427         };
428         static const char *mc_error_class[] = {
429                 "Unknown",
430                 "Hardware error",
431                 "Probable Hardware error (some chance of software cause)",
432                 "Software error",
433                 "Probable Software error (some chance of hardware cause)",
434         };
435 
436         /* Print things out */
437         if (evt->version != MCE_V1) {
438                 pr_err("Machine Check Exception, Unknown event version %d !\n",
439                        evt->version);
440                 return;
441         }
442         switch (evt->severity) {
443         case MCE_SEV_NO_ERROR:
444                 level = KERN_INFO;
445                 sevstr = "Harmless";
446                 break;
447         case MCE_SEV_WARNING:
448                 level = KERN_WARNING;
449                 sevstr = "Warning";
450                 break;
451         case MCE_SEV_SEVERE:
452                 level = KERN_ERR;
453                 sevstr = "Severe";
454                 break;
455         case MCE_SEV_FATAL:
456         default:
457                 level = KERN_ERR;
458                 sevstr = "Fatal";
459                 break;
460         }
461 
462         switch(evt->initiator) {
463         case MCE_INITIATOR_CPU:
464                 initiator = "CPU";
465                 break;
466         case MCE_INITIATOR_PCI:
467                 initiator = "PCI";
468                 break;
469         case MCE_INITIATOR_ISA:
470                 initiator = "ISA";
471                 break;
472         case MCE_INITIATOR_MEMORY:
473                 initiator = "Memory";
474                 break;
475         case MCE_INITIATOR_POWERMGM:
476                 initiator = "Power Management";
477                 break;
478         case MCE_INITIATOR_UNKNOWN:
479         default:
480                 initiator = "Unknown";
481                 break;
482         }
483 
484         switch (evt->error_type) {
485         case MCE_ERROR_TYPE_UE:
486                 err_type = "UE";
487                 subtype = evt->u.ue_error.ue_error_type <
488                         ARRAY_SIZE(mc_ue_types) ?
489                         mc_ue_types[evt->u.ue_error.ue_error_type]
490                         : "Unknown";
491                 if (evt->u.ue_error.effective_address_provided)
492                         ea = evt->u.ue_error.effective_address;
493                 if (evt->u.ue_error.physical_address_provided)
494                         pa = evt->u.ue_error.physical_address;
495                 break;
496         case MCE_ERROR_TYPE_SLB:
497                 err_type = "SLB";
498                 subtype = evt->u.slb_error.slb_error_type <
499                         ARRAY_SIZE(mc_slb_types) ?
500                         mc_slb_types[evt->u.slb_error.slb_error_type]
501                         : "Unknown";
502                 if (evt->u.slb_error.effective_address_provided)
503                         ea = evt->u.slb_error.effective_address;
504                 break;
505         case MCE_ERROR_TYPE_ERAT:
506                 err_type = "ERAT";
507                 subtype = evt->u.erat_error.erat_error_type <
508                         ARRAY_SIZE(mc_erat_types) ?
509                         mc_erat_types[evt->u.erat_error.erat_error_type]
510                         : "Unknown";
511                 if (evt->u.erat_error.effective_address_provided)
512                         ea = evt->u.erat_error.effective_address;
513                 break;
514         case MCE_ERROR_TYPE_TLB:
515                 err_type = "TLB";
516                 subtype = evt->u.tlb_error.tlb_error_type <
517                         ARRAY_SIZE(mc_tlb_types) ?
518                         mc_tlb_types[evt->u.tlb_error.tlb_error_type]
519                         : "Unknown";
520                 if (evt->u.tlb_error.effective_address_provided)
521                         ea = evt->u.tlb_error.effective_address;
522                 break;
523         case MCE_ERROR_TYPE_USER:
524                 err_type = "User";
525                 subtype = evt->u.user_error.user_error_type <
526                         ARRAY_SIZE(mc_user_types) ?
527                         mc_user_types[evt->u.user_error.user_error_type]
528                         : "Unknown";
529                 if (evt->u.user_error.effective_address_provided)
530                         ea = evt->u.user_error.effective_address;
531                 break;
532         case MCE_ERROR_TYPE_RA:
533                 err_type = "Real address";
534                 subtype = evt->u.ra_error.ra_error_type <
535                         ARRAY_SIZE(mc_ra_types) ?
536                         mc_ra_types[evt->u.ra_error.ra_error_type]
537                         : "Unknown";
538                 if (evt->u.ra_error.effective_address_provided)
539                         ea = evt->u.ra_error.effective_address;
540                 break;
541         case MCE_ERROR_TYPE_LINK:
542                 err_type = "Link";
543                 subtype = evt->u.link_error.link_error_type <
544                         ARRAY_SIZE(mc_link_types) ?
545                         mc_link_types[evt->u.link_error.link_error_type]
546                         : "Unknown";
547                 if (evt->u.link_error.effective_address_provided)
548                         ea = evt->u.link_error.effective_address;
549                 break;
550         case MCE_ERROR_TYPE_DCACHE:
551                 err_type = "D-Cache";
552                 subtype = "Unknown";
553                 break;
554         case MCE_ERROR_TYPE_ICACHE:
555                 err_type = "I-Cache";
556                 subtype = "Unknown";
557                 break;
558         default:
559         case MCE_ERROR_TYPE_UNKNOWN:
560                 err_type = "Unknown";
561                 subtype = "";
562                 break;
563         }
564 
565         dar_str[0] = pa_str[0] = '\0';
566         if (ea && evt->srr0 != ea) {
567                 /* Load/Store address */
568                 n = sprintf(dar_str, "DAR: %016llx ", ea);
569                 if (pa)
570                         sprintf(dar_str + n, "paddr: %016llx ", pa);
571         } else if (pa) {
572                 sprintf(pa_str, " paddr: %016llx", pa);
573         }
574 
575         printk("%sMCE: CPU%d: machine check (%s) %s %s %s %s[%s]\n",
576                 level, evt->cpu, sevstr, in_guest ? "Guest" : "",
577                 err_type, subtype, dar_str,
578                 evt->disposition == MCE_DISPOSITION_RECOVERED ?
579                 "Recovered" : "Not recovered");
580 
581         if (in_guest || user_mode) {
582                 printk("%sMCE: CPU%d: PID: %d Comm: %s %sNIP: [%016llx]%s\n",
583                         level, evt->cpu, current->pid, current->comm,
584                         in_guest ? "Guest " : "", evt->srr0, pa_str);
585         } else {
586                 printk("%sMCE: CPU%d: NIP: [%016llx] %pS%s\n",
587                         level, evt->cpu, evt->srr0, (void *)evt->srr0, pa_str);
588         }
589 
590         printk("%sMCE: CPU%d: Initiator %s\n", level, evt->cpu, initiator);
591 
592         subtype = evt->error_class < ARRAY_SIZE(mc_error_class) ?
593                 mc_error_class[evt->error_class] : "Unknown";
594         printk("%sMCE: CPU%d: %s\n", level, evt->cpu, subtype);
595 
596 #ifdef CONFIG_PPC_64S_HASH_MMU
597         /* Display faulty slb contents for SLB errors. */
598         if (evt->error_type == MCE_ERROR_TYPE_SLB && !in_guest)
599                 slb_dump_contents(local_paca->mce_faulty_slbs);
600 #endif
601 }
602 EXPORT_SYMBOL_GPL(machine_check_print_event_info);
603 
604 /*
605  * This function is called in real mode. Strictly no printk's please.
606  *
607  * regs->nip and regs->msr contains srr0 and ssr1.
608  */
609 DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early)
610 {
611         long handled = 0;
612 
613         hv_nmi_check_nonrecoverable(regs);
614 
615         /*
616          * See if platform is capable of handling machine check.
617          */
618         if (ppc_md.machine_check_early)
619                 handled = ppc_md.machine_check_early(regs);
620 
621         return handled;
622 }
623 
624 /* Possible meanings for HMER_DEBUG_TRIG bit being set on POWER9 */
625 static enum {
626         DTRIG_UNKNOWN,
627         DTRIG_VECTOR_CI,        /* need to emulate vector CI load instr */
628         DTRIG_SUSPEND_ESCAPE,   /* need to escape from TM suspend mode */
629 } hmer_debug_trig_function;
630 
631 static int init_debug_trig_function(void)
632 {
633         int pvr;
634         struct device_node *cpun;
635         struct property *prop = NULL;
636         const char *str;
637 
638         /* First look in the device tree */
639         preempt_disable();
640         cpun = of_get_cpu_node(smp_processor_id(), NULL);
641         if (cpun) {
642                 of_property_for_each_string(cpun, "ibm,hmi-special-triggers",
643                                             prop, str) {
644                         if (strcmp(str, "bit17-vector-ci-load") == 0)
645                                 hmer_debug_trig_function = DTRIG_VECTOR_CI;
646                         else if (strcmp(str, "bit17-tm-suspend-escape") == 0)
647                                 hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
648                 }
649                 of_node_put(cpun);
650         }
651         preempt_enable();
652 
653         /* If we found the property, don't look at PVR */
654         if (prop)
655                 goto out;
656 
657         pvr = mfspr(SPRN_PVR);
658         /* Check for POWER9 Nimbus (scale-out) */
659         if ((PVR_VER(pvr) == PVR_POWER9) && (pvr & 0xe000) == 0) {
660                 /* DD2.2 and later */
661                 if ((pvr & 0xfff) >= 0x202)
662                         hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
663                 /* DD2.0 and DD2.1 - used for vector CI load emulation */
664                 else if ((pvr & 0xfff) >= 0x200)
665                         hmer_debug_trig_function = DTRIG_VECTOR_CI;
666         }
667 
668  out:
669         switch (hmer_debug_trig_function) {
670         case DTRIG_VECTOR_CI:
671                 pr_debug("HMI debug trigger used for vector CI load\n");
672                 break;
673         case DTRIG_SUSPEND_ESCAPE:
674                 pr_debug("HMI debug trigger used for TM suspend escape\n");
675                 break;
676         default:
677                 break;
678         }
679         return 0;
680 }
681 __initcall(init_debug_trig_function);
682 
683 /*
684  * Handle HMIs that occur as a result of a debug trigger.
685  * Return values:
686  * -1 means this is not a HMI cause that we know about
687  *  0 means no further handling is required
688  *  1 means further handling is required
689  */
690 long hmi_handle_debugtrig(struct pt_regs *regs)
691 {
692         unsigned long hmer = mfspr(SPRN_HMER);
693         long ret = 0;
694 
695         /* HMER_DEBUG_TRIG bit is used for various workarounds on P9 */
696         if (!((hmer & HMER_DEBUG_TRIG)
697               && hmer_debug_trig_function != DTRIG_UNKNOWN))
698                 return -1;
699                 
700         hmer &= ~HMER_DEBUG_TRIG;
701         /* HMER is a write-AND register */
702         mtspr(SPRN_HMER, ~HMER_DEBUG_TRIG);
703 
704         switch (hmer_debug_trig_function) {
705         case DTRIG_VECTOR_CI:
706                 /*
707                  * Now to avoid problems with soft-disable we
708                  * only do the emulation if we are coming from
709                  * host user space
710                  */
711                 if (regs && user_mode(regs))
712                         ret = local_paca->hmi_p9_special_emu = 1;
713 
714                 break;
715 
716         default:
717                 break;
718         }
719 
720         /*
721          * See if any other HMI causes remain to be handled
722          */
723         if (hmer & mfspr(SPRN_HMEER))
724                 return -1;
725 
726         return ret;
727 }
728 
729 /*
730  * Return values:
731  */
732 DEFINE_INTERRUPT_HANDLER_NMI(hmi_exception_realmode)
733 {       
734         int ret;
735 
736         local_paca->hmi_irqs++;
737 
738         ret = hmi_handle_debugtrig(regs);
739         if (ret >= 0)
740                 return ret;
741 
742         wait_for_subcore_guest_exit();
743 
744         if (ppc_md.hmi_exception_early)
745                 ppc_md.hmi_exception_early(regs);
746 
747         wait_for_tb_resync();
748 
749         return 1;
750 }
751 
752 void __init mce_init(void)
753 {
754         struct mce_info *mce_info;
755         u64 limit;
756         int i;
757 
758         limit = min(ppc64_bolted_size(), ppc64_rma_size);
759         for_each_possible_cpu(i) {
760                 mce_info = memblock_alloc_try_nid(sizeof(*mce_info),
761                                                   __alignof__(*mce_info),
762                                                   MEMBLOCK_LOW_LIMIT,
763                                                   limit, early_cpu_to_node(i));
764                 if (!mce_info)
765                         goto err;
766                 paca_ptrs[i]->mce_info = mce_info;
767         }
768         return;
769 err:
770         panic("Failed to allocate memory for MCE event data\n");
771 }
772 

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