arch/ia64/kernel/mca_drv.c

   1 /*
   2  * File:        mca_drv.c
   3  * Purpose:     Generic MCA handling layer
   4  *
   5  * Copyright (C) 2004 FUJITSU LIMITED
   6  * Copyright (C) Hidetoshi Seto (seto.hidetoshi@jp.fujitsu.com)
   7  * Copyright (C) 2005 Silicon Graphics, Inc
   8  * Copyright (C) 2005 Keith Owens <kaos@sgi.com>
   9  * Copyright (C) 2006 Russ Anderson <rja@sgi.com>
  10  */
  11 #include <linux/types.h>
  12 #include <linux/init.h>
  13 #include <linux/sched.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/irq.h>
  16 #include <linux/kallsyms.h>
  17 #include <linux/bootmem.h>
  18 #include <linux/acpi.h>
  19 #include <linux/timer.h>
  20 #include <linux/module.h>
  21 #include <linux/kernel.h>
  22 #include <linux/smp.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/mm.h>
  25
  26 #include <asm/delay.h>
  27 #include <asm/machvec.h>
  28 #include <asm/page.h>
  29 #include <asm/ptrace.h>
  30 #include <asm/system.h>
  31 #include <asm/sal.h>
  32 #include <asm/mca.h>
  33
  34 #include <asm/irq.h>
  35 #include <asm/hw_irq.h>
  36
  37 #include "mca_drv.h"
  38
  39 /* max size of SAL error record (default) */
  40 static int sal_rec_max = 10000;
  41
  42 /* from mca_drv_asm.S */
  43 extern void *mca_handler_bhhook(void);
  44
  45 static DEFINE_SPINLOCK(mca_bh_lock);
  46
  47 typedef enum {
  48         MCA_IS_LOCAL  = 0,
  49         MCA_IS_GLOBAL = 1
  50 } mca_type_t;
  51
  52 #define MAX_PAGE_ISOLATE 1024
  53
  54 static struct page *page_isolate[MAX_PAGE_ISOLATE];
  55 static int num_page_isolate = 0;
  56
  57 typedef enum {
  58         ISOLATE_NG,
  59         ISOLATE_OK,
  60         ISOLATE_NONE
  61 } isolate_status_t;
  62
  63 typedef enum {
  64         MCA_NOT_RECOVERED = 0,
  65         MCA_RECOVERED     = 1
  66 } recovery_status_t;
  67
  68 /*
  69  *  This pool keeps pointers to the section part of SAL error record
  70  */
  71 static struct {
  72         slidx_list_t *buffer; /* section pointer list pool */
  73         int          cur_idx; /* Current index of section pointer list pool */
  74         int          max_idx; /* Maximum index of section pointer list pool */
  75 } slidx_pool;
  76
  77 static int
  78 fatal_mca(const char *fmt, ...)
  79 {
  80         va_list args;
  81         char buf[256];
  82
  83         va_start(args, fmt);
  84         vsnprintf(buf, sizeof(buf), fmt, args);
  85         va_end(args);
  86         ia64_mca_printk(KERN_ALERT "MCA: %s\n", buf);
  87
  88         return MCA_NOT_RECOVERED;
  89 }
  90
  91 static int
  92 mca_recovered(const char *fmt, ...)
  93 {
  94         va_list args;
  95         char buf[256];
  96
  97         va_start(args, fmt);
  98         vsnprintf(buf, sizeof(buf), fmt, args);
  99         va_end(args);
 100         ia64_mca_printk(KERN_INFO "MCA: %s\n", buf);
 101
 102         return MCA_RECOVERED;
 103 }
 104
 105 /**
 106  * mca_page_isolate - isolate a poisoned page in order not to use it later
 107  * @paddr:      poisoned memory location
 108  *
 109  * Return value:
 110  *      one of isolate_status_t, ISOLATE_OK/NG/NONE.
 111  */
 112
 113 static isolate_status_t
 114 mca_page_isolate(unsigned long paddr)
 115 {
 116         int i;
 117         struct page *p;
 118
 119         /* whether physical address is valid or not */
 120         if (!ia64_phys_addr_valid(paddr))
 121                 return ISOLATE_NONE;
 122
 123         if (!pfn_valid(paddr >> PAGE_SHIFT))
 124                 return ISOLATE_NONE;
 125
 126         /* convert physical address to physical page number */
 127         p = pfn_to_page(paddr>>PAGE_SHIFT);
 128
 129         /* check whether a page number have been already registered or not */
 130         for (i = 0; i < num_page_isolate; i++)
 131                 if (page_isolate[i] == p)
 132                         return ISOLATE_OK; /* already listed */
 133
 134         /* limitation check */
 135         if (num_page_isolate == MAX_PAGE_ISOLATE)
 136                 return ISOLATE_NG;
 137
 138         /* kick pages having attribute 'SLAB' or 'Reserved' */
 139         if (PageSlab(p) || PageReserved(p))
 140                 return ISOLATE_NG;
 141
 142         /* add attribute 'Reserved' and register the page */
 143         get_page(p);
 144         SetPageReserved(p);
 145         page_isolate[num_page_isolate++] = p;
 146
 147         return ISOLATE_OK;
 148 }
 149
 150 /**
 151  * mca_hanlder_bh - Kill the process which occurred memory read error
 152  * @paddr:      poisoned address received from MCA Handler
 153  */
 154
 155 void
 156 mca_handler_bh(unsigned long paddr, void *iip, unsigned long ipsr)
 157 {
 158         ia64_mlogbuf_dump();
 159         printk(KERN_ERR "OS_MCA: process [cpu %d, pid: %d, uid: %d, "
 160                 "iip: %p, psr: 0x%lx,paddr: 0x%lx](%s) encounters MCA.\n",
 161                 raw_smp_processor_id(), current->pid, current->uid,
 162                 iip, ipsr, paddr, current->comm);
 163
 164         spin_lock(&mca_bh_lock);
 165         switch (mca_page_isolate(paddr)) {
 166         case ISOLATE_OK:
 167                 printk(KERN_DEBUG "Page isolation: ( %lx ) success.\n", paddr);
 168                 break;
 169         case ISOLATE_NG:
 170                 printk(KERN_CRIT "Page isolation: ( %lx ) failure.\n", paddr);
 171                 break;
 172         default:
 173                 break;
 174         }
 175         spin_unlock(&mca_bh_lock);
 176
 177         /* This process is about to be killed itself */
 178         do_exit(SIGKILL);
 179 }
 180
 181 /**
 182  * mca_make_peidx - Make index of processor error section
 183  * @slpi:       pointer to record of processor error section
 184  * @peidx:      pointer to index of processor error section
 185  */
 186
 187 static void
 188 mca_make_peidx(sal_log_processor_info_t *slpi, peidx_table_t *peidx)
 189 {
 190         /*
 191          * calculate the start address of
 192          *   "struct cpuid_info" and "sal_processor_static_info_t".
 193          */
 194         u64 total_check_num = slpi->valid.num_cache_check
 195                                 + slpi->valid.num_tlb_check
 196                                 + slpi->valid.num_bus_check
 197                                 + slpi->valid.num_reg_file_check
 198                                 + slpi->valid.num_ms_check;
 199         u64 head_size = sizeof(sal_log_mod_error_info_t) * total_check_num
 200                         + sizeof(sal_log_processor_info_t);
 201         u64 mid_size  = slpi->valid.cpuid_info * sizeof(struct sal_cpuid_info);
 202
 203         peidx_head(peidx)   = slpi;
 204         peidx_mid(peidx)    = (struct sal_cpuid_info *)
 205                 (slpi->valid.cpuid_info ? ((char*)slpi + head_size) : NULL);
 206         peidx_bottom(peidx) = (sal_processor_static_info_t *)
 207                 (slpi->valid.psi_static_struct ?
 208                         ((char*)slpi + head_size + mid_size) : NULL);
 209 }
 210
 211 /**
 212  * mca_make_slidx -  Make index of SAL error record
 213  * @buffer:     pointer to SAL error record
 214  * @slidx:      pointer to index of SAL error record
 215  *
 216  * Return value:
 217  *      1 if record has platform error / 0 if not
 218  */
 219 #define LOG_INDEX_ADD_SECT_PTR(sect, ptr) \
 220         {slidx_list_t *hl = &slidx_pool.buffer[slidx_pool.cur_idx]; \
 221         hl->hdr = ptr; \
 222         list_add(&hl->list, &(sect)); \
 223         slidx_pool.cur_idx = (slidx_pool.cur_idx + 1)%slidx_pool.max_idx; }
 224
 225 static int
 226 mca_make_slidx(void *buffer, slidx_table_t *slidx)
 227 {
 228         int platform_err = 0;
 229         int record_len = ((sal_log_record_header_t*)buffer)->len;
 230         u32 ercd_pos;
 231         int sects;
 232         sal_log_section_hdr_t *sp;
 233
 234         /*
 235          * Initialize index referring current record
 236          */
 237         INIT_LIST_HEAD(&(slidx->proc_err));
 238         INIT_LIST_HEAD(&(slidx->mem_dev_err));
 239         INIT_LIST_HEAD(&(slidx->sel_dev_err));
 240         INIT_LIST_HEAD(&(slidx->pci_bus_err));
 241         INIT_LIST_HEAD(&(slidx->smbios_dev_err));
 242         INIT_LIST_HEAD(&(slidx->pci_comp_err));
 243         INIT_LIST_HEAD(&(slidx->plat_specific_err));
 244         INIT_LIST_HEAD(&(slidx->host_ctlr_err));
 245         INIT_LIST_HEAD(&(slidx->plat_bus_err));
 246         INIT_LIST_HEAD(&(slidx->unsupported));
 247
 248         /*
 249          * Extract a Record Header
 250          */
 251         slidx->header = buffer;
 252
 253         /*
 254          * Extract each section records
 255          * (arranged from "int ia64_log_platform_info_print()")
 256          */
 257         for (ercd_pos = sizeof(sal_log_record_header_t), sects = 0;
 258                 ercd_pos < record_len; ercd_pos += sp->len, sects++) {
 259                 sp = (sal_log_section_hdr_t *)((char*)buffer + ercd_pos);
 260                 if (!efi_guidcmp(sp->guid, SAL_PROC_DEV_ERR_SECT_GUID)) {
 261                         LOG_INDEX_ADD_SECT_PTR(slidx->proc_err, sp);
 262                 } else if (!efi_guidcmp(sp->guid,
 263                                 SAL_PLAT_MEM_DEV_ERR_SECT_GUID)) {
 264                         platform_err = 1;
 265                         LOG_INDEX_ADD_SECT_PTR(slidx->mem_dev_err, sp);
 266                 } else if (!efi_guidcmp(sp->guid,
 267                                 SAL_PLAT_SEL_DEV_ERR_SECT_GUID)) {
 268                         platform_err = 1;
 269                         LOG_INDEX_ADD_SECT_PTR(slidx->sel_dev_err, sp);
 270                 } else if (!efi_guidcmp(sp->guid,
 271                                 SAL_PLAT_PCI_BUS_ERR_SECT_GUID)) {
 272                         platform_err = 1;
 273                         LOG_INDEX_ADD_SECT_PTR(slidx->pci_bus_err, sp);
 274                 } else if (!efi_guidcmp(sp->guid,
 275                                 SAL_PLAT_SMBIOS_DEV_ERR_SECT_GUID)) {
 276                         platform_err = 1;
 277                         LOG_INDEX_ADD_SECT_PTR(slidx->smbios_dev_err, sp);
 278                 } else if (!efi_guidcmp(sp->guid,
 279                                 SAL_PLAT_PCI_COMP_ERR_SECT_GUID)) {
 280                         platform_err = 1;
 281                         LOG_INDEX_ADD_SECT_PTR(slidx->pci_comp_err, sp);
 282                 } else if (!efi_guidcmp(sp->guid,
 283                                 SAL_PLAT_SPECIFIC_ERR_SECT_GUID)) {
 284                         platform_err = 1;
 285                         LOG_INDEX_ADD_SECT_PTR(slidx->plat_specific_err, sp);
 286                 } else if (!efi_guidcmp(sp->guid,
 287                                 SAL_PLAT_HOST_CTLR_ERR_SECT_GUID)) {
 288                         platform_err = 1;
 289                         LOG_INDEX_ADD_SECT_PTR(slidx->host_ctlr_err, sp);
 290                 } else if (!efi_guidcmp(sp->guid,
 291                                 SAL_PLAT_BUS_ERR_SECT_GUID)) {
 292                         platform_err = 1;
 293                         LOG_INDEX_ADD_SECT_PTR(slidx->plat_bus_err, sp);
 294                 } else {
 295                         LOG_INDEX_ADD_SECT_PTR(slidx->unsupported, sp);
 296                 }
 297         }
 298         slidx->n_sections = sects;
 299
 300         return platform_err;
 301 }
 302
 303 /**
 304  * init_record_index_pools - Initialize pool of lists for SAL record index
 305  *
 306  * Return value:
 307  *      0 on Success / -ENOMEM on Failure
 308  */
 309 static int
 310 init_record_index_pools(void)
 311 {
 312         int i;
 313         int rec_max_size;  /* Maximum size of SAL error records */
 314         int sect_min_size; /* Minimum size of SAL error sections */
 315         /* minimum size table of each section */
 316         static int sal_log_sect_min_sizes[] = {
 317                 sizeof(sal_log_processor_info_t)
 318                 + sizeof(sal_processor_static_info_t),
 319                 sizeof(sal_log_mem_dev_err_info_t),
 320                 sizeof(sal_log_sel_dev_err_info_t),
 321                 sizeof(sal_log_pci_bus_err_info_t),
 322                 sizeof(sal_log_smbios_dev_err_info_t),
 323                 sizeof(sal_log_pci_comp_err_info_t),
 324                 sizeof(sal_log_plat_specific_err_info_t),
 325                 sizeof(sal_log_host_ctlr_err_info_t),
 326                 sizeof(sal_log_plat_bus_err_info_t),
 327         };
 328
 329         /*
 330          * MCA handler cannot allocate new memory on flight,
 331          * so we preallocate enough memory to handle a SAL record.
 332          *
 333          * Initialize a handling set of slidx_pool:
 334          *   1. Pick up the max size of SAL error records
 335          *   2. Pick up the min size of SAL error sections
 336          *   3. Allocate the pool as enough to 2 SAL records
 337          *     (now we can estimate the maxinum of section in a record.)
 338          */
 339
 340         /* - 1 - */
 341         rec_max_size = sal_rec_max;
 342
 343         /* - 2 - */
 344         sect_min_size = sal_log_sect_min_sizes[0];
 345         for (i = 1; i < sizeof sal_log_sect_min_sizes/sizeof(size_t); i++)
 346                 if (sect_min_size > sal_log_sect_min_sizes[i])
 347                         sect_min_size = sal_log_sect_min_sizes[i];
 348
 349         /* - 3 - */
 350         slidx_pool.max_idx = (rec_max_size/sect_min_size) * 2 + 1;
 351         slidx_pool.buffer = (slidx_list_t *)
 352                 kmalloc(slidx_pool.max_idx * sizeof(slidx_list_t), GFP_KERNEL);
 353
 354         return slidx_pool.buffer ? 0 : -ENOMEM;
 355 }
 356
 357
 358 /*****************************************************************************
 359  * Recovery functions                                                        *
 360  *****************************************************************************/
 361
 362 /**
 363  * is_mca_global - Check whether this MCA is global or not
 364  * @peidx:      pointer of index of processor error section
 365  * @pbci:       pointer to pal_bus_check_info_t
 366  * @sos:        pointer to hand off struct between SAL and OS
 367  *
 368  * Return value:
 369  *      MCA_IS_LOCAL / MCA_IS_GLOBAL
 370  */
 371
 372 static mca_type_t
 373 is_mca_global(peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 374               struct ia64_sal_os_state *sos)
 375 {
 376         pal_processor_state_info_t *psp =
 377                 (pal_processor_state_info_t*)peidx_psp(peidx);
 378
 379         /*
 380          * PAL can request a rendezvous, if the MCA has a global scope.
 381          * If "rz_always" flag is set, SAL requests MCA rendezvous
 382          * in spite of global MCA.
 383          * Therefore it is local MCA when rendezvous has not been requested.
 384          * Failed to rendezvous, the system must be down.
 385          */
 386         switch (sos->rv_rc) {
 387                 case -1: /* SAL rendezvous unsuccessful */
 388                         return MCA_IS_GLOBAL;
 389                 case  0: /* SAL rendezvous not required */
 390                         return MCA_IS_LOCAL;
 391                 case  1: /* SAL rendezvous successful int */
 392                 case  2: /* SAL rendezvous successful int with init */
 393                 default:
 394                         break;
 395         }
 396
 397         /*
 398          * If One or more Cache/TLB/Reg_File/Uarch_Check is here,
 399          * it would be a local MCA. (i.e. processor internal error)
 400          */
 401         if (psp->tc || psp->cc || psp->rc || psp->uc)
 402                 return MCA_IS_LOCAL;
 403
 404         /*
 405          * Bus_Check structure with Bus_Check.ib (internal bus error) flag set
 406          * would be a global MCA. (e.g. a system bus address parity error)
 407          */
 408         if (!pbci || pbci->ib)
 409                 return MCA_IS_GLOBAL;
 410
 411         /*
 412          * Bus_Check structure with Bus_Check.eb (external bus error) flag set
 413          * could be either a local MCA or a global MCA.
 414          *
 415          * Referring Bus_Check.bsi:
 416          *   0: Unknown/unclassified
 417          *   1: BERR#
 418          *   2: BINIT#
 419          *   3: Hard Fail
 420          * (FIXME: Are these SGI specific or generic bsi values?)
 421          */
 422         if (pbci->eb)
 423                 switch (pbci->bsi) {
 424                         case 0:
 425                                 /* e.g. a load from poisoned memory */
 426                                 return MCA_IS_LOCAL;
 427                         case 1:
 428                         case 2:
 429                         case 3:
 430                                 return MCA_IS_GLOBAL;
 431                 }
 432
 433         return MCA_IS_GLOBAL;
 434 }
 435
 436 /**
 437  * get_target_identifier - Get the valid Cache or Bus check target identifier.
 438  * @peidx:      pointer of index of processor error section
 439  *
 440  * Return value:
 441  *      target address on Success / 0 on Failure
 442  */
 443 static u64
 444 get_target_identifier(peidx_table_t *peidx)
 445 {
 446         u64 target_address = 0;
 447         sal_log_mod_error_info_t *smei;
 448         pal_cache_check_info_t *pcci;
 449         int i, level = 9;
 450
 451         /*
 452          * Look through the cache checks for a valid target identifier
 453          * If more than one valid target identifier, return the one
 454          * with the lowest cache level.
 455          */
 456         for (i = 0; i < peidx_cache_check_num(peidx); i++) {
 457                 smei = (sal_log_mod_error_info_t *)peidx_cache_check(peidx, i);
 458                 if (smei->valid.target_identifier && smei->target_identifier) {
 459                         pcci = (pal_cache_check_info_t *)&(smei->check_info);
 460                         if (!target_address || (pcci->level < level)) {
 461                                 target_address = smei->target_identifier;
 462                                 level = pcci->level;
 463                                 continue;
 464                         }
 465                 }
 466         }
 467         if (target_address)
 468                 return target_address;
 469
 470         /*
 471          * Look at the bus check for a valid target identifier
 472          */
 473         smei = peidx_bus_check(peidx, 0);
 474         if (smei && smei->valid.target_identifier)
 475                 return smei->target_identifier;
 476
 477         return 0;
 478 }
 479
 480 /**
 481  * recover_from_read_error - Try to recover the errors which type are "read"s.
 482  * @slidx:      pointer of index of SAL error record
 483  * @peidx:      pointer of index of processor error section
 484  * @pbci:       pointer of pal_bus_check_info
 485  * @sos:        pointer to hand off struct between SAL and OS
 486  *
 487  * Return value:
 488  *      1 on Success / 0 on Failure
 489  */
 490
 491 static int
 492 recover_from_read_error(slidx_table_t *slidx,
 493                         peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 494                         struct ia64_sal_os_state *sos)
 495 {
 496         u64 target_identifier;
 497         pal_min_state_area_t *pmsa;
 498         struct ia64_psr *psr1, *psr2;
 499         ia64_fptr_t *mca_hdlr_bh = (ia64_fptr_t*)mca_handler_bhhook;
 500
 501         /* Is target address valid? */
 502         target_identifier = get_target_identifier(peidx);
 503         if (!target_identifier)
 504                 return fatal_mca("target address not valid");
 505
 506         /*
 507          * cpu read or memory-mapped io read
 508          *
 509          *    offending process  affected process  OS MCA do
 510          *     kernel mode        kernel mode       down system
 511          *     kernel mode        user   mode       kill the process
 512          *     user   mode        kernel mode       down system (*)
 513          *     user   mode        user   mode       kill the process
 514          *
 515          * (*) You could terminate offending user-mode process
 516          *    if (pbci->pv && pbci->pl != 0) *and* if you sure
 517          *    the process not have any locks of kernel.
 518          */
 519
 520         /* Is minstate valid? */
 521         if (!peidx_bottom(peidx) || !(peidx_bottom(peidx)->valid.minstate))
 522                 return fatal_mca("minstate not valid");
 523         psr1 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_ipsr);
 524         psr2 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_xpsr);
 525
 526         /*
 527          *  Check the privilege level of interrupted context.
 528          *   If it is user-mode, then terminate affected process.
 529          */
 530
 531         pmsa = sos->pal_min_state;
 532         if (psr1->cpl != 0 ||
 533            ((psr2->cpl != 0) && mca_recover_range(pmsa->pmsa_iip))) {
 534                 /*
 535                  *  setup for resume to bottom half of MCA,
 536                  * "mca_handler_bhhook"
 537                  */
 538                 /* pass to bhhook as argument (gr8, ...) */
 539                 pmsa->pmsa_gr[8-1] = target_identifier;
 540                 pmsa->pmsa_gr[9-1] = pmsa->pmsa_iip;
 541                 pmsa->pmsa_gr[10-1] = pmsa->pmsa_ipsr;
 542                 /* set interrupted return address (but no use) */
 543                 pmsa->pmsa_br0 = pmsa->pmsa_iip;
 544                 /* change resume address to bottom half */
 545                 pmsa->pmsa_iip = mca_hdlr_bh->fp;
 546                 pmsa->pmsa_gr[1-1] = mca_hdlr_bh->gp;
 547                 /* set cpl with kernel mode */
 548                 psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
 549                 psr2->cpl = 0;
 550                 psr2->ri  = 0;
 551                 psr2->bn  = 1;
 552                 psr2->i  = 0;
 553
 554                 return mca_recovered("user memory corruption. "
 555                                 "kill affected process - recovered.");
 556         }
 557
 558         return fatal_mca("kernel context not recovered, iip 0x%lx\n",
 559                          pmsa->pmsa_iip);
 560 }
 561
 562 /**
 563  * recover_from_platform_error - Recover from platform error.
 564  * @slidx:      pointer of index of SAL error record
 565  * @peidx:      pointer of index of processor error section
 566  * @pbci:       pointer of pal_bus_check_info
 567  * @sos:        pointer to hand off struct between SAL and OS
 568  *
 569  * Return value:
 570  *      1 on Success / 0 on Failure
 571  */
 572
 573 static int
 574 recover_from_platform_error(slidx_table_t *slidx, peidx_table_t *peidx,
 575                             pal_bus_check_info_t *pbci,
 576                             struct ia64_sal_os_state *sos)
 577 {
 578         int status = 0;
 579         pal_processor_state_info_t *psp =
 580                 (pal_processor_state_info_t*)peidx_psp(peidx);
 581
 582         if (psp->bc && pbci->eb && pbci->bsi == 0) {
 583                 switch(pbci->type) {
 584                 case 1: /* partial read */
 585                 case 3: /* full line(cpu) read */
 586                 case 9: /* I/O space read */
 587                         status = recover_from_read_error(slidx, peidx, pbci,
 588                                                          sos);
 589                         break;
 590                 case 0: /* unknown */
 591                 case 2: /* partial write */
 592                 case 4: /* full line write */
 593                 case 5: /* implicit or explicit write-back operation */
 594                 case 6: /* snoop probe */
 595                 case 7: /* incoming or outgoing ptc.g */
 596                 case 8: /* write coalescing transactions */
 597                 case 10: /* I/O space write */
 598                 case 11: /* inter-processor interrupt message(IPI) */
 599                 case 12: /* interrupt acknowledge or
 600                                 external task priority cycle */
 601                 default:
 602                         break;
 603                 }
 604         } else if (psp->cc && !psp->bc) {       /* Cache error */
 605                 status = recover_from_read_error(slidx, peidx, pbci, sos);
 606         }
 607
 608         return status;
 609 }
 610
 611 /*
 612  * recover_from_tlb_check
 613  * @peidx:      pointer of index of processor error section
 614  *
 615  * Return value:
 616  *      1 on Success / 0 on Failure
 617  */
 618 static int
 619 recover_from_tlb_check(peidx_table_t *peidx)
 620 {
 621         sal_log_mod_error_info_t *smei;
 622         pal_tlb_check_info_t *ptci;
 623
 624         smei = (sal_log_mod_error_info_t *)peidx_tlb_check(peidx, 0);
 625         ptci = (pal_tlb_check_info_t *)&(smei->check_info);
 626
 627         /*
 628          * Look for signature of a duplicate TLB DTC entry, which is
 629          * a SW bug and always fatal.
 630          */
 631         if (ptci->op == PAL_TLB_CHECK_OP_PURGE
 632             && !(ptci->itr || ptci->dtc || ptci->itc))
 633                 return fatal_mca("Duplicate TLB entry");
 634
 635         return mca_recovered("TLB check recovered");
 636 }
 637
 638 /**
 639  * recover_from_processor_error
 640  * @platform:   whether there are some platform error section or not
 641  * @slidx:      pointer of index of SAL error record
 642  * @peidx:      pointer of index of processor error section
 643  * @pbci:       pointer of pal_bus_check_info
 644  * @sos:        pointer to hand off struct between SAL and OS
 645  *
 646  * Return value:
 647  *      1 on Success / 0 on Failure
 648  */
 649
 650 static int
 651 recover_from_processor_error(int platform, slidx_table_t *slidx,
 652                              peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 653                              struct ia64_sal_os_state *sos)
 654 {
 655         pal_processor_state_info_t *psp =
 656                 (pal_processor_state_info_t*)peidx_psp(peidx);
 657
 658         /*
 659          * Processor recovery status must key off of the PAL recovery
 660          * status in the Processor State Parameter.
 661          */
 662
 663         /*
 664          * The machine check is corrected.
 665          */
 666         if (psp->cm == 1)
 667                 return mca_recovered("machine check is already corrected.");
 668
 669         /*
 670          * The error was not contained.  Software must be reset.
 671          */
 672         if (psp->us || psp->ci == 0)
 673                 return fatal_mca("error not contained");
 674
 675         /*
 676          * Look for recoverable TLB check
 677          */
 678         if (psp->tc && !(psp->cc || psp->bc || psp->rc || psp->uc))
 679                 return recover_from_tlb_check(peidx);
 680
 681         /*
 682          * The cache check and bus check bits have four possible states
 683          *   cc bc
 684          *    1  1      Memory error, attempt recovery
 685          *    1  0      Cache error, attempt recovery
 686          *    0  1      I/O error, attempt recovery
 687          *    0  0      Other error type, not recovered
 688          */
 689         if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
 690                 return fatal_mca("No cache or bus check");
 691
 692         /*
 693          * Cannot handle more than one bus check.
 694          */
 695         if (peidx_bus_check_num(peidx) > 1)
 696                 return fatal_mca("Too many bus checks");
 697
 698         if (pbci->ib)
 699                 return fatal_mca("Internal Bus error");
 700         if (pbci->eb && pbci->bsi > 0)
 701                 return fatal_mca("External bus check fatal status");
 702
 703         /*
 704          * This is a local MCA and estimated as a recoverable error.
 705          */
 706         if (platform)
 707                 return recover_from_platform_error(slidx, peidx, pbci, sos);
 708
 709         /*
 710          * On account of strange SAL error record, we cannot recover.
 711          */
 712         return fatal_mca("Strange SAL record");
 713 }
 714
 715 /**
 716  * mca_try_to_recover - Try to recover from MCA
 717  * @rec:        pointer to a SAL error record
 718  * @sos:        pointer to hand off struct between SAL and OS
 719  *
 720  * Return value:
 721  *      1 on Success / 0 on Failure
 722  */
 723
 724 static int
 725 mca_try_to_recover(void *rec, struct ia64_sal_os_state *sos)
 726 {
 727         int platform_err;
 728         int n_proc_err;
 729         slidx_table_t slidx;
 730         peidx_table_t peidx;
 731         pal_bus_check_info_t pbci;
 732
 733         /* Make index of SAL error record */
 734         platform_err = mca_make_slidx(rec, &slidx);
 735
 736         /* Count processor error sections */
 737         n_proc_err = slidx_count(&slidx, proc_err);
 738
 739          /* Now, OS can recover when there is one processor error section */
 740         if (n_proc_err > 1)
 741                 return fatal_mca("Too Many Errors");
 742         else if (n_proc_err == 0)
 743                 /* Weird SAL record ... We can't do anything */
 744                 return fatal_mca("Weird SAL record");
 745
 746         /* Make index of processor error section */
 747         mca_make_peidx((sal_log_processor_info_t*)
 748                 slidx_first_entry(&slidx.proc_err)->hdr, &peidx);
 749
 750         /* Extract Processor BUS_CHECK[0] */
 751         *((u64*)&pbci) = peidx_check_info(&peidx, bus_check, 0);
 752
 753         /* Check whether MCA is global or not */
 754         if (is_mca_global(&peidx, &pbci, sos))
 755                 return fatal_mca("global MCA");
 756
 757         /* Try to recover a processor error */
 758         return recover_from_processor_error(platform_err, &slidx, &peidx,
 759                                             &pbci, sos);
 760 }
 761
 762 /*
 763  * =============================================================================
 764  */
 765
 766 int __init mca_external_handler_init(void)
 767 {
 768         if (init_record_index_pools())
 769                 return -ENOMEM;
 770
 771         /* register external mca handlers */
 772         if (ia64_reg_MCA_extension(mca_try_to_recover)) {
 773                 printk(KERN_ERR "ia64_reg_MCA_extension failed.\n");
 774                 kfree(slidx_pool.buffer);
 775                 return -EFAULT;
 776         }
 777         return 0;
 778 }
 779
 780 void __exit mca_external_handler_exit(void)
 781 {
 782         /* unregister external mca handlers */
 783         ia64_unreg_MCA_extension();
 784         kfree(slidx_pool.buffer);
 785 }
 786
 787 module_init(mca_external_handler_init);
 788 module_exit(mca_external_handler_exit);
 789
 790 module_param(sal_rec_max, int, 0644);
 791 MODULE_PARM_DESC(sal_rec_max, "Max size of SAL error record");
 792
 793 MODULE_DESCRIPTION("ia64 platform dependent mca handler driver");
 794 MODULE_LICENSE("GPL");