root/arch/ia64/kernel/mca_drv.c

DEFINITIONS

1. fatal_mca
2. mca_recovered
3. mca_page_isolate
4. mca_handler_bh
5. mca_make_peidx
6. mca_make_slidx
7. init_record_index_pools
8. is_mca_global
9. get_target_identifier
10. recover_from_read_error
11. recover_from_platform_error
12. recover_from_tlb_check
13. recover_from_processor_error
14. mca_try_to_recover
15. mca_external_handler_init
16. mca_external_handler_exit

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * File:        mca_drv.c
   4  * Purpose:     Generic MCA handling layer
   5  *
   6  * Copyright (C) 2004 FUJITSU LIMITED
   7  * Copyright (C) 2004 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
   8  * Copyright (C) 2005 Silicon Graphics, Inc
   9  * Copyright (C) 2005 Keith Owens <kaos@sgi.com>
  10  * Copyright (C) 2006 Russ Anderson <rja@sgi.com>
  11  */
  12 #include <linux/types.h>
  13 #include <linux/init.h>
  14 #include <linux/sched.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <linux/kallsyms.h>
  18 #include <linux/memblock.h>
  19 #include <linux/acpi.h>
  20 #include <linux/timer.h>
  21 #include <linux/module.h>
  22 #include <linux/kernel.h>
  23 #include <linux/smp.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/mm.h>
  26 #include <linux/slab.h>
  27 
  28 #include <asm/delay.h>
  29 #include <asm/page.h>
  30 #include <asm/ptrace.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,
 162                 from_kuid(&init_user_ns, current_uid()),
 163                 iip, ipsr, paddr, current->comm);
 164 
 165         spin_lock(&mca_bh_lock);
 166         switch (mca_page_isolate(paddr)) {
 167         case ISOLATE_OK:
 168                 printk(KERN_DEBUG "Page isolation: ( %lx ) success.\n", paddr);
 169                 break;
 170         case ISOLATE_NG:
 171                 printk(KERN_CRIT "Page isolation: ( %lx ) failure.\n", paddr);
 172                 break;
 173         default:
 174                 break;
 175         }
 176         spin_unlock(&mca_bh_lock);
 177 
 178         /* This process is about to be killed itself */
 179         do_exit(SIGKILL);
 180 }
 181 
 182 /**
 183  * mca_make_peidx - Make index of processor error section
 184  * @slpi:       pointer to record of processor error section
 185  * @peidx:      pointer to index of processor error section
 186  */
 187 
 188 static void
 189 mca_make_peidx(sal_log_processor_info_t *slpi, peidx_table_t *peidx)
 190 {
 191         /*
 192          * calculate the start address of
 193          *   "struct cpuid_info" and "sal_processor_static_info_t".
 194          */
 195         u64 total_check_num = slpi->valid.num_cache_check
 196                                 + slpi->valid.num_tlb_check
 197                                 + slpi->valid.num_bus_check
 198                                 + slpi->valid.num_reg_file_check
 199                                 + slpi->valid.num_ms_check;
 200         u64 head_size = sizeof(sal_log_mod_error_info_t) * total_check_num
 201                         + sizeof(sal_log_processor_info_t);
 202         u64 mid_size  = slpi->valid.cpuid_info * sizeof(struct sal_cpuid_info);
 203 
 204         peidx_head(peidx)   = slpi;
 205         peidx_mid(peidx)    = (struct sal_cpuid_info *)
 206                 (slpi->valid.cpuid_info ? ((char*)slpi + head_size) : NULL);
 207         peidx_bottom(peidx) = (sal_processor_static_info_t *)
 208                 (slpi->valid.psi_static_struct ?
 209                         ((char*)slpi + head_size + mid_size) : NULL);
 210 }
 211 
 212 /**
 213  * mca_make_slidx -  Make index of SAL error record
 214  * @buffer:     pointer to SAL error record
 215  * @slidx:      pointer to index of SAL error record
 216  *
 217  * Return value:
 218  *      1 if record has platform error / 0 if not
 219  */
 220 #define LOG_INDEX_ADD_SECT_PTR(sect, ptr) \
 221         {slidx_list_t *hl = &slidx_pool.buffer[slidx_pool.cur_idx]; \
 222         hl->hdr = ptr; \
 223         list_add(&hl->list, &(sect)); \
 224         slidx_pool.cur_idx = (slidx_pool.cur_idx + 1)%slidx_pool.max_idx; }
 225 
 226 static int
 227 mca_make_slidx(void *buffer, slidx_table_t *slidx)
 228 {
 229         int platform_err = 0;
 230         int record_len = ((sal_log_record_header_t*)buffer)->len;
 231         u32 ercd_pos;
 232         int sects;
 233         sal_log_section_hdr_t *sp;
 234 
 235         /*
 236          * Initialize index referring current record
 237          */
 238         INIT_LIST_HEAD(&(slidx->proc_err));
 239         INIT_LIST_HEAD(&(slidx->mem_dev_err));
 240         INIT_LIST_HEAD(&(slidx->sel_dev_err));
 241         INIT_LIST_HEAD(&(slidx->pci_bus_err));
 242         INIT_LIST_HEAD(&(slidx->smbios_dev_err));
 243         INIT_LIST_HEAD(&(slidx->pci_comp_err));
 244         INIT_LIST_HEAD(&(slidx->plat_specific_err));
 245         INIT_LIST_HEAD(&(slidx->host_ctlr_err));
 246         INIT_LIST_HEAD(&(slidx->plat_bus_err));
 247         INIT_LIST_HEAD(&(slidx->unsupported));
 248 
 249         /*
 250          * Extract a Record Header
 251          */
 252         slidx->header = buffer;
 253 
 254         /*
 255          * Extract each section records
 256          * (arranged from "int ia64_log_platform_info_print()")
 257          */
 258         for (ercd_pos = sizeof(sal_log_record_header_t), sects = 0;
 259                 ercd_pos < record_len; ercd_pos += sp->len, sects++) {
 260                 sp = (sal_log_section_hdr_t *)((char*)buffer + ercd_pos);
 261                 if (!efi_guidcmp(sp->guid, SAL_PROC_DEV_ERR_SECT_GUID)) {
 262                         LOG_INDEX_ADD_SECT_PTR(slidx->proc_err, sp);
 263                 } else if (!efi_guidcmp(sp->guid,
 264                                 SAL_PLAT_MEM_DEV_ERR_SECT_GUID)) {
 265                         platform_err = 1;
 266                         LOG_INDEX_ADD_SECT_PTR(slidx->mem_dev_err, sp);
 267                 } else if (!efi_guidcmp(sp->guid,
 268                                 SAL_PLAT_SEL_DEV_ERR_SECT_GUID)) {
 269                         platform_err = 1;
 270                         LOG_INDEX_ADD_SECT_PTR(slidx->sel_dev_err, sp);
 271                 } else if (!efi_guidcmp(sp->guid,
 272                                 SAL_PLAT_PCI_BUS_ERR_SECT_GUID)) {
 273                         platform_err = 1;
 274                         LOG_INDEX_ADD_SECT_PTR(slidx->pci_bus_err, sp);
 275                 } else if (!efi_guidcmp(sp->guid,
 276                                 SAL_PLAT_SMBIOS_DEV_ERR_SECT_GUID)) {
 277                         platform_err = 1;
 278                         LOG_INDEX_ADD_SECT_PTR(slidx->smbios_dev_err, sp);
 279                 } else if (!efi_guidcmp(sp->guid,
 280                                 SAL_PLAT_PCI_COMP_ERR_SECT_GUID)) {
 281                         platform_err = 1;
 282                         LOG_INDEX_ADD_SECT_PTR(slidx->pci_comp_err, sp);
 283                 } else if (!efi_guidcmp(sp->guid,
 284                                 SAL_PLAT_SPECIFIC_ERR_SECT_GUID)) {
 285                         platform_err = 1;
 286                         LOG_INDEX_ADD_SECT_PTR(slidx->plat_specific_err, sp);
 287                 } else if (!efi_guidcmp(sp->guid,
 288                                 SAL_PLAT_HOST_CTLR_ERR_SECT_GUID)) {
 289                         platform_err = 1;
 290                         LOG_INDEX_ADD_SECT_PTR(slidx->host_ctlr_err, sp);
 291                 } else if (!efi_guidcmp(sp->guid,
 292                                 SAL_PLAT_BUS_ERR_SECT_GUID)) {
 293                         platform_err = 1;
 294                         LOG_INDEX_ADD_SECT_PTR(slidx->plat_bus_err, sp);
 295                 } else {
 296                         LOG_INDEX_ADD_SECT_PTR(slidx->unsupported, sp);
 297                 }
 298         }
 299         slidx->n_sections = sects;
 300 
 301         return platform_err;
 302 }
 303 
 304 /**
 305  * init_record_index_pools - Initialize pool of lists for SAL record index
 306  *
 307  * Return value:
 308  *      0 on Success / -ENOMEM on Failure
 309  */
 310 static int
 311 init_record_index_pools(void)
 312 {
 313         int i;
 314         int rec_max_size;  /* Maximum size of SAL error records */
 315         int sect_min_size; /* Minimum size of SAL error sections */
 316         /* minimum size table of each section */
 317         static int sal_log_sect_min_sizes[] = {
 318                 sizeof(sal_log_processor_info_t)
 319                 + sizeof(sal_processor_static_info_t),
 320                 sizeof(sal_log_mem_dev_err_info_t),
 321                 sizeof(sal_log_sel_dev_err_info_t),
 322                 sizeof(sal_log_pci_bus_err_info_t),
 323                 sizeof(sal_log_smbios_dev_err_info_t),
 324                 sizeof(sal_log_pci_comp_err_info_t),
 325                 sizeof(sal_log_plat_specific_err_info_t),
 326                 sizeof(sal_log_host_ctlr_err_info_t),
 327                 sizeof(sal_log_plat_bus_err_info_t),
 328         };
 329 
 330         /*
 331          * MCA handler cannot allocate new memory on flight,
 332          * so we preallocate enough memory to handle a SAL record.
 333          *
 334          * Initialize a handling set of slidx_pool:
 335          *   1. Pick up the max size of SAL error records
 336          *   2. Pick up the min size of SAL error sections
 337          *   3. Allocate the pool as enough to 2 SAL records
 338          *     (now we can estimate the maxinum of section in a record.)
 339          */
 340 
 341         /* - 1 - */
 342         rec_max_size = sal_rec_max;
 343 
 344         /* - 2 - */
 345         sect_min_size = sal_log_sect_min_sizes[0];
 346         for (i = 1; i < sizeof sal_log_sect_min_sizes/sizeof(size_t); i++)
 347                 if (sect_min_size > sal_log_sect_min_sizes[i])
 348                         sect_min_size = sal_log_sect_min_sizes[i];
 349 
 350         /* - 3 - */
 351         slidx_pool.max_idx = (rec_max_size/sect_min_size) * 2 + 1;
 352         slidx_pool.buffer =
 353                 kmalloc_array(slidx_pool.max_idx, sizeof(slidx_list_t),
 354                               GFP_KERNEL);
 355 
 356         return slidx_pool.buffer ? 0 : -ENOMEM;
 357 }
 358 
 359 
 360 /*****************************************************************************
 361  * Recovery functions                                                        *
 362  *****************************************************************************/
 363 
 364 /**
 365  * is_mca_global - Check whether this MCA is global or not
 366  * @peidx:      pointer of index of processor error section
 367  * @pbci:       pointer to pal_bus_check_info_t
 368  * @sos:        pointer to hand off struct between SAL and OS
 369  *
 370  * Return value:
 371  *      MCA_IS_LOCAL / MCA_IS_GLOBAL
 372  */
 373 
 374 static mca_type_t
 375 is_mca_global(peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 376               struct ia64_sal_os_state *sos)
 377 {
 378         pal_processor_state_info_t *psp =
 379                 (pal_processor_state_info_t*)peidx_psp(peidx);
 380 
 381         /*
 382          * PAL can request a rendezvous, if the MCA has a global scope.
 383          * If "rz_always" flag is set, SAL requests MCA rendezvous
 384          * in spite of global MCA.
 385          * Therefore it is local MCA when rendezvous has not been requested.
 386          * Failed to rendezvous, the system must be down.
 387          */
 388         switch (sos->rv_rc) {
 389                 case -1: /* SAL rendezvous unsuccessful */
 390                         return MCA_IS_GLOBAL;
 391                 case  0: /* SAL rendezvous not required */
 392                         return MCA_IS_LOCAL;
 393                 case  1: /* SAL rendezvous successful int */
 394                 case  2: /* SAL rendezvous successful int with init */
 395                 default:
 396                         break;
 397         }
 398 
 399         /*
 400          * If One or more Cache/TLB/Reg_File/Uarch_Check is here,
 401          * it would be a local MCA. (i.e. processor internal error)
 402          */
 403         if (psp->tc || psp->cc || psp->rc || psp->uc)
 404                 return MCA_IS_LOCAL;
 405         
 406         /*
 407          * Bus_Check structure with Bus_Check.ib (internal bus error) flag set
 408          * would be a global MCA. (e.g. a system bus address parity error)
 409          */
 410         if (!pbci || pbci->ib)
 411                 return MCA_IS_GLOBAL;
 412 
 413         /*
 414          * Bus_Check structure with Bus_Check.eb (external bus error) flag set
 415          * could be either a local MCA or a global MCA.
 416          *
 417          * Referring Bus_Check.bsi:
 418          *   0: Unknown/unclassified
 419          *   1: BERR#
 420          *   2: BINIT#
 421          *   3: Hard Fail
 422          * (FIXME: Are these SGI specific or generic bsi values?)
 423          */
 424         if (pbci->eb)
 425                 switch (pbci->bsi) {
 426                         case 0:
 427                                 /* e.g. a load from poisoned memory */
 428                                 return MCA_IS_LOCAL;
 429                         case 1:
 430                         case 2:
 431                         case 3:
 432                                 return MCA_IS_GLOBAL;
 433                 }
 434 
 435         return MCA_IS_GLOBAL;
 436 }
 437 
 438 /**
 439  * get_target_identifier - Get the valid Cache or Bus check target identifier.
 440  * @peidx:      pointer of index of processor error section
 441  *
 442  * Return value:
 443  *      target address on Success / 0 on Failure
 444  */
 445 static u64
 446 get_target_identifier(peidx_table_t *peidx)
 447 {
 448         u64 target_address = 0;
 449         sal_log_mod_error_info_t *smei;
 450         pal_cache_check_info_t *pcci;
 451         int i, level = 9;
 452 
 453         /*
 454          * Look through the cache checks for a valid target identifier
 455          * If more than one valid target identifier, return the one
 456          * with the lowest cache level.
 457          */
 458         for (i = 0; i < peidx_cache_check_num(peidx); i++) {
 459                 smei = (sal_log_mod_error_info_t *)peidx_cache_check(peidx, i);
 460                 if (smei->valid.target_identifier && smei->target_identifier) {
 461                         pcci = (pal_cache_check_info_t *)&(smei->check_info);
 462                         if (!target_address || (pcci->level < level)) {
 463                                 target_address = smei->target_identifier;
 464                                 level = pcci->level;
 465                                 continue;
 466                         }
 467                 }
 468         }
 469         if (target_address)
 470                 return target_address;
 471 
 472         /*
 473          * Look at the bus check for a valid target identifier
 474          */
 475         smei = peidx_bus_check(peidx, 0);
 476         if (smei && smei->valid.target_identifier)
 477                 return smei->target_identifier;
 478 
 479         return 0;
 480 }
 481 
 482 /**
 483  * recover_from_read_error - Try to recover the errors which type are "read"s.
 484  * @slidx:      pointer of index of SAL error record
 485  * @peidx:      pointer of index of processor error section
 486  * @pbci:       pointer of pal_bus_check_info
 487  * @sos:        pointer to hand off struct between SAL and OS
 488  *
 489  * Return value:
 490  *      1 on Success / 0 on Failure
 491  */
 492 
 493 static int
 494 recover_from_read_error(slidx_table_t *slidx,
 495                         peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 496                         struct ia64_sal_os_state *sos)
 497 {
 498         u64 target_identifier;
 499         pal_min_state_area_t *pmsa;
 500         struct ia64_psr *psr1, *psr2;
 501         ia64_fptr_t *mca_hdlr_bh = (ia64_fptr_t*)mca_handler_bhhook;
 502 
 503         /* Is target address valid? */
 504         target_identifier = get_target_identifier(peidx);
 505         if (!target_identifier)
 506                 return fatal_mca("target address not valid");
 507 
 508         /*
 509          * cpu read or memory-mapped io read
 510          *
 511          *    offending process  affected process  OS MCA do
 512          *     kernel mode        kernel mode       down system
 513          *     kernel mode        user   mode       kill the process
 514          *     user   mode        kernel mode       down system (*)
 515          *     user   mode        user   mode       kill the process
 516          *
 517          * (*) You could terminate offending user-mode process
 518          *    if (pbci->pv && pbci->pl != 0) *and* if you sure
 519          *    the process not have any locks of kernel.
 520          */
 521 
 522         /* Is minstate valid? */
 523         if (!peidx_bottom(peidx) || !(peidx_bottom(peidx)->valid.minstate))
 524                 return fatal_mca("minstate not valid");
 525         psr1 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_ipsr);
 526         psr2 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_xpsr);
 527 
 528         /*
 529          *  Check the privilege level of interrupted context.
 530          *   If it is user-mode, then terminate affected process.
 531          */
 532 
 533         pmsa = sos->pal_min_state;
 534         if (psr1->cpl != 0 ||
 535            ((psr2->cpl != 0) && mca_recover_range(pmsa->pmsa_iip))) {
 536                 /*
 537                  *  setup for resume to bottom half of MCA,
 538                  * "mca_handler_bhhook"
 539                  */
 540                 /* pass to bhhook as argument (gr8, ...) */
 541                 pmsa->pmsa_gr[8-1] = target_identifier;
 542                 pmsa->pmsa_gr[9-1] = pmsa->pmsa_iip;
 543                 pmsa->pmsa_gr[10-1] = pmsa->pmsa_ipsr;
 544                 /* set interrupted return address (but no use) */
 545                 pmsa->pmsa_br0 = pmsa->pmsa_iip;
 546                 /* change resume address to bottom half */
 547                 pmsa->pmsa_iip = mca_hdlr_bh->fp;
 548                 pmsa->pmsa_gr[1-1] = mca_hdlr_bh->gp;
 549                 /* set cpl with kernel mode */
 550                 psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
 551                 psr2->cpl = 0;
 552                 psr2->ri  = 0;
 553                 psr2->bn  = 1;
 554                 psr2->i  = 0;
 555 
 556                 return mca_recovered("user memory corruption. "
 557                                 "kill affected process - recovered.");
 558         }
 559 
 560         return fatal_mca("kernel context not recovered, iip 0x%lx\n",
 561                          pmsa->pmsa_iip);
 562 }
 563 
 564 /**
 565  * recover_from_platform_error - Recover from platform error.
 566  * @slidx:      pointer of index of SAL error record
 567  * @peidx:      pointer of index of processor error section
 568  * @pbci:       pointer of pal_bus_check_info
 569  * @sos:        pointer to hand off struct between SAL and OS
 570  *
 571  * Return value:
 572  *      1 on Success / 0 on Failure
 573  */
 574 
 575 static int
 576 recover_from_platform_error(slidx_table_t *slidx, peidx_table_t *peidx,
 577                             pal_bus_check_info_t *pbci,
 578                             struct ia64_sal_os_state *sos)
 579 {
 580         int status = 0;
 581         pal_processor_state_info_t *psp =
 582                 (pal_processor_state_info_t*)peidx_psp(peidx);
 583 
 584         if (psp->bc && pbci->eb && pbci->bsi == 0) {
 585                 switch(pbci->type) {
 586                 case 1: /* partial read */
 587                 case 3: /* full line(cpu) read */
 588                 case 9: /* I/O space read */
 589                         status = recover_from_read_error(slidx, peidx, pbci,
 590                                                          sos);
 591                         break;
 592                 case 0: /* unknown */
 593                 case 2: /* partial write */
 594                 case 4: /* full line write */
 595                 case 5: /* implicit or explicit write-back operation */
 596                 case 6: /* snoop probe */
 597                 case 7: /* incoming or outgoing ptc.g */
 598                 case 8: /* write coalescing transactions */
 599                 case 10: /* I/O space write */
 600                 case 11: /* inter-processor interrupt message(IPI) */
 601                 case 12: /* interrupt acknowledge or
 602                                 external task priority cycle */
 603                 default:
 604                         break;
 605                 }
 606         } else if (psp->cc && !psp->bc) {       /* Cache error */
 607                 status = recover_from_read_error(slidx, peidx, pbci, sos);
 608         }
 609 
 610         return status;
 611 }
 612 
 613 /*
 614  * recover_from_tlb_check
 615  * @peidx:      pointer of index of processor error section
 616  *
 617  * Return value:
 618  *      1 on Success / 0 on Failure
 619  */
 620 static int
 621 recover_from_tlb_check(peidx_table_t *peidx)
 622 {
 623         sal_log_mod_error_info_t *smei;
 624         pal_tlb_check_info_t *ptci;
 625 
 626         smei = (sal_log_mod_error_info_t *)peidx_tlb_check(peidx, 0);
 627         ptci = (pal_tlb_check_info_t *)&(smei->check_info);
 628 
 629         /*
 630          * Look for signature of a duplicate TLB DTC entry, which is
 631          * a SW bug and always fatal.
 632          */
 633         if (ptci->op == PAL_TLB_CHECK_OP_PURGE
 634             && !(ptci->itr || ptci->dtc || ptci->itc))
 635                 return fatal_mca("Duplicate TLB entry");
 636 
 637         return mca_recovered("TLB check recovered");
 638 }
 639 
 640 /**
 641  * recover_from_processor_error
 642  * @platform:   whether there are some platform error section or not
 643  * @slidx:      pointer of index of SAL error record
 644  * @peidx:      pointer of index of processor error section
 645  * @pbci:       pointer of pal_bus_check_info
 646  * @sos:        pointer to hand off struct between SAL and OS
 647  *
 648  * Return value:
 649  *      1 on Success / 0 on Failure
 650  */
 651 
 652 static int
 653 recover_from_processor_error(int platform, slidx_table_t *slidx,
 654                              peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 655                              struct ia64_sal_os_state *sos)
 656 {
 657         pal_processor_state_info_t *psp =
 658                 (pal_processor_state_info_t*)peidx_psp(peidx);
 659 
 660         /*
 661          * Processor recovery status must key off of the PAL recovery
 662          * status in the Processor State Parameter.
 663          */
 664 
 665         /*
 666          * The machine check is corrected.
 667          */
 668         if (psp->cm == 1)
 669                 return mca_recovered("machine check is already corrected.");
 670 
 671         /*
 672          * The error was not contained.  Software must be reset.
 673          */
 674         if (psp->us || psp->ci == 0)
 675                 return fatal_mca("error not contained");
 676 
 677         /*
 678          * Look for recoverable TLB check
 679          */
 680         if (psp->tc && !(psp->cc || psp->bc || psp->rc || psp->uc))
 681                 return recover_from_tlb_check(peidx);
 682 
 683         /*
 684          * The cache check and bus check bits have four possible states
 685          *   cc bc
 686          *    1  1      Memory error, attempt recovery
 687          *    1  0      Cache error, attempt recovery
 688          *    0  1      I/O error, attempt recovery
 689          *    0  0      Other error type, not recovered
 690          */
 691         if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
 692                 return fatal_mca("No cache or bus check");
 693 
 694         /*
 695          * Cannot handle more than one bus check.
 696          */
 697         if (peidx_bus_check_num(peidx) > 1)
 698                 return fatal_mca("Too many bus checks");
 699 
 700         if (pbci->ib)
 701                 return fatal_mca("Internal Bus error");
 702         if (pbci->eb && pbci->bsi > 0)
 703                 return fatal_mca("External bus check fatal status");
 704 
 705         /*
 706          * This is a local MCA and estimated as a recoverable error.
 707          */
 708         if (platform)
 709                 return recover_from_platform_error(slidx, peidx, pbci, sos);
 710 
 711         /*
 712          * On account of strange SAL error record, we cannot recover.
 713          */
 714         return fatal_mca("Strange SAL record");
 715 }
 716 
 717 /**
 718  * mca_try_to_recover - Try to recover from MCA
 719  * @rec:        pointer to a SAL error record
 720  * @sos:        pointer to hand off struct between SAL and OS
 721  *
 722  * Return value:
 723  *      1 on Success / 0 on Failure
 724  */
 725 
 726 static int
 727 mca_try_to_recover(void *rec, struct ia64_sal_os_state *sos)
 728 {
 729         int platform_err;
 730         int n_proc_err;
 731         slidx_table_t slidx;
 732         peidx_table_t peidx;
 733         pal_bus_check_info_t pbci;
 734 
 735         /* Make index of SAL error record */
 736         platform_err = mca_make_slidx(rec, &slidx);
 737 
 738         /* Count processor error sections */
 739         n_proc_err = slidx_count(&slidx, proc_err);
 740 
 741          /* Now, OS can recover when there is one processor error section */
 742         if (n_proc_err > 1)
 743                 return fatal_mca("Too Many Errors");
 744         else if (n_proc_err == 0)
 745                 /* Weird SAL record ... We can't do anything */
 746                 return fatal_mca("Weird SAL record");
 747 
 748         /* Make index of processor error section */
 749         mca_make_peidx((sal_log_processor_info_t*)
 750                 slidx_first_entry(&slidx.proc_err)->hdr, &peidx);
 751 
 752         /* Extract Processor BUS_CHECK[0] */
 753         *((u64*)&pbci) = peidx_check_info(&peidx, bus_check, 0);
 754 
 755         /* Check whether MCA is global or not */
 756         if (is_mca_global(&peidx, &pbci, sos))
 757                 return fatal_mca("global MCA");
 758         
 759         /* Try to recover a processor error */
 760         return recover_from_processor_error(platform_err, &slidx, &peidx,
 761                                             &pbci, sos);
 762 }
 763 
 764 /*
 765  * =============================================================================
 766  */
 767 
 768 int __init mca_external_handler_init(void)
 769 {
 770         if (init_record_index_pools())
 771                 return -ENOMEM;
 772 
 773         /* register external mca handlers */
 774         if (ia64_reg_MCA_extension(mca_try_to_recover)) {       
 775                 printk(KERN_ERR "ia64_reg_MCA_extension failed.\n");
 776                 kfree(slidx_pool.buffer);
 777                 return -EFAULT;
 778         }
 779         return 0;
 780 }
 781 
 782 void __exit mca_external_handler_exit(void)
 783 {
 784         /* unregister external mca handlers */
 785         ia64_unreg_MCA_extension();
 786         kfree(slidx_pool.buffer);
 787 }
 788 
 789 module_init(mca_external_handler_init);
 790 module_exit(mca_external_handler_exit);
 791 
 792 module_param(sal_rec_max, int, 0644);
 793 MODULE_PARM_DESC(sal_rec_max, "Max size of SAL error record");
 794 
 795 MODULE_DESCRIPTION("ia64 platform dependent mca handler driver");
 796 MODULE_LICENSE("GPL");