linux/arch/ia64/kernel/mca_drv.c
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   1/*
   2 * File:        mca_drv.c
   3 * Purpose:     Generic MCA handling layer
   4 *
   5 * Copyright (C) 2004 FUJITSU LIMITED
   6 * Copyright (C) 2004 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#include <linux/slab.h>
  26
  27#include <asm/delay.h>
  28#include <asm/machvec.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) */
  40static int sal_rec_max = 10000;
  41
  42/* from mca_drv_asm.S */
  43extern void *mca_handler_bhhook(void);
  44
  45static DEFINE_SPINLOCK(mca_bh_lock);
  46
  47typedef enum {
  48        MCA_IS_LOCAL  = 0,
  49        MCA_IS_GLOBAL = 1
  50} mca_type_t;
  51
  52#define MAX_PAGE_ISOLATE 1024
  53
  54static struct page *page_isolate[MAX_PAGE_ISOLATE];
  55static int num_page_isolate = 0;
  56
  57typedef enum {
  58        ISOLATE_NG,
  59        ISOLATE_OK,
  60        ISOLATE_NONE
  61} isolate_status_t;
  62
  63typedef 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 */
  71static 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
  77static int
  78fatal_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
  91static int
  92mca_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
 113static isolate_status_t
 114mca_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
 155void
 156mca_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
 188static void
 189mca_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
 226static int
 227mca_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 */
 310static int
 311init_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(slidx_pool.max_idx * sizeof(slidx_list_t), GFP_KERNEL);
 354
 355        return slidx_pool.buffer ? 0 : -ENOMEM;
 356}
 357
 358
 359/*****************************************************************************
 360 * Recovery functions                                                        *
 361 *****************************************************************************/
 362
 363/**
 364 * is_mca_global - Check whether this MCA is global or not
 365 * @peidx:      pointer of index of processor error section
 366 * @pbci:       pointer to pal_bus_check_info_t
 367 * @sos:        pointer to hand off struct between SAL and OS
 368 *
 369 * Return value:
 370 *      MCA_IS_LOCAL / MCA_IS_GLOBAL
 371 */
 372
 373static mca_type_t
 374is_mca_global(peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 375              struct ia64_sal_os_state *sos)
 376{
 377        pal_processor_state_info_t *psp =
 378                (pal_processor_state_info_t*)peidx_psp(peidx);
 379
 380        /*
 381         * PAL can request a rendezvous, if the MCA has a global scope.
 382         * If "rz_always" flag is set, SAL requests MCA rendezvous
 383         * in spite of global MCA.
 384         * Therefore it is local MCA when rendezvous has not been requested.
 385         * Failed to rendezvous, the system must be down.
 386         */
 387        switch (sos->rv_rc) {
 388                case -1: /* SAL rendezvous unsuccessful */
 389                        return MCA_IS_GLOBAL;
 390                case  0: /* SAL rendezvous not required */
 391                        return MCA_IS_LOCAL;
 392                case  1: /* SAL rendezvous successful int */
 393                case  2: /* SAL rendezvous successful int with init */
 394                default:
 395                        break;
 396        }
 397
 398        /*
 399         * If One or more Cache/TLB/Reg_File/Uarch_Check is here,
 400         * it would be a local MCA. (i.e. processor internal error)
 401         */
 402        if (psp->tc || psp->cc || psp->rc || psp->uc)
 403                return MCA_IS_LOCAL;
 404        
 405        /*
 406         * Bus_Check structure with Bus_Check.ib (internal bus error) flag set
 407         * would be a global MCA. (e.g. a system bus address parity error)
 408         */
 409        if (!pbci || pbci->ib)
 410                return MCA_IS_GLOBAL;
 411
 412        /*
 413         * Bus_Check structure with Bus_Check.eb (external bus error) flag set
 414         * could be either a local MCA or a global MCA.
 415         *
 416         * Referring Bus_Check.bsi:
 417         *   0: Unknown/unclassified
 418         *   1: BERR#
 419         *   2: BINIT#
 420         *   3: Hard Fail
 421         * (FIXME: Are these SGI specific or generic bsi values?)
 422         */
 423        if (pbci->eb)
 424                switch (pbci->bsi) {
 425                        case 0:
 426                                /* e.g. a load from poisoned memory */
 427                                return MCA_IS_LOCAL;
 428                        case 1:
 429                        case 2:
 430                        case 3:
 431                                return MCA_IS_GLOBAL;
 432                }
 433
 434        return MCA_IS_GLOBAL;
 435}
 436
 437/**
 438 * get_target_identifier - Get the valid Cache or Bus check target identifier.
 439 * @peidx:      pointer of index of processor error section
 440 *
 441 * Return value:
 442 *      target address on Success / 0 on Failure
 443 */
 444static u64
 445get_target_identifier(peidx_table_t *peidx)
 446{
 447        u64 target_address = 0;
 448        sal_log_mod_error_info_t *smei;
 449        pal_cache_check_info_t *pcci;
 450        int i, level = 9;
 451
 452        /*
 453         * Look through the cache checks for a valid target identifier
 454         * If more than one valid target identifier, return the one
 455         * with the lowest cache level.
 456         */
 457        for (i = 0; i < peidx_cache_check_num(peidx); i++) {
 458                smei = (sal_log_mod_error_info_t *)peidx_cache_check(peidx, i);
 459                if (smei->valid.target_identifier && smei->target_identifier) {
 460                        pcci = (pal_cache_check_info_t *)&(smei->check_info);
 461                        if (!target_address || (pcci->level < level)) {
 462                                target_address = smei->target_identifier;
 463                                level = pcci->level;
 464                                continue;
 465                        }
 466                }
 467        }
 468        if (target_address)
 469                return target_address;
 470
 471        /*
 472         * Look at the bus check for a valid target identifier
 473         */
 474        smei = peidx_bus_check(peidx, 0);
 475        if (smei && smei->valid.target_identifier)
 476                return smei->target_identifier;
 477
 478        return 0;
 479}
 480
 481/**
 482 * recover_from_read_error - Try to recover the errors which type are "read"s.
 483 * @slidx:      pointer of index of SAL error record
 484 * @peidx:      pointer of index of processor error section
 485 * @pbci:       pointer of pal_bus_check_info
 486 * @sos:        pointer to hand off struct between SAL and OS
 487 *
 488 * Return value:
 489 *      1 on Success / 0 on Failure
 490 */
 491
 492static int
 493recover_from_read_error(slidx_table_t *slidx,
 494                        peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 495                        struct ia64_sal_os_state *sos)
 496{
 497        u64 target_identifier;
 498        pal_min_state_area_t *pmsa;
 499        struct ia64_psr *psr1, *psr2;
 500        ia64_fptr_t *mca_hdlr_bh = (ia64_fptr_t*)mca_handler_bhhook;
 501
 502        /* Is target address valid? */
 503        target_identifier = get_target_identifier(peidx);
 504        if (!target_identifier)
 505                return fatal_mca("target address not valid");
 506
 507        /*
 508         * cpu read or memory-mapped io read
 509         *
 510         *    offending process  affected process  OS MCA do
 511         *     kernel mode        kernel mode       down system
 512         *     kernel mode        user   mode       kill the process
 513         *     user   mode        kernel mode       down system (*)
 514         *     user   mode        user   mode       kill the process
 515         *
 516         * (*) You could terminate offending user-mode process
 517         *    if (pbci->pv && pbci->pl != 0) *and* if you sure
 518         *    the process not have any locks of kernel.
 519         */
 520
 521        /* Is minstate valid? */
 522        if (!peidx_bottom(peidx) || !(peidx_bottom(peidx)->valid.minstate))
 523                return fatal_mca("minstate not valid");
 524        psr1 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_ipsr);
 525        psr2 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_xpsr);
 526
 527        /*
 528         *  Check the privilege level of interrupted context.
 529         *   If it is user-mode, then terminate affected process.
 530         */
 531
 532        pmsa = sos->pal_min_state;
 533        if (psr1->cpl != 0 ||
 534           ((psr2->cpl != 0) && mca_recover_range(pmsa->pmsa_iip))) {
 535                /*
 536                 *  setup for resume to bottom half of MCA,
 537                 * "mca_handler_bhhook"
 538                 */
 539                /* pass to bhhook as argument (gr8, ...) */
 540                pmsa->pmsa_gr[8-1] = target_identifier;
 541                pmsa->pmsa_gr[9-1] = pmsa->pmsa_iip;
 542                pmsa->pmsa_gr[10-1] = pmsa->pmsa_ipsr;
 543                /* set interrupted return address (but no use) */
 544                pmsa->pmsa_br0 = pmsa->pmsa_iip;
 545                /* change resume address to bottom half */
 546                pmsa->pmsa_iip = mca_hdlr_bh->fp;
 547                pmsa->pmsa_gr[1-1] = mca_hdlr_bh->gp;
 548                /* set cpl with kernel mode */
 549                psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
 550                psr2->cpl = 0;
 551                psr2->ri  = 0;
 552                psr2->bn  = 1;
 553                psr2->i  = 0;
 554
 555                return mca_recovered("user memory corruption. "
 556                                "kill affected process - recovered.");
 557        }
 558
 559        return fatal_mca("kernel context not recovered, iip 0x%lx\n",
 560                         pmsa->pmsa_iip);
 561}
 562
 563/**
 564 * recover_from_platform_error - Recover from platform error.
 565 * @slidx:      pointer of index of SAL error record
 566 * @peidx:      pointer of index of processor error section
 567 * @pbci:       pointer of pal_bus_check_info
 568 * @sos:        pointer to hand off struct between SAL and OS
 569 *
 570 * Return value:
 571 *      1 on Success / 0 on Failure
 572 */
 573
 574static int
 575recover_from_platform_error(slidx_table_t *slidx, peidx_table_t *peidx,
 576                            pal_bus_check_info_t *pbci,
 577                            struct ia64_sal_os_state *sos)
 578{
 579        int status = 0;
 580        pal_processor_state_info_t *psp =
 581                (pal_processor_state_info_t*)peidx_psp(peidx);
 582
 583        if (psp->bc && pbci->eb && pbci->bsi == 0) {
 584                switch(pbci->type) {
 585                case 1: /* partial read */
 586                case 3: /* full line(cpu) read */
 587                case 9: /* I/O space read */
 588                        status = recover_from_read_error(slidx, peidx, pbci,
 589                                                         sos);
 590                        break;
 591                case 0: /* unknown */
 592                case 2: /* partial write */
 593                case 4: /* full line write */
 594                case 5: /* implicit or explicit write-back operation */
 595                case 6: /* snoop probe */
 596                case 7: /* incoming or outgoing ptc.g */
 597                case 8: /* write coalescing transactions */
 598                case 10: /* I/O space write */
 599                case 11: /* inter-processor interrupt message(IPI) */
 600                case 12: /* interrupt acknowledge or
 601                                external task priority cycle */
 602                default:
 603                        break;
 604                }
 605        } else if (psp->cc && !psp->bc) {       /* Cache error */
 606                status = recover_from_read_error(slidx, peidx, pbci, sos);
 607        }
 608
 609        return status;
 610}
 611
 612/*
 613 * recover_from_tlb_check
 614 * @peidx:      pointer of index of processor error section
 615 *
 616 * Return value:
 617 *      1 on Success / 0 on Failure
 618 */
 619static int
 620recover_from_tlb_check(peidx_table_t *peidx)
 621{
 622        sal_log_mod_error_info_t *smei;
 623        pal_tlb_check_info_t *ptci;
 624
 625        smei = (sal_log_mod_error_info_t *)peidx_tlb_check(peidx, 0);
 626        ptci = (pal_tlb_check_info_t *)&(smei->check_info);
 627
 628        /*
 629         * Look for signature of a duplicate TLB DTC entry, which is
 630         * a SW bug and always fatal.
 631         */
 632        if (ptci->op == PAL_TLB_CHECK_OP_PURGE
 633            && !(ptci->itr || ptci->dtc || ptci->itc))
 634                return fatal_mca("Duplicate TLB entry");
 635
 636        return mca_recovered("TLB check recovered");
 637}
 638
 639/**
 640 * recover_from_processor_error
 641 * @platform:   whether there are some platform error section or not
 642 * @slidx:      pointer of index of SAL error record
 643 * @peidx:      pointer of index of processor error section
 644 * @pbci:       pointer of pal_bus_check_info
 645 * @sos:        pointer to hand off struct between SAL and OS
 646 *
 647 * Return value:
 648 *      1 on Success / 0 on Failure
 649 */
 650
 651static int
 652recover_from_processor_error(int platform, slidx_table_t *slidx,
 653                             peidx_table_t *peidx, pal_bus_check_info_t *pbci,
 654                             struct ia64_sal_os_state *sos)
 655{
 656        pal_processor_state_info_t *psp =
 657                (pal_processor_state_info_t*)peidx_psp(peidx);
 658
 659        /*
 660         * Processor recovery status must key off of the PAL recovery
 661         * status in the Processor State Parameter.
 662         */
 663
 664        /*
 665         * The machine check is corrected.
 666         */
 667        if (psp->cm == 1)
 668                return mca_recovered("machine check is already corrected.");
 669
 670        /*
 671         * The error was not contained.  Software must be reset.
 672         */
 673        if (psp->us || psp->ci == 0)
 674                return fatal_mca("error not contained");
 675
 676        /*
 677         * Look for recoverable TLB check
 678         */
 679        if (psp->tc && !(psp->cc || psp->bc || psp->rc || psp->uc))
 680                return recover_from_tlb_check(peidx);
 681
 682        /*
 683         * The cache check and bus check bits have four possible states
 684         *   cc bc
 685         *    1  1      Memory error, attempt recovery
 686         *    1  0      Cache error, attempt recovery
 687         *    0  1      I/O error, attempt recovery
 688         *    0  0      Other error type, not recovered
 689         */
 690        if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
 691                return fatal_mca("No cache or bus check");
 692
 693        /*
 694         * Cannot handle more than one bus check.
 695         */
 696        if (peidx_bus_check_num(peidx) > 1)
 697                return fatal_mca("Too many bus checks");
 698
 699        if (pbci->ib)
 700                return fatal_mca("Internal Bus error");
 701        if (pbci->eb && pbci->bsi > 0)
 702                return fatal_mca("External bus check fatal status");
 703
 704        /*
 705         * This is a local MCA and estimated as a recoverable error.
 706         */
 707        if (platform)
 708                return recover_from_platform_error(slidx, peidx, pbci, sos);
 709
 710        /*
 711         * On account of strange SAL error record, we cannot recover.
 712         */
 713        return fatal_mca("Strange SAL record");
 714}
 715
 716/**
 717 * mca_try_to_recover - Try to recover from MCA
 718 * @rec:        pointer to a SAL error record
 719 * @sos:        pointer to hand off struct between SAL and OS
 720 *
 721 * Return value:
 722 *      1 on Success / 0 on Failure
 723 */
 724
 725static int
 726mca_try_to_recover(void *rec, struct ia64_sal_os_state *sos)
 727{
 728        int platform_err;
 729        int n_proc_err;
 730        slidx_table_t slidx;
 731        peidx_table_t peidx;
 732        pal_bus_check_info_t pbci;
 733
 734        /* Make index of SAL error record */
 735        platform_err = mca_make_slidx(rec, &slidx);
 736
 737        /* Count processor error sections */
 738        n_proc_err = slidx_count(&slidx, proc_err);
 739
 740         /* Now, OS can recover when there is one processor error section */
 741        if (n_proc_err > 1)
 742                return fatal_mca("Too Many Errors");
 743        else if (n_proc_err == 0)
 744                /* Weird SAL record ... We can't do anything */
 745                return fatal_mca("Weird SAL record");
 746
 747        /* Make index of processor error section */
 748        mca_make_peidx((sal_log_processor_info_t*)
 749                slidx_first_entry(&slidx.proc_err)->hdr, &peidx);
 750
 751        /* Extract Processor BUS_CHECK[0] */
 752        *((u64*)&pbci) = peidx_check_info(&peidx, bus_check, 0);
 753
 754        /* Check whether MCA is global or not */
 755        if (is_mca_global(&peidx, &pbci, sos))
 756                return fatal_mca("global MCA");
 757        
 758        /* Try to recover a processor error */
 759        return recover_from_processor_error(platform_err, &slidx, &peidx,
 760                                            &pbci, sos);
 761}
 762
 763/*
 764 * =============================================================================
 765 */
 766
 767int __init mca_external_handler_init(void)
 768{
 769        if (init_record_index_pools())
 770                return -ENOMEM;
 771
 772        /* register external mca handlers */
 773        if (ia64_reg_MCA_extension(mca_try_to_recover)) {       
 774                printk(KERN_ERR "ia64_reg_MCA_extension failed.\n");
 775                kfree(slidx_pool.buffer);
 776                return -EFAULT;
 777        }
 778        return 0;
 779}
 780
 781void __exit mca_external_handler_exit(void)
 782{
 783        /* unregister external mca handlers */
 784        ia64_unreg_MCA_extension();
 785        kfree(slidx_pool.buffer);
 786}
 787
 788module_init(mca_external_handler_init);
 789module_exit(mca_external_handler_exit);
 790
 791module_param(sal_rec_max, int, 0644);
 792MODULE_PARM_DESC(sal_rec_max, "Max size of SAL error record");
 793
 794MODULE_DESCRIPTION("ia64 platform dependent mca handler driver");
 795MODULE_LICENSE("GPL");
 796