linux/drivers/acpi/acpi_extlog.c
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   1/*
   2 * Extended Error Log driver
   3 *
   4 * Copyright (C) 2013 Intel Corp.
   5 * Author: Chen, Gong <gong.chen@intel.com>
   6 *
   7 * This file is licensed under GPLv2.
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/acpi.h>
  12#include <linux/cper.h>
  13#include <linux/ratelimit.h>
  14#include <linux/edac.h>
  15#include <linux/ras.h>
  16#include <asm/cpu.h>
  17#include <asm/mce.h>
  18
  19#include "apei/apei-internal.h"
  20#include <ras/ras_event.h>
  21
  22#define EXT_ELOG_ENTRY_MASK     GENMASK_ULL(51, 0) /* elog entry address mask */
  23
  24#define EXTLOG_DSM_REV          0x0
  25#define EXTLOG_FN_ADDR          0x1
  26
  27#define FLAG_OS_OPTIN           BIT(0)
  28#define ELOG_ENTRY_VALID        (1ULL<<63)
  29#define ELOG_ENTRY_LEN          0x1000
  30
  31#define EMCA_BUG \
  32        "Can not request iomem region <0x%016llx-0x%016llx> - eMCA disabled\n"
  33
  34struct extlog_l1_head {
  35        u32 ver;        /* Header Version */
  36        u32 hdr_len;    /* Header Length */
  37        u64 total_len;  /* entire L1 Directory length including this header */
  38        u64 elog_base;  /* MCA Error Log Directory base address */
  39        u64 elog_len;   /* MCA Error Log Directory length */
  40        u32 flags;      /* bit 0 - OS/VMM Opt-in */
  41        u8  rev0[12];
  42        u32 entries;    /* Valid L1 Directory entries per logical processor */
  43        u8  rev1[12];
  44};
  45
  46static int old_edac_report_status;
  47
  48static u8 extlog_dsm_uuid[] __initdata = "663E35AF-CC10-41A4-88EA-5470AF055295";
  49
  50/* L1 table related physical address */
  51static u64 elog_base;
  52static size_t elog_size;
  53static u64 l1_dirbase;
  54static size_t l1_size;
  55
  56/* L1 table related virtual address */
  57static void __iomem *extlog_l1_addr;
  58static void __iomem *elog_addr;
  59
  60static void *elog_buf;
  61
  62static u64 *l1_entry_base;
  63static u32 l1_percpu_entry;
  64
  65#define ELOG_IDX(cpu, bank) \
  66        (cpu_physical_id(cpu) * l1_percpu_entry + (bank))
  67
  68#define ELOG_ENTRY_DATA(idx) \
  69        (*(l1_entry_base + (idx)))
  70
  71#define ELOG_ENTRY_ADDR(phyaddr) \
  72        (phyaddr - elog_base + (u8 *)elog_addr)
  73
  74static struct acpi_hest_generic_status *extlog_elog_entry_check(int cpu, int bank)
  75{
  76        int idx;
  77        u64 data;
  78        struct acpi_hest_generic_status *estatus;
  79
  80        WARN_ON(cpu < 0);
  81        idx = ELOG_IDX(cpu, bank);
  82        data = ELOG_ENTRY_DATA(idx);
  83        if ((data & ELOG_ENTRY_VALID) == 0)
  84                return NULL;
  85
  86        data &= EXT_ELOG_ENTRY_MASK;
  87        estatus = (struct acpi_hest_generic_status *)ELOG_ENTRY_ADDR(data);
  88
  89        /* if no valid data in elog entry, just return */
  90        if (estatus->block_status == 0)
  91                return NULL;
  92
  93        return estatus;
  94}
  95
  96static void __print_extlog_rcd(const char *pfx,
  97                               struct acpi_hest_generic_status *estatus, int cpu)
  98{
  99        static atomic_t seqno;
 100        unsigned int curr_seqno;
 101        char pfx_seq[64];
 102
 103        if (!pfx) {
 104                if (estatus->error_severity <= CPER_SEV_CORRECTED)
 105                        pfx = KERN_INFO;
 106                else
 107                        pfx = KERN_ERR;
 108        }
 109        curr_seqno = atomic_inc_return(&seqno);
 110        snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}", pfx, curr_seqno);
 111        printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu);
 112        cper_estatus_print(pfx_seq, estatus);
 113}
 114
 115static int print_extlog_rcd(const char *pfx,
 116                            struct acpi_hest_generic_status *estatus, int cpu)
 117{
 118        /* Not more than 2 messages every 5 seconds */
 119        static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
 120        static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
 121        struct ratelimit_state *ratelimit;
 122
 123        if (estatus->error_severity == CPER_SEV_CORRECTED ||
 124            (estatus->error_severity == CPER_SEV_INFORMATIONAL))
 125                ratelimit = &ratelimit_corrected;
 126        else
 127                ratelimit = &ratelimit_uncorrected;
 128        if (__ratelimit(ratelimit)) {
 129                __print_extlog_rcd(pfx, estatus, cpu);
 130                return 0;
 131        }
 132
 133        return 1;
 134}
 135
 136static int extlog_print(struct notifier_block *nb, unsigned long val,
 137                        void *data)
 138{
 139        struct mce *mce = (struct mce *)data;
 140        int     bank = mce->bank;
 141        int     cpu = mce->extcpu;
 142        struct acpi_hest_generic_status *estatus, *tmp;
 143        struct acpi_hest_generic_data *gdata;
 144        const guid_t *fru_id = &guid_null;
 145        char *fru_text = "";
 146        guid_t *sec_type;
 147        static u32 err_seq;
 148
 149        estatus = extlog_elog_entry_check(cpu, bank);
 150        if (estatus == NULL)
 151                return NOTIFY_DONE;
 152
 153        memcpy(elog_buf, (void *)estatus, ELOG_ENTRY_LEN);
 154        /* clear record status to enable BIOS to update it again */
 155        estatus->block_status = 0;
 156
 157        tmp = (struct acpi_hest_generic_status *)elog_buf;
 158
 159        if (!ras_userspace_consumers()) {
 160                print_extlog_rcd(NULL, tmp, cpu);
 161                goto out;
 162        }
 163
 164        /* log event via trace */
 165        err_seq++;
 166        gdata = (struct acpi_hest_generic_data *)(tmp + 1);
 167        if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
 168                fru_id = (guid_t *)gdata->fru_id;
 169        if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
 170                fru_text = gdata->fru_text;
 171        sec_type = (guid_t *)gdata->section_type;
 172        if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
 173                struct cper_sec_mem_err *mem = (void *)(gdata + 1);
 174                if (gdata->error_data_length >= sizeof(*mem))
 175                        trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
 176                                               (u8)gdata->error_severity);
 177        }
 178
 179out:
 180        return NOTIFY_STOP;
 181}
 182
 183static bool __init extlog_get_l1addr(void)
 184{
 185        guid_t guid;
 186        acpi_handle handle;
 187        union acpi_object *obj;
 188
 189        if (guid_parse(extlog_dsm_uuid, &guid))
 190                return false;
 191        if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
 192                return false;
 193        if (!acpi_check_dsm(handle, &guid, EXTLOG_DSM_REV, 1 << EXTLOG_FN_ADDR))
 194                return false;
 195        obj = acpi_evaluate_dsm_typed(handle, &guid, EXTLOG_DSM_REV,
 196                                      EXTLOG_FN_ADDR, NULL, ACPI_TYPE_INTEGER);
 197        if (!obj) {
 198                return false;
 199        } else {
 200                l1_dirbase = obj->integer.value;
 201                ACPI_FREE(obj);
 202        }
 203
 204        /* Spec says L1 directory must be 4K aligned, bail out if it isn't */
 205        if (l1_dirbase & ((1 << 12) - 1)) {
 206                pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n",
 207                        l1_dirbase);
 208                return false;
 209        }
 210
 211        return true;
 212}
 213static struct notifier_block extlog_mce_dec = {
 214        .notifier_call  = extlog_print,
 215        .priority       = MCE_PRIO_EXTLOG,
 216};
 217
 218static int __init extlog_init(void)
 219{
 220        struct extlog_l1_head *l1_head;
 221        void __iomem *extlog_l1_hdr;
 222        size_t l1_hdr_size;
 223        struct resource *r;
 224        u64 cap;
 225        int rc;
 226
 227        rdmsrl(MSR_IA32_MCG_CAP, cap);
 228
 229        if (!(cap & MCG_ELOG_P) || !extlog_get_l1addr())
 230                return -ENODEV;
 231
 232        if (edac_get_report_status() == EDAC_REPORTING_FORCE) {
 233                pr_warn("Not loading eMCA, error reporting force-enabled through EDAC.\n");
 234                return -EPERM;
 235        }
 236
 237        rc = -EINVAL;
 238        /* get L1 header to fetch necessary information */
 239        l1_hdr_size = sizeof(struct extlog_l1_head);
 240        r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR");
 241        if (!r) {
 242                pr_warn(FW_BUG EMCA_BUG,
 243                        (unsigned long long)l1_dirbase,
 244                        (unsigned long long)l1_dirbase + l1_hdr_size);
 245                goto err;
 246        }
 247
 248        extlog_l1_hdr = acpi_os_map_iomem(l1_dirbase, l1_hdr_size);
 249        l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
 250        l1_size = l1_head->total_len;
 251        l1_percpu_entry = l1_head->entries;
 252        elog_base = l1_head->elog_base;
 253        elog_size = l1_head->elog_len;
 254        acpi_os_unmap_iomem(extlog_l1_hdr, l1_hdr_size);
 255        release_mem_region(l1_dirbase, l1_hdr_size);
 256
 257        /* remap L1 header again based on completed information */
 258        r = request_mem_region(l1_dirbase, l1_size, "L1 Table");
 259        if (!r) {
 260                pr_warn(FW_BUG EMCA_BUG,
 261                        (unsigned long long)l1_dirbase,
 262                        (unsigned long long)l1_dirbase + l1_size);
 263                goto err;
 264        }
 265        extlog_l1_addr = acpi_os_map_iomem(l1_dirbase, l1_size);
 266        l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);
 267
 268        /* remap elog table */
 269        r = request_mem_region(elog_base, elog_size, "Elog Table");
 270        if (!r) {
 271                pr_warn(FW_BUG EMCA_BUG,
 272                        (unsigned long long)elog_base,
 273                        (unsigned long long)elog_base + elog_size);
 274                goto err_release_l1_dir;
 275        }
 276        elog_addr = acpi_os_map_iomem(elog_base, elog_size);
 277
 278        rc = -ENOMEM;
 279        /* allocate buffer to save elog record */
 280        elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL);
 281        if (elog_buf == NULL)
 282                goto err_release_elog;
 283
 284        /*
 285         * eMCA event report method has higher priority than EDAC method,
 286         * unless EDAC event report method is mandatory.
 287         */
 288        old_edac_report_status = edac_get_report_status();
 289        edac_set_report_status(EDAC_REPORTING_DISABLED);
 290        mce_register_decode_chain(&extlog_mce_dec);
 291        /* enable OS to be involved to take over management from BIOS */
 292        ((struct extlog_l1_head *)extlog_l1_addr)->flags |= FLAG_OS_OPTIN;
 293
 294        return 0;
 295
 296err_release_elog:
 297        if (elog_addr)
 298                acpi_os_unmap_iomem(elog_addr, elog_size);
 299        release_mem_region(elog_base, elog_size);
 300err_release_l1_dir:
 301        if (extlog_l1_addr)
 302                acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
 303        release_mem_region(l1_dirbase, l1_size);
 304err:
 305        pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n");
 306        return rc;
 307}
 308
 309static void __exit extlog_exit(void)
 310{
 311        edac_set_report_status(old_edac_report_status);
 312        mce_unregister_decode_chain(&extlog_mce_dec);
 313        ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
 314        if (extlog_l1_addr)
 315                acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
 316        if (elog_addr)
 317                acpi_os_unmap_iomem(elog_addr, elog_size);
 318        release_mem_region(elog_base, elog_size);
 319        release_mem_region(l1_dirbase, l1_size);
 320        kfree(elog_buf);
 321}
 322
 323module_init(extlog_init);
 324module_exit(extlog_exit);
 325
 326MODULE_AUTHOR("Chen, Gong <gong.chen@intel.com>");
 327MODULE_DESCRIPTION("Extended MCA Error Log Driver");
 328MODULE_LICENSE("GPL");
 329