linux/drivers/acpi/acpi_extlog.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Extended Error Log driver
   4 *
   5 * Copyright (C) 2013 Intel Corp.
   6 * Author: Chen, Gong <gong.chen@intel.com>
   7 */
   8
   9#include <linux/module.h>
  10#include <linux/acpi.h>
  11#include <linux/cper.h>
  12#include <linux/ratelimit.h>
  13#include <linux/edac.h>
  14#include <linux/ras.h>
  15#include <asm/cpu.h>
  16#include <asm/mce.h>
  17
  18#include "apei/apei-internal.h"
  19#include <ras/ras_event.h>
  20
  21#define EXT_ELOG_ENTRY_MASK     GENMASK_ULL(51, 0) /* elog entry address mask */
  22
  23#define EXTLOG_DSM_REV          0x0
  24#define EXTLOG_FN_ADDR          0x1
  25
  26#define FLAG_OS_OPTIN           BIT(0)
  27#define ELOG_ENTRY_VALID        (1ULL<<63)
  28#define ELOG_ENTRY_LEN          0x1000
  29
  30#define EMCA_BUG \
  31        "Can not request iomem region <0x%016llx-0x%016llx> - eMCA disabled\n"
  32
  33struct extlog_l1_head {
  34        u32 ver;        /* Header Version */
  35        u32 hdr_len;    /* Header Length */
  36        u64 total_len;  /* entire L1 Directory length including this header */
  37        u64 elog_base;  /* MCA Error Log Directory base address */
  38        u64 elog_len;   /* MCA Error Log Directory length */
  39        u32 flags;      /* bit 0 - OS/VMM Opt-in */
  40        u8  rev0[12];
  41        u32 entries;    /* Valid L1 Directory entries per logical processor */
  42        u8  rev1[12];
  43};
  44
  45static int old_edac_report_status;
  46
  47static u8 extlog_dsm_uuid[] __initdata = "663E35AF-CC10-41A4-88EA-5470AF055295";
  48
  49/* L1 table related physical address */
  50static u64 elog_base;
  51static size_t elog_size;
  52static u64 l1_dirbase;
  53static size_t l1_size;
  54
  55/* L1 table related virtual address */
  56static void __iomem *extlog_l1_addr;
  57static void __iomem *elog_addr;
  58
  59static void *elog_buf;
  60
  61static u64 *l1_entry_base;
  62static u32 l1_percpu_entry;
  63
  64#define ELOG_IDX(cpu, bank) \
  65        (cpu_physical_id(cpu) * l1_percpu_entry + (bank))
  66
  67#define ELOG_ENTRY_DATA(idx) \
  68        (*(l1_entry_base + (idx)))
  69
  70#define ELOG_ENTRY_ADDR(phyaddr) \
  71        (phyaddr - elog_base + (u8 *)elog_addr)
  72
  73static struct acpi_hest_generic_status *extlog_elog_entry_check(int cpu, int bank)
  74{
  75        int idx;
  76        u64 data;
  77        struct acpi_hest_generic_status *estatus;
  78
  79        WARN_ON(cpu < 0);
  80        idx = ELOG_IDX(cpu, bank);
  81        data = ELOG_ENTRY_DATA(idx);
  82        if ((data & ELOG_ENTRY_VALID) == 0)
  83                return NULL;
  84
  85        data &= EXT_ELOG_ENTRY_MASK;
  86        estatus = (struct acpi_hest_generic_status *)ELOG_ENTRY_ADDR(data);
  87
  88        /* if no valid data in elog entry, just return */
  89        if (estatus->block_status == 0)
  90                return NULL;
  91
  92        return estatus;
  93}
  94
  95static void __print_extlog_rcd(const char *pfx,
  96                               struct acpi_hest_generic_status *estatus, int cpu)
  97{
  98        static atomic_t seqno;
  99        unsigned int curr_seqno;
 100        char pfx_seq[64];
 101
 102        if (!pfx) {
 103                if (estatus->error_severity <= CPER_SEV_CORRECTED)
 104                        pfx = KERN_INFO;
 105                else
 106                        pfx = KERN_ERR;
 107        }
 108        curr_seqno = atomic_inc_return(&seqno);
 109        snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}", pfx, curr_seqno);
 110        printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu);
 111        cper_estatus_print(pfx_seq, estatus);
 112}
 113
 114static int print_extlog_rcd(const char *pfx,
 115                            struct acpi_hest_generic_status *estatus, int cpu)
 116{
 117        /* Not more than 2 messages every 5 seconds */
 118        static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
 119        static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
 120        struct ratelimit_state *ratelimit;
 121
 122        if (estatus->error_severity == CPER_SEV_CORRECTED ||
 123            (estatus->error_severity == CPER_SEV_INFORMATIONAL))
 124                ratelimit = &ratelimit_corrected;
 125        else
 126                ratelimit = &ratelimit_uncorrected;
 127        if (__ratelimit(ratelimit)) {
 128                __print_extlog_rcd(pfx, estatus, cpu);
 129                return 0;
 130        }
 131
 132        return 1;
 133}
 134
 135static int extlog_print(struct notifier_block *nb, unsigned long val,
 136                        void *data)
 137{
 138        struct mce *mce = (struct mce *)data;
 139        int     bank = mce->bank;
 140        int     cpu = mce->extcpu;
 141        struct acpi_hest_generic_status *estatus, *tmp;
 142        struct acpi_hest_generic_data *gdata;
 143        const guid_t *fru_id = &guid_null;
 144        char *fru_text = "";
 145        guid_t *sec_type;
 146        static u32 err_seq;
 147
 148        estatus = extlog_elog_entry_check(cpu, bank);
 149        if (estatus == NULL)
 150                return NOTIFY_DONE;
 151
 152        memcpy(elog_buf, (void *)estatus, ELOG_ENTRY_LEN);
 153        /* clear record status to enable BIOS to update it again */
 154        estatus->block_status = 0;
 155
 156        tmp = (struct acpi_hest_generic_status *)elog_buf;
 157
 158        if (!ras_userspace_consumers()) {
 159                print_extlog_rcd(NULL, tmp, cpu);
 160                goto out;
 161        }
 162
 163        /* log event via trace */
 164        err_seq++;
 165        gdata = (struct acpi_hest_generic_data *)(tmp + 1);
 166        if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
 167                fru_id = (guid_t *)gdata->fru_id;
 168        if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
 169                fru_text = gdata->fru_text;
 170        sec_type = (guid_t *)gdata->section_type;
 171        if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
 172                struct cper_sec_mem_err *mem = (void *)(gdata + 1);
 173                if (gdata->error_data_length >= sizeof(*mem))
 174                        trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
 175                                               (u8)gdata->error_severity);
 176        }
 177
 178out:
 179        return NOTIFY_STOP;
 180}
 181
 182static bool __init extlog_get_l1addr(void)
 183{
 184        guid_t guid;
 185        acpi_handle handle;
 186        union acpi_object *obj;
 187
 188        if (guid_parse(extlog_dsm_uuid, &guid))
 189                return false;
 190        if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
 191                return false;
 192        if (!acpi_check_dsm(handle, &guid, EXTLOG_DSM_REV, 1 << EXTLOG_FN_ADDR))
 193                return false;
 194        obj = acpi_evaluate_dsm_typed(handle, &guid, EXTLOG_DSM_REV,
 195                                      EXTLOG_FN_ADDR, NULL, ACPI_TYPE_INTEGER);
 196        if (!obj) {
 197                return false;
 198        } else {
 199                l1_dirbase = obj->integer.value;
 200                ACPI_FREE(obj);
 201        }
 202
 203        /* Spec says L1 directory must be 4K aligned, bail out if it isn't */
 204        if (l1_dirbase & ((1 << 12) - 1)) {
 205                pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n",
 206                        l1_dirbase);
 207                return false;
 208        }
 209
 210        return true;
 211}
 212static struct notifier_block extlog_mce_dec = {
 213        .notifier_call  = extlog_print,
 214        .priority       = MCE_PRIO_EXTLOG,
 215};
 216
 217static int __init extlog_init(void)
 218{
 219        struct extlog_l1_head *l1_head;
 220        void __iomem *extlog_l1_hdr;
 221        size_t l1_hdr_size;
 222        struct resource *r;
 223        u64 cap;
 224        int rc;
 225
 226        rdmsrl(MSR_IA32_MCG_CAP, cap);
 227
 228        if (!(cap & MCG_ELOG_P) || !extlog_get_l1addr())
 229                return -ENODEV;
 230
 231        if (edac_get_report_status() == EDAC_REPORTING_FORCE) {
 232                pr_warn("Not loading eMCA, error reporting force-enabled through EDAC.\n");
 233                return -EPERM;
 234        }
 235
 236        rc = -EINVAL;
 237        /* get L1 header to fetch necessary information */
 238        l1_hdr_size = sizeof(struct extlog_l1_head);
 239        r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR");
 240        if (!r) {
 241                pr_warn(FW_BUG EMCA_BUG,
 242                        (unsigned long long)l1_dirbase,
 243                        (unsigned long long)l1_dirbase + l1_hdr_size);
 244                goto err;
 245        }
 246
 247        extlog_l1_hdr = acpi_os_map_iomem(l1_dirbase, l1_hdr_size);
 248        l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
 249        l1_size = l1_head->total_len;
 250        l1_percpu_entry = l1_head->entries;
 251        elog_base = l1_head->elog_base;
 252        elog_size = l1_head->elog_len;
 253        acpi_os_unmap_iomem(extlog_l1_hdr, l1_hdr_size);
 254        release_mem_region(l1_dirbase, l1_hdr_size);
 255
 256        /* remap L1 header again based on completed information */
 257        r = request_mem_region(l1_dirbase, l1_size, "L1 Table");
 258        if (!r) {
 259                pr_warn(FW_BUG EMCA_BUG,
 260                        (unsigned long long)l1_dirbase,
 261                        (unsigned long long)l1_dirbase + l1_size);
 262                goto err;
 263        }
 264        extlog_l1_addr = acpi_os_map_iomem(l1_dirbase, l1_size);
 265        l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);
 266
 267        /* remap elog table */
 268        r = request_mem_region(elog_base, elog_size, "Elog Table");
 269        if (!r) {
 270                pr_warn(FW_BUG EMCA_BUG,
 271                        (unsigned long long)elog_base,
 272                        (unsigned long long)elog_base + elog_size);
 273                goto err_release_l1_dir;
 274        }
 275        elog_addr = acpi_os_map_iomem(elog_base, elog_size);
 276
 277        rc = -ENOMEM;
 278        /* allocate buffer to save elog record */
 279        elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL);
 280        if (elog_buf == NULL)
 281                goto err_release_elog;
 282
 283        /*
 284         * eMCA event report method has higher priority than EDAC method,
 285         * unless EDAC event report method is mandatory.
 286         */
 287        old_edac_report_status = edac_get_report_status();
 288        edac_set_report_status(EDAC_REPORTING_DISABLED);
 289        mce_register_decode_chain(&extlog_mce_dec);
 290        /* enable OS to be involved to take over management from BIOS */
 291        ((struct extlog_l1_head *)extlog_l1_addr)->flags |= FLAG_OS_OPTIN;
 292
 293        return 0;
 294
 295err_release_elog:
 296        if (elog_addr)
 297                acpi_os_unmap_iomem(elog_addr, elog_size);
 298        release_mem_region(elog_base, elog_size);
 299err_release_l1_dir:
 300        if (extlog_l1_addr)
 301                acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
 302        release_mem_region(l1_dirbase, l1_size);
 303err:
 304        pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n");
 305        return rc;
 306}
 307
 308static void __exit extlog_exit(void)
 309{
 310        edac_set_report_status(old_edac_report_status);
 311        mce_unregister_decode_chain(&extlog_mce_dec);
 312        ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
 313        if (extlog_l1_addr)
 314                acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
 315        if (elog_addr)
 316                acpi_os_unmap_iomem(elog_addr, elog_size);
 317        release_mem_region(elog_base, elog_size);
 318        release_mem_region(l1_dirbase, l1_size);
 319        kfree(elog_buf);
 320}
 321
 322module_init(extlog_init);
 323module_exit(extlog_exit);
 324
 325MODULE_AUTHOR("Chen, Gong <gong.chen@intel.com>");
 326MODULE_DESCRIPTION("Extended MCA Error Log Driver");
 327MODULE_LICENSE("GPL");
 328