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