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 <acpi/acpi_bus.h> 13 #include <linux/cper.h> 14 #include <linux/ratelimit.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_QUERY 0x0 24 #define EXTLOG_FN_ADDR 0x1 25 26 #define FLAG_OS_OPTIN BIT(0) 27 #define EXTLOG_QUERY_L1_EXIST BIT(1) 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 34 struct 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 46 static u8 extlog_dsm_uuid[] = "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_DONE; 154 } 155 156 static int extlog_get_dsm(acpi_handle handle, int rev, int func, u64 *ret) 157 { 158 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL}; 159 struct acpi_object_list input; 160 union acpi_object params[4], *obj; 161 u8 uuid[16]; 162 int i; 163 164 acpi_str_to_uuid(extlog_dsm_uuid, uuid); 165 input.count = 4; 166 input.pointer = params; 167 params[0].type = ACPI_TYPE_BUFFER; 168 params[0].buffer.length = 16; 169 params[0].buffer.pointer = uuid; 170 params[1].type = ACPI_TYPE_INTEGER; 171 params[1].integer.value = rev; 172 params[2].type = ACPI_TYPE_INTEGER; 173 params[2].integer.value = func; 174 params[3].type = ACPI_TYPE_PACKAGE; 175 params[3].package.count = 0; 176 params[3].package.elements = NULL; 177 178 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) 179 return -1; 180 181 *ret = 0; 182 obj = (union acpi_object *)buf.pointer; 183 if (obj->type == ACPI_TYPE_INTEGER) { 184 *ret = obj->integer.value; 185 } else if (obj->type == ACPI_TYPE_BUFFER) { 186 if (obj->buffer.length <= 8) { 187 for (i = 0; i < obj->buffer.length; i++) 188 *ret |= (obj->buffer.pointer[i] << (i * 8)); 189 } 190 } 191 kfree(buf.pointer); 192 193 return 0; 194 } 195 196 static bool extlog_get_l1addr(void) 197 { 198 acpi_handle handle; 199 u64 ret; 200 201 if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle))) 202 return false; 203 204 if (extlog_get_dsm(handle, EXTLOG_DSM_REV, EXTLOG_FN_QUERY, &ret) || 205 !(ret & EXTLOG_QUERY_L1_EXIST)) 206 return false; 207 208 if (extlog_get_dsm(handle, EXTLOG_DSM_REV, EXTLOG_FN_ADDR, &ret)) 209 return false; 210 211 l1_dirbase = ret; 212 /* Spec says L1 directory must be 4K aligned, bail out if it isn't */ 213 if (l1_dirbase & ((1 << 12) - 1)) { 214 pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n", 215 l1_dirbase); 216 return false; 217 } 218 219 return true; 220 } 221 static struct notifier_block extlog_mce_dec = { 222 .notifier_call = extlog_print, 223 }; 224 225 static int __init extlog_init(void) 226 { 227 struct extlog_l1_head *l1_head; 228 void __iomem *extlog_l1_hdr; 229 size_t l1_hdr_size; 230 struct resource *r; 231 u64 cap; 232 int rc; 233 234 rc = -ENODEV; 235 236 rdmsrl(MSR_IA32_MCG_CAP, cap); 237 if (!(cap & MCG_ELOG_P)) 238 return rc; 239 240 if (!extlog_get_l1addr()) 241 return rc; 242 243 rc = -EINVAL; 244 /* get L1 header to fetch necessary information */ 245 l1_hdr_size = sizeof(struct extlog_l1_head); 246 r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR"); 247 if (!r) { 248 pr_warn(FW_BUG EMCA_BUG, 249 (unsigned long long)l1_dirbase, 250 (unsigned long long)l1_dirbase + l1_hdr_size); 251 goto err; 252 } 253 254 extlog_l1_hdr = acpi_os_map_memory(l1_dirbase, l1_hdr_size); 255 l1_head = (struct extlog_l1_head *)extlog_l1_hdr; 256 l1_size = l1_head->total_len; 257 l1_percpu_entry = l1_head->entries; 258 elog_base = l1_head->elog_base; 259 elog_size = l1_head->elog_len; 260 acpi_os_unmap_memory(extlog_l1_hdr, l1_hdr_size); 261 release_mem_region(l1_dirbase, l1_hdr_size); 262 263 /* remap L1 header again based on completed information */ 264 r = request_mem_region(l1_dirbase, l1_size, "L1 Table"); 265 if (!r) { 266 pr_warn(FW_BUG EMCA_BUG, 267 (unsigned long long)l1_dirbase, 268 (unsigned long long)l1_dirbase + l1_size); 269 goto err; 270 } 271 extlog_l1_addr = acpi_os_map_memory(l1_dirbase, l1_size); 272 l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size); 273 274 /* remap elog table */ 275 r = request_mem_region(elog_base, elog_size, "Elog Table"); 276 if (!r) { 277 pr_warn(FW_BUG EMCA_BUG, 278 (unsigned long long)elog_base, 279 (unsigned long long)elog_base + elog_size); 280 goto err_release_l1_dir; 281 } 282 elog_addr = acpi_os_map_memory(elog_base, elog_size); 283 284 rc = -ENOMEM; 285 /* allocate buffer to save elog record */ 286 elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL); 287 if (elog_buf == NULL) 288 goto err_release_elog; 289 290 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; 295 296 err_release_elog: 297 if (elog_addr) 298 acpi_os_unmap_memory(elog_addr, elog_size); 299 release_mem_region(elog_base, elog_size); 300 err_release_l1_dir: 301 if (extlog_l1_addr) 302 acpi_os_unmap_memory(extlog_l1_addr, l1_size); 303 release_mem_region(l1_dirbase, l1_size); 304 err: 305 pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n"); 306 return rc; 307 } 308 309 static void __exit extlog_exit(void) 310 { 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_memory(extlog_l1_addr, l1_size); 315 if (elog_addr) 316 acpi_os_unmap_memory(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 } 321 322 module_init(extlog_init); 323 module_exit(extlog_exit); 324 325 MODULE_AUTHOR("Chen, Gong <gong.chen@intel.com>"); 326 MODULE_DESCRIPTION("Extended MCA Error Log Driver"); 327 MODULE_LICENSE("GPL"); 328