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 <asm/cpu.h> 15 #include <asm/mce.h> 16 17 #include "apei/apei-internal.h" 18 19 #define EXT_ELOG_ENTRY_MASK GENMASK_ULL(51, 0) /* elog entry address mask */ 20 21 #define EXTLOG_DSM_REV 0x0 22 #define EXTLOG_FN_QUERY 0x0 23 #define EXTLOG_FN_ADDR 0x1 24 25 #define FLAG_OS_OPTIN BIT(0) 26 #define EXTLOG_QUERY_L1_EXIST BIT(1) 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 33 struct 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 45 static u8 extlog_dsm_uuid[] = "663E35AF-CC10-41A4-88EA-5470AF055295"; 46 47 /* L1 table related physical address */ 48 static u64 elog_base; 49 static size_t elog_size; 50 static u64 l1_dirbase; 51 static size_t l1_size; 52 53 /* L1 table related virtual address */ 54 static void __iomem *extlog_l1_addr; 55 static void __iomem *elog_addr; 56 57 static void *elog_buf; 58 59 static u64 *l1_entry_base; 60 static u32 l1_percpu_entry; 61 62 #define ELOG_IDX(cpu, bank) \ 63 (cpu_physical_id(cpu) * l1_percpu_entry + (bank)) 64 65 #define ELOG_ENTRY_DATA(idx) \ 66 (*(l1_entry_base + (idx))) 67 68 #define ELOG_ENTRY_ADDR(phyaddr) \ 69 (phyaddr - elog_base + (u8 *)elog_addr) 70 71 static struct acpi_generic_status *extlog_elog_entry_check(int cpu, int bank) 72 { 73 int idx; 74 u64 data; 75 struct acpi_generic_status *estatus; 76 77 WARN_ON(cpu < 0); 78 idx = ELOG_IDX(cpu, bank); 79 data = ELOG_ENTRY_DATA(idx); 80 if ((data & ELOG_ENTRY_VALID) == 0) 81 return NULL; 82 83 data &= EXT_ELOG_ENTRY_MASK; 84 estatus = (struct acpi_generic_status *)ELOG_ENTRY_ADDR(data); 85 86 /* if no valid data in elog entry, just return */ 87 if (estatus->block_status == 0) 88 return NULL; 89 90 return estatus; 91 } 92 93 static void __print_extlog_rcd(const char *pfx, 94 struct acpi_generic_status *estatus, int cpu) 95 { 96 static atomic_t seqno; 97 unsigned int curr_seqno; 98 char pfx_seq[64]; 99 100 if (!pfx) { 101 if (estatus->error_severity <= CPER_SEV_CORRECTED) 102 pfx = KERN_INFO; 103 else 104 pfx = KERN_ERR; 105 } 106 curr_seqno = atomic_inc_return(&seqno); 107 snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}", pfx, curr_seqno); 108 printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu); 109 cper_estatus_print(pfx_seq, estatus); 110 } 111 112 static int print_extlog_rcd(const char *pfx, 113 struct acpi_generic_status *estatus, int cpu) 114 { 115 /* Not more than 2 messages every 5 seconds */ 116 static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2); 117 static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2); 118 struct ratelimit_state *ratelimit; 119 120 if (estatus->error_severity == CPER_SEV_CORRECTED || 121 (estatus->error_severity == CPER_SEV_INFORMATIONAL)) 122 ratelimit = &ratelimit_corrected; 123 else 124 ratelimit = &ratelimit_uncorrected; 125 if (__ratelimit(ratelimit)) { 126 __print_extlog_rcd(pfx, estatus, cpu); 127 return 0; 128 } 129 130 return 1; 131 } 132 133 static int extlog_print(struct notifier_block *nb, unsigned long val, 134 void *data) 135 { 136 struct mce *mce = (struct mce *)data; 137 int bank = mce->bank; 138 int cpu = mce->extcpu; 139 struct acpi_generic_status *estatus; 140 int rc; 141 142 estatus = extlog_elog_entry_check(cpu, bank); 143 if (estatus == NULL) 144 return NOTIFY_DONE; 145 146 memcpy(elog_buf, (void *)estatus, ELOG_ENTRY_LEN); 147 /* clear record status to enable BIOS to update it again */ 148 estatus->block_status = 0; 149 150 rc = print_extlog_rcd(NULL, (struct acpi_generic_status *)elog_buf, cpu); 151 152 return NOTIFY_DONE; 153 } 154 155 static int extlog_get_dsm(acpi_handle handle, int rev, int func, u64 *ret) 156 { 157 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL}; 158 struct acpi_object_list input; 159 union acpi_object params[4], *obj; 160 u8 uuid[16]; 161 int i; 162 163 acpi_str_to_uuid(extlog_dsm_uuid, uuid); 164 input.count = 4; 165 input.pointer = params; 166 params[0].type = ACPI_TYPE_BUFFER; 167 params[0].buffer.length = 16; 168 params[0].buffer.pointer = uuid; 169 params[1].type = ACPI_TYPE_INTEGER; 170 params[1].integer.value = rev; 171 params[2].type = ACPI_TYPE_INTEGER; 172 params[2].integer.value = func; 173 params[3].type = ACPI_TYPE_PACKAGE; 174 params[3].package.count = 0; 175 params[3].package.elements = NULL; 176 177 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) 178 return -1; 179 180 *ret = 0; 181 obj = (union acpi_object *)buf.pointer; 182 if (obj->type == ACPI_TYPE_INTEGER) { 183 *ret = obj->integer.value; 184 } else if (obj->type == ACPI_TYPE_BUFFER) { 185 if (obj->buffer.length <= 8) { 186 for (i = 0; i < obj->buffer.length; i++) 187 *ret |= (obj->buffer.pointer[i] << (i * 8)); 188 } 189 } 190 kfree(buf.pointer); 191 192 return 0; 193 } 194 195 static bool extlog_get_l1addr(void) 196 { 197 acpi_handle handle; 198 u64 ret; 199 200 if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle))) 201 return false; 202 203 if (extlog_get_dsm(handle, EXTLOG_DSM_REV, EXTLOG_FN_QUERY, &ret) || 204 !(ret & EXTLOG_QUERY_L1_EXIST)) 205 return false; 206 207 if (extlog_get_dsm(handle, EXTLOG_DSM_REV, EXTLOG_FN_ADDR, &ret)) 208 return false; 209 210 l1_dirbase = ret; 211 /* Spec says L1 directory must be 4K aligned, bail out if it isn't */ 212 if (l1_dirbase & ((1 << 12) - 1)) { 213 pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n", 214 l1_dirbase); 215 return false; 216 } 217 218 return true; 219 } 220 static struct notifier_block extlog_mce_dec = { 221 .notifier_call = extlog_print, 222 }; 223 224 static int __init extlog_init(void) 225 { 226 struct extlog_l1_head *l1_head; 227 void __iomem *extlog_l1_hdr; 228 size_t l1_hdr_size; 229 struct resource *r; 230 u64 cap; 231 int rc; 232 233 rc = -ENODEV; 234 235 rdmsrl(MSR_IA32_MCG_CAP, cap); 236 if (!(cap & MCG_ELOG_P)) 237 return rc; 238 239 if (!extlog_get_l1addr()) 240 return rc; 241 242 rc = -EINVAL; 243 /* get L1 header to fetch necessary information */ 244 l1_hdr_size = sizeof(struct extlog_l1_head); 245 r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR"); 246 if (!r) { 247 pr_warn(FW_BUG EMCA_BUG, 248 (unsigned long long)l1_dirbase, 249 (unsigned long long)l1_dirbase + l1_hdr_size); 250 goto err; 251 } 252 253 extlog_l1_hdr = acpi_os_map_memory(l1_dirbase, l1_hdr_size); 254 l1_head = (struct extlog_l1_head *)extlog_l1_hdr; 255 l1_size = l1_head->total_len; 256 l1_percpu_entry = l1_head->entries; 257 elog_base = l1_head->elog_base; 258 elog_size = l1_head->elog_len; 259 acpi_os_unmap_memory(extlog_l1_hdr, l1_hdr_size); 260 release_mem_region(l1_dirbase, l1_hdr_size); 261 262 /* remap L1 header again based on completed information */ 263 r = request_mem_region(l1_dirbase, l1_size, "L1 Table"); 264 if (!r) { 265 pr_warn(FW_BUG EMCA_BUG, 266 (unsigned long long)l1_dirbase, 267 (unsigned long long)l1_dirbase + l1_size); 268 goto err; 269 } 270 extlog_l1_addr = acpi_os_map_memory(l1_dirbase, l1_size); 271 l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size); 272 273 /* remap elog table */ 274 r = request_mem_region(elog_base, elog_size, "Elog Table"); 275 if (!r) { 276 pr_warn(FW_BUG EMCA_BUG, 277 (unsigned long long)elog_base, 278 (unsigned long long)elog_base + elog_size); 279 goto err_release_l1_dir; 280 } 281 elog_addr = acpi_os_map_memory(elog_base, elog_size); 282 283 rc = -ENOMEM; 284 /* allocate buffer to save elog record */ 285 elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL); 286 if (elog_buf == NULL) 287 goto err_release_elog; 288 289 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; 294 295 err_release_elog: 296 if (elog_addr) 297 acpi_os_unmap_memory(elog_addr, elog_size); 298 release_mem_region(elog_base, elog_size); 299 err_release_l1_dir: 300 if (extlog_l1_addr) 301 acpi_os_unmap_memory(extlog_l1_addr, l1_size); 302 release_mem_region(l1_dirbase, l1_size); 303 err: 304 pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n"); 305 return rc; 306 } 307 308 static void __exit extlog_exit(void) 309 { 310 mce_unregister_decode_chain(&extlog_mce_dec); 311 ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN; 312 if (extlog_l1_addr) 313 acpi_os_unmap_memory(extlog_l1_addr, l1_size); 314 if (elog_addr) 315 acpi_os_unmap_memory(elog_addr, elog_size); 316 release_mem_region(elog_base, elog_size); 317 release_mem_region(l1_dirbase, l1_size); 318 kfree(elog_buf); 319 } 320 321 module_init(extlog_init); 322 module_exit(extlog_exit); 323 324 MODULE_AUTHOR("Chen, Gong <gong.chen@intel.com>"); 325 MODULE_DESCRIPTION("Extended MCA Error Log Driver"); 326 MODULE_LICENSE("GPL"); 327