1 /* 2 * PowerNV OPAL Dump Interface 3 * 4 * Copyright 2013,2014 IBM Corp. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #include <linux/kobject.h> 13 #include <linux/mm.h> 14 #include <linux/slab.h> 15 #include <linux/vmalloc.h> 16 #include <linux/pagemap.h> 17 #include <linux/delay.h> 18 19 #include <asm/opal.h> 20 21 #define DUMP_TYPE_FSP 0x01 22 23 struct dump_obj { 24 struct kobject kobj; 25 struct bin_attribute dump_attr; 26 uint32_t id; /* becomes object name */ 27 uint32_t type; 28 uint32_t size; 29 char *buffer; 30 }; 31 #define to_dump_obj(x) container_of(x, struct dump_obj, kobj) 32 33 struct dump_attribute { 34 struct attribute attr; 35 ssize_t (*show)(struct dump_obj *dump, struct dump_attribute *attr, 36 char *buf); 37 ssize_t (*store)(struct dump_obj *dump, struct dump_attribute *attr, 38 const char *buf, size_t count); 39 }; 40 #define to_dump_attr(x) container_of(x, struct dump_attribute, attr) 41 42 static ssize_t dump_id_show(struct dump_obj *dump_obj, 43 struct dump_attribute *attr, 44 char *buf) 45 { 46 return sprintf(buf, "0x%x\n", dump_obj->id); 47 } 48 49 static const char* dump_type_to_string(uint32_t type) 50 { 51 switch (type) { 52 case 0x01: return "SP Dump"; 53 case 0x02: return "System/Platform Dump"; 54 case 0x03: return "SMA Dump"; 55 default: return "unknown"; 56 } 57 } 58 59 static ssize_t dump_type_show(struct dump_obj *dump_obj, 60 struct dump_attribute *attr, 61 char *buf) 62 { 63 64 return sprintf(buf, "0x%x %s\n", dump_obj->type, 65 dump_type_to_string(dump_obj->type)); 66 } 67 68 static ssize_t dump_ack_show(struct dump_obj *dump_obj, 69 struct dump_attribute *attr, 70 char *buf) 71 { 72 return sprintf(buf, "ack - acknowledge dump\n"); 73 } 74 75 /* 76 * Send acknowledgement to OPAL 77 */ 78 static int64_t dump_send_ack(uint32_t dump_id) 79 { 80 int rc; 81 82 rc = opal_dump_ack(dump_id); 83 if (rc) 84 pr_warn("%s: Failed to send ack to Dump ID 0x%x (%d)\n", 85 __func__, dump_id, rc); 86 return rc; 87 } 88 89 static ssize_t dump_ack_store(struct dump_obj *dump_obj, 90 struct dump_attribute *attr, 91 const char *buf, 92 size_t count) 93 { 94 dump_send_ack(dump_obj->id); 95 sysfs_remove_file_self(&dump_obj->kobj, &attr->attr); 96 kobject_put(&dump_obj->kobj); 97 return count; 98 } 99 100 /* Attributes of a dump 101 * The binary attribute of the dump itself is dynamic 102 * due to the dynamic size of the dump 103 */ 104 static struct dump_attribute id_attribute = 105 __ATTR(id, S_IRUGO, dump_id_show, NULL); 106 static struct dump_attribute type_attribute = 107 __ATTR(type, S_IRUGO, dump_type_show, NULL); 108 static struct dump_attribute ack_attribute = 109 __ATTR(acknowledge, 0660, dump_ack_show, dump_ack_store); 110 111 static ssize_t init_dump_show(struct dump_obj *dump_obj, 112 struct dump_attribute *attr, 113 char *buf) 114 { 115 return sprintf(buf, "1 - initiate dump\n"); 116 } 117 118 static int64_t dump_fips_init(uint8_t type) 119 { 120 int rc; 121 122 rc = opal_dump_init(type); 123 if (rc) 124 pr_warn("%s: Failed to initiate FipS dump (%d)\n", 125 __func__, rc); 126 return rc; 127 } 128 129 static ssize_t init_dump_store(struct dump_obj *dump_obj, 130 struct dump_attribute *attr, 131 const char *buf, 132 size_t count) 133 { 134 dump_fips_init(DUMP_TYPE_FSP); 135 pr_info("%s: Initiated FSP dump\n", __func__); 136 return count; 137 } 138 139 static struct dump_attribute initiate_attribute = 140 __ATTR(initiate_dump, 0600, init_dump_show, init_dump_store); 141 142 static struct attribute *initiate_attrs[] = { 143 &initiate_attribute.attr, 144 NULL, 145 }; 146 147 static struct attribute_group initiate_attr_group = { 148 .attrs = initiate_attrs, 149 }; 150 151 static struct kset *dump_kset; 152 153 static ssize_t dump_attr_show(struct kobject *kobj, 154 struct attribute *attr, 155 char *buf) 156 { 157 struct dump_attribute *attribute; 158 struct dump_obj *dump; 159 160 attribute = to_dump_attr(attr); 161 dump = to_dump_obj(kobj); 162 163 if (!attribute->show) 164 return -EIO; 165 166 return attribute->show(dump, attribute, buf); 167 } 168 169 static ssize_t dump_attr_store(struct kobject *kobj, 170 struct attribute *attr, 171 const char *buf, size_t len) 172 { 173 struct dump_attribute *attribute; 174 struct dump_obj *dump; 175 176 attribute = to_dump_attr(attr); 177 dump = to_dump_obj(kobj); 178 179 if (!attribute->store) 180 return -EIO; 181 182 return attribute->store(dump, attribute, buf, len); 183 } 184 185 static const struct sysfs_ops dump_sysfs_ops = { 186 .show = dump_attr_show, 187 .store = dump_attr_store, 188 }; 189 190 static void dump_release(struct kobject *kobj) 191 { 192 struct dump_obj *dump; 193 194 dump = to_dump_obj(kobj); 195 vfree(dump->buffer); 196 kfree(dump); 197 } 198 199 static struct attribute *dump_default_attrs[] = { 200 &id_attribute.attr, 201 &type_attribute.attr, 202 &ack_attribute.attr, 203 NULL, 204 }; 205 206 static struct kobj_type dump_ktype = { 207 .sysfs_ops = &dump_sysfs_ops, 208 .release = &dump_release, 209 .default_attrs = dump_default_attrs, 210 }; 211 212 static int64_t dump_read_info(uint32_t *dump_id, uint32_t *dump_size, uint32_t *dump_type) 213 { 214 __be32 id, size, type; 215 int rc; 216 217 type = cpu_to_be32(0xffffffff); 218 219 rc = opal_dump_info2(&id, &size, &type); 220 if (rc == OPAL_PARAMETER) 221 rc = opal_dump_info(&id, &size); 222 223 *dump_id = be32_to_cpu(id); 224 *dump_size = be32_to_cpu(size); 225 *dump_type = be32_to_cpu(type); 226 227 if (rc) 228 pr_warn("%s: Failed to get dump info (%d)\n", 229 __func__, rc); 230 return rc; 231 } 232 233 static int64_t dump_read_data(struct dump_obj *dump) 234 { 235 struct opal_sg_list *list; 236 uint64_t addr; 237 int64_t rc; 238 239 /* Allocate memory */ 240 dump->buffer = vzalloc(PAGE_ALIGN(dump->size)); 241 if (!dump->buffer) { 242 pr_err("%s : Failed to allocate memory\n", __func__); 243 rc = -ENOMEM; 244 goto out; 245 } 246 247 /* Generate SG list */ 248 list = opal_vmalloc_to_sg_list(dump->buffer, dump->size); 249 if (!list) { 250 rc = -ENOMEM; 251 goto out; 252 } 253 254 /* First entry address */ 255 addr = __pa(list); 256 257 /* Fetch data */ 258 rc = OPAL_BUSY_EVENT; 259 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 260 rc = opal_dump_read(dump->id, addr); 261 if (rc == OPAL_BUSY_EVENT) { 262 opal_poll_events(NULL); 263 msleep(20); 264 } 265 } 266 267 if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) 268 pr_warn("%s: Extract dump failed for ID 0x%x\n", 269 __func__, dump->id); 270 271 /* Free SG list */ 272 opal_free_sg_list(list); 273 274 out: 275 return rc; 276 } 277 278 static ssize_t dump_attr_read(struct file *filep, struct kobject *kobj, 279 struct bin_attribute *bin_attr, 280 char *buffer, loff_t pos, size_t count) 281 { 282 ssize_t rc; 283 284 struct dump_obj *dump = to_dump_obj(kobj); 285 286 if (!dump->buffer) { 287 rc = dump_read_data(dump); 288 289 if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) { 290 vfree(dump->buffer); 291 dump->buffer = NULL; 292 293 return -EIO; 294 } 295 if (rc == OPAL_PARTIAL) { 296 /* On a partial read, we just return EIO 297 * and rely on userspace to ask us to try 298 * again. 299 */ 300 pr_info("%s: Platform dump partially read.ID = 0x%x\n", 301 __func__, dump->id); 302 return -EIO; 303 } 304 } 305 306 memcpy(buffer, dump->buffer + pos, count); 307 308 /* You may think we could free the dump buffer now and retrieve 309 * it again later if needed, but due to current firmware limitation, 310 * that's not the case. So, once read into userspace once, 311 * we keep the dump around until it's acknowledged by userspace. 312 */ 313 314 return count; 315 } 316 317 static struct dump_obj *create_dump_obj(uint32_t id, size_t size, 318 uint32_t type) 319 { 320 struct dump_obj *dump; 321 int rc; 322 323 dump = kzalloc(sizeof(*dump), GFP_KERNEL); 324 if (!dump) 325 return NULL; 326 327 dump->kobj.kset = dump_kset; 328 329 kobject_init(&dump->kobj, &dump_ktype); 330 331 sysfs_bin_attr_init(&dump->dump_attr); 332 333 dump->dump_attr.attr.name = "dump"; 334 dump->dump_attr.attr.mode = 0400; 335 dump->dump_attr.size = size; 336 dump->dump_attr.read = dump_attr_read; 337 338 dump->id = id; 339 dump->size = size; 340 dump->type = type; 341 342 rc = kobject_add(&dump->kobj, NULL, "0x%x-0x%x", type, id); 343 if (rc) { 344 kobject_put(&dump->kobj); 345 return NULL; 346 } 347 348 rc = sysfs_create_bin_file(&dump->kobj, &dump->dump_attr); 349 if (rc) { 350 kobject_put(&dump->kobj); 351 return NULL; 352 } 353 354 pr_info("%s: New platform dump. ID = 0x%x Size %u\n", 355 __func__, dump->id, dump->size); 356 357 kobject_uevent(&dump->kobj, KOBJ_ADD); 358 359 return dump; 360 } 361 362 static int process_dump(void) 363 { 364 int rc; 365 uint32_t dump_id, dump_size, dump_type; 366 struct dump_obj *dump; 367 char name[22]; 368 369 rc = dump_read_info(&dump_id, &dump_size, &dump_type); 370 if (rc != OPAL_SUCCESS) 371 return rc; 372 373 sprintf(name, "0x%x-0x%x", dump_type, dump_id); 374 375 /* we may get notified twice, let's handle 376 * that gracefully and not create two conflicting 377 * entries. 378 */ 379 if (kset_find_obj(dump_kset, name)) 380 return 0; 381 382 dump = create_dump_obj(dump_id, dump_size, dump_type); 383 if (!dump) 384 return -1; 385 386 return 0; 387 } 388 389 static void dump_work_fn(struct work_struct *work) 390 { 391 process_dump(); 392 } 393 394 static DECLARE_WORK(dump_work, dump_work_fn); 395 396 static void schedule_process_dump(void) 397 { 398 schedule_work(&dump_work); 399 } 400 401 /* 402 * New dump available notification 403 * 404 * Once we get notification, we add sysfs entries for it. 405 * We only fetch the dump on demand, and create sysfs asynchronously. 406 */ 407 static int dump_event(struct notifier_block *nb, 408 unsigned long events, void *change) 409 { 410 if (events & OPAL_EVENT_DUMP_AVAIL) 411 schedule_process_dump(); 412 413 return 0; 414 } 415 416 static struct notifier_block dump_nb = { 417 .notifier_call = dump_event, 418 .next = NULL, 419 .priority = 0 420 }; 421 422 void __init opal_platform_dump_init(void) 423 { 424 int rc; 425 426 dump_kset = kset_create_and_add("dump", NULL, opal_kobj); 427 if (!dump_kset) { 428 pr_warn("%s: Failed to create dump kset\n", __func__); 429 return; 430 } 431 432 rc = sysfs_create_group(&dump_kset->kobj, &initiate_attr_group); 433 if (rc) { 434 pr_warn("%s: Failed to create initiate dump attr group\n", 435 __func__); 436 kobject_put(&dump_kset->kobj); 437 return; 438 } 439 440 rc = opal_notifier_register(&dump_nb); 441 if (rc) { 442 pr_warn("%s: Can't register OPAL event notifier (%d)\n", 443 __func__, rc); 444 return; 445 } 446 447 opal_dump_resend_notification(); 448 } 449