kernel/arch/powerpc/platforms/powernv/opal-dump.c

   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 Service Processor(FSP) 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 FSP 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         int rc;
 135
 136         rc = dump_fips_init(DUMP_TYPE_FSP);
 137         if (rc == OPAL_SUCCESS)
 138                 pr_info("%s: Initiated FSP dump\n", __func__);
 139
 140         return count;
 141 }
 142
 143 static struct dump_attribute initiate_attribute =
 144         __ATTR(initiate_dump, 0600, init_dump_show, init_dump_store);
 145
 146 static struct attribute *initiate_attrs[] = {
 147         &initiate_attribute.attr,
 148         NULL,
 149 };
 150
 151 static struct attribute_group initiate_attr_group = {
 152         .attrs = initiate_attrs,
 153 };
 154
 155 static struct kset *dump_kset;
 156
 157 static ssize_t dump_attr_show(struct kobject *kobj,
 158                               struct attribute *attr,
 159                               char *buf)
 160 {
 161         struct dump_attribute *attribute;
 162         struct dump_obj *dump;
 163
 164         attribute = to_dump_attr(attr);
 165         dump = to_dump_obj(kobj);
 166
 167         if (!attribute->show)
 168                 return -EIO;
 169
 170         return attribute->show(dump, attribute, buf);
 171 }
 172
 173 static ssize_t dump_attr_store(struct kobject *kobj,
 174                                struct attribute *attr,
 175                                const char *buf, size_t len)
 176 {
 177         struct dump_attribute *attribute;
 178         struct dump_obj *dump;
 179
 180         attribute = to_dump_attr(attr);
 181         dump = to_dump_obj(kobj);
 182
 183         if (!attribute->store)
 184                 return -EIO;
 185
 186         return attribute->store(dump, attribute, buf, len);
 187 }
 188
 189 static const struct sysfs_ops dump_sysfs_ops = {
 190         .show = dump_attr_show,
 191         .store = dump_attr_store,
 192 };
 193
 194 static void dump_release(struct kobject *kobj)
 195 {
 196         struct dump_obj *dump;
 197
 198         dump = to_dump_obj(kobj);
 199         vfree(dump->buffer);
 200         kfree(dump);
 201 }
 202
 203 static struct attribute *dump_default_attrs[] = {
 204         &id_attribute.attr,
 205         &type_attribute.attr,
 206         &ack_attribute.attr,
 207         NULL,
 208 };
 209
 210 static struct kobj_type dump_ktype = {
 211         .sysfs_ops = &dump_sysfs_ops,
 212         .release = &dump_release,
 213         .default_attrs = dump_default_attrs,
 214 };
 215
 216 static int64_t dump_read_info(uint32_t *dump_id, uint32_t *dump_size, uint32_t *dump_type)
 217 {
 218         __be32 id, size, type;
 219         int rc;
 220
 221         type = cpu_to_be32(0xffffffff);
 222
 223         rc = opal_dump_info2(&id, &size, &type);
 224         if (rc == OPAL_PARAMETER)
 225                 rc = opal_dump_info(&id, &size);
 226
 227         *dump_id = be32_to_cpu(id);
 228         *dump_size = be32_to_cpu(size);
 229         *dump_type = be32_to_cpu(type);
 230
 231         if (rc)
 232                 pr_warn("%s: Failed to get dump info (%d)\n",
 233                         __func__, rc);
 234         return rc;
 235 }
 236
 237 static int64_t dump_read_data(struct dump_obj *dump)
 238 {
 239         struct opal_sg_list *list;
 240         uint64_t addr;
 241         int64_t rc;
 242
 243         /* Allocate memory */
 244         dump->buffer = vzalloc(PAGE_ALIGN(dump->size));
 245         if (!dump->buffer) {
 246                 pr_err("%s : Failed to allocate memory\n", __func__);
 247                 rc = -ENOMEM;
 248                 goto out;
 249         }
 250
 251         /* Generate SG list */
 252         list = opal_vmalloc_to_sg_list(dump->buffer, dump->size);
 253         if (!list) {
 254                 rc = -ENOMEM;
 255                 goto out;
 256         }
 257
 258         /* First entry address */
 259         addr = __pa(list);
 260
 261         /* Fetch data */
 262         rc = OPAL_BUSY_EVENT;
 263         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 264                 rc = opal_dump_read(dump->id, addr);
 265                 if (rc == OPAL_BUSY_EVENT) {
 266                         opal_poll_events(NULL);
 267                         msleep(20);
 268                 }
 269         }
 270
 271         if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL)
 272                 pr_warn("%s: Extract dump failed for ID 0x%x\n",
 273                         __func__, dump->id);
 274
 275         /* Free SG list */
 276         opal_free_sg_list(list);
 277
 278 out:
 279         return rc;
 280 }
 281
 282 static ssize_t dump_attr_read(struct file *filep, struct kobject *kobj,
 283                               struct bin_attribute *bin_attr,
 284                               char *buffer, loff_t pos, size_t count)
 285 {
 286         ssize_t rc;
 287
 288         struct dump_obj *dump = to_dump_obj(kobj);
 289
 290         if (!dump->buffer) {
 291                 rc = dump_read_data(dump);
 292
 293                 if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
 294                         vfree(dump->buffer);
 295                         dump->buffer = NULL;
 296
 297                         return -EIO;
 298                 }
 299                 if (rc == OPAL_PARTIAL) {
 300                         /* On a partial read, we just return EIO
 301                          * and rely on userspace to ask us to try
 302                          * again.
 303                          */
 304                         pr_info("%s: Platform dump partially read. ID = 0x%x\n",
 305                                 __func__, dump->id);
 306                         return -EIO;
 307                 }
 308         }
 309
 310         memcpy(buffer, dump->buffer + pos, count);
 311
 312         /* You may think we could free the dump buffer now and retrieve
 313          * it again later if needed, but due to current firmware limitation,
 314          * that's not the case. So, once read into userspace once,
 315          * we keep the dump around until it's acknowledged by userspace.
 316          */
 317
 318         return count;
 319 }
 320
 321 static struct dump_obj *create_dump_obj(uint32_t id, size_t size,
 322                                         uint32_t type)
 323 {
 324         struct dump_obj *dump;
 325         int rc;
 326
 327         dump = kzalloc(sizeof(*dump), GFP_KERNEL);
 328         if (!dump)
 329                 return NULL;
 330
 331         dump->kobj.kset = dump_kset;
 332
 333         kobject_init(&dump->kobj, &dump_ktype);
 334
 335         sysfs_bin_attr_init(&dump->dump_attr);
 336
 337         dump->dump_attr.attr.name = "dump";
 338         dump->dump_attr.attr.mode = 0400;
 339         dump->dump_attr.size = size;
 340         dump->dump_attr.read = dump_attr_read;
 341
 342         dump->id = id;
 343         dump->size = size;
 344         dump->type = type;
 345
 346         rc = kobject_add(&dump->kobj, NULL, "0x%x-0x%x", type, id);
 347         if (rc) {
 348                 kobject_put(&dump->kobj);
 349                 return NULL;
 350         }
 351
 352         rc = sysfs_create_bin_file(&dump->kobj, &dump->dump_attr);
 353         if (rc) {
 354                 kobject_put(&dump->kobj);
 355                 return NULL;
 356         }
 357
 358         pr_info("%s: New platform dump. ID = 0x%x Size %u\n",
 359                 __func__, dump->id, dump->size);
 360
 361         kobject_uevent(&dump->kobj, KOBJ_ADD);
 362
 363         return dump;
 364 }
 365
 366 static int process_dump(void)
 367 {
 368         int rc;
 369         uint32_t dump_id, dump_size, dump_type;
 370         struct dump_obj *dump;
 371         char name[22];
 372
 373         rc = dump_read_info(&dump_id, &dump_size, &dump_type);
 374         if (rc != OPAL_SUCCESS)
 375                 return rc;
 376
 377         sprintf(name, "0x%x-0x%x", dump_type, dump_id);
 378
 379         /* we may get notified twice, let's handle
 380          * that gracefully and not create two conflicting
 381          * entries.
 382          */
 383         if (kset_find_obj(dump_kset, name))
 384                 return 0;
 385
 386         dump = create_dump_obj(dump_id, dump_size, dump_type);
 387         if (!dump)
 388                 return -1;
 389
 390         return 0;
 391 }
 392
 393 static void dump_work_fn(struct work_struct *work)
 394 {
 395         process_dump();
 396 }
 397
 398 static DECLARE_WORK(dump_work, dump_work_fn);
 399
 400 static void schedule_process_dump(void)
 401 {
 402         schedule_work(&dump_work);
 403 }
 404
 405 /*
 406  * New dump available notification
 407  *
 408  * Once we get notification, we add sysfs entries for it.
 409  * We only fetch the dump on demand, and create sysfs asynchronously.
 410  */
 411 static int dump_event(struct notifier_block *nb,
 412                       unsigned long events, void *change)
 413 {
 414         if (events & OPAL_EVENT_DUMP_AVAIL)
 415                 schedule_process_dump();
 416
 417         return 0;
 418 }
 419
 420 static struct notifier_block dump_nb = {
 421         .notifier_call  = dump_event,
 422         .next           = NULL,
 423         .priority       = 0
 424 };
 425
 426 void __init opal_platform_dump_init(void)
 427 {
 428         int rc;
 429
 430         /* ELOG not supported by firmware */
 431         if (!opal_check_token(OPAL_DUMP_READ))
 432                 return;
 433
 434         dump_kset = kset_create_and_add("dump", NULL, opal_kobj);
 435         if (!dump_kset) {
 436                 pr_warn("%s: Failed to create dump kset\n", __func__);
 437                 return;
 438         }
 439
 440         rc = sysfs_create_group(&dump_kset->kobj, &initiate_attr_group);
 441         if (rc) {
 442                 pr_warn("%s: Failed to create initiate dump attr group\n",
 443                         __func__);
 444                 kobject_put(&dump_kset->kobj);
 445                 return;
 446         }
 447
 448         rc = opal_notifier_register(&dump_nb);
 449         if (rc) {
 450                 pr_warn("%s: Can't register OPAL event notifier (%d)\n",
 451                         __func__, rc);
 452                 return;
 453         }
 454
 455         if (opal_check_token(OPAL_DUMP_RESEND))
 456                 opal_dump_resend_notification();
 457 }