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 void delay_release_kobj(void *kobj)
  90 {
  91         kobject_put((struct kobject *)kobj);
  92 }
  93
  94 static ssize_t dump_ack_store(struct dump_obj *dump_obj,
  95                               struct dump_attribute *attr,
  96                               const char *buf,
  97                               size_t count)
  98 {
  99         dump_send_ack(dump_obj->id);
 100         sysfs_schedule_callback(&dump_obj->kobj, delay_release_kobj,
 101                                 &dump_obj->kobj, THIS_MODULE);
 102         return count;
 103 }
 104
 105 /* Attributes of a dump
 106  * The binary attribute of the dump itself is dynamic
 107  * due to the dynamic size of the dump
 108  */
 109 static struct dump_attribute id_attribute =
 110         __ATTR(id, 0666, dump_id_show, NULL);
 111 static struct dump_attribute type_attribute =
 112         __ATTR(type, 0666, dump_type_show, NULL);
 113 static struct dump_attribute ack_attribute =
 114         __ATTR(acknowledge, 0660, dump_ack_show, dump_ack_store);
 115
 116 static ssize_t init_dump_show(struct dump_obj *dump_obj,
 117                               struct dump_attribute *attr,
 118                               char *buf)
 119 {
 120         return sprintf(buf, "1 - initiate dump\n");
 121 }
 122
 123 static int64_t dump_fips_init(uint8_t type)
 124 {
 125         int rc;
 126
 127         rc = opal_dump_init(type);
 128         if (rc)
 129                 pr_warn("%s: Failed to initiate FipS dump (%d)\n",
 130                         __func__, rc);
 131         return rc;
 132 }
 133
 134 static ssize_t init_dump_store(struct dump_obj *dump_obj,
 135                                struct dump_attribute *attr,
 136                                const char *buf,
 137                                size_t count)
 138 {
 139         dump_fips_init(DUMP_TYPE_FSP);
 140         pr_info("%s: Initiated FSP dump\n", __func__);
 141         return count;
 142 }
 143
 144 static struct dump_attribute initiate_attribute =
 145         __ATTR(initiate_dump, 0600, init_dump_show, init_dump_store);
 146
 147 static struct attribute *initiate_attrs[] = {
 148         &initiate_attribute.attr,
 149         NULL,
 150 };
 151
 152 static struct attribute_group initiate_attr_group = {
 153         .attrs = initiate_attrs,
 154 };
 155
 156 static struct kset *dump_kset;
 157
 158 static ssize_t dump_attr_show(struct kobject *kobj,
 159                               struct attribute *attr,
 160                               char *buf)
 161 {
 162         struct dump_attribute *attribute;
 163         struct dump_obj *dump;
 164
 165         attribute = to_dump_attr(attr);
 166         dump = to_dump_obj(kobj);
 167
 168         if (!attribute->show)
 169                 return -EIO;
 170
 171         return attribute->show(dump, attribute, buf);
 172 }
 173
 174 static ssize_t dump_attr_store(struct kobject *kobj,
 175                                struct attribute *attr,
 176                                const char *buf, size_t len)
 177 {
 178         struct dump_attribute *attribute;
 179         struct dump_obj *dump;
 180
 181         attribute = to_dump_attr(attr);
 182         dump = to_dump_obj(kobj);
 183
 184         if (!attribute->store)
 185                 return -EIO;
 186
 187         return attribute->store(dump, attribute, buf, len);
 188 }
 189
 190 static const struct sysfs_ops dump_sysfs_ops = {
 191         .show = dump_attr_show,
 192         .store = dump_attr_store,
 193 };
 194
 195 static void dump_release(struct kobject *kobj)
 196 {
 197         struct dump_obj *dump;
 198
 199         dump = to_dump_obj(kobj);
 200         vfree(dump->buffer);
 201         kfree(dump);
 202 }
 203
 204 static struct attribute *dump_default_attrs[] = {
 205         &id_attribute.attr,
 206         &type_attribute.attr,
 207         &ack_attribute.attr,
 208         NULL,
 209 };
 210
 211 static struct kobj_type dump_ktype = {
 212         .sysfs_ops = &dump_sysfs_ops,
 213         .release = &dump_release,
 214         .default_attrs = dump_default_attrs,
 215 };
 216
 217 static void free_dump_sg_list(struct opal_sg_list *list)
 218 {
 219         struct opal_sg_list *sg1;
 220         while (list) {
 221                 sg1 = list->next;
 222                 kfree(list);
 223                 list = sg1;
 224         }
 225         list = NULL;
 226 }
 227
 228 static struct opal_sg_list *dump_data_to_sglist(struct dump_obj *dump)
 229 {
 230         struct opal_sg_list *sg1, *list = NULL;
 231         void *addr;
 232         int64_t size;
 233
 234         addr = dump->buffer;
 235         size = dump->size;
 236
 237         sg1 = kzalloc(PAGE_SIZE, GFP_KERNEL);
 238         if (!sg1)
 239                 goto nomem;
 240
 241         list = sg1;
 242         sg1->num_entries = 0;
 243         while (size > 0) {
 244                 /* Translate virtual address to physical address */
 245                 sg1->entry[sg1->num_entries].data =
 246                         (void *)(vmalloc_to_pfn(addr) << PAGE_SHIFT);
 247
 248                 if (size > PAGE_SIZE)
 249                         sg1->entry[sg1->num_entries].length = PAGE_SIZE;
 250                 else
 251                         sg1->entry[sg1->num_entries].length = size;
 252
 253                 sg1->num_entries++;
 254                 if (sg1->num_entries >= SG_ENTRIES_PER_NODE) {
 255                         sg1->next = kzalloc(PAGE_SIZE, GFP_KERNEL);
 256                         if (!sg1->next)
 257                                 goto nomem;
 258
 259                         sg1 = sg1->next;
 260                         sg1->num_entries = 0;
 261                 }
 262                 addr += PAGE_SIZE;
 263                 size -= PAGE_SIZE;
 264         }
 265         return list;
 266
 267 nomem:
 268         pr_err("%s : Failed to allocate memory\n", __func__);
 269         free_dump_sg_list(list);
 270         return NULL;
 271 }
 272
 273 static void sglist_to_phy_addr(struct opal_sg_list *list)
 274 {
 275         struct opal_sg_list *sg, *next;
 276
 277         for (sg = list; sg; sg = next) {
 278                 next = sg->next;
 279                 /* Don't translate NULL pointer for last entry */
 280                 if (sg->next)
 281                         sg->next = (struct opal_sg_list *)__pa(sg->next);
 282                 else
 283                         sg->next = NULL;
 284
 285                 /* Convert num_entries to length */
 286                 sg->num_entries =
 287                         sg->num_entries * sizeof(struct opal_sg_entry) + 16;
 288         }
 289 }
 290
 291 static int64_t dump_read_info(uint32_t *id, uint32_t *size, uint32_t *type)
 292 {
 293         int rc;
 294         *type = 0xffffffff;
 295
 296         rc = opal_dump_info2(id, size, type);
 297
 298         if (rc == OPAL_PARAMETER)
 299                 rc = opal_dump_info(id, size);
 300
 301         if (rc)
 302                 pr_warn("%s: Failed to get dump info (%d)\n",
 303                         __func__, rc);
 304         return rc;
 305 }
 306
 307 static int64_t dump_read_data(struct dump_obj *dump)
 308 {
 309         struct opal_sg_list *list;
 310         uint64_t addr;
 311         int64_t rc;
 312
 313         /* Allocate memory */
 314         dump->buffer = vzalloc(PAGE_ALIGN(dump->size));
 315         if (!dump->buffer) {
 316                 pr_err("%s : Failed to allocate memory\n", __func__);
 317                 rc = -ENOMEM;
 318                 goto out;
 319         }
 320
 321         /* Generate SG list */
 322         list = dump_data_to_sglist(dump);
 323         if (!list) {
 324                 rc = -ENOMEM;
 325                 goto out;
 326         }
 327
 328         /* Translate sg list addr to real address */
 329         sglist_to_phy_addr(list);
 330
 331         /* First entry address */
 332         addr = __pa(list);
 333
 334         /* Fetch data */
 335         rc = OPAL_BUSY_EVENT;
 336         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 337                 rc = opal_dump_read(dump->id, addr);
 338                 if (rc == OPAL_BUSY_EVENT) {
 339                         opal_poll_events(NULL);
 340                         msleep(20);
 341                 }
 342         }
 343
 344         if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL)
 345                 pr_warn("%s: Extract dump failed for ID 0x%x\n",
 346                         __func__, dump->id);
 347
 348         /* Free SG list */
 349         free_dump_sg_list(list);
 350
 351 out:
 352         return rc;
 353 }
 354
 355 static ssize_t dump_attr_read(struct file *filep, struct kobject *kobj,
 356                               struct bin_attribute *bin_attr,
 357                               char *buffer, loff_t pos, size_t count)
 358 {
 359         ssize_t rc;
 360
 361         struct dump_obj *dump = to_dump_obj(kobj);
 362
 363         if (!dump->buffer) {
 364                 rc = dump_read_data(dump);
 365
 366                 if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
 367                         vfree(dump->buffer);
 368                         dump->buffer = NULL;
 369
 370                         return -EIO;
 371                 }
 372                 if (rc == OPAL_PARTIAL) {
 373                         /* On a partial read, we just return EIO
 374                          * and rely on userspace to ask us to try
 375                          * again.
 376                          */
 377                         pr_info("%s: Platform dump partially read.ID = 0x%x\n",
 378                                 __func__, dump->id);
 379                         return -EIO;
 380                 }
 381         }
 382
 383         memcpy(buffer, dump->buffer + pos, count);
 384
 385         /* You may think we could free the dump buffer now and retrieve
 386          * it again later if needed, but due to current firmware limitation,
 387          * that's not the case. So, once read into userspace once,
 388          * we keep the dump around until it's acknowledged by userspace.
 389          */
 390
 391         return count;
 392 }
 393
 394 static struct dump_obj *create_dump_obj(uint32_t id, size_t size,
 395                                         uint32_t type)
 396 {
 397         struct dump_obj *dump;
 398         int rc;
 399
 400         dump = kzalloc(sizeof(*dump), GFP_KERNEL);
 401         if (!dump)
 402                 return NULL;
 403
 404         dump->kobj.kset = dump_kset;
 405
 406         kobject_init(&dump->kobj, &dump_ktype);
 407
 408         sysfs_bin_attr_init(&dump->dump_attr);
 409
 410         dump->dump_attr.attr.name = "dump";
 411         dump->dump_attr.attr.mode = 0400;
 412         dump->dump_attr.size = size;
 413         dump->dump_attr.read = dump_attr_read;
 414
 415         dump->id = id;
 416         dump->size = size;
 417         dump->type = type;
 418
 419         rc = kobject_add(&dump->kobj, NULL, "0x%x-0x%x", type, id);
 420         if (rc) {
 421                 kobject_put(&dump->kobj);
 422                 return NULL;
 423         }
 424
 425         rc = sysfs_create_bin_file(&dump->kobj, &dump->dump_attr);
 426         if (rc) {
 427                 kobject_put(&dump->kobj);
 428                 return NULL;
 429         }
 430
 431         pr_info("%s: New platform dump. ID = 0x%x Size %u\n",
 432                 __func__, dump->id, dump->size);
 433
 434         kobject_uevent(&dump->kobj, KOBJ_ADD);
 435
 436         return dump;
 437 }
 438
 439 static int process_dump(void)
 440 {
 441         int rc;
 442         uint32_t dump_id, dump_size, dump_type;
 443         struct dump_obj *dump;
 444         char name[22];
 445
 446         rc = dump_read_info(&dump_id, &dump_size, &dump_type);
 447         if (rc != OPAL_SUCCESS)
 448                 return rc;
 449
 450         sprintf(name, "0x%x-0x%x", dump_type, dump_id);
 451
 452         /* we may get notified twice, let's handle
 453          * that gracefully and not create two conflicting
 454          * entries.
 455          */
 456         if (kset_find_obj(dump_kset, name))
 457                 return 0;
 458
 459         dump = create_dump_obj(dump_id, dump_size, dump_type);
 460         if (!dump)
 461                 return -1;
 462
 463         return 0;
 464 }
 465
 466 static void dump_work_fn(struct work_struct *work)
 467 {
 468         process_dump();
 469 }
 470
 471 static DECLARE_WORK(dump_work, dump_work_fn);
 472
 473 static void schedule_process_dump(void)
 474 {
 475         schedule_work(&dump_work);
 476 }
 477
 478 /*
 479  * New dump available notification
 480  *
 481  * Once we get notification, we add sysfs entries for it.
 482  * We only fetch the dump on demand, and create sysfs asynchronously.
 483  */
 484 static int dump_event(struct notifier_block *nb,
 485                       unsigned long events, void *change)
 486 {
 487         if (events & OPAL_EVENT_DUMP_AVAIL)
 488                 schedule_process_dump();
 489
 490         return 0;
 491 }
 492
 493 static struct notifier_block dump_nb = {
 494         .notifier_call  = dump_event,
 495         .next           = NULL,
 496         .priority       = 0
 497 };
 498
 499 void __init opal_platform_dump_init(void)
 500 {
 501         int rc;
 502
 503         dump_kset = kset_create_and_add("dump", NULL, opal_kobj);
 504         if (!dump_kset) {
 505                 pr_warn("%s: Failed to create dump kset\n", __func__);
 506                 return;
 507         }
 508
 509         rc = sysfs_create_group(&dump_kset->kobj, &initiate_attr_group);
 510         if (rc) {
 511                 pr_warn("%s: Failed to create initiate dump attr group\n",
 512                         __func__);
 513                 kobject_put(&dump_kset->kobj);
 514                 return;
 515         }
 516
 517         rc = opal_notifier_register(&dump_nb);
 518         if (rc) {
 519                 pr_warn("%s: Can't register OPAL event notifier (%d)\n",
 520                         __func__, rc);
 521                 return;
 522         }
 523
 524         opal_dump_resend_notification();
 525 }