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, 0666, dump_id_show, NULL);
 106 static struct dump_attribute type_attribute =
 107         __ATTR(type, 0666, 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 void free_dump_sg_list(struct opal_sg_list *list)
 213 {
 214         struct opal_sg_list *sg1;
 215         while (list) {
 216                 sg1 = list->next;
 217                 kfree(list);
 218                 list = sg1;
 219         }
 220         list = NULL;
 221 }
 222
 223 static struct opal_sg_list *dump_data_to_sglist(struct dump_obj *dump)
 224 {
 225         struct opal_sg_list *sg1, *list = NULL;
 226         void *addr;
 227         int64_t size;
 228
 229         addr = dump->buffer;
 230         size = dump->size;
 231
 232         sg1 = kzalloc(PAGE_SIZE, GFP_KERNEL);
 233         if (!sg1)
 234                 goto nomem;
 235
 236         list = sg1;
 237         sg1->num_entries = 0;
 238         while (size > 0) {
 239                 /* Translate virtual address to physical address */
 240                 sg1->entry[sg1->num_entries].data =
 241                         (void *)(vmalloc_to_pfn(addr) << PAGE_SHIFT);
 242
 243                 if (size > PAGE_SIZE)
 244                         sg1->entry[sg1->num_entries].length = PAGE_SIZE;
 245                 else
 246                         sg1->entry[sg1->num_entries].length = size;
 247
 248                 sg1->num_entries++;
 249                 if (sg1->num_entries >= SG_ENTRIES_PER_NODE) {
 250                         sg1->next = kzalloc(PAGE_SIZE, GFP_KERNEL);
 251                         if (!sg1->next)
 252                                 goto nomem;
 253
 254                         sg1 = sg1->next;
 255                         sg1->num_entries = 0;
 256                 }
 257                 addr += PAGE_SIZE;
 258                 size -= PAGE_SIZE;
 259         }
 260         return list;
 261
 262 nomem:
 263         pr_err("%s : Failed to allocate memory\n", __func__);
 264         free_dump_sg_list(list);
 265         return NULL;
 266 }
 267
 268 static void sglist_to_phy_addr(struct opal_sg_list *list)
 269 {
 270         struct opal_sg_list *sg, *next;
 271
 272         for (sg = list; sg; sg = next) {
 273                 next = sg->next;
 274                 /* Don't translate NULL pointer for last entry */
 275                 if (sg->next)
 276                         sg->next = (struct opal_sg_list *)__pa(sg->next);
 277                 else
 278                         sg->next = NULL;
 279
 280                 /* Convert num_entries to length */
 281                 sg->num_entries =
 282                         sg->num_entries * sizeof(struct opal_sg_entry) + 16;
 283         }
 284 }
 285
 286 static int64_t dump_read_info(uint32_t *id, uint32_t *size, uint32_t *type)
 287 {
 288         int rc;
 289         *type = 0xffffffff;
 290
 291         rc = opal_dump_info2(id, size, type);
 292
 293         if (rc == OPAL_PARAMETER)
 294                 rc = opal_dump_info(id, size);
 295
 296         if (rc)
 297                 pr_warn("%s: Failed to get dump info (%d)\n",
 298                         __func__, rc);
 299         return rc;
 300 }
 301
 302 static int64_t dump_read_data(struct dump_obj *dump)
 303 {
 304         struct opal_sg_list *list;
 305         uint64_t addr;
 306         int64_t rc;
 307
 308         /* Allocate memory */
 309         dump->buffer = vzalloc(PAGE_ALIGN(dump->size));
 310         if (!dump->buffer) {
 311                 pr_err("%s : Failed to allocate memory\n", __func__);
 312                 rc = -ENOMEM;
 313                 goto out;
 314         }
 315
 316         /* Generate SG list */
 317         list = dump_data_to_sglist(dump);
 318         if (!list) {
 319                 rc = -ENOMEM;
 320                 goto out;
 321         }
 322
 323         /* Translate sg list addr to real address */
 324         sglist_to_phy_addr(list);
 325
 326         /* First entry address */
 327         addr = __pa(list);
 328
 329         /* Fetch data */
 330         rc = OPAL_BUSY_EVENT;
 331         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 332                 rc = opal_dump_read(dump->id, addr);
 333                 if (rc == OPAL_BUSY_EVENT) {
 334                         opal_poll_events(NULL);
 335                         msleep(20);
 336                 }
 337         }
 338
 339         if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL)
 340                 pr_warn("%s: Extract dump failed for ID 0x%x\n",
 341                         __func__, dump->id);
 342
 343         /* Free SG list */
 344         free_dump_sg_list(list);
 345
 346 out:
 347         return rc;
 348 }
 349
 350 static ssize_t dump_attr_read(struct file *filep, struct kobject *kobj,
 351                               struct bin_attribute *bin_attr,
 352                               char *buffer, loff_t pos, size_t count)
 353 {
 354         ssize_t rc;
 355
 356         struct dump_obj *dump = to_dump_obj(kobj);
 357
 358         if (!dump->buffer) {
 359                 rc = dump_read_data(dump);
 360
 361                 if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
 362                         vfree(dump->buffer);
 363                         dump->buffer = NULL;
 364
 365                         return -EIO;
 366                 }
 367                 if (rc == OPAL_PARTIAL) {
 368                         /* On a partial read, we just return EIO
 369                          * and rely on userspace to ask us to try
 370                          * again.
 371                          */
 372                         pr_info("%s: Platform dump partially read.ID = 0x%x\n",
 373                                 __func__, dump->id);
 374                         return -EIO;
 375                 }
 376         }
 377
 378         memcpy(buffer, dump->buffer + pos, count);
 379
 380         /* You may think we could free the dump buffer now and retrieve
 381          * it again later if needed, but due to current firmware limitation,
 382          * that's not the case. So, once read into userspace once,
 383          * we keep the dump around until it's acknowledged by userspace.
 384          */
 385
 386         return count;
 387 }
 388
 389 static struct dump_obj *create_dump_obj(uint32_t id, size_t size,
 390                                         uint32_t type)
 391 {
 392         struct dump_obj *dump;
 393         int rc;
 394
 395         dump = kzalloc(sizeof(*dump), GFP_KERNEL);
 396         if (!dump)
 397                 return NULL;
 398
 399         dump->kobj.kset = dump_kset;
 400
 401         kobject_init(&dump->kobj, &dump_ktype);
 402
 403         sysfs_bin_attr_init(&dump->dump_attr);
 404
 405         dump->dump_attr.attr.name = "dump";
 406         dump->dump_attr.attr.mode = 0400;
 407         dump->dump_attr.size = size;
 408         dump->dump_attr.read = dump_attr_read;
 409
 410         dump->id = id;
 411         dump->size = size;
 412         dump->type = type;
 413
 414         rc = kobject_add(&dump->kobj, NULL, "0x%x-0x%x", type, id);
 415         if (rc) {
 416                 kobject_put(&dump->kobj);
 417                 return NULL;
 418         }
 419
 420         rc = sysfs_create_bin_file(&dump->kobj, &dump->dump_attr);
 421         if (rc) {
 422                 kobject_put(&dump->kobj);
 423                 return NULL;
 424         }
 425
 426         pr_info("%s: New platform dump. ID = 0x%x Size %u\n",
 427                 __func__, dump->id, dump->size);
 428
 429         kobject_uevent(&dump->kobj, KOBJ_ADD);
 430
 431         return dump;
 432 }
 433
 434 static int process_dump(void)
 435 {
 436         int rc;
 437         uint32_t dump_id, dump_size, dump_type;
 438         struct dump_obj *dump;
 439         char name[22];
 440
 441         rc = dump_read_info(&dump_id, &dump_size, &dump_type);
 442         if (rc != OPAL_SUCCESS)
 443                 return rc;
 444
 445         sprintf(name, "0x%x-0x%x", dump_type, dump_id);
 446
 447         /* we may get notified twice, let's handle
 448          * that gracefully and not create two conflicting
 449          * entries.
 450          */
 451         if (kset_find_obj(dump_kset, name))
 452                 return 0;
 453
 454         dump = create_dump_obj(dump_id, dump_size, dump_type);
 455         if (!dump)
 456                 return -1;
 457
 458         return 0;
 459 }
 460
 461 static void dump_work_fn(struct work_struct *work)
 462 {
 463         process_dump();
 464 }
 465
 466 static DECLARE_WORK(dump_work, dump_work_fn);
 467
 468 static void schedule_process_dump(void)
 469 {
 470         schedule_work(&dump_work);
 471 }
 472
 473 /*
 474  * New dump available notification
 475  *
 476  * Once we get notification, we add sysfs entries for it.
 477  * We only fetch the dump on demand, and create sysfs asynchronously.
 478  */
 479 static int dump_event(struct notifier_block *nb,
 480                       unsigned long events, void *change)
 481 {
 482         if (events & OPAL_EVENT_DUMP_AVAIL)
 483                 schedule_process_dump();
 484
 485         return 0;
 486 }
 487
 488 static struct notifier_block dump_nb = {
 489         .notifier_call  = dump_event,
 490         .next           = NULL,
 491         .priority       = 0
 492 };
 493
 494 void __init opal_platform_dump_init(void)
 495 {
 496         int rc;
 497
 498         dump_kset = kset_create_and_add("dump", NULL, opal_kobj);
 499         if (!dump_kset) {
 500                 pr_warn("%s: Failed to create dump kset\n", __func__);
 501                 return;
 502         }
 503
 504         rc = sysfs_create_group(&dump_kset->kobj, &initiate_attr_group);
 505         if (rc) {
 506                 pr_warn("%s: Failed to create initiate dump attr group\n",
 507                         __func__);
 508                 kobject_put(&dump_kset->kobj);
 509                 return;
 510         }
 511
 512         rc = opal_notifier_register(&dump_nb);
 513         if (rc) {
 514                 pr_warn("%s: Can't register OPAL event notifier (%d)\n",
 515                         __func__, rc);
 516                 return;
 517         }
 518
 519         opal_dump_resend_notification();
 520 }