linux/drivers/base/firmware_class.c
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   1/*
   2 * firmware_class.c - Multi purpose firmware loading support
   3 *
   4 * Copyright (c) 2003 Manuel Estrada Sainz
   5 *
   6 * Please see Documentation/firmware_class/ for more information.
   7 *
   8 */
   9
  10#include <linux/capability.h>
  11#include <linux/device.h>
  12#include <linux/module.h>
  13#include <linux/init.h>
  14#include <linux/timer.h>
  15#include <linux/vmalloc.h>
  16#include <linux/interrupt.h>
  17#include <linux/bitops.h>
  18#include <linux/mutex.h>
  19#include <linux/workqueue.h>
  20#include <linux/highmem.h>
  21#include <linux/firmware.h>
  22#include <linux/slab.h>
  23#include <linux/sched.h>
  24#include <linux/file.h>
  25#include <linux/list.h>
  26#include <linux/async.h>
  27#include <linux/pm.h>
  28#include <linux/suspend.h>
  29#include <linux/syscore_ops.h>
  30
  31#include <generated/utsrelease.h>
  32
  33#include "base.h"
  34
  35MODULE_AUTHOR("Manuel Estrada Sainz");
  36MODULE_DESCRIPTION("Multi purpose firmware loading support");
  37MODULE_LICENSE("GPL");
  38
  39/* Builtin firmware support */
  40
  41#ifdef CONFIG_FW_LOADER
  42
  43extern struct builtin_fw __start_builtin_fw[];
  44extern struct builtin_fw __end_builtin_fw[];
  45
  46static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  47{
  48        struct builtin_fw *b_fw;
  49
  50        for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
  51                if (strcmp(name, b_fw->name) == 0) {
  52                        fw->size = b_fw->size;
  53                        fw->data = b_fw->data;
  54                        return true;
  55                }
  56        }
  57
  58        return false;
  59}
  60
  61static bool fw_is_builtin_firmware(const struct firmware *fw)
  62{
  63        struct builtin_fw *b_fw;
  64
  65        for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
  66                if (fw->data == b_fw->data)
  67                        return true;
  68
  69        return false;
  70}
  71
  72#else /* Module case - no builtin firmware support */
  73
  74static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  75{
  76        return false;
  77}
  78
  79static inline bool fw_is_builtin_firmware(const struct firmware *fw)
  80{
  81        return false;
  82}
  83#endif
  84
  85enum {
  86        FW_STATUS_LOADING,
  87        FW_STATUS_DONE,
  88        FW_STATUS_ABORT,
  89};
  90
  91enum fw_buf_fmt {
  92        VMALLOC_BUF,    /* used in direct loading */
  93        PAGE_BUF,       /* used in loading via userspace */
  94};
  95
  96static int loading_timeout = 60;        /* In seconds */
  97
  98static inline long firmware_loading_timeout(void)
  99{
 100        return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
 101}
 102
 103struct firmware_cache {
 104        /* firmware_buf instance will be added into the below list */
 105        spinlock_t lock;
 106        struct list_head head;
 107        int state;
 108
 109#ifdef CONFIG_PM_SLEEP
 110        /*
 111         * Names of firmware images which have been cached successfully
 112         * will be added into the below list so that device uncache
 113         * helper can trace which firmware images have been cached
 114         * before.
 115         */
 116        spinlock_t name_lock;
 117        struct list_head fw_names;
 118
 119        struct delayed_work work;
 120
 121        struct notifier_block   pm_notify;
 122#endif
 123};
 124
 125struct firmware_buf {
 126        struct kref ref;
 127        struct list_head list;
 128        struct completion completion;
 129        struct firmware_cache *fwc;
 130        unsigned long status;
 131        enum fw_buf_fmt fmt;
 132        void *data;
 133        size_t size;
 134        struct page **pages;
 135        int nr_pages;
 136        int page_array_size;
 137        char fw_id[];
 138};
 139
 140struct fw_cache_entry {
 141        struct list_head list;
 142        char name[];
 143};
 144
 145struct firmware_priv {
 146        struct timer_list timeout;
 147        bool nowait;
 148        struct device dev;
 149        struct firmware_buf *buf;
 150        struct firmware *fw;
 151};
 152
 153struct fw_name_devm {
 154        unsigned long magic;
 155        char name[];
 156};
 157
 158#define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 159
 160#define FW_LOADER_NO_CACHE      0
 161#define FW_LOADER_START_CACHE   1
 162
 163static int fw_cache_piggyback_on_request(const char *name);
 164
 165/* fw_lock could be moved to 'struct firmware_priv' but since it is just
 166 * guarding for corner cases a global lock should be OK */
 167static DEFINE_MUTEX(fw_lock);
 168
 169static struct firmware_cache fw_cache;
 170
 171static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
 172                                              struct firmware_cache *fwc)
 173{
 174        struct firmware_buf *buf;
 175
 176        buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1 , GFP_ATOMIC);
 177
 178        if (!buf)
 179                return buf;
 180
 181        kref_init(&buf->ref);
 182        strcpy(buf->fw_id, fw_name);
 183        buf->fwc = fwc;
 184        init_completion(&buf->completion);
 185        buf->fmt = VMALLOC_BUF;
 186
 187        pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
 188
 189        return buf;
 190}
 191
 192static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
 193{
 194        struct firmware_buf *tmp;
 195        struct firmware_cache *fwc = &fw_cache;
 196
 197        list_for_each_entry(tmp, &fwc->head, list)
 198                if (!strcmp(tmp->fw_id, fw_name))
 199                        return tmp;
 200        return NULL;
 201}
 202
 203static int fw_lookup_and_allocate_buf(const char *fw_name,
 204                                      struct firmware_cache *fwc,
 205                                      struct firmware_buf **buf)
 206{
 207        struct firmware_buf *tmp;
 208
 209        spin_lock(&fwc->lock);
 210        tmp = __fw_lookup_buf(fw_name);
 211        if (tmp) {
 212                kref_get(&tmp->ref);
 213                spin_unlock(&fwc->lock);
 214                *buf = tmp;
 215                return 1;
 216        }
 217        tmp = __allocate_fw_buf(fw_name, fwc);
 218        if (tmp)
 219                list_add(&tmp->list, &fwc->head);
 220        spin_unlock(&fwc->lock);
 221
 222        *buf = tmp;
 223
 224        return tmp ? 0 : -ENOMEM;
 225}
 226
 227static struct firmware_buf *fw_lookup_buf(const char *fw_name)
 228{
 229        struct firmware_buf *tmp;
 230        struct firmware_cache *fwc = &fw_cache;
 231
 232        spin_lock(&fwc->lock);
 233        tmp = __fw_lookup_buf(fw_name);
 234        spin_unlock(&fwc->lock);
 235
 236        return tmp;
 237}
 238
 239static void __fw_free_buf(struct kref *ref)
 240{
 241        struct firmware_buf *buf = to_fwbuf(ref);
 242        struct firmware_cache *fwc = buf->fwc;
 243        int i;
 244
 245        pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 246                 __func__, buf->fw_id, buf, buf->data,
 247                 (unsigned int)buf->size);
 248
 249        spin_lock(&fwc->lock);
 250        list_del(&buf->list);
 251        spin_unlock(&fwc->lock);
 252
 253
 254        if (buf->fmt == PAGE_BUF) {
 255                vunmap(buf->data);
 256                for (i = 0; i < buf->nr_pages; i++)
 257                        __free_page(buf->pages[i]);
 258                kfree(buf->pages);
 259        } else
 260                vfree(buf->data);
 261        kfree(buf);
 262}
 263
 264static void fw_free_buf(struct firmware_buf *buf)
 265{
 266        kref_put(&buf->ref, __fw_free_buf);
 267}
 268
 269/* direct firmware loading support */
 270static const char *fw_path[] = {
 271        "/lib/firmware/updates/" UTS_RELEASE,
 272        "/lib/firmware/updates",
 273        "/lib/firmware/" UTS_RELEASE,
 274        "/lib/firmware"
 275};
 276
 277/* Don't inline this: 'struct kstat' is biggish */
 278static noinline long fw_file_size(struct file *file)
 279{
 280        struct kstat st;
 281        if (vfs_getattr(file->f_path.mnt, file->f_path.dentry, &st))
 282                return -1;
 283        if (!S_ISREG(st.mode))
 284                return -1;
 285        if (st.size != (long)st.size)
 286                return -1;
 287        return st.size;
 288}
 289
 290static bool fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf)
 291{
 292        long size;
 293        char *buf;
 294
 295        size = fw_file_size(file);
 296        if (size < 0)
 297                return false;
 298        buf = vmalloc(size);
 299        if (!buf)
 300                return false;
 301        if (kernel_read(file, 0, buf, size) != size) {
 302                vfree(buf);
 303                return false;
 304        }
 305        fw_buf->data = buf;
 306        fw_buf->size = size;
 307        return true;
 308}
 309
 310static bool fw_get_filesystem_firmware(struct firmware_buf *buf)
 311{
 312        int i;
 313        bool success = false;
 314        char *path = __getname();
 315
 316        for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 317                struct file *file;
 318                snprintf(path, PATH_MAX, "%s/%s", fw_path[i], buf->fw_id);
 319
 320                file = filp_open(path, O_RDONLY, 0);
 321                if (IS_ERR(file))
 322                        continue;
 323                success = fw_read_file_contents(file, buf);
 324                fput(file);
 325                if (success)
 326                        break;
 327        }
 328        __putname(path);
 329        return success;
 330}
 331
 332static struct firmware_priv *to_firmware_priv(struct device *dev)
 333{
 334        return container_of(dev, struct firmware_priv, dev);
 335}
 336
 337static void fw_load_abort(struct firmware_priv *fw_priv)
 338{
 339        struct firmware_buf *buf = fw_priv->buf;
 340
 341        set_bit(FW_STATUS_ABORT, &buf->status);
 342        complete_all(&buf->completion);
 343}
 344
 345static ssize_t firmware_timeout_show(struct class *class,
 346                                     struct class_attribute *attr,
 347                                     char *buf)
 348{
 349        return sprintf(buf, "%d\n", loading_timeout);
 350}
 351
 352/**
 353 * firmware_timeout_store - set number of seconds to wait for firmware
 354 * @class: device class pointer
 355 * @attr: device attribute pointer
 356 * @buf: buffer to scan for timeout value
 357 * @count: number of bytes in @buf
 358 *
 359 *      Sets the number of seconds to wait for the firmware.  Once
 360 *      this expires an error will be returned to the driver and no
 361 *      firmware will be provided.
 362 *
 363 *      Note: zero means 'wait forever'.
 364 **/
 365static ssize_t firmware_timeout_store(struct class *class,
 366                                      struct class_attribute *attr,
 367                                      const char *buf, size_t count)
 368{
 369        loading_timeout = simple_strtol(buf, NULL, 10);
 370        if (loading_timeout < 0)
 371                loading_timeout = 0;
 372
 373        return count;
 374}
 375
 376static struct class_attribute firmware_class_attrs[] = {
 377        __ATTR(timeout, S_IWUSR | S_IRUGO,
 378                firmware_timeout_show, firmware_timeout_store),
 379        __ATTR_NULL
 380};
 381
 382static void fw_dev_release(struct device *dev)
 383{
 384        struct firmware_priv *fw_priv = to_firmware_priv(dev);
 385
 386        kfree(fw_priv);
 387
 388        module_put(THIS_MODULE);
 389}
 390
 391static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 392{
 393        struct firmware_priv *fw_priv = to_firmware_priv(dev);
 394
 395        if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 396                return -ENOMEM;
 397        if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 398                return -ENOMEM;
 399        if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 400                return -ENOMEM;
 401
 402        return 0;
 403}
 404
 405static struct class firmware_class = {
 406        .name           = "firmware",
 407        .class_attrs    = firmware_class_attrs,
 408        .dev_uevent     = firmware_uevent,
 409        .dev_release    = fw_dev_release,
 410};
 411
 412static ssize_t firmware_loading_show(struct device *dev,
 413                                     struct device_attribute *attr, char *buf)
 414{
 415        struct firmware_priv *fw_priv = to_firmware_priv(dev);
 416        int loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
 417
 418        return sprintf(buf, "%d\n", loading);
 419}
 420
 421/* firmware holds the ownership of pages */
 422static void firmware_free_data(const struct firmware *fw)
 423{
 424        /* Loaded directly? */
 425        if (!fw->priv) {
 426                vfree(fw->data);
 427                return;
 428        }
 429        fw_free_buf(fw->priv);
 430}
 431
 432/* Some architectures don't have PAGE_KERNEL_RO */
 433#ifndef PAGE_KERNEL_RO
 434#define PAGE_KERNEL_RO PAGE_KERNEL
 435#endif
 436
 437/* one pages buffer should be mapped/unmapped only once */
 438static int fw_map_pages_buf(struct firmware_buf *buf)
 439{
 440        if (buf->fmt != PAGE_BUF)
 441                return 0;
 442
 443        if (buf->data)
 444                vunmap(buf->data);
 445        buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 446        if (!buf->data)
 447                return -ENOMEM;
 448        return 0;
 449}
 450
 451/**
 452 * firmware_loading_store - set value in the 'loading' control file
 453 * @dev: device pointer
 454 * @attr: device attribute pointer
 455 * @buf: buffer to scan for loading control value
 456 * @count: number of bytes in @buf
 457 *
 458 *      The relevant values are:
 459 *
 460 *       1: Start a load, discarding any previous partial load.
 461 *       0: Conclude the load and hand the data to the driver code.
 462 *      -1: Conclude the load with an error and discard any written data.
 463 **/
 464static ssize_t firmware_loading_store(struct device *dev,
 465                                      struct device_attribute *attr,
 466                                      const char *buf, size_t count)
 467{
 468        struct firmware_priv *fw_priv = to_firmware_priv(dev);
 469        struct firmware_buf *fw_buf = fw_priv->buf;
 470        int loading = simple_strtol(buf, NULL, 10);
 471        int i;
 472
 473        mutex_lock(&fw_lock);
 474
 475        if (!fw_buf)
 476                goto out;
 477
 478        switch (loading) {
 479        case 1:
 480                /* discarding any previous partial load */
 481                if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
 482                        for (i = 0; i < fw_buf->nr_pages; i++)
 483                                __free_page(fw_buf->pages[i]);
 484                        kfree(fw_buf->pages);
 485                        fw_buf->pages = NULL;
 486                        fw_buf->page_array_size = 0;
 487                        fw_buf->nr_pages = 0;
 488                        set_bit(FW_STATUS_LOADING, &fw_buf->status);
 489                }
 490                break;
 491        case 0:
 492                if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
 493                        set_bit(FW_STATUS_DONE, &fw_buf->status);
 494                        clear_bit(FW_STATUS_LOADING, &fw_buf->status);
 495
 496                        /*
 497                         * Several loading requests may be pending on
 498                         * one same firmware buf, so let all requests
 499                         * see the mapped 'buf->data' once the loading
 500                         * is completed.
 501                         * */
 502                        fw_map_pages_buf(fw_buf);
 503                        complete_all(&fw_buf->completion);
 504                        break;
 505                }
 506                /* fallthrough */
 507        default:
 508                dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 509                /* fallthrough */
 510        case -1:
 511                fw_load_abort(fw_priv);
 512                break;
 513        }
 514out:
 515        mutex_unlock(&fw_lock);
 516        return count;
 517}
 518
 519static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 520
 521static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 522                                  struct bin_attribute *bin_attr,
 523                                  char *buffer, loff_t offset, size_t count)
 524{
 525        struct device *dev = kobj_to_dev(kobj);
 526        struct firmware_priv *fw_priv = to_firmware_priv(dev);
 527        struct firmware_buf *buf;
 528        ssize_t ret_count;
 529
 530        mutex_lock(&fw_lock);
 531        buf = fw_priv->buf;
 532        if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 533                ret_count = -ENODEV;
 534                goto out;
 535        }
 536        if (offset > buf->size) {
 537                ret_count = 0;
 538                goto out;
 539        }
 540        if (count > buf->size - offset)
 541                count = buf->size - offset;
 542
 543        ret_count = count;
 544
 545        while (count) {
 546                void *page_data;
 547                int page_nr = offset >> PAGE_SHIFT;
 548                int page_ofs = offset & (PAGE_SIZE-1);
 549                int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 550
 551                page_data = kmap(buf->pages[page_nr]);
 552
 553                memcpy(buffer, page_data + page_ofs, page_cnt);
 554
 555                kunmap(buf->pages[page_nr]);
 556                buffer += page_cnt;
 557                offset += page_cnt;
 558                count -= page_cnt;
 559        }
 560out:
 561        mutex_unlock(&fw_lock);
 562        return ret_count;
 563}
 564
 565static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 566{
 567        struct firmware_buf *buf = fw_priv->buf;
 568        int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
 569
 570        /* If the array of pages is too small, grow it... */
 571        if (buf->page_array_size < pages_needed) {
 572                int new_array_size = max(pages_needed,
 573                                         buf->page_array_size * 2);
 574                struct page **new_pages;
 575
 576                new_pages = kmalloc(new_array_size * sizeof(void *),
 577                                    GFP_KERNEL);
 578                if (!new_pages) {
 579                        fw_load_abort(fw_priv);
 580                        return -ENOMEM;
 581                }
 582                memcpy(new_pages, buf->pages,
 583                       buf->page_array_size * sizeof(void *));
 584                memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 585                       (new_array_size - buf->page_array_size));
 586                kfree(buf->pages);
 587                buf->pages = new_pages;
 588                buf->page_array_size = new_array_size;
 589        }
 590
 591        while (buf->nr_pages < pages_needed) {
 592                buf->pages[buf->nr_pages] =
 593                        alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 594
 595                if (!buf->pages[buf->nr_pages]) {
 596                        fw_load_abort(fw_priv);
 597                        return -ENOMEM;
 598                }
 599                buf->nr_pages++;
 600        }
 601        return 0;
 602}
 603
 604/**
 605 * firmware_data_write - write method for firmware
 606 * @filp: open sysfs file
 607 * @kobj: kobject for the device
 608 * @bin_attr: bin_attr structure
 609 * @buffer: buffer being written
 610 * @offset: buffer offset for write in total data store area
 611 * @count: buffer size
 612 *
 613 *      Data written to the 'data' attribute will be later handed to
 614 *      the driver as a firmware image.
 615 **/
 616static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 617                                   struct bin_attribute *bin_attr,
 618                                   char *buffer, loff_t offset, size_t count)
 619{
 620        struct device *dev = kobj_to_dev(kobj);
 621        struct firmware_priv *fw_priv = to_firmware_priv(dev);
 622        struct firmware_buf *buf;
 623        ssize_t retval;
 624
 625        if (!capable(CAP_SYS_RAWIO))
 626                return -EPERM;
 627
 628        mutex_lock(&fw_lock);
 629        buf = fw_priv->buf;
 630        if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 631                retval = -ENODEV;
 632                goto out;
 633        }
 634
 635        retval = fw_realloc_buffer(fw_priv, offset + count);
 636        if (retval)
 637                goto out;
 638
 639        retval = count;
 640
 641        while (count) {
 642                void *page_data;
 643                int page_nr = offset >> PAGE_SHIFT;
 644                int page_ofs = offset & (PAGE_SIZE - 1);
 645                int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 646
 647                page_data = kmap(buf->pages[page_nr]);
 648
 649                memcpy(page_data + page_ofs, buffer, page_cnt);
 650
 651                kunmap(buf->pages[page_nr]);
 652                buffer += page_cnt;
 653                offset += page_cnt;
 654                count -= page_cnt;
 655        }
 656
 657        buf->size = max_t(size_t, offset, buf->size);
 658out:
 659        mutex_unlock(&fw_lock);
 660        return retval;
 661}
 662
 663static struct bin_attribute firmware_attr_data = {
 664        .attr = { .name = "data", .mode = 0644 },
 665        .size = 0,
 666        .read = firmware_data_read,
 667        .write = firmware_data_write,
 668};
 669
 670static void firmware_class_timeout(u_long data)
 671{
 672        struct firmware_priv *fw_priv = (struct firmware_priv *) data;
 673
 674        fw_load_abort(fw_priv);
 675}
 676
 677static struct firmware_priv *
 678fw_create_instance(struct firmware *firmware, const char *fw_name,
 679                   struct device *device, bool uevent, bool nowait)
 680{
 681        struct firmware_priv *fw_priv;
 682        struct device *f_dev;
 683
 684        fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 685        if (!fw_priv) {
 686                dev_err(device, "%s: kmalloc failed\n", __func__);
 687                fw_priv = ERR_PTR(-ENOMEM);
 688                goto exit;
 689        }
 690
 691        fw_priv->nowait = nowait;
 692        fw_priv->fw = firmware;
 693        setup_timer(&fw_priv->timeout,
 694                    firmware_class_timeout, (u_long) fw_priv);
 695
 696        f_dev = &fw_priv->dev;
 697
 698        device_initialize(f_dev);
 699        dev_set_name(f_dev, "%s", fw_name);
 700        f_dev->parent = device;
 701        f_dev->class = &firmware_class;
 702exit:
 703        return fw_priv;
 704}
 705
 706/* store the pages buffer info firmware from buf */
 707static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 708{
 709        fw->priv = buf;
 710        fw->pages = buf->pages;
 711        fw->size = buf->size;
 712        fw->data = buf->data;
 713
 714        pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 715                 __func__, buf->fw_id, buf, buf->data,
 716                 (unsigned int)buf->size);
 717}
 718
 719#ifdef CONFIG_PM_SLEEP
 720static void fw_name_devm_release(struct device *dev, void *res)
 721{
 722        struct fw_name_devm *fwn = res;
 723
 724        if (fwn->magic == (unsigned long)&fw_cache)
 725                pr_debug("%s: fw_name-%s devm-%p released\n",
 726                                __func__, fwn->name, res);
 727}
 728
 729static int fw_devm_match(struct device *dev, void *res,
 730                void *match_data)
 731{
 732        struct fw_name_devm *fwn = res;
 733
 734        return (fwn->magic == (unsigned long)&fw_cache) &&
 735                !strcmp(fwn->name, match_data);
 736}
 737
 738static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 739                const char *name)
 740{
 741        struct fw_name_devm *fwn;
 742
 743        fwn = devres_find(dev, fw_name_devm_release,
 744                          fw_devm_match, (void *)name);
 745        return fwn;
 746}
 747
 748/* add firmware name into devres list */
 749static int fw_add_devm_name(struct device *dev, const char *name)
 750{
 751        struct fw_name_devm *fwn;
 752
 753        fwn = fw_find_devm_name(dev, name);
 754        if (fwn)
 755                return 1;
 756
 757        fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm) +
 758                           strlen(name) + 1, GFP_KERNEL);
 759        if (!fwn)
 760                return -ENOMEM;
 761
 762        fwn->magic = (unsigned long)&fw_cache;
 763        strcpy(fwn->name, name);
 764        devres_add(dev, fwn);
 765
 766        return 0;
 767}
 768#else
 769static int fw_add_devm_name(struct device *dev, const char *name)
 770{
 771        return 0;
 772}
 773#endif
 774
 775static void _request_firmware_cleanup(const struct firmware **firmware_p)
 776{
 777        release_firmware(*firmware_p);
 778        *firmware_p = NULL;
 779}
 780
 781static struct firmware_priv *
 782_request_firmware_prepare(const struct firmware **firmware_p, const char *name,
 783                          struct device *device, bool uevent, bool nowait)
 784{
 785        struct firmware *firmware;
 786        struct firmware_priv *fw_priv = NULL;
 787        struct firmware_buf *buf;
 788        int ret;
 789
 790        if (!firmware_p)
 791                return ERR_PTR(-EINVAL);
 792
 793        *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 794        if (!firmware) {
 795                dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 796                        __func__);
 797                return ERR_PTR(-ENOMEM);
 798        }
 799
 800        if (fw_get_builtin_firmware(firmware, name)) {
 801                dev_dbg(device, "firmware: using built-in firmware %s\n", name);
 802                return NULL;
 803        }
 804
 805        ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
 806        if (!ret)
 807                fw_priv = fw_create_instance(firmware, name, device,
 808                                uevent, nowait);
 809
 810        if (IS_ERR(fw_priv) || ret < 0) {
 811                kfree(firmware);
 812                *firmware_p = NULL;
 813                return ERR_PTR(-ENOMEM);
 814        } else if (fw_priv) {
 815                fw_priv->buf = buf;
 816
 817                /*
 818                 * bind with 'buf' now to avoid warning in failure path
 819                 * of requesting firmware.
 820                 */
 821                firmware->priv = buf;
 822                return fw_priv;
 823        }
 824
 825        /* share the cached buf, which is inprogessing or completed */
 826 check_status:
 827        mutex_lock(&fw_lock);
 828        if (test_bit(FW_STATUS_ABORT, &buf->status)) {
 829                fw_priv = ERR_PTR(-ENOENT);
 830                firmware->priv = buf;
 831                _request_firmware_cleanup(firmware_p);
 832                goto exit;
 833        } else if (test_bit(FW_STATUS_DONE, &buf->status)) {
 834                fw_priv = NULL;
 835                fw_set_page_data(buf, firmware);
 836                goto exit;
 837        }
 838        mutex_unlock(&fw_lock);
 839        wait_for_completion(&buf->completion);
 840        goto check_status;
 841
 842exit:
 843        mutex_unlock(&fw_lock);
 844        return fw_priv;
 845}
 846
 847static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
 848                                  long timeout)
 849{
 850        int retval = 0;
 851        struct device *f_dev = &fw_priv->dev;
 852        struct firmware_buf *buf = fw_priv->buf;
 853        struct firmware_cache *fwc = &fw_cache;
 854        int direct_load = 0;
 855
 856        /* try direct loading from fs first */
 857        if (fw_get_filesystem_firmware(buf)) {
 858                dev_dbg(f_dev->parent, "firmware: direct-loading"
 859                        " firmware %s\n", buf->fw_id);
 860
 861                set_bit(FW_STATUS_DONE, &buf->status);
 862                complete_all(&buf->completion);
 863                direct_load = 1;
 864                goto handle_fw;
 865        }
 866
 867        /* fall back on userspace loading */
 868        buf->fmt = PAGE_BUF;
 869
 870        dev_set_uevent_suppress(f_dev, true);
 871
 872        /* Need to pin this module until class device is destroyed */
 873        __module_get(THIS_MODULE);
 874
 875        retval = device_add(f_dev);
 876        if (retval) {
 877                dev_err(f_dev, "%s: device_register failed\n", __func__);
 878                goto err_put_dev;
 879        }
 880
 881        retval = device_create_bin_file(f_dev, &firmware_attr_data);
 882        if (retval) {
 883                dev_err(f_dev, "%s: sysfs_create_bin_file failed\n", __func__);
 884                goto err_del_dev;
 885        }
 886
 887        retval = device_create_file(f_dev, &dev_attr_loading);
 888        if (retval) {
 889                dev_err(f_dev, "%s: device_create_file failed\n", __func__);
 890                goto err_del_bin_attr;
 891        }
 892
 893        if (uevent) {
 894                dev_set_uevent_suppress(f_dev, false);
 895                dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
 896                if (timeout != MAX_SCHEDULE_TIMEOUT)
 897                        mod_timer(&fw_priv->timeout,
 898                                  round_jiffies_up(jiffies + timeout));
 899
 900                kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 901        }
 902
 903        wait_for_completion(&buf->completion);
 904
 905        del_timer_sync(&fw_priv->timeout);
 906
 907handle_fw:
 908        mutex_lock(&fw_lock);
 909        if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status))
 910                retval = -ENOENT;
 911
 912        /*
 913         * add firmware name into devres list so that we can auto cache
 914         * and uncache firmware for device.
 915         *
 916         * f_dev->parent may has been deleted already, but the problem
 917         * should be fixed in devres or driver core.
 918         */
 919        if (!retval && f_dev->parent)
 920                fw_add_devm_name(f_dev->parent, buf->fw_id);
 921
 922        /*
 923         * After caching firmware image is started, let it piggyback
 924         * on request firmware.
 925         */
 926        if (!retval && fwc->state == FW_LOADER_START_CACHE) {
 927                if (fw_cache_piggyback_on_request(buf->fw_id))
 928                        kref_get(&buf->ref);
 929        }
 930
 931        /* pass the pages buffer to driver at the last minute */
 932        fw_set_page_data(buf, fw_priv->fw);
 933
 934        fw_priv->buf = NULL;
 935        mutex_unlock(&fw_lock);
 936
 937        if (direct_load)
 938                goto err_put_dev;
 939
 940        device_remove_file(f_dev, &dev_attr_loading);
 941err_del_bin_attr:
 942        device_remove_bin_file(f_dev, &firmware_attr_data);
 943err_del_dev:
 944        device_del(f_dev);
 945err_put_dev:
 946        put_device(f_dev);
 947        return retval;
 948}
 949
 950/**
 951 * request_firmware: - send firmware request and wait for it
 952 * @firmware_p: pointer to firmware image
 953 * @name: name of firmware file
 954 * @device: device for which firmware is being loaded
 955 *
 956 *      @firmware_p will be used to return a firmware image by the name
 957 *      of @name for device @device.
 958 *
 959 *      Should be called from user context where sleeping is allowed.
 960 *
 961 *      @name will be used as $FIRMWARE in the uevent environment and
 962 *      should be distinctive enough not to be confused with any other
 963 *      firmware image for this or any other device.
 964 *
 965 *      Caller must hold the reference count of @device.
 966 **/
 967int
 968request_firmware(const struct firmware **firmware_p, const char *name,
 969                 struct device *device)
 970{
 971        struct firmware_priv *fw_priv;
 972        int ret;
 973
 974        fw_priv = _request_firmware_prepare(firmware_p, name, device, true,
 975                                            false);
 976        if (IS_ERR_OR_NULL(fw_priv))
 977                return PTR_RET(fw_priv);
 978
 979        ret = usermodehelper_read_trylock();
 980        if (WARN_ON(ret)) {
 981                dev_err(device, "firmware: %s will not be loaded\n", name);
 982        } else {
 983                ret = _request_firmware_load(fw_priv, true,
 984                                        firmware_loading_timeout());
 985                usermodehelper_read_unlock();
 986        }
 987        if (ret)
 988                _request_firmware_cleanup(firmware_p);
 989
 990        return ret;
 991}
 992
 993/**
 994 * release_firmware: - release the resource associated with a firmware image
 995 * @fw: firmware resource to release
 996 **/
 997void release_firmware(const struct firmware *fw)
 998{
 999        if (fw) {
1000                if (!fw_is_builtin_firmware(fw))
1001                        firmware_free_data(fw);
1002                kfree(fw);
1003        }
1004}
1005
1006/* Async support */
1007struct firmware_work {
1008        struct work_struct work;
1009        struct module *module;
1010        const char *name;
1011        struct device *device;
1012        void *context;
1013        void (*cont)(const struct firmware *fw, void *context);
1014        bool uevent;
1015};
1016
1017static void request_firmware_work_func(struct work_struct *work)
1018{
1019        struct firmware_work *fw_work;
1020        const struct firmware *fw;
1021        struct firmware_priv *fw_priv;
1022        long timeout;
1023        int ret;
1024
1025        fw_work = container_of(work, struct firmware_work, work);
1026        fw_priv = _request_firmware_prepare(&fw, fw_work->name, fw_work->device,
1027                        fw_work->uevent, true);
1028        if (IS_ERR_OR_NULL(fw_priv)) {
1029                ret = PTR_RET(fw_priv);
1030                goto out;
1031        }
1032
1033        timeout = usermodehelper_read_lock_wait(firmware_loading_timeout());
1034        if (timeout) {
1035                ret = _request_firmware_load(fw_priv, fw_work->uevent, timeout);
1036                usermodehelper_read_unlock();
1037        } else {
1038                dev_dbg(fw_work->device, "firmware: %s loading timed out\n",
1039                        fw_work->name);
1040                ret = -EAGAIN;
1041        }
1042        if (ret)
1043                _request_firmware_cleanup(&fw);
1044
1045 out:
1046        fw_work->cont(fw, fw_work->context);
1047        put_device(fw_work->device);
1048
1049        module_put(fw_work->module);
1050        kfree(fw_work);
1051}
1052
1053/**
1054 * request_firmware_nowait - asynchronous version of request_firmware
1055 * @module: module requesting the firmware
1056 * @uevent: sends uevent to copy the firmware image if this flag
1057 *      is non-zero else the firmware copy must be done manually.
1058 * @name: name of firmware file
1059 * @device: device for which firmware is being loaded
1060 * @gfp: allocation flags
1061 * @context: will be passed over to @cont, and
1062 *      @fw may be %NULL if firmware request fails.
1063 * @cont: function will be called asynchronously when the firmware
1064 *      request is over.
1065 *
1066 *      Caller must hold the reference count of @device.
1067 *
1068 *      Asynchronous variant of request_firmware() for user contexts:
1069 *              - sleep for as small periods as possible since it may
1070 *              increase kernel boot time of built-in device drivers
1071 *              requesting firmware in their ->probe() methods, if
1072 *              @gfp is GFP_KERNEL.
1073 *
1074 *              - can't sleep at all if @gfp is GFP_ATOMIC.
1075 **/
1076int
1077request_firmware_nowait(
1078        struct module *module, bool uevent,
1079        const char *name, struct device *device, gfp_t gfp, void *context,
1080        void (*cont)(const struct firmware *fw, void *context))
1081{
1082        struct firmware_work *fw_work;
1083
1084        fw_work = kzalloc(sizeof (struct firmware_work), gfp);
1085        if (!fw_work)
1086                return -ENOMEM;
1087
1088        fw_work->module = module;
1089        fw_work->name = name;
1090        fw_work->device = device;
1091        fw_work->context = context;
1092        fw_work->cont = cont;
1093        fw_work->uevent = uevent;
1094
1095        if (!try_module_get(module)) {
1096                kfree(fw_work);
1097                return -EFAULT;
1098        }
1099
1100        get_device(fw_work->device);
1101        INIT_WORK(&fw_work->work, request_firmware_work_func);
1102        schedule_work(&fw_work->work);
1103        return 0;
1104}
1105
1106/**
1107 * cache_firmware - cache one firmware image in kernel memory space
1108 * @fw_name: the firmware image name
1109 *
1110 * Cache firmware in kernel memory so that drivers can use it when
1111 * system isn't ready for them to request firmware image from userspace.
1112 * Once it returns successfully, driver can use request_firmware or its
1113 * nowait version to get the cached firmware without any interacting
1114 * with userspace
1115 *
1116 * Return 0 if the firmware image has been cached successfully
1117 * Return !0 otherwise
1118 *
1119 */
1120int cache_firmware(const char *fw_name)
1121{
1122        int ret;
1123        const struct firmware *fw;
1124
1125        pr_debug("%s: %s\n", __func__, fw_name);
1126
1127        ret = request_firmware(&fw, fw_name, NULL);
1128        if (!ret)
1129                kfree(fw);
1130
1131        pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1132
1133        return ret;
1134}
1135
1136/**
1137 * uncache_firmware - remove one cached firmware image
1138 * @fw_name: the firmware image name
1139 *
1140 * Uncache one firmware image which has been cached successfully
1141 * before.
1142 *
1143 * Return 0 if the firmware cache has been removed successfully
1144 * Return !0 otherwise
1145 *
1146 */
1147int uncache_firmware(const char *fw_name)
1148{
1149        struct firmware_buf *buf;
1150        struct firmware fw;
1151
1152        pr_debug("%s: %s\n", __func__, fw_name);
1153
1154        if (fw_get_builtin_firmware(&fw, fw_name))
1155                return 0;
1156
1157        buf = fw_lookup_buf(fw_name);
1158        if (buf) {
1159                fw_free_buf(buf);
1160                return 0;
1161        }
1162
1163        return -EINVAL;
1164}
1165
1166#ifdef CONFIG_PM_SLEEP
1167static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1168
1169static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1170{
1171        struct fw_cache_entry *fce;
1172
1173        fce = kzalloc(sizeof(*fce) + strlen(name) + 1, GFP_ATOMIC);
1174        if (!fce)
1175                goto exit;
1176
1177        strcpy(fce->name, name);
1178exit:
1179        return fce;
1180}
1181
1182static int __fw_entry_found(const char *name)
1183{
1184        struct firmware_cache *fwc = &fw_cache;
1185        struct fw_cache_entry *fce;
1186
1187        list_for_each_entry(fce, &fwc->fw_names, list) {
1188                if (!strcmp(fce->name, name))
1189                        return 1;
1190        }
1191        return 0;
1192}
1193
1194static int fw_cache_piggyback_on_request(const char *name)
1195{
1196        struct firmware_cache *fwc = &fw_cache;
1197        struct fw_cache_entry *fce;
1198        int ret = 0;
1199
1200        spin_lock(&fwc->name_lock);
1201        if (__fw_entry_found(name))
1202                goto found;
1203
1204        fce = alloc_fw_cache_entry(name);
1205        if (fce) {
1206                ret = 1;
1207                list_add(&fce->list, &fwc->fw_names);
1208                pr_debug("%s: fw: %s\n", __func__, name);
1209        }
1210found:
1211        spin_unlock(&fwc->name_lock);
1212        return ret;
1213}
1214
1215static void free_fw_cache_entry(struct fw_cache_entry *fce)
1216{
1217        kfree(fce);
1218}
1219
1220static void __async_dev_cache_fw_image(void *fw_entry,
1221                                       async_cookie_t cookie)
1222{
1223        struct fw_cache_entry *fce = fw_entry;
1224        struct firmware_cache *fwc = &fw_cache;
1225        int ret;
1226
1227        ret = cache_firmware(fce->name);
1228        if (ret) {
1229                spin_lock(&fwc->name_lock);
1230                list_del(&fce->list);
1231                spin_unlock(&fwc->name_lock);
1232
1233                free_fw_cache_entry(fce);
1234        }
1235}
1236
1237/* called with dev->devres_lock held */
1238static void dev_create_fw_entry(struct device *dev, void *res,
1239                                void *data)
1240{
1241        struct fw_name_devm *fwn = res;
1242        const char *fw_name = fwn->name;
1243        struct list_head *head = data;
1244        struct fw_cache_entry *fce;
1245
1246        fce = alloc_fw_cache_entry(fw_name);
1247        if (fce)
1248                list_add(&fce->list, head);
1249}
1250
1251static int devm_name_match(struct device *dev, void *res,
1252                           void *match_data)
1253{
1254        struct fw_name_devm *fwn = res;
1255        return (fwn->magic == (unsigned long)match_data);
1256}
1257
1258static void dev_cache_fw_image(struct device *dev, void *data)
1259{
1260        LIST_HEAD(todo);
1261        struct fw_cache_entry *fce;
1262        struct fw_cache_entry *fce_next;
1263        struct firmware_cache *fwc = &fw_cache;
1264
1265        devres_for_each_res(dev, fw_name_devm_release,
1266                            devm_name_match, &fw_cache,
1267                            dev_create_fw_entry, &todo);
1268
1269        list_for_each_entry_safe(fce, fce_next, &todo, list) {
1270                list_del(&fce->list);
1271
1272                spin_lock(&fwc->name_lock);
1273                /* only one cache entry for one firmware */
1274                if (!__fw_entry_found(fce->name)) {
1275                        list_add(&fce->list, &fwc->fw_names);
1276                } else {
1277                        free_fw_cache_entry(fce);
1278                        fce = NULL;
1279                }
1280                spin_unlock(&fwc->name_lock);
1281
1282                if (fce)
1283                        async_schedule_domain(__async_dev_cache_fw_image,
1284                                              (void *)fce,
1285                                              &fw_cache_domain);
1286        }
1287}
1288
1289static void __device_uncache_fw_images(void)
1290{
1291        struct firmware_cache *fwc = &fw_cache;
1292        struct fw_cache_entry *fce;
1293
1294        spin_lock(&fwc->name_lock);
1295        while (!list_empty(&fwc->fw_names)) {
1296                fce = list_entry(fwc->fw_names.next,
1297                                struct fw_cache_entry, list);
1298                list_del(&fce->list);
1299                spin_unlock(&fwc->name_lock);
1300
1301                uncache_firmware(fce->name);
1302                free_fw_cache_entry(fce);
1303
1304                spin_lock(&fwc->name_lock);
1305        }
1306        spin_unlock(&fwc->name_lock);
1307}
1308
1309/**
1310 * device_cache_fw_images - cache devices' firmware
1311 *
1312 * If one device called request_firmware or its nowait version
1313 * successfully before, the firmware names are recored into the
1314 * device's devres link list, so device_cache_fw_images can call
1315 * cache_firmware() to cache these firmwares for the device,
1316 * then the device driver can load its firmwares easily at
1317 * time when system is not ready to complete loading firmware.
1318 */
1319static void device_cache_fw_images(void)
1320{
1321        struct firmware_cache *fwc = &fw_cache;
1322        int old_timeout;
1323        DEFINE_WAIT(wait);
1324
1325        pr_debug("%s\n", __func__);
1326
1327        /* cancel uncache work */
1328        cancel_delayed_work_sync(&fwc->work);
1329
1330        /*
1331         * use small loading timeout for caching devices' firmware
1332         * because all these firmware images have been loaded
1333         * successfully at lease once, also system is ready for
1334         * completing firmware loading now. The maximum size of
1335         * firmware in current distributions is about 2M bytes,
1336         * so 10 secs should be enough.
1337         */
1338        old_timeout = loading_timeout;
1339        loading_timeout = 10;
1340
1341        mutex_lock(&fw_lock);
1342        fwc->state = FW_LOADER_START_CACHE;
1343        dpm_for_each_dev(NULL, dev_cache_fw_image);
1344        mutex_unlock(&fw_lock);
1345
1346        /* wait for completion of caching firmware for all devices */
1347        async_synchronize_full_domain(&fw_cache_domain);
1348
1349        loading_timeout = old_timeout;
1350}
1351
1352/**
1353 * device_uncache_fw_images - uncache devices' firmware
1354 *
1355 * uncache all firmwares which have been cached successfully
1356 * by device_uncache_fw_images earlier
1357 */
1358static void device_uncache_fw_images(void)
1359{
1360        pr_debug("%s\n", __func__);
1361        __device_uncache_fw_images();
1362}
1363
1364static void device_uncache_fw_images_work(struct work_struct *work)
1365{
1366        device_uncache_fw_images();
1367}
1368
1369/**
1370 * device_uncache_fw_images_delay - uncache devices firmwares
1371 * @delay: number of milliseconds to delay uncache device firmwares
1372 *
1373 * uncache all devices's firmwares which has been cached successfully
1374 * by device_cache_fw_images after @delay milliseconds.
1375 */
1376static void device_uncache_fw_images_delay(unsigned long delay)
1377{
1378        schedule_delayed_work(&fw_cache.work,
1379                        msecs_to_jiffies(delay));
1380}
1381
1382static int fw_pm_notify(struct notifier_block *notify_block,
1383                        unsigned long mode, void *unused)
1384{
1385        switch (mode) {
1386        case PM_HIBERNATION_PREPARE:
1387        case PM_SUSPEND_PREPARE:
1388                device_cache_fw_images();
1389                break;
1390
1391        case PM_POST_SUSPEND:
1392        case PM_POST_HIBERNATION:
1393        case PM_POST_RESTORE:
1394                /*
1395                 * In case that system sleep failed and syscore_suspend is
1396                 * not called.
1397                 */
1398                mutex_lock(&fw_lock);
1399                fw_cache.state = FW_LOADER_NO_CACHE;
1400                mutex_unlock(&fw_lock);
1401
1402                device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1403                break;
1404        }
1405
1406        return 0;
1407}
1408
1409/* stop caching firmware once syscore_suspend is reached */
1410static int fw_suspend(void)
1411{
1412        fw_cache.state = FW_LOADER_NO_CACHE;
1413        return 0;
1414}
1415
1416static struct syscore_ops fw_syscore_ops = {
1417        .suspend = fw_suspend,
1418};
1419#else
1420static int fw_cache_piggyback_on_request(const char *name)
1421{
1422        return 0;
1423}
1424#endif
1425
1426static void __init fw_cache_init(void)
1427{
1428        spin_lock_init(&fw_cache.lock);
1429        INIT_LIST_HEAD(&fw_cache.head);
1430        fw_cache.state = FW_LOADER_NO_CACHE;
1431
1432#ifdef CONFIG_PM_SLEEP
1433        spin_lock_init(&fw_cache.name_lock);
1434        INIT_LIST_HEAD(&fw_cache.fw_names);
1435
1436        INIT_DELAYED_WORK(&fw_cache.work,
1437                          device_uncache_fw_images_work);
1438
1439        fw_cache.pm_notify.notifier_call = fw_pm_notify;
1440        register_pm_notifier(&fw_cache.pm_notify);
1441
1442        register_syscore_ops(&fw_syscore_ops);
1443#endif
1444}
1445
1446static int __init firmware_class_init(void)
1447{
1448        fw_cache_init();
1449        return class_register(&firmware_class);
1450}
1451
1452static void __exit firmware_class_exit(void)
1453{
1454#ifdef CONFIG_PM_SLEEP
1455        unregister_syscore_ops(&fw_syscore_ops);
1456        unregister_pm_notifier(&fw_cache.pm_notify);
1457#endif
1458        class_unregister(&firmware_class);
1459}
1460
1461fs_initcall(firmware_class_init);
1462module_exit(firmware_class_exit);
1463
1464EXPORT_SYMBOL(release_firmware);
1465EXPORT_SYMBOL(request_firmware);
1466EXPORT_SYMBOL(request_firmware_nowait);
1467EXPORT_SYMBOL_GPL(cache_firmware);
1468EXPORT_SYMBOL_GPL(uncache_firmware);
1469
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