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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * main.c - Multi purpose firmware loading support
   4 *
   5 * Copyright (c) 2003 Manuel Estrada Sainz
   6 *
   7 * Please see Documentation/driver-api/firmware/ for more information.
   8 *
   9 */
  10
  11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13#include <linux/capability.h>
  14#include <linux/device.h>
  15#include <linux/kernel_read_file.h>
  16#include <linux/module.h>
  17#include <linux/init.h>
  18#include <linux/initrd.h>
  19#include <linux/timer.h>
  20#include <linux/vmalloc.h>
  21#include <linux/interrupt.h>
  22#include <linux/bitops.h>
  23#include <linux/mutex.h>
  24#include <linux/workqueue.h>
  25#include <linux/highmem.h>
  26#include <linux/firmware.h>
  27#include <linux/slab.h>
  28#include <linux/sched.h>
  29#include <linux/file.h>
  30#include <linux/list.h>
  31#include <linux/fs.h>
  32#include <linux/async.h>
  33#include <linux/pm.h>
  34#include <linux/suspend.h>
  35#include <linux/syscore_ops.h>
  36#include <linux/reboot.h>
  37#include <linux/security.h>
  38#include <linux/zstd.h>
  39#include <linux/xz.h>
  40
  41#include <generated/utsrelease.h>
  42
  43#include "../base.h"
  44#include "firmware.h"
  45#include "fallback.h"
  46
  47MODULE_AUTHOR("Manuel Estrada Sainz");
  48MODULE_DESCRIPTION("Multi purpose firmware loading support");
  49MODULE_LICENSE("GPL");
  50
  51struct firmware_cache {
  52	/* firmware_buf instance will be added into the below list */
  53	spinlock_t lock;
  54	struct list_head head;
  55	int state;
  56
  57#ifdef CONFIG_FW_CACHE
  58	/*
  59	 * Names of firmware images which have been cached successfully
  60	 * will be added into the below list so that device uncache
  61	 * helper can trace which firmware images have been cached
  62	 * before.
  63	 */
  64	spinlock_t name_lock;
  65	struct list_head fw_names;
  66
  67	struct delayed_work work;
  68
  69	struct notifier_block   pm_notify;
  70#endif
  71};
  72
  73struct fw_cache_entry {
  74	struct list_head list;
  75	const char *name;
  76};
  77
  78struct fw_name_devm {
  79	unsigned long magic;
  80	const char *name;
  81};
  82
  83static inline struct fw_priv *to_fw_priv(struct kref *ref)
  84{
  85	return container_of(ref, struct fw_priv, ref);
  86}
  87
  88#define	FW_LOADER_NO_CACHE	0
  89#define	FW_LOADER_START_CACHE	1
  90
  91/* fw_lock could be moved to 'struct fw_sysfs' but since it is just
  92 * guarding for corner cases a global lock should be OK */
  93DEFINE_MUTEX(fw_lock);
  94
  95struct firmware_cache fw_cache;
  96
  97void fw_state_init(struct fw_priv *fw_priv)
  98{
  99	struct fw_state *fw_st = &fw_priv->fw_st;
 100
 101	init_completion(&fw_st->completion);
 102	fw_st->status = FW_STATUS_UNKNOWN;
 103}
 104
 105static inline int fw_state_wait(struct fw_priv *fw_priv)
 106{
 107	return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
 108}
 109
 110static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv);
 111
 112static struct fw_priv *__allocate_fw_priv(const char *fw_name,
 113					  struct firmware_cache *fwc,
 114					  void *dbuf,
 115					  size_t size,
 116					  size_t offset,
 117					  u32 opt_flags)
 118{
 119	struct fw_priv *fw_priv;
 120
 121	/* For a partial read, the buffer must be preallocated. */
 122	if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
 123		return NULL;
 124
 125	/* Only partial reads are allowed to use an offset. */
 126	if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
 127		return NULL;
 128
 129	fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
 130	if (!fw_priv)
 131		return NULL;
 132
 133	fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
 134	if (!fw_priv->fw_name) {
 135		kfree(fw_priv);
 136		return NULL;
 137	}
 138
 139	kref_init(&fw_priv->ref);
 140	fw_priv->fwc = fwc;
 141	fw_priv->data = dbuf;
 142	fw_priv->allocated_size = size;
 143	fw_priv->offset = offset;
 144	fw_priv->opt_flags = opt_flags;
 145	fw_state_init(fw_priv);
 146#ifdef CONFIG_FW_LOADER_USER_HELPER
 147	INIT_LIST_HEAD(&fw_priv->pending_list);
 148#endif
 149
 150	pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
 151
 152	return fw_priv;
 153}
 154
 155static struct fw_priv *__lookup_fw_priv(const char *fw_name)
 156{
 157	struct fw_priv *tmp;
 158	struct firmware_cache *fwc = &fw_cache;
 159
 160	list_for_each_entry(tmp, &fwc->head, list)
 161		if (!strcmp(tmp->fw_name, fw_name))
 162			return tmp;
 163	return NULL;
 164}
 165
 166/* Returns 1 for batching firmware requests with the same name */
 167int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
 168			 struct fw_priv **fw_priv, void *dbuf, size_t size,
 169			 size_t offset, u32 opt_flags)
 170{
 171	struct fw_priv *tmp;
 172
 173	spin_lock(&fwc->lock);
 174	/*
 175	 * Do not merge requests that are marked to be non-cached or
 176	 * are performing partial reads.
 177	 */
 178	if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
 179		tmp = __lookup_fw_priv(fw_name);
 180		if (tmp) {
 181			kref_get(&tmp->ref);
 182			spin_unlock(&fwc->lock);
 183			*fw_priv = tmp;
 184			pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
 185			return 1;
 186		}
 187	}
 188
 189	tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
 190	if (tmp) {
 191		INIT_LIST_HEAD(&tmp->list);
 192		if (!(opt_flags & FW_OPT_NOCACHE))
 193			list_add(&tmp->list, &fwc->head);
 194	}
 195	spin_unlock(&fwc->lock);
 196
 197	*fw_priv = tmp;
 198
 199	return tmp ? 0 : -ENOMEM;
 200}
 201
 202static void __free_fw_priv(struct kref *ref)
 203	__releases(&fwc->lock)
 204{
 205	struct fw_priv *fw_priv = to_fw_priv(ref);
 206	struct firmware_cache *fwc = fw_priv->fwc;
 207
 208	pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 209		 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 210		 (unsigned int)fw_priv->size);
 211
 212	list_del(&fw_priv->list);
 213	spin_unlock(&fwc->lock);
 214
 215	if (fw_is_paged_buf(fw_priv))
 216		fw_free_paged_buf(fw_priv);
 217	else if (!fw_priv->allocated_size)
 218		vfree(fw_priv->data);
 219
 220	kfree_const(fw_priv->fw_name);
 221	kfree(fw_priv);
 222}
 223
 224void free_fw_priv(struct fw_priv *fw_priv)
 225{
 226	struct firmware_cache *fwc = fw_priv->fwc;
 227	spin_lock(&fwc->lock);
 228	if (!kref_put(&fw_priv->ref, __free_fw_priv))
 229		spin_unlock(&fwc->lock);
 230}
 231
 232#ifdef CONFIG_FW_LOADER_PAGED_BUF
 233bool fw_is_paged_buf(struct fw_priv *fw_priv)
 234{
 235	return fw_priv->is_paged_buf;
 236}
 237
 238void fw_free_paged_buf(struct fw_priv *fw_priv)
 239{
 240	int i;
 241
 242	if (!fw_priv->pages)
 243		return;
 244
 245	vunmap(fw_priv->data);
 246
 247	for (i = 0; i < fw_priv->nr_pages; i++)
 248		__free_page(fw_priv->pages[i]);
 249	kvfree(fw_priv->pages);
 250	fw_priv->pages = NULL;
 251	fw_priv->page_array_size = 0;
 252	fw_priv->nr_pages = 0;
 253	fw_priv->data = NULL;
 254	fw_priv->size = 0;
 255}
 256
 257int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
 258{
 259	/* If the array of pages is too small, grow it */
 260	if (fw_priv->page_array_size < pages_needed) {
 261		int new_array_size = max(pages_needed,
 262					 fw_priv->page_array_size * 2);
 263		struct page **new_pages;
 264
 265		new_pages = kvmalloc_array(new_array_size, sizeof(void *),
 266					   GFP_KERNEL);
 267		if (!new_pages)
 268			return -ENOMEM;
 269		memcpy(new_pages, fw_priv->pages,
 270		       fw_priv->page_array_size * sizeof(void *));
 271		memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 272		       (new_array_size - fw_priv->page_array_size));
 273		kvfree(fw_priv->pages);
 274		fw_priv->pages = new_pages;
 275		fw_priv->page_array_size = new_array_size;
 276	}
 277
 278	while (fw_priv->nr_pages < pages_needed) {
 279		fw_priv->pages[fw_priv->nr_pages] =
 280			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 281
 282		if (!fw_priv->pages[fw_priv->nr_pages])
 283			return -ENOMEM;
 284		fw_priv->nr_pages++;
 285	}
 286
 287	return 0;
 288}
 289
 290int fw_map_paged_buf(struct fw_priv *fw_priv)
 291{
 292	/* one pages buffer should be mapped/unmapped only once */
 293	if (!fw_priv->pages)
 294		return 0;
 295
 296	vunmap(fw_priv->data);
 297	fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
 298			     PAGE_KERNEL_RO);
 299	if (!fw_priv->data)
 300		return -ENOMEM;
 301
 302	return 0;
 303}
 304#endif
 305
 306/*
 307 * ZSTD-compressed firmware support
 308 */
 309#ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
 310static int fw_decompress_zstd(struct device *dev, struct fw_priv *fw_priv,
 311			      size_t in_size, const void *in_buffer)
 312{
 313	size_t len, out_size, workspace_size;
 314	void *workspace, *out_buf;
 315	zstd_dctx *ctx;
 316	int err;
 317
 318	if (fw_priv->allocated_size) {
 319		out_size = fw_priv->allocated_size;
 320		out_buf = fw_priv->data;
 321	} else {
 322		zstd_frame_header params;
 323
 324		if (zstd_get_frame_header(&params, in_buffer, in_size) ||
 325		    params.frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN) {
 326			dev_dbg(dev, "%s: invalid zstd header\n", __func__);
 327			return -EINVAL;
 328		}
 329		out_size = params.frameContentSize;
 330		out_buf = vzalloc(out_size);
 331		if (!out_buf)
 332			return -ENOMEM;
 333	}
 334
 335	workspace_size = zstd_dctx_workspace_bound();
 336	workspace = kvzalloc(workspace_size, GFP_KERNEL);
 337	if (!workspace) {
 338		err = -ENOMEM;
 339		goto error;
 340	}
 341
 342	ctx = zstd_init_dctx(workspace, workspace_size);
 343	if (!ctx) {
 344		dev_dbg(dev, "%s: failed to initialize context\n", __func__);
 345		err = -EINVAL;
 346		goto error;
 347	}
 348
 349	len = zstd_decompress_dctx(ctx, out_buf, out_size, in_buffer, in_size);
 350	if (zstd_is_error(len)) {
 351		dev_dbg(dev, "%s: failed to decompress: %d\n", __func__,
 352			zstd_get_error_code(len));
 353		err = -EINVAL;
 354		goto error;
 355	}
 356
 357	if (!fw_priv->allocated_size)
 358		fw_priv->data = out_buf;
 359	fw_priv->size = len;
 360	err = 0;
 361
 362 error:
 363	kvfree(workspace);
 364	if (err && !fw_priv->allocated_size)
 365		vfree(out_buf);
 366	return err;
 367}
 368#endif /* CONFIG_FW_LOADER_COMPRESS_ZSTD */
 369
 370/*
 371 * XZ-compressed firmware support
 372 */
 373#ifdef CONFIG_FW_LOADER_COMPRESS_XZ
 374/* show an error and return the standard error code */
 375static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
 376{
 377	if (xz_ret != XZ_STREAM_END) {
 378		dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
 379		return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
 380	}
 381	return 0;
 382}
 383
 384/* single-shot decompression onto the pre-allocated buffer */
 385static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
 386				   size_t in_size, const void *in_buffer)
 387{
 388	struct xz_dec *xz_dec;
 389	struct xz_buf xz_buf;
 390	enum xz_ret xz_ret;
 391
 392	xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
 393	if (!xz_dec)
 394		return -ENOMEM;
 395
 396	xz_buf.in_size = in_size;
 397	xz_buf.in = in_buffer;
 398	xz_buf.in_pos = 0;
 399	xz_buf.out_size = fw_priv->allocated_size;
 400	xz_buf.out = fw_priv->data;
 401	xz_buf.out_pos = 0;
 402
 403	xz_ret = xz_dec_run(xz_dec, &xz_buf);
 404	xz_dec_end(xz_dec);
 405
 406	fw_priv->size = xz_buf.out_pos;
 407	return fw_decompress_xz_error(dev, xz_ret);
 408}
 409
 410/* decompression on paged buffer and map it */
 411static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
 412				  size_t in_size, const void *in_buffer)
 413{
 414	struct xz_dec *xz_dec;
 415	struct xz_buf xz_buf;
 416	enum xz_ret xz_ret;
 417	struct page *page;
 418	int err = 0;
 419
 420	xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
 421	if (!xz_dec)
 422		return -ENOMEM;
 423
 424	xz_buf.in_size = in_size;
 425	xz_buf.in = in_buffer;
 426	xz_buf.in_pos = 0;
 427
 428	fw_priv->is_paged_buf = true;
 429	fw_priv->size = 0;
 430	do {
 431		if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
 432			err = -ENOMEM;
 433			goto out;
 434		}
 435
 436		/* decompress onto the new allocated page */
 437		page = fw_priv->pages[fw_priv->nr_pages - 1];
 438		xz_buf.out = kmap_local_page(page);
 439		xz_buf.out_pos = 0;
 440		xz_buf.out_size = PAGE_SIZE;
 441		xz_ret = xz_dec_run(xz_dec, &xz_buf);
 442		kunmap_local(xz_buf.out);
 443		fw_priv->size += xz_buf.out_pos;
 444		/* partial decompression means either end or error */
 445		if (xz_buf.out_pos != PAGE_SIZE)
 446			break;
 447	} while (xz_ret == XZ_OK);
 448
 449	err = fw_decompress_xz_error(dev, xz_ret);
 450	if (!err)
 451		err = fw_map_paged_buf(fw_priv);
 452
 453 out:
 454	xz_dec_end(xz_dec);
 455	return err;
 456}
 457
 458static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
 459			    size_t in_size, const void *in_buffer)
 460{
 461	/* if the buffer is pre-allocated, we can perform in single-shot mode */
 462	if (fw_priv->data)
 463		return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
 464	else
 465		return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
 466}
 467#endif /* CONFIG_FW_LOADER_COMPRESS_XZ */
 468
 469/* direct firmware loading support */
 470static char fw_path_para[256];
 471static const char * const fw_path[] = {
 472	fw_path_para,
 473	"/lib/firmware/updates/" UTS_RELEASE,
 474	"/lib/firmware/updates",
 475	"/lib/firmware/" UTS_RELEASE,
 476	"/lib/firmware"
 477};
 478
 479/*
 480 * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 481 * from kernel command line because firmware_class is generally built in
 482 * kernel instead of module.
 483 */
 484module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 485MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 486
 487static int
 488fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
 489			   const char *suffix,
 490			   int (*decompress)(struct device *dev,
 491					     struct fw_priv *fw_priv,
 492					     size_t in_size,
 493					     const void *in_buffer))
 494{
 495	size_t size;
 496	int i, len;
 497	int rc = -ENOENT;
 498	char *path;
 499	size_t msize = INT_MAX;
 500	void *buffer = NULL;
 501
 502	/* Already populated data member means we're loading into a buffer */
 503	if (!decompress && fw_priv->data) {
 504		buffer = fw_priv->data;
 505		msize = fw_priv->allocated_size;
 506	}
 507
 508	path = __getname();
 509	if (!path)
 510		return -ENOMEM;
 511
 512	wait_for_initramfs();
 513	for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 514		size_t file_size = 0;
 515		size_t *file_size_ptr = NULL;
 516
 517		/* skip the unset customized path */
 518		if (!fw_path[i][0])
 519			continue;
 520
 521		len = snprintf(path, PATH_MAX, "%s/%s%s",
 522			       fw_path[i], fw_priv->fw_name, suffix);
 523		if (len >= PATH_MAX) {
 524			rc = -ENAMETOOLONG;
 525			break;
 526		}
 527
 528		fw_priv->size = 0;
 529
 530		/*
 531		 * The total file size is only examined when doing a partial
 532		 * read; the "full read" case needs to fail if the whole
 533		 * firmware was not completely loaded.
 534		 */
 535		if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
 536			file_size_ptr = &file_size;
 537
 538		/* load firmware files from the mount namespace of init */
 539		rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
 540						       &buffer, msize,
 541						       file_size_ptr,
 542						       READING_FIRMWARE);
 543		if (rc < 0) {
 544			if (rc != -ENOENT)
 545				dev_warn(device, "loading %s failed with error %d\n",
 546					 path, rc);
 547			else
 548				dev_dbg(device, "loading %s failed for no such file or directory.\n",
 549					 path);
 550			continue;
 551		}
 552		size = rc;
 553		rc = 0;
 554
 555		dev_dbg(device, "Loading firmware from %s\n", path);
 556		if (decompress) {
 557			dev_dbg(device, "f/w decompressing %s\n",
 558				fw_priv->fw_name);
 559			rc = decompress(device, fw_priv, size, buffer);
 560			/* discard the superfluous original content */
 561			vfree(buffer);
 562			buffer = NULL;
 563			if (rc) {
 564				fw_free_paged_buf(fw_priv);
 565				continue;
 566			}
 567		} else {
 568			dev_dbg(device, "direct-loading %s\n",
 569				fw_priv->fw_name);
 570			if (!fw_priv->data)
 571				fw_priv->data = buffer;
 572			fw_priv->size = size;
 573		}
 574		fw_state_done(fw_priv);
 575		break;
 576	}
 577	__putname(path);
 578
 579	return rc;
 580}
 581
 582/* firmware holds the ownership of pages */
 583static void firmware_free_data(const struct firmware *fw)
 584{
 585	/* Loaded directly? */
 586	if (!fw->priv) {
 587		vfree(fw->data);
 588		return;
 589	}
 590	free_fw_priv(fw->priv);
 591}
 592
 593/* store the pages buffer info firmware from buf */
 594static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
 595{
 596	fw->priv = fw_priv;
 597	fw->size = fw_priv->size;
 598	fw->data = fw_priv->data;
 599
 600	pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 601		 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 602		 (unsigned int)fw_priv->size);
 603}
 604
 605#ifdef CONFIG_FW_CACHE
 606static void fw_name_devm_release(struct device *dev, void *res)
 607{
 608	struct fw_name_devm *fwn = res;
 609
 610	if (fwn->magic == (unsigned long)&fw_cache)
 611		pr_debug("%s: fw_name-%s devm-%p released\n",
 612				__func__, fwn->name, res);
 613	kfree_const(fwn->name);
 614}
 615
 616static int fw_devm_match(struct device *dev, void *res,
 617		void *match_data)
 618{
 619	struct fw_name_devm *fwn = res;
 620
 621	return (fwn->magic == (unsigned long)&fw_cache) &&
 622		!strcmp(fwn->name, match_data);
 623}
 624
 625static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 626		const char *name)
 627{
 628	struct fw_name_devm *fwn;
 629
 630	fwn = devres_find(dev, fw_name_devm_release,
 631			  fw_devm_match, (void *)name);
 632	return fwn;
 633}
 634
 635static bool fw_cache_is_setup(struct device *dev, const char *name)
 636{
 637	struct fw_name_devm *fwn;
 638
 639	fwn = fw_find_devm_name(dev, name);
 640	if (fwn)
 641		return true;
 642
 643	return false;
 644}
 645
 646/* add firmware name into devres list */
 647static int fw_add_devm_name(struct device *dev, const char *name)
 648{
 649	struct fw_name_devm *fwn;
 650
 651	if (fw_cache_is_setup(dev, name))
 652		return 0;
 653
 654	fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 655			   GFP_KERNEL);
 656	if (!fwn)
 657		return -ENOMEM;
 658	fwn->name = kstrdup_const(name, GFP_KERNEL);
 659	if (!fwn->name) {
 660		devres_free(fwn);
 661		return -ENOMEM;
 662	}
 663
 664	fwn->magic = (unsigned long)&fw_cache;
 665	devres_add(dev, fwn);
 666
 667	return 0;
 668}
 669#else
 670static bool fw_cache_is_setup(struct device *dev, const char *name)
 671{
 672	return false;
 673}
 674
 675static int fw_add_devm_name(struct device *dev, const char *name)
 676{
 677	return 0;
 678}
 679#endif
 680
 681int assign_fw(struct firmware *fw, struct device *device)
 682{
 683	struct fw_priv *fw_priv = fw->priv;
 684	int ret;
 685
 686	mutex_lock(&fw_lock);
 687	if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
 688		mutex_unlock(&fw_lock);
 689		return -ENOENT;
 690	}
 691
 692	/*
 693	 * add firmware name into devres list so that we can auto cache
 694	 * and uncache firmware for device.
 695	 *
 696	 * device may has been deleted already, but the problem
 697	 * should be fixed in devres or driver core.
 698	 */
 699	/* don't cache firmware handled without uevent */
 700	if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
 701	    !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
 702		ret = fw_add_devm_name(device, fw_priv->fw_name);
 703		if (ret) {
 704			mutex_unlock(&fw_lock);
 705			return ret;
 706		}
 707	}
 708
 709	/*
 710	 * After caching firmware image is started, let it piggyback
 711	 * on request firmware.
 712	 */
 713	if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
 714	    fw_priv->fwc->state == FW_LOADER_START_CACHE)
 715		fw_cache_piggyback_on_request(fw_priv);
 716
 717	/* pass the pages buffer to driver at the last minute */
 718	fw_set_page_data(fw_priv, fw);
 719	mutex_unlock(&fw_lock);
 720	return 0;
 721}
 722
 723/* prepare firmware and firmware_buf structs;
 724 * return 0 if a firmware is already assigned, 1 if need to load one,
 725 * or a negative error code
 726 */
 727static int
 728_request_firmware_prepare(struct firmware **firmware_p, const char *name,
 729			  struct device *device, void *dbuf, size_t size,
 730			  size_t offset, u32 opt_flags)
 731{
 732	struct firmware *firmware;
 733	struct fw_priv *fw_priv;
 734	int ret;
 735
 736	*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 737	if (!firmware) {
 738		dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 739			__func__);
 740		return -ENOMEM;
 741	}
 742
 743	if (firmware_request_builtin_buf(firmware, name, dbuf, size)) {
 744		dev_dbg(device, "using built-in %s\n", name);
 745		return 0; /* assigned */
 746	}
 747
 748	ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
 749				   offset, opt_flags);
 750
 751	/*
 752	 * bind with 'priv' now to avoid warning in failure path
 753	 * of requesting firmware.
 754	 */
 755	firmware->priv = fw_priv;
 756
 757	if (ret > 0) {
 758		ret = fw_state_wait(fw_priv);
 759		if (!ret) {
 760			fw_set_page_data(fw_priv, firmware);
 761			return 0; /* assigned */
 762		}
 763	}
 764
 765	if (ret < 0)
 766		return ret;
 767	return 1; /* need to load */
 768}
 769
 770/*
 771 * Batched requests need only one wake, we need to do this step last due to the
 772 * fallback mechanism. The buf is protected with kref_get(), and it won't be
 773 * released until the last user calls release_firmware().
 774 *
 775 * Failed batched requests are possible as well, in such cases we just share
 776 * the struct fw_priv and won't release it until all requests are woken
 777 * and have gone through this same path.
 778 */
 779static void fw_abort_batch_reqs(struct firmware *fw)
 780{
 781	struct fw_priv *fw_priv;
 782
 783	/* Loaded directly? */
 784	if (!fw || !fw->priv)
 785		return;
 786
 787	fw_priv = fw->priv;
 788	mutex_lock(&fw_lock);
 789	if (!fw_state_is_aborted(fw_priv))
 790		fw_state_aborted(fw_priv);
 791	mutex_unlock(&fw_lock);
 792}
 793
 794/* called from request_firmware() and request_firmware_work_func() */
 795static int
 796_request_firmware(const struct firmware **firmware_p, const char *name,
 797		  struct device *device, void *buf, size_t size,
 798		  size_t offset, u32 opt_flags)
 799{
 800	struct firmware *fw = NULL;
 801	struct cred *kern_cred = NULL;
 802	const struct cred *old_cred;
 803	bool nondirect = false;
 804	int ret;
 805
 806	if (!firmware_p)
 807		return -EINVAL;
 808
 809	if (!name || name[0] == '\0') {
 810		ret = -EINVAL;
 811		goto out;
 812	}
 813
 814	ret = _request_firmware_prepare(&fw, name, device, buf, size,
 815					offset, opt_flags);
 816	if (ret <= 0) /* error or already assigned */
 817		goto out;
 818
 819	/*
 820	 * We are about to try to access the firmware file. Because we may have been
 821	 * called by a driver when serving an unrelated request from userland, we use
 822	 * the kernel credentials to read the file.
 823	 */
 824	kern_cred = prepare_kernel_cred(&init_task);
 825	if (!kern_cred) {
 826		ret = -ENOMEM;
 827		goto out;
 828	}
 829	old_cred = override_creds(kern_cred);
 830
 831	ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
 832
 833	/* Only full reads can support decompression, platform, and sysfs. */
 834	if (!(opt_flags & FW_OPT_PARTIAL))
 835		nondirect = true;
 836
 837#ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
 838	if (ret == -ENOENT && nondirect)
 839		ret = fw_get_filesystem_firmware(device, fw->priv, ".zst",
 840						 fw_decompress_zstd);
 841#endif
 842#ifdef CONFIG_FW_LOADER_COMPRESS_XZ
 843	if (ret == -ENOENT && nondirect)
 844		ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
 845						 fw_decompress_xz);
 846#endif
 847	if (ret == -ENOENT && nondirect)
 848		ret = firmware_fallback_platform(fw->priv);
 849
 850	if (ret) {
 851		if (!(opt_flags & FW_OPT_NO_WARN))
 852			dev_warn(device,
 853				 "Direct firmware load for %s failed with error %d\n",
 854				 name, ret);
 855		if (nondirect)
 856			ret = firmware_fallback_sysfs(fw, name, device,
 857						      opt_flags, ret);
 858	} else
 859		ret = assign_fw(fw, device);
 860
 861	revert_creds(old_cred);
 862	put_cred(kern_cred);
 863
 864 out:
 865	if (ret < 0) {
 866		fw_abort_batch_reqs(fw);
 867		release_firmware(fw);
 868		fw = NULL;
 869	}
 870
 871	*firmware_p = fw;
 872	return ret;
 873}
 874
 875/**
 876 * request_firmware() - send firmware request and wait for it
 877 * @firmware_p: pointer to firmware image
 878 * @name: name of firmware file
 879 * @device: device for which firmware is being loaded
 880 *
 881 *      @firmware_p will be used to return a firmware image by the name
 882 *      of @name for device @device.
 883 *
 884 *      Should be called from user context where sleeping is allowed.
 885 *
 886 *      @name will be used as $FIRMWARE in the uevent environment and
 887 *      should be distinctive enough not to be confused with any other
 888 *      firmware image for this or any other device.
 889 *
 890 *	Caller must hold the reference count of @device.
 891 *
 892 *	The function can be called safely inside device's suspend and
 893 *	resume callback.
 894 **/
 895int
 896request_firmware(const struct firmware **firmware_p, const char *name,
 897		 struct device *device)
 898{
 899	int ret;
 900
 901	/* Need to pin this module until return */
 902	__module_get(THIS_MODULE);
 903	ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
 904				FW_OPT_UEVENT);
 905	module_put(THIS_MODULE);
 906	return ret;
 907}
 908EXPORT_SYMBOL(request_firmware);
 909
 910/**
 911 * firmware_request_nowarn() - request for an optional fw module
 912 * @firmware: pointer to firmware image
 913 * @name: name of firmware file
 914 * @device: device for which firmware is being loaded
 915 *
 916 * This function is similar in behaviour to request_firmware(), except it
 917 * doesn't produce warning messages when the file is not found. The sysfs
 918 * fallback mechanism is enabled if direct filesystem lookup fails. However,
 919 * failures to find the firmware file with it are still suppressed. It is
 920 * therefore up to the driver to check for the return value of this call and to
 921 * decide when to inform the users of errors.
 922 **/
 923int firmware_request_nowarn(const struct firmware **firmware, const char *name,
 924			    struct device *device)
 925{
 926	int ret;
 927
 928	/* Need to pin this module until return */
 929	__module_get(THIS_MODULE);
 930	ret = _request_firmware(firmware, name, device, NULL, 0, 0,
 931				FW_OPT_UEVENT | FW_OPT_NO_WARN);
 932	module_put(THIS_MODULE);
 933	return ret;
 934}
 935EXPORT_SYMBOL_GPL(firmware_request_nowarn);
 936
 937/**
 938 * request_firmware_direct() - load firmware directly without usermode helper
 939 * @firmware_p: pointer to firmware image
 940 * @name: name of firmware file
 941 * @device: device for which firmware is being loaded
 942 *
 943 * This function works pretty much like request_firmware(), but this doesn't
 944 * fall back to usermode helper even if the firmware couldn't be loaded
 945 * directly from fs.  Hence it's useful for loading optional firmwares, which
 946 * aren't always present, without extra long timeouts of udev.
 947 **/
 948int request_firmware_direct(const struct firmware **firmware_p,
 949			    const char *name, struct device *device)
 950{
 951	int ret;
 952
 953	__module_get(THIS_MODULE);
 954	ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
 955				FW_OPT_UEVENT | FW_OPT_NO_WARN |
 956				FW_OPT_NOFALLBACK_SYSFS);
 957	module_put(THIS_MODULE);
 958	return ret;
 959}
 960EXPORT_SYMBOL_GPL(request_firmware_direct);
 961
 962/**
 963 * firmware_request_platform() - request firmware with platform-fw fallback
 964 * @firmware: pointer to firmware image
 965 * @name: name of firmware file
 966 * @device: device for which firmware is being loaded
 967 *
 968 * This function is similar in behaviour to request_firmware, except that if
 969 * direct filesystem lookup fails, it will fallback to looking for a copy of the
 970 * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
 971 **/
 972int firmware_request_platform(const struct firmware **firmware,
 973			      const char *name, struct device *device)
 974{
 975	int ret;
 976
 977	/* Need to pin this module until return */
 978	__module_get(THIS_MODULE);
 979	ret = _request_firmware(firmware, name, device, NULL, 0, 0,
 980				FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
 981	module_put(THIS_MODULE);
 982	return ret;
 983}
 984EXPORT_SYMBOL_GPL(firmware_request_platform);
 985
 986/**
 987 * firmware_request_cache() - cache firmware for suspend so resume can use it
 988 * @name: name of firmware file
 989 * @device: device for which firmware should be cached for
 990 *
 991 * There are some devices with an optimization that enables the device to not
 992 * require loading firmware on system reboot. This optimization may still
 993 * require the firmware present on resume from suspend. This routine can be
 994 * used to ensure the firmware is present on resume from suspend in these
 995 * situations. This helper is not compatible with drivers which use
 996 * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
 997 **/
 998int firmware_request_cache(struct device *device, const char *name)
 999{
1000	int ret;
1001
1002	mutex_lock(&fw_lock);
1003	ret = fw_add_devm_name(device, name);
1004	mutex_unlock(&fw_lock);
1005
1006	return ret;
1007}
1008EXPORT_SYMBOL_GPL(firmware_request_cache);
1009
1010/**
1011 * request_firmware_into_buf() - load firmware into a previously allocated buffer
1012 * @firmware_p: pointer to firmware image
1013 * @name: name of firmware file
1014 * @device: device for which firmware is being loaded and DMA region allocated
1015 * @buf: address of buffer to load firmware into
1016 * @size: size of buffer
1017 *
1018 * This function works pretty much like request_firmware(), but it doesn't
1019 * allocate a buffer to hold the firmware data. Instead, the firmware
1020 * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1021 * data member is pointed at @buf.
1022 *
1023 * This function doesn't cache firmware either.
1024 */
1025int
1026request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1027			  struct device *device, void *buf, size_t size)
1028{
1029	int ret;
1030
1031	if (fw_cache_is_setup(device, name))
1032		return -EOPNOTSUPP;
1033
1034	__module_get(THIS_MODULE);
1035	ret = _request_firmware(firmware_p, name, device, buf, size, 0,
1036				FW_OPT_UEVENT | FW_OPT_NOCACHE);
1037	module_put(THIS_MODULE);
1038	return ret;
1039}
1040EXPORT_SYMBOL(request_firmware_into_buf);
1041
1042/**
1043 * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
1044 * @firmware_p: pointer to firmware image
1045 * @name: name of firmware file
1046 * @device: device for which firmware is being loaded and DMA region allocated
1047 * @buf: address of buffer to load firmware into
1048 * @size: size of buffer
1049 * @offset: offset into file to read
1050 *
1051 * This function works pretty much like request_firmware_into_buf except
1052 * it allows a partial read of the file.
1053 */
1054int
1055request_partial_firmware_into_buf(const struct firmware **firmware_p,
1056				  const char *name, struct device *device,
1057				  void *buf, size_t size, size_t offset)
1058{
1059	int ret;
1060
1061	if (fw_cache_is_setup(device, name))
1062		return -EOPNOTSUPP;
1063
1064	__module_get(THIS_MODULE);
1065	ret = _request_firmware(firmware_p, name, device, buf, size, offset,
1066				FW_OPT_UEVENT | FW_OPT_NOCACHE |
1067				FW_OPT_PARTIAL);
1068	module_put(THIS_MODULE);
1069	return ret;
1070}
1071EXPORT_SYMBOL(request_partial_firmware_into_buf);
1072
1073/**
1074 * release_firmware() - release the resource associated with a firmware image
1075 * @fw: firmware resource to release
1076 **/
1077void release_firmware(const struct firmware *fw)
1078{
1079	if (fw) {
1080		if (!firmware_is_builtin(fw))
1081			firmware_free_data(fw);
1082		kfree(fw);
1083	}
1084}
1085EXPORT_SYMBOL(release_firmware);
1086
1087/* Async support */
1088struct firmware_work {
1089	struct work_struct work;
1090	struct module *module;
1091	const char *name;
1092	struct device *device;
1093	void *context;
1094	void (*cont)(const struct firmware *fw, void *context);
1095	u32 opt_flags;
1096};
1097
1098static void request_firmware_work_func(struct work_struct *work)
1099{
1100	struct firmware_work *fw_work;
1101	const struct firmware *fw;
1102
1103	fw_work = container_of(work, struct firmware_work, work);
1104
1105	_request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
1106			  fw_work->opt_flags);
1107	fw_work->cont(fw, fw_work->context);
1108	put_device(fw_work->device); /* taken in request_firmware_nowait() */
1109
1110	module_put(fw_work->module);
1111	kfree_const(fw_work->name);
1112	kfree(fw_work);
1113}
1114
1115/**
1116 * request_firmware_nowait() - asynchronous version of request_firmware
1117 * @module: module requesting the firmware
1118 * @uevent: sends uevent to copy the firmware image if this flag
1119 *	is non-zero else the firmware copy must be done manually.
1120 * @name: name of firmware file
1121 * @device: device for which firmware is being loaded
1122 * @gfp: allocation flags
1123 * @context: will be passed over to @cont, and
1124 *	@fw may be %NULL if firmware request fails.
1125 * @cont: function will be called asynchronously when the firmware
1126 *	request is over.
1127 *
1128 *	Caller must hold the reference count of @device.
1129 *
1130 *	Asynchronous variant of request_firmware() for user contexts:
1131 *		- sleep for as small periods as possible since it may
1132 *		  increase kernel boot time of built-in device drivers
1133 *		  requesting firmware in their ->probe() methods, if
1134 *		  @gfp is GFP_KERNEL.
1135 *
1136 *		- can't sleep at all if @gfp is GFP_ATOMIC.
1137 **/
1138int
1139request_firmware_nowait(
1140	struct module *module, bool uevent,
1141	const char *name, struct device *device, gfp_t gfp, void *context,
1142	void (*cont)(const struct firmware *fw, void *context))
1143{
1144	struct firmware_work *fw_work;
1145
1146	fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1147	if (!fw_work)
1148		return -ENOMEM;
1149
1150	fw_work->module = module;
1151	fw_work->name = kstrdup_const(name, gfp);
1152	if (!fw_work->name) {
1153		kfree(fw_work);
1154		return -ENOMEM;
1155	}
1156	fw_work->device = device;
1157	fw_work->context = context;
1158	fw_work->cont = cont;
1159	fw_work->opt_flags = FW_OPT_NOWAIT |
1160		(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1161
1162	if (!uevent && fw_cache_is_setup(device, name)) {
1163		kfree_const(fw_work->name);
1164		kfree(fw_work);
1165		return -EOPNOTSUPP;
1166	}
1167
1168	if (!try_module_get(module)) {
1169		kfree_const(fw_work->name);
1170		kfree(fw_work);
1171		return -EFAULT;
1172	}
1173
1174	get_device(fw_work->device);
1175	INIT_WORK(&fw_work->work, request_firmware_work_func);
1176	schedule_work(&fw_work->work);
1177	return 0;
1178}
1179EXPORT_SYMBOL(request_firmware_nowait);
1180
1181#ifdef CONFIG_FW_CACHE
1182static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1183
1184/**
1185 * cache_firmware() - cache one firmware image in kernel memory space
1186 * @fw_name: the firmware image name
1187 *
1188 * Cache firmware in kernel memory so that drivers can use it when
1189 * system isn't ready for them to request firmware image from userspace.
1190 * Once it returns successfully, driver can use request_firmware or its
1191 * nowait version to get the cached firmware without any interacting
1192 * with userspace
1193 *
1194 * Return 0 if the firmware image has been cached successfully
1195 * Return !0 otherwise
1196 *
1197 */
1198static int cache_firmware(const char *fw_name)
1199{
1200	int ret;
1201	const struct firmware *fw;
1202
1203	pr_debug("%s: %s\n", __func__, fw_name);
1204
1205	ret = request_firmware(&fw, fw_name, NULL);
1206	if (!ret)
1207		kfree(fw);
1208
1209	pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1210
1211	return ret;
1212}
1213
1214static struct fw_priv *lookup_fw_priv(const char *fw_name)
1215{
1216	struct fw_priv *tmp;
1217	struct firmware_cache *fwc = &fw_cache;
1218
1219	spin_lock(&fwc->lock);
1220	tmp = __lookup_fw_priv(fw_name);
1221	spin_unlock(&fwc->lock);
1222
1223	return tmp;
1224}
1225
1226/**
1227 * uncache_firmware() - remove one cached firmware image
1228 * @fw_name: the firmware image name
1229 *
1230 * Uncache one firmware image which has been cached successfully
1231 * before.
1232 *
1233 * Return 0 if the firmware cache has been removed successfully
1234 * Return !0 otherwise
1235 *
1236 */
1237static int uncache_firmware(const char *fw_name)
1238{
1239	struct fw_priv *fw_priv;
1240	struct firmware fw;
1241
1242	pr_debug("%s: %s\n", __func__, fw_name);
1243
1244	if (firmware_request_builtin(&fw, fw_name))
1245		return 0;
1246
1247	fw_priv = lookup_fw_priv(fw_name);
1248	if (fw_priv) {
1249		free_fw_priv(fw_priv);
1250		return 0;
1251	}
1252
1253	return -EINVAL;
1254}
1255
1256static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1257{
1258	struct fw_cache_entry *fce;
1259
1260	fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1261	if (!fce)
1262		goto exit;
1263
1264	fce->name = kstrdup_const(name, GFP_ATOMIC);
1265	if (!fce->name) {
1266		kfree(fce);
1267		fce = NULL;
1268		goto exit;
1269	}
1270exit:
1271	return fce;
1272}
1273
1274static int __fw_entry_found(const char *name)
1275{
1276	struct firmware_cache *fwc = &fw_cache;
1277	struct fw_cache_entry *fce;
1278
1279	list_for_each_entry(fce, &fwc->fw_names, list) {
1280		if (!strcmp(fce->name, name))
1281			return 1;
1282	}
1283	return 0;
1284}
1285
1286static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1287{
1288	const char *name = fw_priv->fw_name;
1289	struct firmware_cache *fwc = fw_priv->fwc;
1290	struct fw_cache_entry *fce;
1291
1292	spin_lock(&fwc->name_lock);
1293	if (__fw_entry_found(name))
1294		goto found;
1295
1296	fce = alloc_fw_cache_entry(name);
1297	if (fce) {
1298		list_add(&fce->list, &fwc->fw_names);
1299		kref_get(&fw_priv->ref);
1300		pr_debug("%s: fw: %s\n", __func__, name);
1301	}
1302found:
1303	spin_unlock(&fwc->name_lock);
1304}
1305
1306static void free_fw_cache_entry(struct fw_cache_entry *fce)
1307{
1308	kfree_const(fce->name);
1309	kfree(fce);
1310}
1311
1312static void __async_dev_cache_fw_image(void *fw_entry,
1313				       async_cookie_t cookie)
1314{
1315	struct fw_cache_entry *fce = fw_entry;
1316	struct firmware_cache *fwc = &fw_cache;
1317	int ret;
1318
1319	ret = cache_firmware(fce->name);
1320	if (ret) {
1321		spin_lock(&fwc->name_lock);
1322		list_del(&fce->list);
1323		spin_unlock(&fwc->name_lock);
1324
1325		free_fw_cache_entry(fce);
1326	}
1327}
1328
1329/* called with dev->devres_lock held */
1330static void dev_create_fw_entry(struct device *dev, void *res,
1331				void *data)
1332{
1333	struct fw_name_devm *fwn = res;
1334	const char *fw_name = fwn->name;
1335	struct list_head *head = data;
1336	struct fw_cache_entry *fce;
1337
1338	fce = alloc_fw_cache_entry(fw_name);
1339	if (fce)
1340		list_add(&fce->list, head);
1341}
1342
1343static int devm_name_match(struct device *dev, void *res,
1344			   void *match_data)
1345{
1346	struct fw_name_devm *fwn = res;
1347	return (fwn->magic == (unsigned long)match_data);
1348}
1349
1350static void dev_cache_fw_image(struct device *dev, void *data)
1351{
1352	LIST_HEAD(todo);
1353	struct fw_cache_entry *fce;
1354	struct fw_cache_entry *fce_next;
1355	struct firmware_cache *fwc = &fw_cache;
1356
1357	devres_for_each_res(dev, fw_name_devm_release,
1358			    devm_name_match, &fw_cache,
1359			    dev_create_fw_entry, &todo);
1360
1361	list_for_each_entry_safe(fce, fce_next, &todo, list) {
1362		list_del(&fce->list);
1363
1364		spin_lock(&fwc->name_lock);
1365		/* only one cache entry for one firmware */
1366		if (!__fw_entry_found(fce->name)) {
1367			list_add(&fce->list, &fwc->fw_names);
1368		} else {
1369			free_fw_cache_entry(fce);
1370			fce = NULL;
1371		}
1372		spin_unlock(&fwc->name_lock);
1373
1374		if (fce)
1375			async_schedule_domain(__async_dev_cache_fw_image,
1376					      (void *)fce,
1377					      &fw_cache_domain);
1378	}
1379}
1380
1381static void __device_uncache_fw_images(void)
1382{
1383	struct firmware_cache *fwc = &fw_cache;
1384	struct fw_cache_entry *fce;
1385
1386	spin_lock(&fwc->name_lock);
1387	while (!list_empty(&fwc->fw_names)) {
1388		fce = list_entry(fwc->fw_names.next,
1389				struct fw_cache_entry, list);
1390		list_del(&fce->list);
1391		spin_unlock(&fwc->name_lock);
1392
1393		uncache_firmware(fce->name);
1394		free_fw_cache_entry(fce);
1395
1396		spin_lock(&fwc->name_lock);
1397	}
1398	spin_unlock(&fwc->name_lock);
1399}
1400
1401/**
1402 * device_cache_fw_images() - cache devices' firmware
1403 *
1404 * If one device called request_firmware or its nowait version
1405 * successfully before, the firmware names are recored into the
1406 * device's devres link list, so device_cache_fw_images can call
1407 * cache_firmware() to cache these firmwares for the device,
1408 * then the device driver can load its firmwares easily at
1409 * time when system is not ready to complete loading firmware.
1410 */
1411static void device_cache_fw_images(void)
1412{
1413	struct firmware_cache *fwc = &fw_cache;
1414	DEFINE_WAIT(wait);
1415
1416	pr_debug("%s\n", __func__);
1417
1418	/* cancel uncache work */
1419	cancel_delayed_work_sync(&fwc->work);
1420
1421	fw_fallback_set_cache_timeout();
1422
1423	mutex_lock(&fw_lock);
1424	fwc->state = FW_LOADER_START_CACHE;
1425	dpm_for_each_dev(NULL, dev_cache_fw_image);
1426	mutex_unlock(&fw_lock);
1427
1428	/* wait for completion of caching firmware for all devices */
1429	async_synchronize_full_domain(&fw_cache_domain);
1430
1431	fw_fallback_set_default_timeout();
1432}
1433
1434/**
1435 * device_uncache_fw_images() - uncache devices' firmware
1436 *
1437 * uncache all firmwares which have been cached successfully
1438 * by device_uncache_fw_images earlier
1439 */
1440static void device_uncache_fw_images(void)
1441{
1442	pr_debug("%s\n", __func__);
1443	__device_uncache_fw_images();
1444}
1445
1446static void device_uncache_fw_images_work(struct work_struct *work)
1447{
1448	device_uncache_fw_images();
1449}
1450
1451/**
1452 * device_uncache_fw_images_delay() - uncache devices firmwares
1453 * @delay: number of milliseconds to delay uncache device firmwares
1454 *
1455 * uncache all devices's firmwares which has been cached successfully
1456 * by device_cache_fw_images after @delay milliseconds.
1457 */
1458static void device_uncache_fw_images_delay(unsigned long delay)
1459{
1460	queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1461			   msecs_to_jiffies(delay));
1462}
1463
1464static int fw_pm_notify(struct notifier_block *notify_block,
1465			unsigned long mode, void *unused)
1466{
1467	switch (mode) {
1468	case PM_HIBERNATION_PREPARE:
1469	case PM_SUSPEND_PREPARE:
1470	case PM_RESTORE_PREPARE:
1471		/*
1472		 * kill pending fallback requests with a custom fallback
1473		 * to avoid stalling suspend.
1474		 */
1475		kill_pending_fw_fallback_reqs(true);
1476		device_cache_fw_images();
1477		break;
1478
1479	case PM_POST_SUSPEND:
1480	case PM_POST_HIBERNATION:
1481	case PM_POST_RESTORE:
1482		/*
1483		 * In case that system sleep failed and syscore_suspend is
1484		 * not called.
1485		 */
1486		mutex_lock(&fw_lock);
1487		fw_cache.state = FW_LOADER_NO_CACHE;
1488		mutex_unlock(&fw_lock);
1489
1490		device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1491		break;
1492	}
1493
1494	return 0;
1495}
1496
1497/* stop caching firmware once syscore_suspend is reached */
1498static int fw_suspend(void)
1499{
1500	fw_cache.state = FW_LOADER_NO_CACHE;
1501	return 0;
1502}
1503
1504static struct syscore_ops fw_syscore_ops = {
1505	.suspend = fw_suspend,
1506};
1507
1508static int __init register_fw_pm_ops(void)
1509{
1510	int ret;
1511
1512	spin_lock_init(&fw_cache.name_lock);
1513	INIT_LIST_HEAD(&fw_cache.fw_names);
1514
1515	INIT_DELAYED_WORK(&fw_cache.work,
1516			  device_uncache_fw_images_work);
1517
1518	fw_cache.pm_notify.notifier_call = fw_pm_notify;
1519	ret = register_pm_notifier(&fw_cache.pm_notify);
1520	if (ret)
1521		return ret;
1522
1523	register_syscore_ops(&fw_syscore_ops);
1524
1525	return ret;
1526}
1527
1528static inline void unregister_fw_pm_ops(void)
1529{
1530	unregister_syscore_ops(&fw_syscore_ops);
1531	unregister_pm_notifier(&fw_cache.pm_notify);
1532}
1533#else
1534static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1535{
1536}
1537static inline int register_fw_pm_ops(void)
1538{
1539	return 0;
1540}
1541static inline void unregister_fw_pm_ops(void)
1542{
1543}
1544#endif
1545
1546static void __init fw_cache_init(void)
1547{
1548	spin_lock_init(&fw_cache.lock);
1549	INIT_LIST_HEAD(&fw_cache.head);
1550	fw_cache.state = FW_LOADER_NO_CACHE;
1551}
1552
1553static int fw_shutdown_notify(struct notifier_block *unused1,
1554			      unsigned long unused2, void *unused3)
1555{
1556	/*
1557	 * Kill all pending fallback requests to avoid both stalling shutdown,
1558	 * and avoid a deadlock with the usermode_lock.
1559	 */
1560	kill_pending_fw_fallback_reqs(false);
1561
1562	return NOTIFY_DONE;
1563}
1564
1565static struct notifier_block fw_shutdown_nb = {
1566	.notifier_call = fw_shutdown_notify,
1567};
1568
1569static int __init firmware_class_init(void)
1570{
1571	int ret;
1572
1573	/* No need to unfold these on exit */
1574	fw_cache_init();
1575
1576	ret = register_fw_pm_ops();
1577	if (ret)
1578		return ret;
1579
1580	ret = register_reboot_notifier(&fw_shutdown_nb);
1581	if (ret)
1582		goto out;
1583
1584	return register_sysfs_loader();
1585
1586out:
1587	unregister_fw_pm_ops();
1588	return ret;
1589}
1590
1591static void __exit firmware_class_exit(void)
1592{
1593	unregister_fw_pm_ops();
1594	unregister_reboot_notifier(&fw_shutdown_nb);
1595	unregister_sysfs_loader();
1596}
1597
1598fs_initcall(firmware_class_init);
1599module_exit(firmware_class_exit);