firmware_class.c

/*
 * firmware_class.c - Multi purpose firmware loading support
 *
 * Copyright (c) 2003 Manuel Estrada Sainz
 *
 * Please see Documentation/firmware_class/ for more information.
 *
 */

#include <linux/capability.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/vmalloc.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/highmem.h>
#include <linux/firmware.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/list.h>
#include <linux/async.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/reboot.h>

#include <generated/utsrelease.h>

#include "base.h"

MODULE_AUTHOR("Manuel Estrada Sainz");
MODULE_DESCRIPTION("Multi purpose firmware loading support");
MODULE_LICENSE("GPL");

/* Builtin firmware support */

#ifdef CONFIG_FW_LOADER

extern struct builtin_fw __start_builtin_fw[];
extern struct builtin_fw __end_builtin_fw[];

static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
{
	struct builtin_fw *b_fw;

	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
		if (strcmp(name, b_fw->name) == 0) {
			fw->size = b_fw->size;
			fw->data = b_fw->data;
			return true;
		}
	}

	return false;
}

static bool fw_is_builtin_firmware(const struct firmware *fw)
{
	struct builtin_fw *b_fw;

	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
		if (fw->data == b_fw->data)
			return true;

	return false;
}

#else /* Module case - no builtin firmware support */

static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
{
	return false;
}

static inline bool fw_is_builtin_firmware(const struct firmware *fw)
{
	return false;
}
#endif

enum {
	FW_STATUS_LOADING,
	FW_STATUS_DONE,
	FW_STATUS_ABORT,
};

static int loading_timeout = 60;	/* In seconds */

static inline long firmware_loading_timeout(void)
{
	return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
}

struct firmware_cache {
	/* firmware_buf instance will be added into the below list */
	spinlock_t lock;
	struct list_head head;
	int state;

#ifdef CONFIG_PM_SLEEP
	/*
	 * Names of firmware images which have been cached successfully
	 * will be added into the below list so that device uncache
	 * helper can trace which firmware images have been cached
	 * before.
	 */
	spinlock_t name_lock;
	struct list_head fw_names;

	struct delayed_work work;

	struct notifier_block   pm_notify;
#endif
};

struct firmware_buf {
	struct kref ref;
	struct list_head list;
	struct completion completion;
	struct firmware_cache *fwc;
	unsigned long status;
	void *data;
	size_t size;
#ifdef CONFIG_FW_LOADER_USER_HELPER
	bool is_paged_buf;
	bool need_uevent;
	struct page **pages;
	int nr_pages;
	int page_array_size;
	struct list_head pending_list;
#endif
	char fw_id[];
};

struct fw_cache_entry {
	struct list_head list;
	char name[];
};

struct fw_name_devm {
	unsigned long magic;
	char name[];
};

#define to_fwbuf(d) container_of(d, struct firmware_buf, ref)

#define	FW_LOADER_NO_CACHE	0
#define	FW_LOADER_START_CACHE	1

static int fw_cache_piggyback_on_request(const char *name);

/* fw_lock could be moved to 'struct firmware_priv' but since it is just
 * guarding for corner cases a global lock should be OK */
static DEFINE_MUTEX(fw_lock);

static struct firmware_cache fw_cache;

static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
					      struct firmware_cache *fwc)
{
	struct firmware_buf *buf;

	buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1 , GFP_ATOMIC);

	if (!buf)
		return buf;

	kref_init(&buf->ref);
	strcpy(buf->fw_id, fw_name);
	buf->fwc = fwc;
	init_completion(&buf->completion);
#ifdef CONFIG_FW_LOADER_USER_HELPER
	INIT_LIST_HEAD(&buf->pending_list);
#endif

	pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);

	return buf;
}

static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
{
	struct firmware_buf *tmp;
	struct firmware_cache *fwc = &fw_cache;

	list_for_each_entry(tmp, &fwc->head, list)
		if (!strcmp(tmp->fw_id, fw_name))
			return tmp;
	return NULL;
}

static int fw_lookup_and_allocate_buf(const char *fw_name,
				      struct firmware_cache *fwc,
				      struct firmware_buf **buf)
{