LXR linux/drivers/base/firmware

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __FIRMWARE_LOADER_H
   3#define __FIRMWARE_LOADER_H
   4
   5#include <linux/bitops.h>
   6#include <linux/firmware.h>
   7#include <linux/types.h>
   8#include <linux/kref.h>
   9#include <linux/list.h>
  10#include <linux/completion.h>
  11
  12#include <generated/utsrelease.h>
  13
  14/**
  15 * enum fw_opt - options to control firmware loading behaviour
  16 *
  17 * @FW_OPT_UEVENT: Enables the fallback mechanism to send a kobject uevent
  18 *      when the firmware is not found. Userspace is in charge to load the
  19 *      firmware using the sysfs loading facility.
  20 * @FW_OPT_NOWAIT: Used to describe the firmware request is asynchronous.
  21 * @FW_OPT_USERHELPER: Enable the fallback mechanism, in case the direct
  22 *      filesystem lookup fails at finding the firmware.  For details refer to
  23 *      firmware_fallback_sysfs().
  24 * @FW_OPT_NO_WARN: Quiet, avoid printing warning messages.
  25 * @FW_OPT_NOCACHE: Disables firmware caching. Firmware caching is used to
  26 *      cache the firmware upon suspend, so that upon resume races against the
  27 *      firmware file lookup on storage is avoided. Used for calls where the
  28 *      file may be too big, or where the driver takes charge of its own
  29 *      firmware caching mechanism.
  30 * @FW_OPT_NOFALLBACK: Disable the fallback mechanism. Takes precedence over
  31 *      &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
  32 */
  33enum fw_opt {
  34        FW_OPT_UEVENT =         BIT(0),
  35        FW_OPT_NOWAIT =         BIT(1),
  36        FW_OPT_USERHELPER =     BIT(2),
  37        FW_OPT_NO_WARN =        BIT(3),
  38        FW_OPT_NOCACHE =        BIT(4),
  39        FW_OPT_NOFALLBACK =     BIT(5),
  40};
  41
  42enum fw_status {
  43        FW_STATUS_UNKNOWN,
  44        FW_STATUS_LOADING,
  45        FW_STATUS_DONE,
  46        FW_STATUS_ABORTED,
  47};
  48
  49/*
  50 * Concurrent request_firmware() for the same firmware need to be
  51 * serialized.  struct fw_state is simple state machine which hold the
  52 * state of the firmware loading.
  53 */
  54struct fw_state {
  55        struct completion completion;
  56        enum fw_status status;
  57};
  58
  59struct fw_priv {
  60        struct kref ref;
  61        struct list_head list;
  62        struct firmware_cache *fwc;
  63        struct fw_state fw_st;
  64        void *data;
  65        size_t size;
  66        size_t allocated_size;
  67#ifdef CONFIG_FW_LOADER_USER_HELPER
  68        bool is_paged_buf;
  69        bool need_uevent;
  70        struct page **pages;
  71        int nr_pages;
  72        int page_array_size;
  73        struct list_head pending_list;
  74#endif
  75        const char *fw_name;
  76};
  77
  78extern struct mutex fw_lock;
  79
  80static inline bool __fw_state_check(struct fw_priv *fw_priv,
  81                                    enum fw_status status)
  82{
  83        struct fw_state *fw_st = &fw_priv->fw_st;
  84
  85        return fw_st->status == status;
  86}
  87
  88static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
  89{
  90        struct fw_state *fw_st = &fw_priv->fw_st;
  91        long ret;
  92
  93        ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
  94        if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
  95                return -ENOENT;
  96        if (!ret)
  97                return -ETIMEDOUT;
  98
  99        return ret < 0 ? ret : 0;
 100}
 101
 102static inline void __fw_state_set(struct fw_priv *fw_priv,
 103                                  enum fw_status status)
 104{
 105        struct fw_state *fw_st = &fw_priv->fw_st;
 106
 107        WRITE_ONCE(fw_st->status, status);
 108
 109        if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
 110                complete_all(&fw_st->completion);
 111}
 112
 113static inline void fw_state_aborted(struct fw_priv *fw_priv)
 114{
 115        __fw_state_set(fw_priv, FW_STATUS_ABORTED);
 116}
 117
 118static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
 119{
 120        return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
 121}
 122
 123static inline void fw_state_start(struct fw_priv *fw_priv)
 124{
 125        __fw_state_set(fw_priv, FW_STATUS_LOADING);
 126}
 127
 128static inline void fw_state_done(struct fw_priv *fw_priv)
 129{
 130        __fw_state_set(fw_priv, FW_STATUS_DONE);
 131}
 132
 133int assign_fw(struct firmware *fw, struct device *device,
 134              enum fw_opt opt_flags);
 135
 136#endif /* __FIRMWARE_LOADER_H */
 137