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_SYSFS: Disable the sysfs fallback mechanism. Takes
  31 *      precedence over &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
  32 * @FW_OPT_FALLBACK_PLATFORM: Enable fallback to device fw copy embedded in
  33 *      the platform's main firmware. If both this fallback and the sysfs
  34 *      fallback are enabled, then this fallback will be tried first.
  35 */
  36enum fw_opt {
  37        FW_OPT_UEVENT                   = BIT(0),
  38        FW_OPT_NOWAIT                   = BIT(1),
  39        FW_OPT_USERHELPER               = BIT(2),
  40        FW_OPT_NO_WARN                  = BIT(3),
  41        FW_OPT_NOCACHE                  = BIT(4),
  42        FW_OPT_NOFALLBACK_SYSFS         = BIT(5),
  43        FW_OPT_FALLBACK_PLATFORM        = BIT(6),
  44};
  45
  46enum fw_status {
  47        FW_STATUS_UNKNOWN,
  48        FW_STATUS_LOADING,
  49        FW_STATUS_DONE,
  50        FW_STATUS_ABORTED,
  51};
  52
  53/*
  54 * Concurrent request_firmware() for the same firmware need to be
  55 * serialized.  struct fw_state is simple state machine which hold the
  56 * state of the firmware loading.
  57 */
  58struct fw_state {
  59        struct completion completion;
  60        enum fw_status status;
  61};
  62
  63struct fw_priv {
  64        struct kref ref;
  65        struct list_head list;
  66        struct firmware_cache *fwc;
  67        struct fw_state fw_st;
  68        void *data;
  69        size_t size;
  70        size_t allocated_size;
  71#ifdef CONFIG_FW_LOADER_PAGED_BUF
  72        bool is_paged_buf;
  73        struct page **pages;
  74        int nr_pages;
  75        int page_array_size;
  76#endif
  77#ifdef CONFIG_FW_LOADER_USER_HELPER
  78        bool need_uevent;
  79        struct list_head pending_list;
  80#endif
  81        const char *fw_name;
  82};
  83
  84extern struct mutex fw_lock;
  85
  86static inline bool __fw_state_check(struct fw_priv *fw_priv,
  87                                    enum fw_status status)
  88{
  89        struct fw_state *fw_st = &fw_priv->fw_st;
  90
  91        return fw_st->status == status;
  92}
  93
  94static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
  95{
  96        struct fw_state *fw_st = &fw_priv->fw_st;
  97        long ret;
  98
  99        ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
 100        if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
 101                return -ENOENT;
 102        if (!ret)
 103                return -ETIMEDOUT;
 104
 105        return ret < 0 ? ret : 0;
 106}
 107
 108static inline void __fw_state_set(struct fw_priv *fw_priv,
 109                                  enum fw_status status)
 110{
 111        struct fw_state *fw_st = &fw_priv->fw_st;
 112
 113        WRITE_ONCE(fw_st->status, status);
 114
 115        if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
 116                complete_all(&fw_st->completion);
 117}
 118
 119static inline void fw_state_aborted(struct fw_priv *fw_priv)
 120{
 121        __fw_state_set(fw_priv, FW_STATUS_ABORTED);
 122}
 123
 124static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
 125{
 126        return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
 127}
 128
 129static inline void fw_state_start(struct fw_priv *fw_priv)
 130{
 131        __fw_state_set(fw_priv, FW_STATUS_LOADING);
 132}
 133
 134static inline void fw_state_done(struct fw_priv *fw_priv)
 135{
 136        __fw_state_set(fw_priv, FW_STATUS_DONE);
 137}
 138
 139int assign_fw(struct firmware *fw, struct device *device, u32 opt_flags);
 140
 141#ifdef CONFIG_FW_LOADER_PAGED_BUF
 142void fw_free_paged_buf(struct fw_priv *fw_priv);
 143int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
 144int fw_map_paged_buf(struct fw_priv *fw_priv);
 145bool fw_is_paged_buf(struct fw_priv *fw_priv);
 146#else
 147static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
 148static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
 149static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
 150static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
 151#endif
 152
 153#endif /* __FIRMWARE_LOADER_H */
 154