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 * @FW_OPT_PARTIAL: Allow partial read of firmware instead of needing to read
  36 *      entire file.
  37 */
  38enum fw_opt {
  39        FW_OPT_UEVENT                   = BIT(0),
  40        FW_OPT_NOWAIT                   = BIT(1),
  41        FW_OPT_USERHELPER               = BIT(2),
  42        FW_OPT_NO_WARN                  = BIT(3),
  43        FW_OPT_NOCACHE                  = BIT(4),
  44        FW_OPT_NOFALLBACK_SYSFS         = BIT(5),
  45        FW_OPT_FALLBACK_PLATFORM        = BIT(6),
  46        FW_OPT_PARTIAL                  = BIT(7),
  47};
  48
  49enum fw_status {
  50        FW_STATUS_UNKNOWN,
  51        FW_STATUS_LOADING,
  52        FW_STATUS_DONE,
  53        FW_STATUS_ABORTED,
  54};
  55
  56/*
  57 * Concurrent request_firmware() for the same firmware need to be
  58 * serialized.  struct fw_state is simple state machine which hold the
  59 * state of the firmware loading.
  60 */
  61struct fw_state {
  62        struct completion completion;
  63        enum fw_status status;
  64};
  65
  66struct fw_priv {
  67        struct kref ref;
  68        struct list_head list;
  69        struct firmware_cache *fwc;
  70        struct fw_state fw_st;
  71        void *data;
  72        size_t size;
  73        size_t allocated_size;
  74        size_t offset;
  75        u32 opt_flags;
  76#ifdef CONFIG_FW_LOADER_PAGED_BUF
  77        bool is_paged_buf;
  78        struct page **pages;
  79        int nr_pages;
  80        int page_array_size;
  81#endif
  82#ifdef CONFIG_FW_LOADER_USER_HELPER
  83        bool need_uevent;
  84        struct list_head pending_list;
  85#endif
  86        const char *fw_name;
  87};
  88
  89extern struct mutex fw_lock;
  90
  91static inline bool __fw_state_check(struct fw_priv *fw_priv,
  92                                    enum fw_status status)
  93{
  94        struct fw_state *fw_st = &fw_priv->fw_st;
  95
  96        return fw_st->status == status;
  97}
  98
  99static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
 100{
 101        struct fw_state *fw_st = &fw_priv->fw_st;
 102        long ret;
 103
 104        ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
 105        if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
 106                return -ENOENT;
 107        if (!ret)
 108                return -ETIMEDOUT;
 109
 110        return ret < 0 ? ret : 0;
 111}
 112
 113static inline void __fw_state_set(struct fw_priv *fw_priv,
 114                                  enum fw_status status)
 115{
 116        struct fw_state *fw_st = &fw_priv->fw_st;
 117
 118        WRITE_ONCE(fw_st->status, status);
 119
 120        if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) {
 121#ifdef CONFIG_FW_LOADER_USER_HELPER
 122                /*
 123                 * Doing this here ensures that the fw_priv is deleted from
 124                 * the pending list in all abort/done paths.
 125                 */
 126                list_del_init(&fw_priv->pending_list);
 127#endif
 128                complete_all(&fw_st->completion);
 129        }
 130}
 131
 132static inline void fw_state_aborted(struct fw_priv *fw_priv)
 133{
 134        __fw_state_set(fw_priv, FW_STATUS_ABORTED);
 135}
 136
 137static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
 138{
 139        return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
 140}
 141
 142static inline void fw_state_start(struct fw_priv *fw_priv)
 143{
 144        __fw_state_set(fw_priv, FW_STATUS_LOADING);
 145}
 146
 147static inline void fw_state_done(struct fw_priv *fw_priv)
 148{
 149        __fw_state_set(fw_priv, FW_STATUS_DONE);
 150}
 151
 152int assign_fw(struct firmware *fw, struct device *device);
 153
 154#ifdef CONFIG_FW_LOADER_PAGED_BUF
 155void fw_free_paged_buf(struct fw_priv *fw_priv);
 156int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
 157int fw_map_paged_buf(struct fw_priv *fw_priv);
 158bool fw_is_paged_buf(struct fw_priv *fw_priv);
 159#else
 160static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
 161static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
 162static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
 163static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
 164#endif
 165
 166#endif /* __FIRMWARE_LOADER_H */
 167