drivers/base/firmware_loader/firmware.h

   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  */
  38 enum 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
  49 enum 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  */
  61 struct fw_state {
  62         struct completion completion;
  63         enum fw_status status;
  64 };
  65
  66 struct 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
  89 extern struct mutex fw_lock;
  90
  91 static 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
  99 static 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
 113 static 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                 complete_all(&fw_st->completion);
 122 }
 123
 124 static inline void fw_state_aborted(struct fw_priv *fw_priv)
 125 {
 126         __fw_state_set(fw_priv, FW_STATUS_ABORTED);
 127 }
 128
 129 static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
 130 {
 131         return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
 132 }
 133
 134 static inline void fw_state_start(struct fw_priv *fw_priv)
 135 {
 136         __fw_state_set(fw_priv, FW_STATUS_LOADING);
 137 }
 138
 139 static inline void fw_state_done(struct fw_priv *fw_priv)
 140 {
 141         __fw_state_set(fw_priv, FW_STATUS_DONE);
 142 }
 143
 144 int assign_fw(struct firmware *fw, struct device *device);
 145
 146 #ifdef CONFIG_FW_LOADER_PAGED_BUF
 147 void fw_free_paged_buf(struct fw_priv *fw_priv);
 148 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
 149 int fw_map_paged_buf(struct fw_priv *fw_priv);
 150 bool fw_is_paged_buf(struct fw_priv *fw_priv);
 151 #else
 152 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
 153 static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
 154 static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
 155 static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
 156 #endif
 157
 158 #endif /* __FIRMWARE_LOADER_H */