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 /**
  13  * enum fw_opt - options to control firmware loading behaviour
  14  *
  15  * @FW_OPT_UEVENT: Enables the fallback mechanism to send a kobject uevent
  16  *      when the firmware is not found. Userspace is in charge to load the
  17  *      firmware using the sysfs loading facility.
  18  * @FW_OPT_NOWAIT: Used to describe the firmware request is asynchronous.
  19  * @FW_OPT_USERHELPER: Enable the fallback mechanism, in case the direct
  20  *      filesystem lookup fails at finding the firmware.  For details refer to
  21  *      firmware_fallback_sysfs().
  22  * @FW_OPT_NO_WARN: Quiet, avoid printing warning messages.
  23  * @FW_OPT_NOCACHE: Disables firmware caching. Firmware caching is used to
  24  *      cache the firmware upon suspend, so that upon resume races against the
  25  *      firmware file lookup on storage is avoided. Used for calls where the
  26  *      file may be too big, or where the driver takes charge of its own
  27  *      firmware caching mechanism.
  28  * @FW_OPT_NOFALLBACK_SYSFS: Disable the sysfs fallback mechanism. Takes
  29  *      precedence over &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
  30  * @FW_OPT_FALLBACK_PLATFORM: Enable fallback to device fw copy embedded in
  31  *      the platform's main firmware. If both this fallback and the sysfs
  32  *      fallback are enabled, then this fallback will be tried first.
  33  * @FW_OPT_PARTIAL: Allow partial read of firmware instead of needing to read
  34  *      entire file.
  35  */
  36 enum 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         FW_OPT_PARTIAL                  = BIT(7),
  45 };
  46
  47 enum fw_status {
  48         FW_STATUS_UNKNOWN,
  49         FW_STATUS_LOADING,
  50         FW_STATUS_DONE,
  51         FW_STATUS_ABORTED,
  52 };
  53
  54 /*
  55  * Concurrent request_firmware() for the same firmware need to be
  56  * serialized.  struct fw_state is simple state machine which hold the
  57  * state of the firmware loading.
  58  */
  59 struct fw_state {
  60         struct completion completion;
  61         enum fw_status status;
  62 };
  63
  64 struct fw_priv {
  65         struct kref ref;
  66         struct list_head list;
  67         struct firmware_cache *fwc;
  68         struct fw_state fw_st;
  69         void *data;
  70         size_t size;
  71         size_t allocated_size;
  72         size_t offset;
  73         u32 opt_flags;
  74 #ifdef CONFIG_FW_LOADER_PAGED_BUF
  75         bool is_paged_buf;
  76         struct page **pages;
  77         int nr_pages;
  78         int page_array_size;
  79 #endif
  80 #ifdef CONFIG_FW_LOADER_USER_HELPER
  81         bool need_uevent;
  82         struct list_head pending_list;
  83 #endif
  84         const char *fw_name;
  85 };
  86
  87 extern struct mutex fw_lock;
  88 extern struct firmware_cache fw_cache;
  89 extern bool fw_load_abort_all;
  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 #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
 132 static inline void fw_state_aborted(struct fw_priv *fw_priv)
 133 {
 134         __fw_state_set(fw_priv, FW_STATUS_ABORTED);
 135 }
 136
 137 static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
 138 {
 139         return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
 140 }
 141
 142 static inline void fw_state_start(struct fw_priv *fw_priv)
 143 {
 144         __fw_state_set(fw_priv, FW_STATUS_LOADING);
 145 }
 146
 147 static inline void fw_state_done(struct fw_priv *fw_priv)
 148 {
 149         __fw_state_set(fw_priv, FW_STATUS_DONE);
 150 }
 151
 152 static inline bool fw_state_is_done(struct fw_priv *fw_priv)
 153 {
 154         return __fw_state_check(fw_priv, FW_STATUS_DONE);
 155 }
 156
 157 static inline bool fw_state_is_loading(struct fw_priv *fw_priv)
 158 {
 159         return __fw_state_check(fw_priv, FW_STATUS_LOADING);
 160 }
 161
 162 int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
 163                          struct fw_priv **fw_priv, void *dbuf, size_t size,
 164                          size_t offset, u32 opt_flags);
 165 int assign_fw(struct firmware *fw, struct device *device);
 166 void free_fw_priv(struct fw_priv *fw_priv);
 167 void fw_state_init(struct fw_priv *fw_priv);
 168
 169 #ifdef CONFIG_FW_LOADER
 170 bool firmware_is_builtin(const struct firmware *fw);
 171 bool firmware_request_builtin_buf(struct firmware *fw, const char *name,
 172                                   void *buf, size_t size);
 173 #else /* module case */
 174 static inline bool firmware_is_builtin(const struct firmware *fw)
 175 {
 176         return false;
 177 }
 178 static inline bool firmware_request_builtin_buf(struct firmware *fw,
 179                                                 const char *name,
 180                                                 void *buf, size_t size)
 181 {
 182         return false;
 183 }
 184 #endif
 185
 186 #ifdef CONFIG_FW_LOADER_PAGED_BUF
 187 void fw_free_paged_buf(struct fw_priv *fw_priv);
 188 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
 189 int fw_map_paged_buf(struct fw_priv *fw_priv);
 190 bool fw_is_paged_buf(struct fw_priv *fw_priv);
 191 #else
 192 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
 193 static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
 194 static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
 195 static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
 196 #endif
 197
 198 #endif /* __FIRMWARE_LOADER_H */