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: Disable the fallback mechanism. Takes precedence over
  31  *      &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
  32  */
  33 enum 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
  42 enum 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  */
  54 struct fw_state {
  55         struct completion completion;
  56         enum fw_status status;
  57 };
  58
  59 struct 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
  78 extern struct mutex fw_lock;
  79
  80 static 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
  88 static 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
 102 static 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
 113 static inline void fw_state_aborted(struct fw_priv *fw_priv)
 114 {
 115         __fw_state_set(fw_priv, FW_STATUS_ABORTED);
 116 }
 117
 118 static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
 119 {
 120         return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
 121 }
 122
 123 static inline void fw_state_start(struct fw_priv *fw_priv)
 124 {
 125         __fw_state_set(fw_priv, FW_STATUS_LOADING);
 126 }
 127
 128 static inline void fw_state_done(struct fw_priv *fw_priv)
 129 {
 130         __fw_state_set(fw_priv, FW_STATUS_DONE);
 131 }
 132
 133 int assign_fw(struct firmware *fw, struct device *device,
 134               enum fw_opt opt_flags);
 135
 136 #endif /* __FIRMWARE_LOADER_H */