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 */
 33enum 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
 42enum 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 */
 54struct fw_state {
 55	struct completion completion;
 56	enum fw_status status;
 57};
 58
 59struct 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_PAGED_BUF
 68	bool is_paged_buf;
 69	struct page **pages;
 70	int nr_pages;
 71	int page_array_size;
 72#endif
 73#ifdef CONFIG_FW_LOADER_USER_HELPER
 74	bool need_uevent;
 75	struct list_head pending_list;
 76#endif
 77	const char *fw_name;
 78};
 79
 80extern struct mutex fw_lock;
 81
 82static inline bool __fw_state_check(struct fw_priv *fw_priv,
 83				    enum fw_status status)
 84{
 85	struct fw_state *fw_st = &fw_priv->fw_st;
 86
 87	return fw_st->status == status;
 88}
 89
 90static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
 91{
 92	struct fw_state *fw_st = &fw_priv->fw_st;
 93	long ret;
 94
 95	ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
 96	if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
 97		return -ENOENT;
 98	if (!ret)
 99		return -ETIMEDOUT;
100
101	return ret < 0 ? ret : 0;
102}
103
104static inline void __fw_state_set(struct fw_priv *fw_priv,
105				  enum fw_status status)
106{
107	struct fw_state *fw_st = &fw_priv->fw_st;
108
109	WRITE_ONCE(fw_st->status, status);
110
111	if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
112		complete_all(&fw_st->completion);
113}
114
115static inline void fw_state_aborted(struct fw_priv *fw_priv)
116{
117	__fw_state_set(fw_priv, FW_STATUS_ABORTED);
118}
119
120static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
121{
122	return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
123}
124
125static inline void fw_state_start(struct fw_priv *fw_priv)
126{
127	__fw_state_set(fw_priv, FW_STATUS_LOADING);
128}
129
130static inline void fw_state_done(struct fw_priv *fw_priv)
131{
132	__fw_state_set(fw_priv, FW_STATUS_DONE);
133}
134
135int assign_fw(struct firmware *fw, struct device *device,
136	      enum fw_opt opt_flags);
137
138#ifdef CONFIG_FW_LOADER_PAGED_BUF
139void fw_free_paged_buf(struct fw_priv *fw_priv);
140int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
141int fw_map_paged_buf(struct fw_priv *fw_priv);
142#else
143static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
144static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
145static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
146#endif
147
148#endif /* __FIRMWARE_LOADER_H */