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 */
 36enum 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};
 45
 46enum fw_status {
 47	FW_STATUS_UNKNOWN,
 48	FW_STATUS_LOADING,
 49	FW_STATUS_DONE,
 50	FW_STATUS_ABORTED,
 51};
 52
 53/*
 54 * Concurrent request_firmware() for the same firmware need to be
 55 * serialized.  struct fw_state is simple state machine which hold the
 56 * state of the firmware loading.
 57 */
 58struct fw_state {
 59	struct completion completion;
 60	enum fw_status status;
 61};
 62
 63struct fw_priv {
 64	struct kref ref;
 65	struct list_head list;
 66	struct firmware_cache *fwc;
 67	struct fw_state fw_st;
 68	void *data;
 69	size_t size;
 70	size_t allocated_size;
 71#ifdef CONFIG_FW_LOADER_PAGED_BUF
 72	bool is_paged_buf;
 73	struct page **pages;
 74	int nr_pages;
 75	int page_array_size;
 76#endif
 77#ifdef CONFIG_FW_LOADER_USER_HELPER
 78	bool need_uevent;
 79	struct list_head pending_list;
 80#endif
 81	const char *fw_name;
 82};
 83
 84extern struct mutex fw_lock;
 85
 86static inline bool __fw_state_check(struct fw_priv *fw_priv,
 87				    enum fw_status status)
 88{
 89	struct fw_state *fw_st = &fw_priv->fw_st;
 90
 91	return fw_st->status == status;
 92}
 93
 94static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
 95{
 96	struct fw_state *fw_st = &fw_priv->fw_st;
 97	long ret;
 98
 99	ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
100	if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
101		return -ENOENT;
102	if (!ret)
103		return -ETIMEDOUT;
104
105	return ret < 0 ? ret : 0;
106}
107
108static inline void __fw_state_set(struct fw_priv *fw_priv,
109				  enum fw_status status)
110{
111	struct fw_state *fw_st = &fw_priv->fw_st;
112
113	WRITE_ONCE(fw_st->status, status);
114
115	if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
116		complete_all(&fw_st->completion);
117}
118
119static inline void fw_state_aborted(struct fw_priv *fw_priv)
120{
121	__fw_state_set(fw_priv, FW_STATUS_ABORTED);
122}
123
124static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
125{
126	return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
127}
128
129static inline void fw_state_start(struct fw_priv *fw_priv)
130{
131	__fw_state_set(fw_priv, FW_STATUS_LOADING);
132}
133
134static inline void fw_state_done(struct fw_priv *fw_priv)
135{
136	__fw_state_set(fw_priv, FW_STATUS_DONE);
137}
138
139int assign_fw(struct firmware *fw, struct device *device, u32 opt_flags);
140
141#ifdef CONFIG_FW_LOADER_PAGED_BUF
142void fw_free_paged_buf(struct fw_priv *fw_priv);
143int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
144int fw_map_paged_buf(struct fw_priv *fw_priv);
145bool fw_is_paged_buf(struct fw_priv *fw_priv);
146#else
147static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
148static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
149static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
150static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
151#endif
152
153#endif /* __FIRMWARE_LOADER_H */