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 */
 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	FW_OPT_PARTIAL			= BIT(7),
 45};
 46
 47enum 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 */
 59struct fw_state {
 60	struct completion completion;
 61	enum fw_status status;
 62};
 63
 64struct 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
 87extern struct mutex fw_lock;
 88extern struct firmware_cache fw_cache;
 89
 90static inline bool __fw_state_check(struct fw_priv *fw_priv,
 91				    enum fw_status status)
 92{
 93	struct fw_state *fw_st = &fw_priv->fw_st;
 94
 95	return fw_st->status == status;
 96}
 97
 98static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
 99{
100	struct fw_state *fw_st = &fw_priv->fw_st;
101	long ret;
102
103	ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
104	if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
105		return -ENOENT;
106	if (!ret)
107		return -ETIMEDOUT;
108
109	return ret < 0 ? ret : 0;
110}
111
112static inline void __fw_state_set(struct fw_priv *fw_priv,
113				  enum fw_status status)
114{
115	struct fw_state *fw_st = &fw_priv->fw_st;
116
117	WRITE_ONCE(fw_st->status, status);
118
119	if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) {
120#ifdef CONFIG_FW_LOADER_USER_HELPER
121		/*
122		 * Doing this here ensures that the fw_priv is deleted from
123		 * the pending list in all abort/done paths.
124		 */
125		list_del_init(&fw_priv->pending_list);
126#endif
127		complete_all(&fw_st->completion);
128	}
129}
130
131static inline void fw_state_aborted(struct fw_priv *fw_priv)
132{
133	__fw_state_set(fw_priv, FW_STATUS_ABORTED);
134}
135
136static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
137{
138	return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
139}
140
141static inline void fw_state_start(struct fw_priv *fw_priv)
142{
143	__fw_state_set(fw_priv, FW_STATUS_LOADING);
144}
145
146static inline void fw_state_done(struct fw_priv *fw_priv)
147{
148	__fw_state_set(fw_priv, FW_STATUS_DONE);
149}
150
151static inline bool fw_state_is_done(struct fw_priv *fw_priv)
152{
153	return __fw_state_check(fw_priv, FW_STATUS_DONE);
154}
155
156static inline bool fw_state_is_loading(struct fw_priv *fw_priv)
157{
158	return __fw_state_check(fw_priv, FW_STATUS_LOADING);
159}
160
161int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
162			 struct fw_priv **fw_priv, void *dbuf, size_t size,
163			 size_t offset, u32 opt_flags);
164int assign_fw(struct firmware *fw, struct device *device);
165void free_fw_priv(struct fw_priv *fw_priv);
166void fw_state_init(struct fw_priv *fw_priv);
167
168#ifdef CONFIG_FW_LOADER
169bool firmware_is_builtin(const struct firmware *fw);
170bool firmware_request_builtin_buf(struct firmware *fw, const char *name,
171				  void *buf, size_t size);
172#else /* module case */
173static inline bool firmware_is_builtin(const struct firmware *fw)
174{
175	return false;
176}
177static inline bool firmware_request_builtin_buf(struct firmware *fw,
178						const char *name,
179						void *buf, size_t size)
180{
181	return false;
182}
183#endif
184
185#ifdef CONFIG_FW_LOADER_PAGED_BUF
186void fw_free_paged_buf(struct fw_priv *fw_priv);
187int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
188int fw_map_paged_buf(struct fw_priv *fw_priv);
189bool fw_is_paged_buf(struct fw_priv *fw_priv);
190#else
191static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
192static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
193static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
194static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
195#endif
196
197#endif /* __FIRMWARE_LOADER_H */