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 */
198