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  */
36 enum 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 
47 enum 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  */
59 struct fw_state {
60 	struct completion completion;
61 	enum fw_status status;
62 };
63 
64 struct 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 
87 extern struct mutex fw_lock;
88 extern struct firmware_cache fw_cache;
89 
90 static 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 
98 static 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 
112 static 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 
131 static inline void fw_state_aborted(struct fw_priv *fw_priv)
132 {
133 	__fw_state_set(fw_priv, FW_STATUS_ABORTED);
134 }
135 
136 static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
137 {
138 	return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
139 }
140 
141 static inline void fw_state_start(struct fw_priv *fw_priv)
142 {
143 	__fw_state_set(fw_priv, FW_STATUS_LOADING);
144 }
145 
146 static inline void fw_state_done(struct fw_priv *fw_priv)
147 {
148 	__fw_state_set(fw_priv, FW_STATUS_DONE);
149 }
150 
151 static inline bool fw_state_is_done(struct fw_priv *fw_priv)
152 {
153 	return __fw_state_check(fw_priv, FW_STATUS_DONE);
154 }
155 
156 static inline bool fw_state_is_loading(struct fw_priv *fw_priv)
157 {
158 	return __fw_state_check(fw_priv, FW_STATUS_LOADING);
159 }
160 
161 int 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);
164 int assign_fw(struct firmware *fw, struct device *device);
165 void free_fw_priv(struct fw_priv *fw_priv);
166 void fw_state_init(struct fw_priv *fw_priv);
167 
168 #ifdef CONFIG_FW_LOADER
169 bool firmware_is_builtin(const struct firmware *fw);
170 bool firmware_request_builtin_buf(struct firmware *fw, const char *name,
171 				  void *buf, size_t size);
172 #else /* module case */
173 static inline bool firmware_is_builtin(const struct firmware *fw)
174 {
175 	return false;
176 }
177 static 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
186 void fw_free_paged_buf(struct fw_priv *fw_priv);
187 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
188 int fw_map_paged_buf(struct fw_priv *fw_priv);
189 bool fw_is_paged_buf(struct fw_priv *fw_priv);
190 #else
191 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
192 static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
193 static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
194 static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
195 #endif
196 
197 #endif /* __FIRMWARE_LOADER_H */
198