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
__fw_state_check(struct fw_priv * fw_priv,enum fw_status status)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
__fw_state_wait_common(struct fw_priv * fw_priv,long timeout)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
__fw_state_set(struct fw_priv * fw_priv,enum fw_status status)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
fw_state_aborted(struct fw_priv * fw_priv)131 static inline void fw_state_aborted(struct fw_priv *fw_priv)
132 {
133 __fw_state_set(fw_priv, FW_STATUS_ABORTED);
134 }
135
fw_state_is_aborted(struct fw_priv * fw_priv)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
fw_state_start(struct fw_priv * fw_priv)141 static inline void fw_state_start(struct fw_priv *fw_priv)
142 {
143 __fw_state_set(fw_priv, FW_STATUS_LOADING);
144 }
145
fw_state_done(struct fw_priv * fw_priv)146 static inline void fw_state_done(struct fw_priv *fw_priv)
147 {
148 __fw_state_set(fw_priv, FW_STATUS_DONE);
149 }
150
fw_state_is_done(struct fw_priv * fw_priv)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
fw_state_is_loading(struct fw_priv * fw_priv)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 */
firmware_is_builtin(const struct firmware * fw)173 static inline bool firmware_is_builtin(const struct firmware *fw)
174 {
175 return false;
176 }
firmware_request_builtin_buf(struct firmware * fw,const char * name,void * buf,size_t size)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
fw_free_paged_buf(struct fw_priv * fw_priv)191 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
fw_grow_paged_buf(struct fw_priv * fw_priv,int pages_needed)192 static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
fw_map_paged_buf(struct fw_priv * fw_priv)193 static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
fw_is_paged_buf(struct fw_priv * fw_priv)194 static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
195 #endif
196
197 #endif /* __FIRMWARE_LOADER_H */
198