Line data Source code
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 0 : struct fw_state *fw_st = &fw_priv->fw_st;
94 :
95 0 : return fw_st->status == status;
96 : }
97 :
98 0 : static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
99 : {
100 0 : struct fw_state *fw_st = &fw_priv->fw_st;
101 : long ret;
102 :
103 0 : ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
104 0 : if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
105 : return -ENOENT;
106 0 : if (!ret)
107 : return -ETIMEDOUT;
108 :
109 0 : 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 0 : struct fw_state *fw_st = &fw_priv->fw_st;
116 :
117 0 : 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 0 : complete_all(&fw_st->completion);
128 : }
129 : }
130 :
131 : static inline void fw_state_aborted(struct fw_priv *fw_priv)
132 : {
133 0 : __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 0 : 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 0 : __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 */
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