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 #include <generated/utsrelease.h>
13
14 /**
15 * enum fw_opt - options to control firmware loading behaviour
16 *
17 * @FW_OPT_UEVENT: Enables the fallback mechanism to send a kobject uevent
18 * when the firmware is not found. Userspace is in charge to load the
19 * firmware using the sysfs loading facility.
20 * @FW_OPT_NOWAIT: Used to describe the firmware request is asynchronous.
21 * @FW_OPT_USERHELPER: Enable the fallback mechanism, in case the direct
22 * filesystem lookup fails at finding the firmware. For details refer to
23 * firmware_fallback_sysfs().
24 * @FW_OPT_NO_WARN: Quiet, avoid printing warning messages.
25 * @FW_OPT_NOCACHE: Disables firmware caching. Firmware caching is used to
26 * cache the firmware upon suspend, so that upon resume races against the
27 * firmware file lookup on storage is avoided. Used for calls where the
28 * file may be too big, or where the driver takes charge of its own
29 * firmware caching mechanism.
30 * @FW_OPT_NOFALLBACK_SYSFS: Disable the sysfs fallback mechanism. Takes
31 * precedence over &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
32 * @FW_OPT_FALLBACK_PLATFORM: Enable fallback to device fw copy embedded in
33 * the platform's main firmware. If both this fallback and the sysfs
34 * fallback are enabled, then this fallback will be tried first.
35 * @FW_OPT_PARTIAL: Allow partial read of firmware instead of needing to read
36 * entire file.
37 */
38 enum fw_opt {
39 FW_OPT_UEVENT = BIT(0),
40 FW_OPT_NOWAIT = BIT(1),
41 FW_OPT_USERHELPER = BIT(2),
42 FW_OPT_NO_WARN = BIT(3),
43 FW_OPT_NOCACHE = BIT(4),
44 FW_OPT_NOFALLBACK_SYSFS = BIT(5),
45 FW_OPT_FALLBACK_PLATFORM = BIT(6),
46 FW_OPT_PARTIAL = BIT(7),
47 };
48
49 enum fw_status {
50 FW_STATUS_UNKNOWN,
51 FW_STATUS_LOADING,
52 FW_STATUS_DONE,
53 FW_STATUS_ABORTED,
54 };
55
56 /*
57 * Concurrent request_firmware() for the same firmware need to be
58 * serialized. struct fw_state is simple state machine which hold the
59 * state of the firmware loading.
60 */
61 struct fw_state {
62 struct completion completion;
63 enum fw_status status;
64 };
65
66 struct fw_priv {
67 struct kref ref;
68 struct list_head list;
69 struct firmware_cache *fwc;
70 struct fw_state fw_st;
71 void *data;
72 size_t size;
73 size_t allocated_size;
74 size_t offset;
75 u32 opt_flags;
76 #ifdef CONFIG_FW_LOADER_PAGED_BUF
77 bool is_paged_buf;
78 struct page **pages;
79 int nr_pages;
80 int page_array_size;
81 #endif
82 #ifdef CONFIG_FW_LOADER_USER_HELPER
83 bool need_uevent;
84 struct list_head pending_list;
85 #endif
86 const char *fw_name;
87 };
88
89 extern struct mutex fw_lock;
90 extern struct firmware_cache fw_cache;
91
__fw_state_check(struct fw_priv * fw_priv,enum fw_status status)92 static inline bool __fw_state_check(struct fw_priv *fw_priv,
93 enum fw_status status)
94 {
95 struct fw_state *fw_st = &fw_priv->fw_st;
96
97 return fw_st->status == status;
98 }
99
__fw_state_wait_common(struct fw_priv * fw_priv,long timeout)100 static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
101 {
102 struct fw_state *fw_st = &fw_priv->fw_st;
103 long ret;
104
105 ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
106 if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
107 return -ENOENT;
108 if (!ret)
109 return -ETIMEDOUT;
110
111 return ret < 0 ? ret : 0;
112 }
113
__fw_state_set(struct fw_priv * fw_priv,enum fw_status status)114 static inline void __fw_state_set(struct fw_priv *fw_priv,
115 enum fw_status status)
116 {
117 struct fw_state *fw_st = &fw_priv->fw_st;
118
119 WRITE_ONCE(fw_st->status, status);
120
121 if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) {
122 #ifdef CONFIG_FW_LOADER_USER_HELPER
123 /*
124 * Doing this here ensures that the fw_priv is deleted from
125 * the pending list in all abort/done paths.
126 */
127 list_del_init(&fw_priv->pending_list);
128 #endif
129 complete_all(&fw_st->completion);
130 }
131 }
132
fw_state_aborted(struct fw_priv * fw_priv)133 static inline void fw_state_aborted(struct fw_priv *fw_priv)
134 {
135 __fw_state_set(fw_priv, FW_STATUS_ABORTED);
136 }
137
fw_state_is_aborted(struct fw_priv * fw_priv)138 static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
139 {
140 return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
141 }
142
fw_state_start(struct fw_priv * fw_priv)143 static inline void fw_state_start(struct fw_priv *fw_priv)
144 {
145 __fw_state_set(fw_priv, FW_STATUS_LOADING);
146 }
147
fw_state_done(struct fw_priv * fw_priv)148 static inline void fw_state_done(struct fw_priv *fw_priv)
149 {
150 __fw_state_set(fw_priv, FW_STATUS_DONE);
151 }
152
fw_state_is_done(struct fw_priv * fw_priv)153 static inline bool fw_state_is_done(struct fw_priv *fw_priv)
154 {
155 return __fw_state_check(fw_priv, FW_STATUS_DONE);
156 }
157
fw_state_is_loading(struct fw_priv * fw_priv)158 static inline bool fw_state_is_loading(struct fw_priv *fw_priv)
159 {
160 return __fw_state_check(fw_priv, FW_STATUS_LOADING);
161 }
162
163 int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
164 struct fw_priv **fw_priv, void *dbuf, size_t size,
165 size_t offset, u32 opt_flags);
166 int assign_fw(struct firmware *fw, struct device *device);
167 void free_fw_priv(struct fw_priv *fw_priv);
168 void fw_state_init(struct fw_priv *fw_priv);
169
170 #ifdef CONFIG_FW_LOADER
171 bool firmware_is_builtin(const struct firmware *fw);
172 bool firmware_request_builtin_buf(struct firmware *fw, const char *name,
173 void *buf, size_t size);
174 #else /* module case */
firmware_is_builtin(const struct firmware * fw)175 static inline bool firmware_is_builtin(const struct firmware *fw)
176 {
177 return false;
178 }
firmware_request_builtin_buf(struct firmware * fw,const char * name,void * buf,size_t size)179 static inline bool firmware_request_builtin_buf(struct firmware *fw,
180 const char *name,
181 void *buf, size_t size)
182 {
183 return false;
184 }
185 #endif
186
187 #ifdef CONFIG_FW_LOADER_PAGED_BUF
188 void fw_free_paged_buf(struct fw_priv *fw_priv);
189 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
190 int fw_map_paged_buf(struct fw_priv *fw_priv);
191 bool fw_is_paged_buf(struct fw_priv *fw_priv);
192 #else
fw_free_paged_buf(struct fw_priv * fw_priv)193 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
fw_grow_paged_buf(struct fw_priv * fw_priv,int pages_needed)194 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)195 static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
fw_is_paged_buf(struct fw_priv * fw_priv)196 static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
197 #endif
198
199 #endif /* __FIRMWARE_LOADER_H */
200