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  */
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 };
45 
46 enum fw_status {
47 	FW_STATUS_UNKNOWN,
48 	FW_STATUS_LOADING,
49 	FW_STATUS_DONE,
50 	FW_STATUS_ABORTED,
51 };
52 
53 /*
54  * Concurrent request_firmware() for the same firmware need to be
55  * serialized.  struct fw_state is simple state machine which hold the
56  * state of the firmware loading.
57  */
58 struct fw_state {
59 	struct completion completion;
60 	enum fw_status status;
61 };
62 
63 struct fw_priv {
64 	struct kref ref;
65 	struct list_head list;
66 	struct firmware_cache *fwc;
67 	struct fw_state fw_st;
68 	void *data;
69 	size_t size;
70 	size_t allocated_size;
71 	u32 opt_flags;
72 #ifdef CONFIG_FW_LOADER_PAGED_BUF
73 	bool is_paged_buf;
74 	struct page **pages;
75 	int nr_pages;
76 	int page_array_size;
77 #endif
78 #ifdef CONFIG_FW_LOADER_USER_HELPER
79 	bool need_uevent;
80 	struct list_head pending_list;
81 #endif
82 	const char *fw_name;
83 };
84 
85 extern struct mutex fw_lock;
86 
87 static inline bool __fw_state_check(struct fw_priv *fw_priv,
88 				    enum fw_status status)
89 {
90 	struct fw_state *fw_st = &fw_priv->fw_st;
91 
92 	return fw_st->status == status;
93 }
94 
95 static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
96 {
97 	struct fw_state *fw_st = &fw_priv->fw_st;
98 	long ret;
99 
100 	ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
101 	if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
102 		return -ENOENT;
103 	if (!ret)
104 		return -ETIMEDOUT;
105 
106 	return ret < 0 ? ret : 0;
107 }
108 
109 static inline void __fw_state_set(struct fw_priv *fw_priv,
110 				  enum fw_status status)
111 {
112 	struct fw_state *fw_st = &fw_priv->fw_st;
113 
114 	WRITE_ONCE(fw_st->status, status);
115 
116 	if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
117 		complete_all(&fw_st->completion);
118 }
119 
120 static inline void fw_state_aborted(struct fw_priv *fw_priv)
121 {
122 	__fw_state_set(fw_priv, FW_STATUS_ABORTED);
123 }
124 
125 static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
126 {
127 	return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
128 }
129 
130 static inline void fw_state_start(struct fw_priv *fw_priv)
131 {
132 	__fw_state_set(fw_priv, FW_STATUS_LOADING);
133 }
134 
135 static inline void fw_state_done(struct fw_priv *fw_priv)
136 {
137 	__fw_state_set(fw_priv, FW_STATUS_DONE);
138 }
139 
140 int assign_fw(struct firmware *fw, struct device *device);
141 
142 #ifdef CONFIG_FW_LOADER_PAGED_BUF
143 void fw_free_paged_buf(struct fw_priv *fw_priv);
144 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
145 int fw_map_paged_buf(struct fw_priv *fw_priv);
146 bool fw_is_paged_buf(struct fw_priv *fw_priv);
147 #else
148 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
149 static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
150 static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
151 static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
152 #endif
153 
154 #endif /* __FIRMWARE_LOADER_H */
155