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  */
33 enum fw_opt {
34 	FW_OPT_UEVENT			= BIT(0),
35 	FW_OPT_NOWAIT			= BIT(1),
36 	FW_OPT_USERHELPER		= BIT(2),
37 	FW_OPT_NO_WARN			= BIT(3),
38 	FW_OPT_NOCACHE			= BIT(4),
39 	FW_OPT_NOFALLBACK_SYSFS		= BIT(5),
40 };
41 
42 enum fw_status {
43 	FW_STATUS_UNKNOWN,
44 	FW_STATUS_LOADING,
45 	FW_STATUS_DONE,
46 	FW_STATUS_ABORTED,
47 };
48 
49 /*
50  * Concurrent request_firmware() for the same firmware need to be
51  * serialized.  struct fw_state is simple state machine which hold the
52  * state of the firmware loading.
53  */
54 struct fw_state {
55 	struct completion completion;
56 	enum fw_status status;
57 };
58 
59 struct fw_priv {
60 	struct kref ref;
61 	struct list_head list;
62 	struct firmware_cache *fwc;
63 	struct fw_state fw_st;
64 	void *data;
65 	size_t size;
66 	size_t allocated_size;
67 #ifdef CONFIG_FW_LOADER_PAGED_BUF
68 	bool is_paged_buf;
69 	struct page **pages;
70 	int nr_pages;
71 	int page_array_size;
72 #endif
73 #ifdef CONFIG_FW_LOADER_USER_HELPER
74 	bool need_uevent;
75 	struct list_head pending_list;
76 #endif
77 	const char *fw_name;
78 };
79 
80 extern struct mutex fw_lock;
81 
82 static inline bool __fw_state_check(struct fw_priv *fw_priv,
83 				    enum fw_status status)
84 {
85 	struct fw_state *fw_st = &fw_priv->fw_st;
86 
87 	return fw_st->status == status;
88 }
89 
90 static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
91 {
92 	struct fw_state *fw_st = &fw_priv->fw_st;
93 	long ret;
94 
95 	ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
96 	if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
97 		return -ENOENT;
98 	if (!ret)
99 		return -ETIMEDOUT;
100 
101 	return ret < 0 ? ret : 0;
102 }
103 
104 static inline void __fw_state_set(struct fw_priv *fw_priv,
105 				  enum fw_status status)
106 {
107 	struct fw_state *fw_st = &fw_priv->fw_st;
108 
109 	WRITE_ONCE(fw_st->status, status);
110 
111 	if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
112 		complete_all(&fw_st->completion);
113 }
114 
115 static inline void fw_state_aborted(struct fw_priv *fw_priv)
116 {
117 	__fw_state_set(fw_priv, FW_STATUS_ABORTED);
118 }
119 
120 static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
121 {
122 	return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
123 }
124 
125 static inline void fw_state_start(struct fw_priv *fw_priv)
126 {
127 	__fw_state_set(fw_priv, FW_STATUS_LOADING);
128 }
129 
130 static inline void fw_state_done(struct fw_priv *fw_priv)
131 {
132 	__fw_state_set(fw_priv, FW_STATUS_DONE);
133 }
134 
135 int assign_fw(struct firmware *fw, struct device *device,
136 	      enum fw_opt opt_flags);
137 
138 #ifdef CONFIG_FW_LOADER_PAGED_BUF
139 void fw_free_paged_buf(struct fw_priv *fw_priv);
140 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
141 int fw_map_paged_buf(struct fw_priv *fw_priv);
142 #else
143 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
144 static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
145 static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
146 #endif
147 
148 #endif /* __FIRMWARE_LOADER_H */
149