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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 */
38enum 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
49enum 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 */
61struct fw_state {
62 struct completion completion;
63 enum fw_status status;
64};
65
66struct 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
89extern struct mutex fw_lock;
90extern struct firmware_cache fw_cache;
91
92static 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
100static 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
114static 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
133static inline void fw_state_aborted(struct fw_priv *fw_priv)
134{
135 __fw_state_set(fw_priv, FW_STATUS_ABORTED);
136}
137
138static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
139{
140 return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
141}
142
143static inline void fw_state_start(struct fw_priv *fw_priv)
144{
145 __fw_state_set(fw_priv, FW_STATUS_LOADING);
146}
147
148static inline void fw_state_done(struct fw_priv *fw_priv)
149{
150 __fw_state_set(fw_priv, FW_STATUS_DONE);
151}
152
153static inline bool fw_state_is_done(struct fw_priv *fw_priv)
154{
155 return __fw_state_check(fw_priv, FW_STATUS_DONE);
156}
157
158static inline bool fw_state_is_loading(struct fw_priv *fw_priv)
159{
160 return __fw_state_check(fw_priv, FW_STATUS_LOADING);
161}
162
163int 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);
166int assign_fw(struct firmware *fw, struct device *device);
167void free_fw_priv(struct fw_priv *fw_priv);
168void fw_state_init(struct fw_priv *fw_priv);
169
170#ifdef CONFIG_FW_LOADER
171bool firmware_is_builtin(const struct firmware *fw);
172bool firmware_request_builtin_buf(struct firmware *fw, const char *name,
173 void *buf, size_t size);
174#else /* module case */
175static inline bool firmware_is_builtin(const struct firmware *fw)
176{
177 return false;
178}
179static 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
188void fw_free_paged_buf(struct fw_priv *fw_priv);
189int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
190int fw_map_paged_buf(struct fw_priv *fw_priv);
191bool fw_is_paged_buf(struct fw_priv *fw_priv);
192#else
193static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
194static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
195static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
196static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
197#endif
198
199#endif /* __FIRMWARE_LOADER_H */