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 */
36enum 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
47enum 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 */
59struct fw_state {
60 struct completion completion;
61 enum fw_status status;
62};
63
64struct 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
87extern struct mutex fw_lock;
88extern struct firmware_cache fw_cache;
89extern bool fw_load_abort_all;
90
91static inline bool __fw_state_check(struct fw_priv *fw_priv,
92 enum fw_status status)
93{
94 struct fw_state *fw_st = &fw_priv->fw_st;
95
96 return fw_st->status == status;
97}
98
99static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
100{
101 struct fw_state *fw_st = &fw_priv->fw_st;
102 long ret;
103
104 ret = wait_for_completion_killable_timeout(x: &fw_st->completion, timeout);
105 if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
106 return -ENOENT;
107 if (!ret)
108 return -ETIMEDOUT;
109
110 return ret < 0 ? ret : 0;
111}
112
113static inline void __fw_state_set(struct fw_priv *fw_priv,
114 enum fw_status status)
115{
116 struct fw_state *fw_st = &fw_priv->fw_st;
117
118 WRITE_ONCE(fw_st->status, status);
119
120 if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) {
121#ifdef CONFIG_FW_LOADER_USER_HELPER
122 /*
123 * Doing this here ensures that the fw_priv is deleted from
124 * the pending list in all abort/done paths.
125 */
126 list_del_init(entry: &fw_priv->pending_list);
127#endif
128 complete_all(&fw_st->completion);
129 }
130}
131
132static inline void fw_state_aborted(struct fw_priv *fw_priv)
133{
134 __fw_state_set(fw_priv, status: FW_STATUS_ABORTED);
135}
136
137static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
138{
139 return __fw_state_check(fw_priv, status: FW_STATUS_ABORTED);
140}
141
142static inline void fw_state_start(struct fw_priv *fw_priv)
143{
144 __fw_state_set(fw_priv, status: FW_STATUS_LOADING);
145}
146
147static inline void fw_state_done(struct fw_priv *fw_priv)
148{
149 __fw_state_set(fw_priv, status: FW_STATUS_DONE);
150}
151
152static inline bool fw_state_is_done(struct fw_priv *fw_priv)
153{
154 return __fw_state_check(fw_priv, status: FW_STATUS_DONE);
155}
156
157static inline bool fw_state_is_loading(struct fw_priv *fw_priv)
158{
159 return __fw_state_check(fw_priv, status: FW_STATUS_LOADING);
160}
161
162int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
163 struct fw_priv **fw_priv, void *dbuf, size_t size,
164 size_t offset, u32 opt_flags);
165int assign_fw(struct firmware *fw, struct device *device);
166void free_fw_priv(struct fw_priv *fw_priv);
167void fw_state_init(struct fw_priv *fw_priv);
168
169#ifdef CONFIG_FW_LOADER
170bool firmware_is_builtin(const struct firmware *fw);
171bool firmware_request_builtin_buf(struct firmware *fw, const char *name,
172 void *buf, size_t size);
173#else /* module case */
174static inline bool firmware_is_builtin(const struct firmware *fw)
175{
176 return false;
177}
178static inline bool firmware_request_builtin_buf(struct firmware *fw,
179 const char *name,
180 void *buf, size_t size)
181{
182 return false;
183}
184#endif
185
186#ifdef CONFIG_FW_LOADER_PAGED_BUF
187void fw_free_paged_buf(struct fw_priv *fw_priv);
188int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
189int fw_map_paged_buf(struct fw_priv *fw_priv);
190bool fw_is_paged_buf(struct fw_priv *fw_priv);
191#else
192static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
193static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
194static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
195static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
196#endif
197
198#endif /* __FIRMWARE_LOADER_H */
199

source code of linux/drivers/base/firmware_loader/firmware.h