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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: Disable the fallback mechanism. Takes precedence over
31 * &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
32 */
33enum 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 = BIT(5),
40};
41
42enum 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 */
54struct fw_state {
55 struct completion completion;
56 enum fw_status status;
57};
58
59struct 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
80extern struct mutex fw_lock;
81
82static 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
90static 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
104static 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
115static inline void fw_state_aborted(struct fw_priv *fw_priv)
116{
117 __fw_state_set(fw_priv, FW_STATUS_ABORTED);
118}
119
120static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
121{
122 return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
123}
124
125static inline void fw_state_start(struct fw_priv *fw_priv)
126{
127 __fw_state_set(fw_priv, FW_STATUS_LOADING);
128}
129
130static inline void fw_state_done(struct fw_priv *fw_priv)
131{
132 __fw_state_set(fw_priv, FW_STATUS_DONE);
133}
134
135int assign_fw(struct firmware *fw, struct device *device,
136 enum fw_opt opt_flags);
137
138#ifdef CONFIG_FW_LOADER_PAGED_BUF
139void fw_free_paged_buf(struct fw_priv *fw_priv);
140int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
141int fw_map_paged_buf(struct fw_priv *fw_priv);
142#else
143static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
144static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
145static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
146#endif
147
148#endif /* __FIRMWARE_LOADER_H */