1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Events provide a general-purpose way to react to / subscribe to changes
* within U-Boot
*
* Copyright 2021 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#ifndef __event_h
#define __event_h
#include <dm/ofnode_decl.h>
/**
* enum event_t - Types of events supported by U-Boot
*
* @EVT_DM_PRE_PROBE: Device is about to be probed
*/
enum event_t {
EVT_NONE,
EVT_TEST,
/* Events related to driver model */
EVT_DM_POST_INIT,
EVT_DM_PRE_PROBE,
EVT_DM_POST_PROBE,
EVT_DM_PRE_REMOVE,
EVT_DM_POST_REMOVE,
/* Init hooks */
EVT_MISC_INIT_F,
/* Device tree fixups before booting */
EVT_FT_FIXUP,
EVT_COUNT
};
union event_data {
/**
* struct event_data_test - test data
*
* @signal: A value to update the state with
*/
struct event_data_test {
int signal;
} test;
/**
* struct event_dm - driver model event
*
* @dev: Device this event relates to
*/
struct event_dm {
struct udevice *dev;
} dm;
/**
* struct event_ft_fixup - FDT fixup before booting
*
* @tree: tree to update
* @images: images which are being booted
*/
struct event_ft_fixup {
oftree tree;
struct bootm_headers *images;
} ft_fixup;
};
/**
* struct event - an event that can be sent and received
*
* @type: Event type
* @data: Data for this particular event
*/
struct event {
enum event_t type;
union event_data data;
};
/** Function type for event handlers */
typedef int (*event_handler_t)(void *ctx, struct event *event);
/**
* struct evspy_info - information about an event spy
*
* @func: Function to call when the event is activated (must be first)
* @type: Event type
* @id: Event id string
*/
struct evspy_info {
event_handler_t func;
enum event_t type;
#if CONFIG_IS_ENABLED(EVENT_DEBUG)
const char *id;
#endif
};
/* Declare a new event spy */
#if CONFIG_IS_ENABLED(EVENT_DEBUG)
#define _ESPY_REC(_type, _func) { _func, _type, #_func, }
#else
#define _ESPY_REC(_type, _func) { _func, _type, }
#endif
static inline const char *event_spy_id(struct evspy_info *spy)
{
#if CONFIG_IS_ENABLED(EVENT_DEBUG)
return spy->id;
#else
return "?";
#endif
}
/*
* It seems that LTO will drop list entries if it decides they are not used,
* although the conditions that cause this are unclear.
*
* The example found is the following:
*
* static int sandbox_misc_init_f(void *ctx, struct event *event)
* {
* return sandbox_early_getopt_check();
* }
* EVENT_SPY(EVT_MISC_INIT_F, sandbox_misc_init_f);
*
* where EVENT_SPY uses ll_entry_declare()
*
* In this case, LTO decides to drop the sandbox_misc_init_f() function
* (which is fine) but then drops the linker-list entry too. This means
* that the code no longer works, in this case sandbox no-longer checks its
* command-line arguments properly.
*
* Without LTO, the KEEP() command in the .lds file is enough to keep the
* entry around. But with LTO it seems that the entry has already been
* dropped before the link script is considered.
*
* The only solution I can think of is to mark linker-list entries as 'used'
* using an attribute. This should be safe, since we don't actually want to drop
* any of these. However this does slightly limit LTO's optimisation choices.
*
* Another issue has come up, only with clang: using 'static' makes it throw
* away the linker-list entry sometimes, e.g. with the EVT_FT_FIXUP entry in
* vbe_simple.c - so for now, make it global.
*/
#define EVENT_SPY(_type, _func) \
__used ll_entry_declare(struct evspy_info, _type ## _3_ ## _func, \
evspy_info) = _ESPY_REC(_type, _func)
/**
* event_register - register a new spy
*
* @id: Spy ID
* @type: Event type to subscribe to
* @func: Function to call when the event is sent
* @ctx: Context to pass to the function
* @return 0 if OK, -ve on error
*/
int event_register(const char *id, enum event_t type, event_handler_t func,
void *ctx);
/** event_show_spy_list( - Show a list of event spies */
void event_show_spy_list(void);
/**
* event_manual_reloc() - Relocate event handler pointers
*
* Relocate event handler pointers for all static event spies. It is called
* during the generic board init sequence, after relocation.
*
* Return: 0 if OK
*/
int event_manual_reloc(void);
/**
* event_notify() - notify spies about an event
*
* It is possible to pass in union event_data here but that may not be
* convenient if the data is elsewhere, or is one of the members of the union.
* So this uses a void * for @data, with a separate @size.
*
* @type: Event type
* @data: Event data to be sent (e.g. union_event_data)
* @size: Size of data in bytes
* @return 0 if OK, -ve on error
*/
int event_notify(enum event_t type, void *data, int size);
#if CONFIG_IS_ENABLED(EVENT)
/**
* event_notify_null() - notify spies about an event
*
* Data is NULL and the size is 0
*
* @type: Event type
* @return 0 if OK, -ve on error
*/
int event_notify_null(enum event_t type);
#else
static inline int event_notify_null(enum event_t type)
{
return 0;
}
#endif
#if CONFIG_IS_ENABLED(EVENT_DYNAMIC)
/**
* event_uninit() - Clean up dynamic events
*
* This removes all dynamic event handlers
*/
int event_uninit(void);
/**
* event_uninit() - Set up dynamic events
*
* Init a list of dynamic event handlers, so that these can be added as
* needed
*/
int event_init(void);
#else
static inline int event_uninit(void)
{
return 0;
}
static inline int event_init(void)
{
return 0;
}
#endif
#endif
|
