common/event.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Events provide a general-purpose way to react to / subscribe to changes
   4  * within U-Boot
   5  *
   6  * Copyright 2021 Google LLC
   7  * Written by Simon Glass <[email protected]>
   8  */
   9
  10 #define LOG_CATEGORY    LOGC_EVENT
  11
  12 #include <common.h>
  13 #include <event.h>
  14 #include <event_internal.h>
  15 #include <log.h>
  16 #include <linker_lists.h>
  17 #include <malloc.h>
  18 #include <asm/global_data.h>
  19 #include <linux/list.h>
  20 #include <relocate.h>
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23
  24 #if CONFIG_IS_ENABLED(EVENT_DEBUG)
  25 const char *const type_name[] = {
  26         "none",
  27         "test",
  28
  29         /* Events related to driver model */
  30         "dm_post_init",
  31         "dm_pre_probe",
  32         "dm_post_probe",
  33         "dm_pre_remove",
  34         "dm_post_remove",
  35
  36         /* init hooks */
  37         "misc_init_f",
  38
  39         /* fdt hooks */
  40         "ft_fixup",
  41 };
  42
  43 _Static_assert(ARRAY_SIZE(type_name) == EVT_COUNT, "event type_name size");
  44 #endif
  45
  46 static const char *event_type_name(enum event_t type)
  47 {
  48 #if CONFIG_IS_ENABLED(EVENT_DEBUG)
  49         return type_name[type];
  50 #else
  51         return "(unknown)";
  52 #endif
  53 }
  54
  55 static int notify_static(struct event *ev)
  56 {
  57         struct evspy_info *start =
  58                 ll_entry_start(struct evspy_info, evspy_info);
  59         const int n_ents = ll_entry_count(struct evspy_info, evspy_info);
  60         struct evspy_info *spy;
  61
  62         for (spy = start; spy != start + n_ents; spy++) {
  63                 if (spy->type == ev->type) {
  64                         int ret;
  65
  66                         log_debug("Sending event %x/%s to spy '%s'\n", ev->type,
  67                                   event_type_name(ev->type), event_spy_id(spy));
  68                         ret = spy->func(NULL, ev);
  69
  70                         /*
  71                          * TODO: Handle various return codes to
  72                          *
  73                          * - claim an event (no others will see it)
  74                          * - return an error from the event
  75                          */
  76                         if (ret)
  77                                 return log_msg_ret("spy", ret);
  78                 }
  79         }
  80
  81         return 0;
  82 }
  83
  84 static int notify_dynamic(struct event *ev)
  85 {
  86         struct event_state *state = gd_event_state();
  87         struct event_spy *spy, *next;
  88
  89         list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node) {
  90                 if (spy->type == ev->type) {
  91                         int ret;
  92
  93                         log_debug("Sending event %x/%s to spy '%s'\n", ev->type,
  94                                   event_type_name(ev->type), spy->id);
  95                         ret = spy->func(spy->ctx, ev);
  96
  97                         /*
  98                          * TODO: Handle various return codes to
  99                          *
 100                          * - claim an event (no others will see it)
 101                          * - return an error from the event
 102                          */
 103                         if (ret)
 104                                 return log_msg_ret("spy", ret);
 105                 }
 106         }
 107
 108         return 0;
 109 }
 110
 111 int event_notify(enum event_t type, void *data, int size)
 112 {
 113         struct event event;
 114         int ret;
 115
 116         event.type = type;
 117         if (size > sizeof(event.data))
 118                 return log_msg_ret("size", -E2BIG);
 119         memcpy(&event.data, data, size);
 120
 121         ret = notify_static(&event);
 122         if (ret)
 123                 return log_msg_ret("dyn", ret);
 124
 125         if (CONFIG_IS_ENABLED(EVENT_DYNAMIC)) {
 126                 ret = notify_dynamic(&event);
 127                 if (ret)
 128                         return log_msg_ret("dyn", ret);
 129         }
 130
 131         return 0;
 132 }
 133
 134 int event_notify_null(enum event_t type)
 135 {
 136         return event_notify(type, NULL, 0);
 137 }
 138
 139 void event_show_spy_list(void)
 140 {
 141         struct evspy_info *start =
 142                 ll_entry_start(struct evspy_info, evspy_info);
 143         const int n_ents = ll_entry_count(struct evspy_info, evspy_info);
 144         struct evspy_info *spy;
 145         const int size = sizeof(ulong) * 2;
 146
 147         printf("Seq  %-24s  %*s  %s\n", "Type", size, "Function", "ID");
 148         for (spy = start; spy != start + n_ents; spy++) {
 149                 printf("%3x  %-3x %-20s  %*p  %s\n", (uint)(spy - start),
 150                        spy->type, event_type_name(spy->type), size, spy->func,
 151                        event_spy_id(spy));
 152         }
 153 }
 154
 155 #if CONFIG_IS_ENABLED(NEEDS_MANUAL_RELOC)
 156 int event_manual_reloc(void)
 157 {
 158         struct evspy_info *spy, *end;
 159
 160         spy = ll_entry_start(struct evspy_info, evspy_info);
 161         end = ll_entry_end(struct evspy_info, evspy_info);
 162         for (; spy < end; spy++)
 163                 MANUAL_RELOC(spy->func);
 164
 165         return 0;
 166 }
 167 #endif
 168
 169 #if CONFIG_IS_ENABLED(EVENT_DYNAMIC)
 170 static void spy_free(struct event_spy *spy)
 171 {
 172         list_del(&spy->sibling_node);
 173 }
 174
 175 int event_register(const char *id, enum event_t type, event_handler_t func, void *ctx)
 176 {
 177         struct event_state *state = gd_event_state();
 178         struct event_spy *spy;
 179
 180         spy = malloc(sizeof(*spy));
 181         if (!spy)
 182                 return log_msg_ret("alloc", -ENOMEM);
 183
 184         spy->id = id;
 185         spy->type = type;
 186         spy->func = func;
 187         spy->ctx = ctx;
 188         list_add_tail(&spy->sibling_node, &state->spy_head);
 189
 190         return 0;
 191 }
 192
 193 int event_uninit(void)
 194 {
 195         struct event_state *state = gd_event_state();
 196         struct event_spy *spy, *next;
 197
 198         list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node)
 199                 spy_free(spy);
 200
 201         return 0;
 202 }
 203
 204 int event_init(void)
 205 {
 206         struct event_state *state = gd_event_state();
 207
 208         INIT_LIST_HEAD(&state->spy_head);
 209
 210         return 0;
 211 }
 212 #endif /* EVENT_DYNAMIC */