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_f",
  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         /* Fpga load hook */
  40         "fpga_load",
  41
  42         /* fdt hooks */
  43         "ft_fixup",
  44
  45         /* main loop events */
  46         "main_loop",
  47 };
  48
  49 _Static_assert(ARRAY_SIZE(type_name) == EVT_COUNT, "event type_name size");
  50 #endif
  51
  52 static const char *event_type_name(enum event_t type)
  53 {
  54 #if CONFIG_IS_ENABLED(EVENT_DEBUG)
  55         return type_name[type];
  56 #else
  57         return "(unknown)";
  58 #endif
  59 }
  60
  61 static int notify_static(struct event *ev)
  62 {
  63         struct evspy_info *start =
  64                 ll_entry_start(struct evspy_info, evspy_info);
  65         const int n_ents = ll_entry_count(struct evspy_info, evspy_info);
  66         struct evspy_info *spy;
  67
  68         for (spy = start; spy != start + n_ents; spy++) {
  69                 if (spy->type == ev->type) {
  70                         int ret;
  71
  72                         log_debug("Sending event %x/%s to spy '%s'\n", ev->type,
  73                                   event_type_name(ev->type), event_spy_id(spy));
  74                         if (spy->flags & EVSPYF_SIMPLE) {
  75                                 const struct evspy_info_simple *simple;
  76
  77                                 simple = (struct evspy_info_simple *)spy;
  78                                 ret = simple->func();
  79                         } else {
  80                                 ret = spy->func(NULL, ev);
  81                         }
  82
  83                         /*
  84                          * TODO: Handle various return codes to
  85                          *
  86                          * - claim an event (no others will see it)
  87                          * - return an error from the event
  88                          */
  89                         if (ret)
  90                                 return log_msg_ret("spy", ret);
  91                 }
  92         }
  93
  94         return 0;
  95 }
  96
  97 static int notify_dynamic(struct event *ev)
  98 {
  99         struct event_state *state = gd_event_state();
 100         struct event_spy *spy, *next;
 101
 102         list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node) {
 103                 if (spy->type == ev->type) {
 104                         int ret;
 105
 106                         log_debug("Sending event %x/%s to spy '%s'\n", ev->type,
 107                                   event_type_name(ev->type), spy->id);
 108                         ret = spy->func(spy->ctx, ev);
 109
 110                         /*
 111                          * TODO: Handle various return codes to
 112                          *
 113                          * - claim an event (no others will see it)
 114                          * - return an error from the event
 115                          */
 116                         if (ret)
 117                                 return log_msg_ret("spy", ret);
 118                 }
 119         }
 120
 121         return 0;
 122 }
 123
 124 int event_notify(enum event_t type, void *data, int size)
 125 {
 126         struct event event;
 127         int ret;
 128
 129         event.type = type;
 130         if (size > sizeof(event.data))
 131                 return log_msg_ret("size", -E2BIG);
 132         memcpy(&event.data, data, size);
 133
 134         ret = notify_static(&event);
 135         if (ret)
 136                 return log_msg_ret("sta", ret);
 137
 138         if (CONFIG_IS_ENABLED(EVENT_DYNAMIC)) {
 139                 ret = notify_dynamic(&event);
 140                 if (ret)
 141                         return log_msg_ret("dyn", ret);
 142         }
 143
 144         return 0;
 145 }
 146
 147 int event_notify_null(enum event_t type)
 148 {
 149         return event_notify(type, NULL, 0);
 150 }
 151
 152 void event_show_spy_list(void)
 153 {
 154         struct evspy_info *start =
 155                 ll_entry_start(struct evspy_info, evspy_info);
 156         const int n_ents = ll_entry_count(struct evspy_info, evspy_info);
 157         struct evspy_info *spy;
 158         const int size = sizeof(ulong) * 2;
 159
 160         printf("Seq  %-24s  %*s  %s\n", "Type", size, "Function", "ID");
 161         for (spy = start; spy != start + n_ents; spy++) {
 162                 printf("%3x  %-3x %-20s  %*p  %s\n", (uint)(spy - start),
 163                        spy->type, event_type_name(spy->type), size, spy->func,
 164                        event_spy_id(spy));
 165         }
 166 }
 167
 168 #if IS_ENABLED(CONFIG_NEEDS_MANUAL_RELOC)
 169 int event_manual_reloc(void)
 170 {
 171         struct evspy_info *spy, *end;
 172
 173         spy = ll_entry_start(struct evspy_info, evspy_info);
 174         end = ll_entry_end(struct evspy_info, evspy_info);
 175         for (; spy < end; spy++)
 176                 MANUAL_RELOC(spy->func);
 177
 178         return 0;
 179 }
 180 #endif
 181
 182 #if CONFIG_IS_ENABLED(EVENT_DYNAMIC)
 183 static void spy_free(struct event_spy *spy)
 184 {
 185         list_del(&spy->sibling_node);
 186 }
 187
 188 int event_register(const char *id, enum event_t type, event_handler_t func, void *ctx)
 189 {
 190         struct event_state *state = gd_event_state();
 191         struct event_spy *spy;
 192
 193         spy = malloc(sizeof(*spy));
 194         if (!spy)
 195                 return log_msg_ret("alloc", -ENOMEM);
 196
 197         spy->id = id;
 198         spy->type = type;
 199         spy->func = func;
 200         spy->ctx = ctx;
 201         list_add_tail(&spy->sibling_node, &state->spy_head);
 202
 203         return 0;
 204 }
 205
 206 int event_uninit(void)
 207 {
 208         struct event_state *state = gd_event_state();
 209         struct event_spy *spy, *next;
 210
 211         list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node)
 212                 spy_free(spy);
 213
 214         return 0;
 215 }
 216
 217 int event_init(void)
 218 {
 219         struct event_state *state = gd_event_state();
 220
 221         INIT_LIST_HEAD(&state->spy_head);
 222
 223         return 0;
 224 }
 225 #endif /* EVENT_DYNAMIC */