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         "fsp_init_r",
  39
  40         /* Fpga load hook */
  41         "fpga_load",
  42
  43         /* fdt hooks */
  44         "ft_fixup",
  45
  46         /* main loop events */
  47         "main_loop",
  48 };
  49
  50 _Static_assert(ARRAY_SIZE(type_name) == EVT_COUNT, "event type_name size");
  51 #endif
  52
  53 const char *event_type_name(enum event_t type)
  54 {
  55 #if CONFIG_IS_ENABLED(EVENT_DEBUG)
  56         return type_name[type];
  57 #else
  58         return "(unknown)";
  59 #endif
  60 }
  61
  62 static int notify_static(struct event *ev)
  63 {
  64         struct evspy_info *start =
  65                 ll_entry_start(struct evspy_info, evspy_info);
  66         const int n_ents = ll_entry_count(struct evspy_info, evspy_info);
  67         struct evspy_info *spy;
  68
  69         for (spy = start; spy != start + n_ents; spy++) {
  70                 if (spy->type == ev->type) {
  71                         int ret;
  72
  73                         log_debug("Sending event %x/%s to spy '%s'\n", ev->type,
  74                                   event_type_name(ev->type), event_spy_id(spy));
  75                         if (spy->flags & EVSPYF_SIMPLE) {
  76                                 const struct evspy_info_simple *simple;
  77
  78                                 simple = (struct evspy_info_simple *)spy;
  79                                 ret = simple->func();
  80                         } else {
  81                                 ret = spy->func(NULL, ev);
  82                         }
  83
  84                         /*
  85                          * TODO: Handle various return codes to
  86                          *
  87                          * - claim an event (no others will see it)
  88                          * - return an error from the event
  89                          */
  90                         if (ret)
  91                                 return log_msg_ret("spy", ret);
  92                 }
  93         }
  94
  95         return 0;
  96 }
  97
  98 static int notify_dynamic(struct event *ev)
  99 {
 100         struct event_state *state = gd_event_state();
 101         struct event_spy *spy, *next;
 102
 103         list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node) {
 104                 if (spy->type == ev->type) {
 105                         int ret;
 106
 107                         log_debug("Sending event %x/%s to spy '%s'\n", ev->type,
 108                                   event_type_name(ev->type), spy->id);
 109                         ret = spy->func(spy->ctx, ev);
 110
 111                         /*
 112                          * TODO: Handle various return codes to
 113                          *
 114                          * - claim an event (no others will see it)
 115                          * - return an error from the event
 116                          */
 117                         if (ret)
 118                                 return log_msg_ret("spy", ret);
 119                 }
 120         }
 121
 122         return 0;
 123 }
 124
 125 int event_notify(enum event_t type, void *data, int size)
 126 {
 127         struct event event;
 128         int ret;
 129
 130         event.type = type;
 131         if (size > sizeof(event.data))
 132                 return log_msg_ret("size", -E2BIG);
 133         memcpy(&event.data, data, size);
 134
 135         ret = notify_static(&event);
 136         if (ret)
 137                 return log_msg_ret("sta", ret);
 138
 139         if (CONFIG_IS_ENABLED(EVENT_DYNAMIC)) {
 140                 ret = notify_dynamic(&event);
 141                 if (ret)
 142                         return log_msg_ret("dyn", ret);
 143         }
 144
 145         return 0;
 146 }
 147
 148 int event_notify_null(enum event_t type)
 149 {
 150         return event_notify(type, NULL, 0);
 151 }
 152
 153 void event_show_spy_list(void)
 154 {
 155         struct evspy_info *start =
 156                 ll_entry_start(struct evspy_info, evspy_info);
 157         const int n_ents = ll_entry_count(struct evspy_info, evspy_info);
 158         struct evspy_info *spy;
 159         const int size = sizeof(ulong) * 2;
 160
 161         printf("Seq  %-24s  %*s  %s\n", "Type", size, "Function", "ID");
 162         for (spy = start; spy != start + n_ents; spy++) {
 163                 printf("%3x  %-3x %-20s  %*p  %s\n", (uint)(spy - start),
 164                        spy->type, event_type_name(spy->type), size, spy->func,
 165                        event_spy_id(spy));
 166         }
 167 }
 168
 169 #if IS_ENABLED(CONFIG_NEEDS_MANUAL_RELOC)
 170 int event_manual_reloc(void)
 171 {
 172         struct evspy_info *spy, *end;
 173
 174         spy = ll_entry_start(struct evspy_info, evspy_info);
 175         end = ll_entry_end(struct evspy_info, evspy_info);
 176         for (; spy < end; spy++)
 177                 MANUAL_RELOC(spy->func);
 178
 179         return 0;
 180 }
 181 #endif
 182
 183 #if CONFIG_IS_ENABLED(EVENT_DYNAMIC)
 184 static void spy_free(struct event_spy *spy)
 185 {
 186         list_del(&spy->sibling_node);
 187 }
 188
 189 int event_register(const char *id, enum event_t type, event_handler_t func, void *ctx)
 190 {
 191         struct event_state *state = gd_event_state();
 192         struct event_spy *spy;
 193
 194         spy = malloc(sizeof(*spy));
 195         if (!spy)
 196                 return log_msg_ret("alloc", -ENOMEM);
 197
 198         spy->id = id;
 199         spy->type = type;
 200         spy->func = func;
 201         spy->ctx = ctx;
 202         list_add_tail(&spy->sibling_node, &state->spy_head);
 203
 204         return 0;
 205 }
 206
 207 int event_uninit(void)
 208 {
 209         struct event_state *state = gd_event_state();
 210         struct event_spy *spy, *next;
 211
 212         list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node)
 213                 spy_free(spy);
 214
 215         return 0;
 216 }
 217
 218 int event_init(void)
 219 {
 220         struct event_state *state = gd_event_state();
 221
 222         INIT_LIST_HEAD(&state->spy_head);
 223
 224         return 0;
 225 }
 226 #endif /* EVENT_DYNAMIC */