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