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         /* 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                         ret = spy->func(NULL, ev);
  75
  76                         /*
  77                          * TODO: Handle various return codes to
  78                          *
  79                          * - claim an event (no others will see it)
  80                          * - return an error from the event
  81                          */
  82                         if (ret)
  83                                 return log_msg_ret("spy", ret);
  84                 }
  85         }
  86
  87         return 0;
  88 }
  89
  90 static int notify_dynamic(struct event *ev)
  91 {
  92         struct event_state *state = gd_event_state();
  93         struct event_spy *spy, *next;
  94
  95         list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node) {
  96                 if (spy->type == ev->type) {
  97                         int ret;
  98
  99                         log_debug("Sending event %x/%s to spy '%s'\n", ev->type,
 100                                   event_type_name(ev->type), spy->id);
 101                         ret = spy->func(spy->ctx, ev);
 102
 103                         /*
 104                          * TODO: Handle various return codes to
 105                          *
 106                          * - claim an event (no others will see it)
 107                          * - return an error from the event
 108                          */
 109                         if (ret)
 110                                 return log_msg_ret("spy", ret);
 111                 }
 112         }
 113
 114         return 0;
 115 }
 116
 117 int event_notify(enum event_t type, void *data, int size)
 118 {
 119         struct event event;
 120         int ret;
 121
 122         event.type = type;
 123         if (size > sizeof(event.data))
 124                 return log_msg_ret("size", -E2BIG);
 125         memcpy(&event.data, data, size);
 126
 127         ret = notify_static(&event);
 128         if (ret)
 129                 return log_msg_ret("sta", ret);
 130
 131         if (CONFIG_IS_ENABLED(EVENT_DYNAMIC)) {
 132                 ret = notify_dynamic(&event);
 133                 if (ret)
 134                         return log_msg_ret("dyn", ret);
 135         }
 136
 137         return 0;
 138 }
 139
 140 int event_notify_null(enum event_t type)
 141 {
 142         return event_notify(type, NULL, 0);
 143 }
 144
 145 void event_show_spy_list(void)
 146 {
 147         struct evspy_info *start =
 148                 ll_entry_start(struct evspy_info, evspy_info);
 149         const int n_ents = ll_entry_count(struct evspy_info, evspy_info);
 150         struct evspy_info *spy;
 151         const int size = sizeof(ulong) * 2;
 152
 153         printf("Seq  %-24s  %*s  %s\n", "Type", size, "Function", "ID");
 154         for (spy = start; spy != start + n_ents; spy++) {
 155                 printf("%3x  %-3x %-20s  %*p  %s\n", (uint)(spy - start),
 156                        spy->type, event_type_name(spy->type), size, spy->func,
 157                        event_spy_id(spy));
 158         }
 159 }
 160
 161 #if IS_ENABLED(CONFIG_NEEDS_MANUAL_RELOC)
 162 int event_manual_reloc(void)
 163 {
 164         struct evspy_info *spy, *end;
 165
 166         spy = ll_entry_start(struct evspy_info, evspy_info);
 167         end = ll_entry_end(struct evspy_info, evspy_info);
 168         for (; spy < end; spy++)
 169                 MANUAL_RELOC(spy->func);
 170
 171         return 0;
 172 }
 173 #endif
 174
 175 #if CONFIG_IS_ENABLED(EVENT_DYNAMIC)
 176 static void spy_free(struct event_spy *spy)
 177 {
 178         list_del(&spy->sibling_node);
 179 }
 180
 181 int event_register(const char *id, enum event_t type, event_handler_t func, void *ctx)
 182 {
 183         struct event_state *state = gd_event_state();
 184         struct event_spy *spy;
 185
 186         spy = malloc(sizeof(*spy));
 187         if (!spy)
 188                 return log_msg_ret("alloc", -ENOMEM);
 189
 190         spy->id = id;
 191         spy->type = type;
 192         spy->func = func;
 193         spy->ctx = ctx;
 194         list_add_tail(&spy->sibling_node, &state->spy_head);
 195
 196         return 0;
 197 }
 198
 199 int event_uninit(void)
 200 {
 201         struct event_state *state = gd_event_state();
 202         struct event_spy *spy, *next;
 203
 204         list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node)
 205                 spy_free(spy);
 206
 207         return 0;
 208 }
 209
 210 int event_init(void)
 211 {
 212         struct event_state *state = gd_event_state();
 213
 214         INIT_LIST_HEAD(&state->spy_head);
 215
 216         return 0;
 217 }
 218 #endif /* EVENT_DYNAMIC */