module.c

   1 /*
   2  * QEMU Module Infrastructure
   3  *
   4  * Copyright IBM, Corp. 2009
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "qemu-common.h"
  15 #include "sys-queue.h"
  16 #include "module.h"
  17
  18 typedef struct ModuleEntry
  19 {
  20     module_init_type type;
  21     void (*init)(void);
  22     TAILQ_ENTRY(ModuleEntry) node;
  23 } ModuleEntry;
  24
  25 typedef struct ModuleTypeList
  26 {
  27     module_init_type type;
  28     TAILQ_HEAD(, ModuleEntry) entry_list;
  29     TAILQ_ENTRY(ModuleTypeList) node;
  30 } ModuleTypeList;
  31
  32 static TAILQ_HEAD(, ModuleTypeList) init_type_list;
  33
  34 static ModuleTypeList *find_type_or_alloc(module_init_type type, int alloc)
  35 {
  36     ModuleTypeList *n;
  37
  38     TAILQ_FOREACH(n, &init_type_list, node) {
  39         if (type >= n->type)
  40             break;
  41     }
  42
  43     if (!n || n->type != type) {
  44         ModuleTypeList *o;
  45
  46         if (!alloc)
  47             return NULL;
  48
  49         o = qemu_mallocz(sizeof(*o));
  50         o->type = type;
  51         TAILQ_INIT(&o->entry_list);
  52
  53         if (n) {
  54             TAILQ_INSERT_AFTER(&init_type_list, n, o, node);
  55         } else {
  56             TAILQ_INSERT_HEAD(&init_type_list, o, node);
  57         }
  58
  59         n = o;
  60     }
  61
  62     return n;
  63 }
  64
  65 void register_module_init(void (*fn)(void), module_init_type type)
  66 {
  67     ModuleEntry *e;
  68     ModuleTypeList *l;
  69
  70     e = qemu_mallocz(sizeof(*e));
  71     e->init = fn;
  72
  73     l = find_type_or_alloc(type, 1);
  74
  75     TAILQ_INSERT_TAIL(&l->entry_list, e, node);
  76 }
  77
  78 void module_call_init(module_init_type type)
  79 {
  80     ModuleTypeList *l;
  81     ModuleEntry *e;
  82
  83     l = find_type_or_alloc(type, 0);
  84     if (!l) {
  85         return;
  86     }
  87
  88     TAILQ_FOREACH(e, &l->entry_list, node) {
  89         e->init();
  90     }
  91 }