1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * (C) Copyright 2012
3*4882a593Smuzhiyun * Joe Hershberger, National Instruments, joe.hershberger@ni.com
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <common.h>
9*4882a593Smuzhiyun #include <environment.h>
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #if defined(CONFIG_NEEDS_MANUAL_RELOC)
12*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
13*4882a593Smuzhiyun #endif
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun /*
16*4882a593Smuzhiyun * Look up a callback function pointer by name
17*4882a593Smuzhiyun */
find_env_callback(const char * name)18*4882a593Smuzhiyun static struct env_clbk_tbl *find_env_callback(const char *name)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun struct env_clbk_tbl *clbkp;
21*4882a593Smuzhiyun int i;
22*4882a593Smuzhiyun int num_callbacks = ll_entry_count(struct env_clbk_tbl, env_clbk);
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun if (name == NULL)
25*4882a593Smuzhiyun return NULL;
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun /* look up the callback in the linker-list */
28*4882a593Smuzhiyun for (i = 0, clbkp = ll_entry_start(struct env_clbk_tbl, env_clbk);
29*4882a593Smuzhiyun i < num_callbacks;
30*4882a593Smuzhiyun i++, clbkp++) {
31*4882a593Smuzhiyun if (strcmp(name, clbkp->name) == 0)
32*4882a593Smuzhiyun return clbkp;
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun return NULL;
36*4882a593Smuzhiyun }
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun static int first_call = 1;
39*4882a593Smuzhiyun static const char *callback_list;
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun /*
42*4882a593Smuzhiyun * Look for a possible callback for a newly added variable
43*4882a593Smuzhiyun * This is called specifically when the variable did not exist in the hash
44*4882a593Smuzhiyun * previously, so the blanket update did not find this variable.
45*4882a593Smuzhiyun */
env_callback_init(ENTRY * var_entry)46*4882a593Smuzhiyun void env_callback_init(ENTRY *var_entry)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun const char *var_name = var_entry->key;
49*4882a593Smuzhiyun char callback_name[256] = "";
50*4882a593Smuzhiyun struct env_clbk_tbl *clbkp;
51*4882a593Smuzhiyun int ret = 1;
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun if (first_call) {
54*4882a593Smuzhiyun callback_list = env_get(ENV_CALLBACK_VAR);
55*4882a593Smuzhiyun first_call = 0;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun /* look in the ".callbacks" var for a reference to this variable */
59*4882a593Smuzhiyun if (callback_list != NULL)
60*4882a593Smuzhiyun ret = env_attr_lookup(callback_list, var_name, callback_name);
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun /* only if not found there, look in the static list */
63*4882a593Smuzhiyun if (ret)
64*4882a593Smuzhiyun ret = env_attr_lookup(ENV_CALLBACK_LIST_STATIC, var_name,
65*4882a593Smuzhiyun callback_name);
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun /* if an association was found, set the callback pointer */
68*4882a593Smuzhiyun if (!ret && strlen(callback_name)) {
69*4882a593Smuzhiyun clbkp = find_env_callback(callback_name);
70*4882a593Smuzhiyun if (clbkp != NULL)
71*4882a593Smuzhiyun #if defined(CONFIG_NEEDS_MANUAL_RELOC)
72*4882a593Smuzhiyun var_entry->callback = clbkp->callback + gd->reloc_off;
73*4882a593Smuzhiyun #else
74*4882a593Smuzhiyun var_entry->callback = clbkp->callback;
75*4882a593Smuzhiyun #endif
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun /*
80*4882a593Smuzhiyun * Called on each existing env var prior to the blanket update since removing
81*4882a593Smuzhiyun * a callback association should remove its callback.
82*4882a593Smuzhiyun */
clear_callback(ENTRY * entry)83*4882a593Smuzhiyun static int clear_callback(ENTRY *entry)
84*4882a593Smuzhiyun {
85*4882a593Smuzhiyun entry->callback = NULL;
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun return 0;
88*4882a593Smuzhiyun }
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun /*
91*4882a593Smuzhiyun * Call for each element in the list that associates variables to callbacks
92*4882a593Smuzhiyun */
set_callback(const char * name,const char * value,void * priv)93*4882a593Smuzhiyun static int set_callback(const char *name, const char *value, void *priv)
94*4882a593Smuzhiyun {
95*4882a593Smuzhiyun ENTRY e, *ep;
96*4882a593Smuzhiyun struct env_clbk_tbl *clbkp;
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun e.key = name;
99*4882a593Smuzhiyun e.data = NULL;
100*4882a593Smuzhiyun e.callback = NULL;
101*4882a593Smuzhiyun hsearch_r(e, FIND, &ep, &env_htab, 0);
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun /* does the env variable actually exist? */
104*4882a593Smuzhiyun if (ep != NULL) {
105*4882a593Smuzhiyun /* the assocaition delares no callback, so remove the pointer */
106*4882a593Smuzhiyun if (value == NULL || strlen(value) == 0)
107*4882a593Smuzhiyun ep->callback = NULL;
108*4882a593Smuzhiyun else {
109*4882a593Smuzhiyun /* assign the requested callback */
110*4882a593Smuzhiyun clbkp = find_env_callback(value);
111*4882a593Smuzhiyun if (clbkp != NULL)
112*4882a593Smuzhiyun #if defined(CONFIG_NEEDS_MANUAL_RELOC)
113*4882a593Smuzhiyun ep->callback = clbkp->callback + gd->reloc_off;
114*4882a593Smuzhiyun #else
115*4882a593Smuzhiyun ep->callback = clbkp->callback;
116*4882a593Smuzhiyun #endif
117*4882a593Smuzhiyun }
118*4882a593Smuzhiyun }
119*4882a593Smuzhiyun
120*4882a593Smuzhiyun return 0;
121*4882a593Smuzhiyun }
122*4882a593Smuzhiyun
on_callbacks(const char * name,const char * value,enum env_op op,int flags)123*4882a593Smuzhiyun static int on_callbacks(const char *name, const char *value, enum env_op op,
124*4882a593Smuzhiyun int flags)
125*4882a593Smuzhiyun {
126*4882a593Smuzhiyun /* remove all callbacks */
127*4882a593Smuzhiyun hwalk_r(&env_htab, clear_callback);
128*4882a593Smuzhiyun
129*4882a593Smuzhiyun /* configure any static callback bindings */
130*4882a593Smuzhiyun env_attr_walk(ENV_CALLBACK_LIST_STATIC, set_callback, NULL);
131*4882a593Smuzhiyun /* configure any dynamic callback bindings */
132*4882a593Smuzhiyun env_attr_walk(value, set_callback, NULL);
133*4882a593Smuzhiyun
134*4882a593Smuzhiyun return 0;
135*4882a593Smuzhiyun }
136*4882a593Smuzhiyun U_BOOT_ENV_CALLBACK(callbacks, on_callbacks);
137