[thirdparty/u-boot.git] / env / callback.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2012
 * Joe Hershberger, National Instruments, joe.hershberger@ni.com
 */

#include <common.h>
#include <environment.h>

#if defined(CONFIG_NEEDS_MANUAL_RELOC)
DECLARE_GLOBAL_DATA_PTR;
#endif

/*
 * Look up a callback function pointer by name
 */
static struct env_clbk_tbl *find_env_callback(const char *name)
{
	struct env_clbk_tbl *clbkp;
	int i;
	int num_callbacks = ll_entry_count(struct env_clbk_tbl, env_clbk);

	if (name == NULL)
		return NULL;

	/* look up the callback in the linker-list */
	for (i = 0, clbkp = ll_entry_start(struct env_clbk_tbl, env_clbk);
	     i < num_callbacks;
	     i++, clbkp++) {
		if (strcmp(name, clbkp->name) == 0)
			return clbkp;
	}

	return NULL;
}

static int first_call = 1;
static const char *callback_list;

/*
 * Look for a possible callback for a newly added variable
 * This is called specifically when the variable did not exist in the hash
 * previously, so the blanket update did not find this variable.
 */
void env_callback_init(ENTRY *var_entry)
{
	const char *var_name = var_entry->key;
	char callback_name[256] = "";
	struct env_clbk_tbl *clbkp;
	int ret = 1;

	if (first_call) {
		callback_list = env_get(ENV_CALLBACK_VAR);
		first_call = 0;
	}

	/* look in the ".callbacks" var for a reference to this variable */
	if (callback_list != NULL)
		ret = env_attr_lookup(callback_list, var_name, callback_name);

	/* only if not found there, look in the static list */
	if (ret)
		ret = env_attr_lookup(ENV_CALLBACK_LIST_STATIC, var_name,
			callback_name);

	/* if an association was found, set the callback pointer */
	if (!ret && strlen(callback_name)) {
		clbkp = find_env_callback(callback_name);
		if (clbkp != NULL)
#if defined(CONFIG_NEEDS_MANUAL_RELOC)
			var_entry->callback = clbkp->callback + gd->reloc_off;
#else
			var_entry->callback = clbkp->callback;
#endif
	}
}

/*
 * Called on each existing env var prior to the blanket update since removing
 * a callback association should remove its callback.
 */
static int clear_callback(ENTRY *entry)
{
	entry->callback = NULL;

	return 0;
}

/*
 * Call for each element in the list that associates variables to callbacks
 */
static int set_callback(const char *name, const char *value, void *priv)
{
	ENTRY e, *ep;
	struct env_clbk_tbl *clbkp;

	e.key	= name;
	e.data	= NULL;
	e.callback = NULL;
	hsearch_r(e, FIND, &ep, &env_htab, 0);

	/* does the env variable actually exist? */
	if (ep != NULL) {
		/* the assocaition delares no callback, so remove the pointer */
		if (value == NULL || strlen(value) == 0)
			ep->callback = NULL;
		else {
			/* assign the requested callback */
			clbkp = find_env_callback(value);
			if (clbkp != NULL)
#if defined(CONFIG_NEEDS_MANUAL_RELOC)
				ep->callback = clbkp->callback + gd->reloc_off;
#else
				ep->callback = clbkp->callback;
#endif
		}
	}

	return 0;
}

static int on_callbacks(const char *name, const char *value, enum env_op op,
	int flags)
{
	/* remove all callbacks */
	hwalk_r(&env_htab, clear_callback);

	/* configure any static callback bindings */
	env_attr_walk(ENV_CALLBACK_LIST_STATIC, set_callback, NULL);
	/* configure any dynamic callback bindings */
	env_attr_walk(value, set_callback, NULL);

	return 0;
}
U_BOOT_ENV_CALLBACK(callbacks, on_callbacks);
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
170ab110 JH	2	/*
	3	* (C) Copyright 2012
	4	* Joe Hershberger, National Instruments, joe.hershberger@ni.com
170ab110 JH	5	*/
	6
	7	#include <common.h>
	8	#include <environment.h>
	9
	10	#if defined(CONFIG_NEEDS_MANUAL_RELOC)
	11	DECLARE_GLOBAL_DATA_PTR;
	12	#endif
	13
	14	/*
	15	* Look up a callback function pointer by name
	16	*/
268d966d	17	static struct env_clbk_tbl find_env_callback(const char name)
170ab110 JH	18	{
	19	struct env_clbk_tbl *clbkp;
	20	int i;
	21	int num_callbacks = ll_entry_count(struct env_clbk_tbl, env_clbk);
	22
	23	if (name == NULL)
	24	return NULL;
	25
	26	/* look up the callback in the linker-list */
	27	for (i = 0, clbkp = ll_entry_start(struct env_clbk_tbl, env_clbk);
	28	i < num_callbacks;
	29	i++, clbkp++) {
	30	if (strcmp(name, clbkp->name) == 0)
	31	return clbkp;
	32	}
	33
	34	return NULL;
	35	}
	36
1b610271 HS	37	static int first_call = 1;
	38	static const char *callback_list;
	39
170ab110 JH	40	/*
	41	* Look for a possible callback for a newly added variable
	42	* This is called specifically when the variable did not exist in the hash
	43	* previously, so the blanket update did not find this variable.
	44	*/
	45	void env_callback_init(ENTRY *var_entry)
	46	{
	47	const char *var_name = var_entry->key;
170ab110 JH	48	char callback_name[256] = "";
	49	struct env_clbk_tbl *clbkp;
	50	int ret = 1;
	51
1b610271	52	if (first_call) {
00caae6d	53	callback_list = env_get(ENV_CALLBACK_VAR);
1b610271 HS	54	first_call = 0;
	55	}
	56
170ab110 JH	57	/* look in the ".callbacks" var for a reference to this variable */
	58	if (callback_list != NULL)
	59	ret = env_attr_lookup(callback_list, var_name, callback_name);
	60
	61	/* only if not found there, look in the static list */
	62	if (ret)
	63	ret = env_attr_lookup(ENV_CALLBACK_LIST_STATIC, var_name,
	64	callback_name);
	65
	66	/* if an association was found, set the callback pointer */
	67	if (!ret && strlen(callback_name)) {
	68	clbkp = find_env_callback(callback_name);
	69	if (clbkp != NULL)
	70	#if defined(CONFIG_NEEDS_MANUAL_RELOC)
	71	var_entry->callback = clbkp->callback + gd->reloc_off;
	72	#else
	73	var_entry->callback = clbkp->callback;
	74	#endif
	75	}
	76	}
	77
	78	/*
	79	* Called on each existing env var prior to the blanket update since removing
	80	* a callback association should remove its callback.
	81	*/
	82	static int clear_callback(ENTRY *entry)
	83	{
	84	entry->callback = NULL;
	85
	86	return 0;
	87	}
	88
	89	/*
	90	* Call for each element in the list that associates variables to callbacks
	91	*/
cca98fd6	92	static int set_callback(const char name, const char value, void *priv)
170ab110 JH	93	{
	94	ENTRY e, *ep;
	95	struct env_clbk_tbl *clbkp;
	96
	97	e.key = name;
	98	e.data = NULL;
5a689439	99	e.callback = NULL;
170ab110 JH	100	hsearch_r(e, FIND, &ep, &env_htab, 0);
	101
	102	/* does the env variable actually exist? */
	103	if (ep != NULL) {
	104	/* the assocaition delares no callback, so remove the pointer */
	105	if (value == NULL \|\| strlen(value) == 0)
	106	ep->callback = NULL;
	107	else {
	108	/* assign the requested callback */
	109	clbkp = find_env_callback(value);
	110	if (clbkp != NULL)
	111	#if defined(CONFIG_NEEDS_MANUAL_RELOC)
	112	ep->callback = clbkp->callback + gd->reloc_off;
	113	#else
	114	ep->callback = clbkp->callback;
	115	#endif
	116	}
	117	}
	118
	119	return 0;
	120	}
	121
	122	static int on_callbacks(const char name, const char value, enum env_op op,
	123	int flags)
	124	{
	125	/* remove all callbacks */
	126	hwalk_r(&env_htab, clear_callback);
	127
	128	/* configure any static callback bindings */
cca98fd6	129	env_attr_walk(ENV_CALLBACK_LIST_STATIC, set_callback, NULL);
170ab110	130	/* configure any dynamic callback bindings */
cca98fd6	131	env_attr_walk(value, set_callback, NULL);
170ab110 JH	132
	133	return 0;
	134	}
	135	U_BOOT_ENV_CALLBACK(callbacks, on_callbacks);