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path: root/include/linux/rcutiny.h
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/*
 * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright IBM Corporation, 2008
 *
 * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
 *
 * For detailed explanation of Read-Copy Update mechanism see -
 *		Documentation/RCU
 */
#ifndef __LINUX_TINY_H
#define __LINUX_TINY_H

#include <linux/cache.h>

void rcu_sched_qs(int cpu);
void rcu_bh_qs(int cpu);

#define __rcu_read_lock()	preempt_disable()
#define __rcu_read_unlock()	preempt_enable()
#define __rcu_read_lock_bh()	local_bh_disable()
#define __rcu_read_unlock_bh()	local_bh_enable()
#define call_rcu_sched		call_rcu

#define rcu_init_sched()	do { } while (0)
extern void rcu_check_callbacks(int cpu, int user);

static inline int rcu_needs_cpu(int cpu)
{
	return 0;
}

/*
 * Return the number of grace periods.
 */
static inline long rcu_batches_completed(void)
{
	return 0;
}

/*
 * Return the number of bottom-half grace periods.
 */
static inline long rcu_batches_completed_bh(void)
{
	return 0;
}

extern int rcu_expedited_torture_stats(char *page);

static inline void rcu_force_quiescent_state(void)
{
}

static inline void rcu_bh_force_quiescent_state(void)
{
}

static inline void rcu_sched_force_quiescent_state(void)
{
}

#define synchronize_rcu synchronize_sched

static inline void synchronize_rcu_expedited(void)
{
	synchronize_sched();
}

static inline void synchronize_rcu_bh_expedited(void)
{
	synchronize_sched();
}

struct notifier_block;

#ifdef CONFIG_NO_HZ

extern void rcu_enter_nohz(void);
extern void rcu_exit_nohz(void);

#else /* #ifdef CONFIG_NO_HZ */

static inline void rcu_enter_nohz(void)
{
}

static inline void rcu_exit_nohz(void)
{
}

#endif /* #else #ifdef CONFIG_NO_HZ */

static inline void exit_rcu(void)
{
}

static inline int rcu_preempt_depth(void)
{
	return 0;
}

#endif /* __LINUX_RCUTINY_H */
lass="hl opt">->description); if (subtype) { seq_puts(m, ": "); subtype->describe(key, m); if (kid) { seq_putc(m, ' '); n = strlen(kid); if (n <= 8) seq_puts(m, kid); else seq_puts(m, kid + n - 8); } seq_puts(m, " ["); /* put something here to indicate the key's capabilities */ seq_putc(m, ']'); } } /* * Preparse a asymmetric payload to get format the contents appropriately for the * internal payload to cut down on the number of scans of the data performed. * * We also generate a proposed description from the contents of the key that * can be used to name the key if the user doesn't want to provide one. */ static int asymmetric_key_preparse(struct key_preparsed_payload *prep) { struct asymmetric_key_parser *parser; int ret; pr_devel("==>%s()\n", __func__); if (prep->datalen == 0) return -EINVAL; down_read(&asymmetric_key_parsers_sem); ret = -EBADMSG; list_for_each_entry(parser, &asymmetric_key_parsers, link) { pr_debug("Trying parser '%s'\n", parser->name); ret = parser->parse(prep); if (ret != -EBADMSG) { pr_debug("Parser recognised the format (ret %d)\n", ret); break; } } up_read(&asymmetric_key_parsers_sem); pr_devel("<==%s() = %d\n", __func__, ret); return ret; } /* * Clean up the preparse data */ static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep) { struct asymmetric_key_subtype *subtype = prep->type_data[0]; pr_devel("==>%s()\n", __func__); if (subtype) { subtype->destroy(prep->payload); module_put(subtype->owner); } kfree(prep->type_data[1]); kfree(prep->description); } /* * Instantiate a asymmetric_key defined key. The key was preparsed, so we just * have to transfer the data here. */ static int asymmetric_key_instantiate(struct key *key, struct key_preparsed_payload *prep) { int ret; pr_devel("==>%s()\n", __func__); ret = key_payload_reserve(key, prep->quotalen); if (ret == 0) { key->type_data.p[0] = prep->type_data[0]; key->type_data.p[1] = prep->type_data[1]; key->payload.data = prep->payload; prep->type_data[0] = NULL; prep->type_data[1] = NULL; prep->payload = NULL; } pr_devel("<==%s() = %d\n", __func__, ret); return ret; } /* * dispose of the data dangling from the corpse of a asymmetric key */ static void asymmetric_key_destroy(struct key *key) { struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key); if (subtype) { subtype->destroy(key->payload.data); module_put(subtype->owner); key->type_data.p[0] = NULL; } kfree(key->type_data.p[1]); key->type_data.p[1] = NULL; } struct key_type key_type_asymmetric = { .name = "asymmetric", .preparse = asymmetric_key_preparse, .free_preparse = asymmetric_key_free_preparse, .instantiate = asymmetric_key_instantiate, .match = asymmetric_key_match, .destroy = asymmetric_key_destroy, .describe = asymmetric_key_describe, }; EXPORT_SYMBOL_GPL(key_type_asymmetric); /** * register_asymmetric_key_parser - Register a asymmetric key blob parser * @parser: The parser to register */ int register_asymmetric_key_parser(struct asymmetric_key_parser *parser) { struct asymmetric_key_parser *cursor; int ret; down_write(&asymmetric_key_parsers_sem); list_for_each_entry(cursor, &asymmetric_key_parsers, link) { if (strcmp(cursor->name, parser->name) == 0) { pr_err("Asymmetric key parser '%s' already registered\n", parser->name); ret = -EEXIST; goto out; } } list_add_tail(&parser->link, &asymmetric_key_parsers); pr_notice("Asymmetric key parser '%s' registered\n", parser->name); ret = 0; out: up_write(&asymmetric_key_parsers_sem); return ret; } EXPORT_SYMBOL_GPL(register_asymmetric_key_parser); /** * unregister_asymmetric_key_parser - Unregister a asymmetric key blob parser * @parser: The parser to unregister */ void unregister_asymmetric_key_parser(struct asymmetric_key_parser *parser) { down_write(&asymmetric_key_parsers_sem); list_del(&parser->link); up_write(&asymmetric_key_parsers_sem); pr_notice("Asymmetric key parser '%s' unregistered\n", parser->name); } EXPORT_SYMBOL_GPL(unregister_asymmetric_key_parser); /* * Module stuff */ static int __init asymmetric_key_init(void) { return register_key_type(&key_type_asymmetric); } static void __exit asymmetric_key_cleanup(void) { unregister_key_type(&key_type_asymmetric); } module_init(asymmetric_key_init); module_exit(asymmetric_key_cleanup);