mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 17:08:10 +00:00
c430728526
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
131 lines
3.9 KiB
C
131 lines
3.9 KiB
C
/*
|
|
* net/tipc/ref.h: Include file for TIPC object registry code
|
|
*
|
|
* Copyright (c) 1991-2006, Ericsson AB
|
|
* Copyright (c) 2005, Wind River Systems
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the names of the copyright holders nor the names of its
|
|
* contributors may be used to endorse or promote products derived from
|
|
* this software without specific prior written permission.
|
|
*
|
|
* Alternatively, this software may be distributed under the terms of the
|
|
* GNU General Public License ("GPL") version 2 as published by the Free
|
|
* Software Foundation.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef _TIPC_REF_H
|
|
#define _TIPC_REF_H
|
|
|
|
/**
|
|
* struct reference - TIPC object reference entry
|
|
* @object: pointer to object associated with reference entry
|
|
* @lock: spinlock controlling access to object
|
|
* @data: reference value associated with object (or link to next unused entry)
|
|
*/
|
|
|
|
struct reference {
|
|
void *object;
|
|
spinlock_t lock;
|
|
union {
|
|
u32 next_plus_upper;
|
|
u32 reference;
|
|
} data;
|
|
};
|
|
|
|
/**
|
|
* struct tipc_ref_table - table of TIPC object reference entries
|
|
* @entries: pointer to array of reference entries
|
|
* @index_mask: bitmask for array index portion of reference values
|
|
* @first_free: array index of first unused object reference entry
|
|
* @last_free: array index of last unused object reference entry
|
|
*/
|
|
|
|
struct ref_table {
|
|
struct reference *entries;
|
|
u32 index_mask;
|
|
u32 first_free;
|
|
u32 last_free;
|
|
};
|
|
|
|
extern struct ref_table tipc_ref_table;
|
|
|
|
int tipc_ref_table_init(u32 requested_size, u32 start);
|
|
void tipc_ref_table_stop(void);
|
|
|
|
u32 tipc_ref_acquire(void *object, spinlock_t **lock);
|
|
void tipc_ref_discard(u32 ref);
|
|
|
|
|
|
/**
|
|
* tipc_ref_lock - lock referenced object and return pointer to it
|
|
*/
|
|
|
|
static inline void *tipc_ref_lock(u32 ref)
|
|
{
|
|
if (likely(tipc_ref_table.entries)) {
|
|
struct reference *r =
|
|
&tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
|
|
|
|
spin_lock_bh(&r->lock);
|
|
if (likely(r->data.reference == ref))
|
|
return r->object;
|
|
spin_unlock_bh(&r->lock);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* tipc_ref_unlock - unlock referenced object
|
|
*/
|
|
|
|
static inline void tipc_ref_unlock(u32 ref)
|
|
{
|
|
if (likely(tipc_ref_table.entries)) {
|
|
struct reference *r =
|
|
&tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
|
|
|
|
if (likely(r->data.reference == ref))
|
|
spin_unlock_bh(&r->lock);
|
|
else
|
|
err("tipc_ref_unlock() invoked using obsolete reference\n");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tipc_ref_deref - return pointer referenced object (without locking it)
|
|
*/
|
|
|
|
static inline void *tipc_ref_deref(u32 ref)
|
|
{
|
|
if (likely(tipc_ref_table.entries)) {
|
|
struct reference *r =
|
|
&tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
|
|
|
|
if (likely(r->data.reference == ref))
|
|
return r->object;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
#endif
|