e0386005ff
Use cmpxchg() to get rid of spinlocks in inet_add_protocol() and friends. inet_protos[] & inet6_protos[] are moved to read_mostly section Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
52 lines
1.5 KiB
C
52 lines
1.5 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* PF_INET6 protocol dispatch tables.
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*
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* Authors: Pedro Roque <roque@di.fc.ul.pt>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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/*
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* Changes:
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*
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* Vince Laviano (vince@cs.stanford.edu) 16 May 2001
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* - Removed unused variable 'inet6_protocol_base'
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* - Modified inet6_del_protocol() to correctly maintain copy bit.
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*/
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/spinlock.h>
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#include <net/protocol.h>
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const struct inet6_protocol *inet6_protos[MAX_INET_PROTOS] __read_mostly;
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int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char protocol)
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{
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int hash = protocol & (MAX_INET_PROTOS - 1);
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return !cmpxchg(&inet6_protos[hash], NULL, prot) ? 0 : -1;
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}
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EXPORT_SYMBOL(inet6_add_protocol);
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/*
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* Remove a protocol from the hash tables.
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*/
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int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char protocol)
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{
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int ret, hash = protocol & (MAX_INET_PROTOS - 1);
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ret = (cmpxchg(&inet6_protos[hash], prot, NULL) == prot) ? 0 : -1;
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synchronize_net();
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return ret;
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}
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EXPORT_SYMBOL(inet6_del_protocol);
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