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/*
* Helpers used by both rw spinlocks and rw semaphores.
*
* Based in part on code from semaphore.h and
* spinlock.h Copyright 1996 Linus Torvalds.
*
* Copyright 1999 Red Hat, Inc.
*
* Written by Benjamin LaHaise.
*
* Modified by Matsushita Electric Industrial Co., Ltd.
* Modifications:
* 13-Nov-2006 MEI Temporarily delete lock functions for SMP support.
*
* 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.
*/
#ifndef _ASM_RWLOCK_H
#define _ASM_RWLOCK_H
#define RW_LOCK_BIAS 0x01000000
#ifndef CONFIG_SMP
typedef struct { unsigned long a[100]; } __dummy_lock_t;
#define __dummy_lock(lock) (*(__dummy_lock_t *)(lock))
#define RW_LOCK_BIAS_STR "0x01000000"
#define __build_read_lock_ptr(rw, helper) \
do { \
asm volatile( \
" mov (%0),d3 \n" \
" sub 1,d3 \n" \
" mov d3,(%0) \n" \
" blt 1f \n" \
" bra 2f \n" \
"1: jmp 3f \n" \
"2: \n" \
" .section .text.lock,\"ax\" \n" \
"3: call "helper"[],0 \n" \
" jmp 2b \n" \
" .previous" \
: \
: "d" (rw) \
: "memory", "d3", "cc"); \
} while (0)
#define __build_read_lock_const(rw, helper) \
do { \
asm volatile( \
" mov (%0),d3 \n" \
" sub 1,d3 \n" \
" mov d3,(%0) \n" \
" blt 1f \n" \
" bra 2f \n" \
"1: jmp 3f \n" \
"2: \n" \
" .section .text.lock,\"ax\" \n" \
"3: call "helper"[],0 \n" \
" jmp 2b \n" \
" .previous" \
: \
: "d" (rw) \
: "memory", "d3", "cc"); \
} while (0)
#define __build_read_lock(rw, helper) \
do { \
if (__builtin_constant_p(rw)) \
__build_read_lock_const(rw, helper); \
else \
__build_read_lock_ptr(rw, helper); \
} while (0)
#define __build_write_lock_ptr(rw, helper) \
do { \
asm volatile( \
" mov (%0),d3 \n" \
" sub 1,d3 \n" \
" mov d3,(%0) \n" \
" blt 1f \n" \
" bra 2f \n" \
"1: jmp 3f \n" \
"2: \n" \
" .section .text.lock,\"ax\" \n" \
"3: call "helper"[],0 \n" \
" jmp 2b \n" \
" .previous" \
: \
: "d" (rw) \
: "memory", "d3", "cc"); \
} while (0)
#define __build_write_lock_const(rw, helper) \
do { \
asm volatile( \
" mov (%0),d3 \n" \
" sub 1,d3 \n" \
" mov d3,(%0) \n" \
" blt 1f \n" \
" bra 2f \n" \
"1: jmp 3f \n" \
"2: \n" \
" .section .text.lock,\"ax\" \n" \
"3: call "helper"[],0 \n" \
" jmp 2b \n" \
" .previous" \
: \
: "d" (rw) \
: "memory", "d3", "cc"); \
} while (0)
#define __build_write_lock(rw, helper) \
do { \
if (__builtin_constant_p(rw)) \
__build_write_lock_const(rw, helper); \
else \
__build_write_lock_ptr(rw, helper); \
} while (0)
#endif /* CONFIG_SMP */
#endif /* _ASM_RWLOCK_H */
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