mirror of https://gitee.com/openkylin/linux.git
126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
/*
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* Helpers used by both rw spinlocks and rw semaphores.
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*
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* Based in part on code from semaphore.h and
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* spinlock.h Copyright 1996 Linus Torvalds.
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*
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* Copyright 1999 Red Hat, Inc.
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*
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* Written by Benjamin LaHaise.
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*
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* Modified by Matsushita Electric Industrial Co., Ltd.
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* Modifications:
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* 13-Nov-2006 MEI Temporarily delete lock functions for SMP support.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*/
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#ifndef _ASM_RWLOCK_H
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#define _ASM_RWLOCK_H
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#define RW_LOCK_BIAS 0x01000000
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#ifndef CONFIG_SMP
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typedef struct { unsigned long a[100]; } __dummy_lock_t;
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#define __dummy_lock(lock) (*(__dummy_lock_t *)(lock))
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#define RW_LOCK_BIAS_STR "0x01000000"
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#define __build_read_lock_ptr(rw, helper) \
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do { \
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asm volatile( \
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" mov (%0),d3 \n" \
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" sub 1,d3 \n" \
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" mov d3,(%0) \n" \
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" blt 1f \n" \
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" bra 2f \n" \
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"1: jmp 3f \n" \
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"2: \n" \
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" .section .text.lock,\"ax\" \n" \
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"3: call "helper"[],0 \n" \
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" jmp 2b \n" \
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" .previous" \
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: \
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: "d" (rw) \
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: "memory", "d3", "cc"); \
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} while (0)
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#define __build_read_lock_const(rw, helper) \
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do { \
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asm volatile( \
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" mov (%0),d3 \n" \
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" sub 1,d3 \n" \
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" mov d3,(%0) \n" \
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" blt 1f \n" \
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" bra 2f \n" \
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"1: jmp 3f \n" \
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"2: \n" \
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" .section .text.lock,\"ax\" \n" \
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"3: call "helper"[],0 \n" \
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" jmp 2b \n" \
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" .previous" \
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: \
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: "d" (rw) \
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: "memory", "d3", "cc"); \
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} while (0)
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#define __build_read_lock(rw, helper) \
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do { \
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if (__builtin_constant_p(rw)) \
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__build_read_lock_const(rw, helper); \
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else \
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__build_read_lock_ptr(rw, helper); \
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} while (0)
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#define __build_write_lock_ptr(rw, helper) \
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do { \
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asm volatile( \
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" mov (%0),d3 \n" \
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" sub 1,d3 \n" \
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" mov d3,(%0) \n" \
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" blt 1f \n" \
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" bra 2f \n" \
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"1: jmp 3f \n" \
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"2: \n" \
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" .section .text.lock,\"ax\" \n" \
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"3: call "helper"[],0 \n" \
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" jmp 2b \n" \
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" .previous" \
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: \
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: "d" (rw) \
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: "memory", "d3", "cc"); \
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} while (0)
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#define __build_write_lock_const(rw, helper) \
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do { \
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asm volatile( \
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" mov (%0),d3 \n" \
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" sub 1,d3 \n" \
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" mov d3,(%0) \n" \
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" blt 1f \n" \
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" bra 2f \n" \
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"1: jmp 3f \n" \
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"2: \n" \
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" .section .text.lock,\"ax\" \n" \
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"3: call "helper"[],0 \n" \
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" jmp 2b \n" \
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" .previous" \
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: \
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: "d" (rw) \
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: "memory", "d3", "cc"); \
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} while (0)
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#define __build_write_lock(rw, helper) \
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do { \
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if (__builtin_constant_p(rw)) \
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__build_write_lock_const(rw, helper); \
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else \
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__build_write_lock_ptr(rw, helper); \
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} while (0)
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#endif /* CONFIG_SMP */
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#endif /* _ASM_RWLOCK_H */
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