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Release 4.14 arch/mn10300/include/asm/spinlock.h

/* MN10300 spinlock support
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#ifndef _ASM_SPINLOCK_H

#define _ASM_SPINLOCK_H

#include <linux/atomic.h>
#include <asm/barrier.h>
#include <asm/processor.h>
#include <asm/rwlock.h>
#include <asm/page.h>

/*
 * Simple spin lock operations.  There are two variants, one clears IRQ's
 * on the local processor, one does not.
 *
 * We make no fairness assumptions. They have a cost.
 */


#define arch_spin_is_locked(x)	(*(volatile signed char *)(&(x)->slock) != 0)


static inline void arch_spin_unlock(arch_spinlock_t *lock) { asm volatile( " bclr 1,(0,%0) \n" : : "a"(&lock->slock) : "memory", "cc"); }

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Akira Takeuchi14100.00%1100.00%
Total14100.00%1100.00%


static inline int arch_spin_trylock(arch_spinlock_t *lock) { int ret; asm volatile( " mov 1,%0 \n" " bset %0,(%1) \n" " bne 1f \n" " clr %0 \n" "1: xor 1,%0 \n" : "=d"(ret) : "a"(&lock->slock) : "memory", "cc"); return ret; }

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Akira Takeuchi20100.00%1100.00%
Total20100.00%1100.00%


static inline void arch_spin_lock(arch_spinlock_t *lock) { asm volatile( "1: bset 1,(0,%0) \n" " bne 1b \n" : : "a"(&lock->slock) : "memory", "cc"); }

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Akira Takeuchi14100.00%1100.00%
Total14100.00%1100.00%


static inline void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags) { int temp; asm volatile( "1: bset 1,(0,%2) \n" " beq 3f \n" " mov %1,epsw \n" "2: mov (0,%2),%0 \n" " or %0,%0 \n" " bne 2b \n" " mov %3,%0 \n" " mov %0,epsw \n" " nop \n" " nop \n" " bra 1b\n" "3: \n" : "=&d" (temp) : "d" (flags), "a"(&lock->slock), "i"(EPSW_IE | MN10300_CLI_LEVEL) : "memory", "cc"); }

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Akira Takeuchi21100.00%1100.00%
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#ifdef __KERNEL__ /* * Read-write spinlocks, allowing multiple readers * but only one writer. * * NOTE! it is quite common to have readers in interrupts * but no interrupt writers. For those circumstances we * can "mix" irq-safe locks - any writer needs to get a * irq-safe write-lock, but readers can get non-irqsafe * read-locks. */ /** * read_can_lock - would read_trylock() succeed? * @lock: the rwlock in question. */ #define arch_read_can_lock(x) ((int)(x)->lock > 0) /** * write_can_lock - would write_trylock() succeed? * @lock: the rwlock in question. */ #define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) /* * On mn10300, we implement read-write locks as a 32-bit counter * with the high bit (sign) being the "contended" bit. */
static inline void arch_read_lock(arch_rwlock_t *rw) { #if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT __build_read_lock(rw, "__read_lock_failed"); #else { atomic_t *count = (atomic_t *)rw; while (atomic_dec_return(count) < 0) atomic_inc(count); } #endif }

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Akira Takeuchi46100.00%1100.00%
Total46100.00%1100.00%


static inline void arch_write_lock(arch_rwlock_t *rw) { #if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT __build_write_lock(rw, "__write_lock_failed"); #else { atomic_t *count = (atomic_t *)rw; while (!atomic_sub_and_test(RW_LOCK_BIAS, count)) atomic_add(RW_LOCK_BIAS, count); } #endif }

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Akira Takeuchi49100.00%1100.00%
Total49100.00%1100.00%


static inline void arch_read_unlock(arch_rwlock_t *rw) { #if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT __build_read_unlock(rw); #else { atomic_t *count = (atomic_t *)rw; atomic_inc(count); } #endif }

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Akira Takeuchi37100.00%1100.00%
Total37100.00%1100.00%


static inline void arch_write_unlock(arch_rwlock_t *rw) { #if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT __build_write_unlock(rw); #else { atomic_t *count = (atomic_t *)rw; atomic_add(RW_LOCK_BIAS, count); } #endif }

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Akira Takeuchi39100.00%1100.00%
Total39100.00%1100.00%


static inline int arch_read_trylock(arch_rwlock_t *lock) { atomic_t *count = (atomic_t *)lock; atomic_dec(count); if (atomic_read(count) >= 0) return 1; atomic_inc(count); return 0; }

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Akira Takeuchi46100.00%1100.00%
Total46100.00%1100.00%


static inline int arch_write_trylock(arch_rwlock_t *lock) { atomic_t *count = (atomic_t *)lock; if (atomic_sub_and_test(RW_LOCK_BIAS, count)) return 1; atomic_add(RW_LOCK_BIAS, count); return 0; }

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Akira Takeuchi43100.00%1100.00%
Total43100.00%1100.00%

#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) #define _raw_spin_relax(lock) cpu_relax() #define _raw_read_relax(lock) cpu_relax() #define _raw_write_relax(lock) cpu_relax() #endif /* __KERNEL__ */ #endif /* _ASM_SPINLOCK_H */

Overall Contributors

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Akira Takeuchi40896.00%125.00%
David Howells102.35%125.00%
Peter Zijlstra61.41%125.00%
Arun Sharma10.24%125.00%
Total425100.00%4100.00%
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