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Release 4.14 arch/sh/include/asm/spinlock-llsc.h

/*
 * include/asm-sh/spinlock-llsc.h
 *
 * Copyright (C) 2002, 2003 Paul Mundt
 * Copyright (C) 2006, 2007 Akio Idehara
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#ifndef __ASM_SH_SPINLOCK_LLSC_H

#define __ASM_SH_SPINLOCK_LLSC_H

#include <asm/barrier.h>
#include <asm/processor.h>

/*
 * Your basic SMP spinlocks, allowing only a single CPU anywhere
 */


#define arch_spin_is_locked(x)		((x)->lock <= 0)

#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock)

/*
 * 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.
 */

static inline void arch_spin_lock(arch_spinlock_t *lock) { unsigned long tmp; unsigned long oldval; __asm__ __volatile__ ( "1: \n\t" "movli.l @%2, %0 ! arch_spin_lock \n\t" "mov %0, %1 \n\t" "mov #0, %0 \n\t" "movco.l %0, @%2 \n\t" "bf 1b \n\t" "cmp/pl %1 \n\t" "bf 1b \n\t" : "=&z" (tmp), "=&r" (oldval) : "r" (&lock->lock) : "t", "memory" ); }

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static inline void arch_spin_unlock(arch_spinlock_t *lock) { unsigned long tmp; __asm__ __volatile__ ( "mov #1, %0 ! arch_spin_unlock \n\t" "mov.l %0, @%1 \n\t" : "=&z" (tmp) : "r" (&lock->lock) : "t", "memory" ); }

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static inline int arch_spin_trylock(arch_spinlock_t *lock) { unsigned long tmp, oldval; __asm__ __volatile__ ( "1: \n\t" "movli.l @%2, %0 ! arch_spin_trylock \n\t" "mov %0, %1 \n\t" "mov #0, %0 \n\t" "movco.l %0, @%2 \n\t" "bf 1b \n\t" "synco \n\t" : "=&z" (tmp), "=&r" (oldval) : "r" (&lock->lock) : "t", "memory" ); return oldval; }

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/* * 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) ((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)
static inline void arch_read_lock(arch_rwlock_t *rw) { unsigned long tmp; __asm__ __volatile__ ( "1: \n\t" "movli.l @%1, %0 ! arch_read_lock \n\t" "cmp/pl %0 \n\t" "bf 1b \n\t" "add #-1, %0 \n\t" "movco.l %0, @%1 \n\t" "bf 1b \n\t" : "=&z" (tmp) : "r" (&rw->lock) : "t", "memory" ); }

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static inline void arch_read_unlock(arch_rwlock_t *rw) { unsigned long tmp; __asm__ __volatile__ ( "1: \n\t" "movli.l @%1, %0 ! arch_read_unlock \n\t" "add #1, %0 \n\t" "movco.l %0, @%1 \n\t" "bf 1b \n\t" : "=&z" (tmp) : "r" (&rw->lock) : "t", "memory" ); }

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static inline void arch_write_lock(arch_rwlock_t *rw) { unsigned long tmp; __asm__ __volatile__ ( "1: \n\t" "movli.l @%1, %0 ! arch_write_lock \n\t" "cmp/hs %2, %0 \n\t" "bf 1b \n\t" "sub %2, %0 \n\t" "movco.l %0, @%1 \n\t" "bf 1b \n\t" : "=&z" (tmp) : "r" (&rw->lock), "r" (RW_LOCK_BIAS) : "t", "memory" ); }

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static inline void arch_write_unlock(arch_rwlock_t *rw) { __asm__ __volatile__ ( "mov.l %1, @%0 ! arch_write_unlock \n\t" : : "r" (&rw->lock), "r" (RW_LOCK_BIAS) : "t", "memory" ); }

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static inline int arch_read_trylock(arch_rwlock_t *rw) { unsigned long tmp, oldval; __asm__ __volatile__ ( "1: \n\t" "movli.l @%2, %0 ! arch_read_trylock \n\t" "mov %0, %1 \n\t" "cmp/pl %0 \n\t" "bf 2f \n\t" "add #-1, %0 \n\t" "movco.l %0, @%2 \n\t" "bf 1b \n\t" "2: \n\t" "synco \n\t" : "=&z" (tmp), "=&r" (oldval) : "r" (&rw->lock) : "t", "memory" ); return (oldval > 0); }

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static inline int arch_write_trylock(arch_rwlock_t *rw) { unsigned long tmp, oldval; __asm__ __volatile__ ( "1: \n\t" "movli.l @%2, %0 ! arch_write_trylock \n\t" "mov %0, %1 \n\t" "cmp/hs %3, %0 \n\t" "bf 2f \n\t" "sub %3, %0 \n\t" "2: \n\t" "movco.l %0, @%2 \n\t" "bf 1b \n\t" "synco \n\t" : "=&z" (tmp), "=&r" (oldval) : "r" (&rw->lock), "r" (RW_LOCK_BIAS) : "t", "memory" ); return (oldval > (RW_LOCK_BIAS - 1)); }

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#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) #define arch_spin_relax(lock) cpu_relax() #define arch_read_relax(lock) cpu_relax() #define arch_write_relax(lock) cpu_relax() #endif /* __ASM_SH_SPINLOCK_LLSC_H */

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