forked from Minki/linux
e5931943d0
Name space cleanup for rwlock functions. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
327 lines
7.7 KiB
C
327 lines
7.7 KiB
C
#ifndef _ASM_M32R_SPINLOCK_H
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#define _ASM_M32R_SPINLOCK_H
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/*
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* linux/include/asm-m32r/spinlock.h
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*
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* M32R version:
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* Copyright (C) 2001, 2002 Hitoshi Yamamoto
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* Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
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*/
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#include <linux/compiler.h>
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#include <asm/atomic.h>
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#include <asm/page.h>
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/*
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* Your basic SMP spinlocks, allowing only a single CPU anywhere
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*
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* (the type definitions are in asm/spinlock_types.h)
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*
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* Simple spin lock operations. There are two variants, one clears IRQ's
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* on the local processor, one does not.
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*
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* We make no fairness assumptions. They have a cost.
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*/
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#define arch_spin_is_locked(x) (*(volatile int *)(&(x)->slock) <= 0)
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#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock)
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#define arch_spin_unlock_wait(x) \
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do { cpu_relax(); } while (arch_spin_is_locked(x))
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/**
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* arch_spin_trylock - Try spin lock and return a result
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* @lock: Pointer to the lock variable
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*
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* arch_spin_trylock() tries to get the lock and returns a result.
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* On the m32r, the result value is 1 (= Success) or 0 (= Failure).
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*/
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static inline int arch_spin_trylock(arch_spinlock_t *lock)
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{
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int oldval;
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unsigned long tmp1, tmp2;
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/*
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* lock->slock : =1 : unlock
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* : <=0 : lock
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* {
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* oldval = lock->slock; <--+ need atomic operation
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* lock->slock = 0; <--+
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* }
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*/
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__asm__ __volatile__ (
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"# arch_spin_trylock \n\t"
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"ldi %1, #0; \n\t"
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"mvfc %2, psw; \n\t"
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"clrpsw #0x40 -> nop; \n\t"
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DCACHE_CLEAR("%0", "r6", "%3")
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"lock %0, @%3; \n\t"
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"unlock %1, @%3; \n\t"
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"mvtc %2, psw; \n\t"
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: "=&r" (oldval), "=&r" (tmp1), "=&r" (tmp2)
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: "r" (&lock->slock)
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: "memory"
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#ifdef CONFIG_CHIP_M32700_TS1
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, "r6"
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#endif /* CONFIG_CHIP_M32700_TS1 */
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);
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return (oldval > 0);
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}
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static inline void arch_spin_lock(arch_spinlock_t *lock)
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{
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unsigned long tmp0, tmp1;
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/*
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* lock->slock : =1 : unlock
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* : <=0 : lock
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*
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* for ( ; ; ) {
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* lock->slock -= 1; <-- need atomic operation
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* if (lock->slock == 0) break;
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* for ( ; lock->slock <= 0 ; );
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* }
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*/
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__asm__ __volatile__ (
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"# arch_spin_lock \n\t"
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".fillinsn \n"
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"1: \n\t"
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"mvfc %1, psw; \n\t"
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"clrpsw #0x40 -> nop; \n\t"
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DCACHE_CLEAR("%0", "r6", "%2")
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"lock %0, @%2; \n\t"
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"addi %0, #-1; \n\t"
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"unlock %0, @%2; \n\t"
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"mvtc %1, psw; \n\t"
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"bltz %0, 2f; \n\t"
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LOCK_SECTION_START(".balign 4 \n\t")
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".fillinsn \n"
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"2: \n\t"
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"ld %0, @%2; \n\t"
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"bgtz %0, 1b; \n\t"
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"bra 2b; \n\t"
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LOCK_SECTION_END
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: "=&r" (tmp0), "=&r" (tmp1)
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: "r" (&lock->slock)
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: "memory"
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#ifdef CONFIG_CHIP_M32700_TS1
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, "r6"
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#endif /* CONFIG_CHIP_M32700_TS1 */
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);
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}
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static inline void arch_spin_unlock(arch_spinlock_t *lock)
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{
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mb();
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lock->slock = 1;
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}
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/*
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* Read-write spinlocks, allowing multiple readers
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* but only one writer.
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*
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* NOTE! it is quite common to have readers in interrupts
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* but no interrupt writers. For those circumstances we
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* can "mix" irq-safe locks - any writer needs to get a
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* irq-safe write-lock, but readers can get non-irqsafe
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* read-locks.
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*
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* On x86, we implement read-write locks as a 32-bit counter
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* with the high bit (sign) being the "contended" bit.
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*
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* The inline assembly is non-obvious. Think about it.
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*
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* Changed to use the same technique as rw semaphores. See
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* semaphore.h for details. -ben
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*/
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/**
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* read_can_lock - would read_trylock() succeed?
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* @lock: the rwlock in question.
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*/
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#define arch_read_can_lock(x) ((int)(x)->lock > 0)
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/**
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* write_can_lock - would write_trylock() succeed?
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* @lock: the rwlock in question.
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*/
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#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS)
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static inline void arch_read_lock(arch_rwlock_t *rw)
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{
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unsigned long tmp0, tmp1;
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/*
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* rw->lock : >0 : unlock
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* : <=0 : lock
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*
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* for ( ; ; ) {
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* rw->lock -= 1; <-- need atomic operation
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* if (rw->lock >= 0) break;
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* rw->lock += 1; <-- need atomic operation
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* for ( ; rw->lock <= 0 ; );
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* }
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*/
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__asm__ __volatile__ (
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"# read_lock \n\t"
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".fillinsn \n"
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"1: \n\t"
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"mvfc %1, psw; \n\t"
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"clrpsw #0x40 -> nop; \n\t"
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DCACHE_CLEAR("%0", "r6", "%2")
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"lock %0, @%2; \n\t"
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"addi %0, #-1; \n\t"
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"unlock %0, @%2; \n\t"
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"mvtc %1, psw; \n\t"
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"bltz %0, 2f; \n\t"
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LOCK_SECTION_START(".balign 4 \n\t")
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".fillinsn \n"
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"2: \n\t"
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"clrpsw #0x40 -> nop; \n\t"
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DCACHE_CLEAR("%0", "r6", "%2")
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"lock %0, @%2; \n\t"
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"addi %0, #1; \n\t"
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"unlock %0, @%2; \n\t"
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"mvtc %1, psw; \n\t"
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".fillinsn \n"
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"3: \n\t"
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"ld %0, @%2; \n\t"
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"bgtz %0, 1b; \n\t"
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"bra 3b; \n\t"
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LOCK_SECTION_END
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: "=&r" (tmp0), "=&r" (tmp1)
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: "r" (&rw->lock)
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: "memory"
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#ifdef CONFIG_CHIP_M32700_TS1
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, "r6"
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#endif /* CONFIG_CHIP_M32700_TS1 */
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);
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}
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static inline void arch_write_lock(arch_rwlock_t *rw)
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{
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unsigned long tmp0, tmp1, tmp2;
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/*
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* rw->lock : =RW_LOCK_BIAS_STR : unlock
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* : !=RW_LOCK_BIAS_STR : lock
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*
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* for ( ; ; ) {
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* rw->lock -= RW_LOCK_BIAS_STR; <-- need atomic operation
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* if (rw->lock == 0) break;
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* rw->lock += RW_LOCK_BIAS_STR; <-- need atomic operation
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* for ( ; rw->lock != RW_LOCK_BIAS_STR ; ) ;
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* }
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*/
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__asm__ __volatile__ (
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"# write_lock \n\t"
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"seth %1, #high(" RW_LOCK_BIAS_STR "); \n\t"
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"or3 %1, %1, #low(" RW_LOCK_BIAS_STR "); \n\t"
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".fillinsn \n"
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"1: \n\t"
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"mvfc %2, psw; \n\t"
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"clrpsw #0x40 -> nop; \n\t"
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DCACHE_CLEAR("%0", "r7", "%3")
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"lock %0, @%3; \n\t"
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"sub %0, %1; \n\t"
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"unlock %0, @%3; \n\t"
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"mvtc %2, psw; \n\t"
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"bnez %0, 2f; \n\t"
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LOCK_SECTION_START(".balign 4 \n\t")
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".fillinsn \n"
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"2: \n\t"
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"clrpsw #0x40 -> nop; \n\t"
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DCACHE_CLEAR("%0", "r7", "%3")
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"lock %0, @%3; \n\t"
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"add %0, %1; \n\t"
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"unlock %0, @%3; \n\t"
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"mvtc %2, psw; \n\t"
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".fillinsn \n"
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"3: \n\t"
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"ld %0, @%3; \n\t"
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"beq %0, %1, 1b; \n\t"
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"bra 3b; \n\t"
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LOCK_SECTION_END
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: "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2)
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: "r" (&rw->lock)
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: "memory"
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#ifdef CONFIG_CHIP_M32700_TS1
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, "r7"
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#endif /* CONFIG_CHIP_M32700_TS1 */
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);
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}
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static inline void arch_read_unlock(arch_rwlock_t *rw)
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{
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unsigned long tmp0, tmp1;
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__asm__ __volatile__ (
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"# read_unlock \n\t"
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"mvfc %1, psw; \n\t"
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"clrpsw #0x40 -> nop; \n\t"
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DCACHE_CLEAR("%0", "r6", "%2")
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"lock %0, @%2; \n\t"
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"addi %0, #1; \n\t"
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"unlock %0, @%2; \n\t"
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"mvtc %1, psw; \n\t"
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: "=&r" (tmp0), "=&r" (tmp1)
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: "r" (&rw->lock)
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: "memory"
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#ifdef CONFIG_CHIP_M32700_TS1
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, "r6"
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#endif /* CONFIG_CHIP_M32700_TS1 */
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);
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}
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static inline void arch_write_unlock(arch_rwlock_t *rw)
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{
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unsigned long tmp0, tmp1, tmp2;
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__asm__ __volatile__ (
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"# write_unlock \n\t"
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"seth %1, #high(" RW_LOCK_BIAS_STR "); \n\t"
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"or3 %1, %1, #low(" RW_LOCK_BIAS_STR "); \n\t"
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"mvfc %2, psw; \n\t"
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"clrpsw #0x40 -> nop; \n\t"
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DCACHE_CLEAR("%0", "r7", "%3")
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"lock %0, @%3; \n\t"
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"add %0, %1; \n\t"
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"unlock %0, @%3; \n\t"
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"mvtc %2, psw; \n\t"
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: "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2)
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: "r" (&rw->lock)
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: "memory"
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#ifdef CONFIG_CHIP_M32700_TS1
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, "r7"
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#endif /* CONFIG_CHIP_M32700_TS1 */
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);
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}
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static inline int arch_read_trylock(arch_rwlock_t *lock)
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{
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atomic_t *count = (atomic_t*)lock;
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if (atomic_dec_return(count) >= 0)
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return 1;
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atomic_inc(count);
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return 0;
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}
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static inline int arch_write_trylock(arch_rwlock_t *lock)
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{
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atomic_t *count = (atomic_t *)lock;
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if (atomic_sub_and_test(RW_LOCK_BIAS, count))
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return 1;
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atomic_add(RW_LOCK_BIAS, count);
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return 0;
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}
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#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
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#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
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#define arch_spin_relax(lock) cpu_relax()
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#define arch_read_relax(lock) cpu_relax()
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#define arch_write_relax(lock) cpu_relax()
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#endif /* _ASM_M32R_SPINLOCK_H */
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