91bbefe6b0
MIPS is interesting and has hardware variants that reorder over ll/sc as well as those that do not. Implement the 2 new barrier functions as per the old barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-9ph49jbae3hol9v721sbc2g6@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maciej W. Rozycki" <macro@codesourcery.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
764 lines
17 KiB
C
764 lines
17 KiB
C
/*
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* Atomic operations that C can't guarantee us. Useful for
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* resource counting etc..
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*
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* But use these as seldom as possible since they are much more slower
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* than regular operations.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
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*/
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#ifndef _ASM_ATOMIC_H
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#define _ASM_ATOMIC_H
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#include <linux/irqflags.h>
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#include <linux/types.h>
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#include <asm/barrier.h>
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#include <asm/cpu-features.h>
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#include <asm/cmpxchg.h>
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#include <asm/war.h>
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#define ATOMIC_INIT(i) { (i) }
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/*
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* atomic_read - read atomic variable
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* @v: pointer of type atomic_t
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*
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* Atomically reads the value of @v.
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*/
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#define atomic_read(v) (*(volatile int *)&(v)->counter)
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/*
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* atomic_set - set atomic variable
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* @v: pointer of type atomic_t
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* @i: required value
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*
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* Atomically sets the value of @v to @i.
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*/
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#define atomic_set(v, i) ((v)->counter = (i))
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/*
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* atomic_add - add integer to atomic variable
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* @i: integer value to add
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* @v: pointer of type atomic_t
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*
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* Atomically adds @i to @v.
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*/
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static __inline__ void atomic_add(int i, atomic_t * v)
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{
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if (kernel_uses_llsc && R10000_LLSC_WAR) {
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int temp;
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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"1: ll %0, %1 # atomic_add \n"
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" addu %0, %2 \n"
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" sc %0, %1 \n"
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" beqzl %0, 1b \n"
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" .set mips0 \n"
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: "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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} else if (kernel_uses_llsc) {
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int temp;
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do {
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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" ll %0, %1 # atomic_add \n"
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" addu %0, %2 \n"
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" sc %0, %1 \n"
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" .set mips0 \n"
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: "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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} while (unlikely(!temp));
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} else {
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unsigned long flags;
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raw_local_irq_save(flags);
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v->counter += i;
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raw_local_irq_restore(flags);
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}
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}
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/*
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* atomic_sub - subtract the atomic variable
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* @i: integer value to subtract
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* @v: pointer of type atomic_t
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*
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* Atomically subtracts @i from @v.
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*/
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static __inline__ void atomic_sub(int i, atomic_t * v)
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{
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if (kernel_uses_llsc && R10000_LLSC_WAR) {
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int temp;
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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"1: ll %0, %1 # atomic_sub \n"
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" subu %0, %2 \n"
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" sc %0, %1 \n"
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" beqzl %0, 1b \n"
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" .set mips0 \n"
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: "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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} else if (kernel_uses_llsc) {
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int temp;
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do {
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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" ll %0, %1 # atomic_sub \n"
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" subu %0, %2 \n"
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" sc %0, %1 \n"
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" .set mips0 \n"
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: "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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} while (unlikely(!temp));
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} else {
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unsigned long flags;
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raw_local_irq_save(flags);
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v->counter -= i;
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raw_local_irq_restore(flags);
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}
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}
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/*
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* Same as above, but return the result value
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*/
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static __inline__ int atomic_add_return(int i, atomic_t * v)
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{
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int result;
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smp_mb__before_llsc();
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if (kernel_uses_llsc && R10000_LLSC_WAR) {
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int temp;
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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"1: ll %1, %2 # atomic_add_return \n"
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" addu %0, %1, %3 \n"
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" sc %0, %2 \n"
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" beqzl %0, 1b \n"
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" addu %0, %1, %3 \n"
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" .set mips0 \n"
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: "=&r" (result), "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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} else if (kernel_uses_llsc) {
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int temp;
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do {
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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" ll %1, %2 # atomic_add_return \n"
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" addu %0, %1, %3 \n"
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" sc %0, %2 \n"
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" .set mips0 \n"
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: "=&r" (result), "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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} while (unlikely(!result));
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result = temp + i;
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} else {
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unsigned long flags;
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raw_local_irq_save(flags);
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result = v->counter;
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result += i;
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v->counter = result;
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raw_local_irq_restore(flags);
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}
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smp_llsc_mb();
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return result;
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}
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static __inline__ int atomic_sub_return(int i, atomic_t * v)
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{
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int result;
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smp_mb__before_llsc();
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if (kernel_uses_llsc && R10000_LLSC_WAR) {
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int temp;
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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"1: ll %1, %2 # atomic_sub_return \n"
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" subu %0, %1, %3 \n"
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" sc %0, %2 \n"
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" beqzl %0, 1b \n"
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" subu %0, %1, %3 \n"
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" .set mips0 \n"
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: "=&r" (result), "=&r" (temp), "=m" (v->counter)
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: "Ir" (i), "m" (v->counter)
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: "memory");
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result = temp - i;
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} else if (kernel_uses_llsc) {
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int temp;
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do {
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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" ll %1, %2 # atomic_sub_return \n"
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" subu %0, %1, %3 \n"
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" sc %0, %2 \n"
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" .set mips0 \n"
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: "=&r" (result), "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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} while (unlikely(!result));
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result = temp - i;
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} else {
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unsigned long flags;
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raw_local_irq_save(flags);
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result = v->counter;
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result -= i;
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v->counter = result;
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raw_local_irq_restore(flags);
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}
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smp_llsc_mb();
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return result;
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}
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/*
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* atomic_sub_if_positive - conditionally subtract integer from atomic variable
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* @i: integer value to subtract
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* @v: pointer of type atomic_t
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*
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* Atomically test @v and subtract @i if @v is greater or equal than @i.
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* The function returns the old value of @v minus @i.
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*/
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static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
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{
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int result;
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smp_mb__before_llsc();
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if (kernel_uses_llsc && R10000_LLSC_WAR) {
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int temp;
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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"1: ll %1, %2 # atomic_sub_if_positive\n"
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" subu %0, %1, %3 \n"
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" bltz %0, 1f \n"
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" sc %0, %2 \n"
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" .set noreorder \n"
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" beqzl %0, 1b \n"
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" subu %0, %1, %3 \n"
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" .set reorder \n"
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"1: \n"
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" .set mips0 \n"
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: "=&r" (result), "=&r" (temp), "+m" (v->counter)
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: "Ir" (i), "m" (v->counter)
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: "memory");
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} else if (kernel_uses_llsc) {
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int temp;
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__asm__ __volatile__(
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" .set arch=r4000 \n"
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"1: ll %1, %2 # atomic_sub_if_positive\n"
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" subu %0, %1, %3 \n"
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" bltz %0, 1f \n"
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" sc %0, %2 \n"
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" .set noreorder \n"
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" beqz %0, 1b \n"
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" subu %0, %1, %3 \n"
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" .set reorder \n"
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"1: \n"
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" .set mips0 \n"
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: "=&r" (result), "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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} else {
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unsigned long flags;
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raw_local_irq_save(flags);
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result = v->counter;
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result -= i;
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if (result >= 0)
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v->counter = result;
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raw_local_irq_restore(flags);
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}
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smp_llsc_mb();
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return result;
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}
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#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
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#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
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/**
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* __atomic_add_unless - add unless the number is a given value
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* @v: pointer of type atomic_t
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* @a: the amount to add to v...
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* @u: ...unless v is equal to u.
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*
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* Atomically adds @a to @v, so long as it was not @u.
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* Returns the old value of @v.
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*/
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static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
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{
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int c, old;
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c = atomic_read(v);
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for (;;) {
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if (unlikely(c == (u)))
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break;
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old = atomic_cmpxchg((v), c, c + (a));
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if (likely(old == c))
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break;
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c = old;
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}
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return c;
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}
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#define atomic_dec_return(v) atomic_sub_return(1, (v))
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#define atomic_inc_return(v) atomic_add_return(1, (v))
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/*
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* atomic_sub_and_test - subtract value from variable and test result
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* @i: integer value to subtract
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* @v: pointer of type atomic_t
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*
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* Atomically subtracts @i from @v and returns
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* true if the result is zero, or false for all
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* other cases.
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*/
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#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
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/*
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* atomic_inc_and_test - increment and test
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* @v: pointer of type atomic_t
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*
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* Atomically increments @v by 1
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* and returns true if the result is zero, or false for all
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* other cases.
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*/
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#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
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/*
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* atomic_dec_and_test - decrement by 1 and test
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* @v: pointer of type atomic_t
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*
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* Atomically decrements @v by 1 and
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* returns true if the result is 0, or false for all other
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* cases.
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*/
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#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
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/*
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* atomic_dec_if_positive - decrement by 1 if old value positive
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* @v: pointer of type atomic_t
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*/
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#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
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/*
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* atomic_inc - increment atomic variable
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* @v: pointer of type atomic_t
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*
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* Atomically increments @v by 1.
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*/
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#define atomic_inc(v) atomic_add(1, (v))
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/*
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* atomic_dec - decrement and test
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* @v: pointer of type atomic_t
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*
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* Atomically decrements @v by 1.
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*/
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#define atomic_dec(v) atomic_sub(1, (v))
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/*
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* atomic_add_negative - add and test if negative
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* @v: pointer of type atomic_t
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* @i: integer value to add
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*
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* Atomically adds @i to @v and returns true
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* if the result is negative, or false when
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* result is greater than or equal to zero.
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*/
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#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
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#ifdef CONFIG_64BIT
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#define ATOMIC64_INIT(i) { (i) }
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/*
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* atomic64_read - read atomic variable
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* @v: pointer of type atomic64_t
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*
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*/
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#define atomic64_read(v) (*(volatile long *)&(v)->counter)
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/*
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* atomic64_set - set atomic variable
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* @v: pointer of type atomic64_t
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* @i: required value
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*/
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#define atomic64_set(v, i) ((v)->counter = (i))
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|
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/*
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* atomic64_add - add integer to atomic variable
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* @i: integer value to add
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* @v: pointer of type atomic64_t
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*
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* Atomically adds @i to @v.
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*/
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static __inline__ void atomic64_add(long i, atomic64_t * v)
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{
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if (kernel_uses_llsc && R10000_LLSC_WAR) {
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long temp;
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__asm__ __volatile__(
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|
" .set arch=r4000 \n"
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"1: lld %0, %1 # atomic64_add \n"
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" daddu %0, %2 \n"
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" scd %0, %1 \n"
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" beqzl %0, 1b \n"
|
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" .set mips0 \n"
|
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: "=&r" (temp), "+m" (v->counter)
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: "Ir" (i));
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|
} else if (kernel_uses_llsc) {
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|
long temp;
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|
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do {
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|
__asm__ __volatile__(
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|
" .set arch=r4000 \n"
|
|
" lld %0, %1 # atomic64_add \n"
|
|
" daddu %0, %2 \n"
|
|
" scd %0, %1 \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (temp), "+m" (v->counter)
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|
: "Ir" (i));
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|
} while (unlikely(!temp));
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
raw_local_irq_save(flags);
|
|
v->counter += i;
|
|
raw_local_irq_restore(flags);
|
|
}
|
|
}
|
|
|
|
/*
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|
* atomic64_sub - subtract the atomic variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically subtracts @i from @v.
|
|
*/
|
|
static __inline__ void atomic64_sub(long i, atomic64_t * v)
|
|
{
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) {
|
|
long temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
"1: lld %0, %1 # atomic64_sub \n"
|
|
" dsubu %0, %2 \n"
|
|
" scd %0, %1 \n"
|
|
" beqzl %0, 1b \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (temp), "+m" (v->counter)
|
|
: "Ir" (i));
|
|
} else if (kernel_uses_llsc) {
|
|
long temp;
|
|
|
|
do {
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
" lld %0, %1 # atomic64_sub \n"
|
|
" dsubu %0, %2 \n"
|
|
" scd %0, %1 \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (temp), "+m" (v->counter)
|
|
: "Ir" (i));
|
|
} while (unlikely(!temp));
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
raw_local_irq_save(flags);
|
|
v->counter -= i;
|
|
raw_local_irq_restore(flags);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Same as above, but return the result value
|
|
*/
|
|
static __inline__ long atomic64_add_return(long i, atomic64_t * v)
|
|
{
|
|
long result;
|
|
|
|
smp_mb__before_llsc();
|
|
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) {
|
|
long temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
"1: lld %1, %2 # atomic64_add_return \n"
|
|
" daddu %0, %1, %3 \n"
|
|
" scd %0, %2 \n"
|
|
" beqzl %0, 1b \n"
|
|
" daddu %0, %1, %3 \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp), "+m" (v->counter)
|
|
: "Ir" (i));
|
|
} else if (kernel_uses_llsc) {
|
|
long temp;
|
|
|
|
do {
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
" lld %1, %2 # atomic64_add_return \n"
|
|
" daddu %0, %1, %3 \n"
|
|
" scd %0, %2 \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
|
|
: "Ir" (i), "m" (v->counter)
|
|
: "memory");
|
|
} while (unlikely(!result));
|
|
|
|
result = temp + i;
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
raw_local_irq_save(flags);
|
|
result = v->counter;
|
|
result += i;
|
|
v->counter = result;
|
|
raw_local_irq_restore(flags);
|
|
}
|
|
|
|
smp_llsc_mb();
|
|
|
|
return result;
|
|
}
|
|
|
|
static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
|
|
{
|
|
long result;
|
|
|
|
smp_mb__before_llsc();
|
|
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) {
|
|
long temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
"1: lld %1, %2 # atomic64_sub_return \n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" scd %0, %2 \n"
|
|
" beqzl %0, 1b \n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
|
|
: "Ir" (i), "m" (v->counter)
|
|
: "memory");
|
|
} else if (kernel_uses_llsc) {
|
|
long temp;
|
|
|
|
do {
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
" lld %1, %2 # atomic64_sub_return \n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" scd %0, %2 \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
|
|
: "Ir" (i), "m" (v->counter)
|
|
: "memory");
|
|
} while (unlikely(!result));
|
|
|
|
result = temp - i;
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
raw_local_irq_save(flags);
|
|
result = v->counter;
|
|
result -= i;
|
|
v->counter = result;
|
|
raw_local_irq_restore(flags);
|
|
}
|
|
|
|
smp_llsc_mb();
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* atomic64_sub_if_positive - conditionally subtract integer from atomic variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically test @v and subtract @i if @v is greater or equal than @i.
|
|
* The function returns the old value of @v minus @i.
|
|
*/
|
|
static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
|
|
{
|
|
long result;
|
|
|
|
smp_mb__before_llsc();
|
|
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) {
|
|
long temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
"1: lld %1, %2 # atomic64_sub_if_positive\n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" bltz %0, 1f \n"
|
|
" scd %0, %2 \n"
|
|
" .set noreorder \n"
|
|
" beqzl %0, 1b \n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" .set reorder \n"
|
|
"1: \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
|
|
: "Ir" (i), "m" (v->counter)
|
|
: "memory");
|
|
} else if (kernel_uses_llsc) {
|
|
long temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
"1: lld %1, %2 # atomic64_sub_if_positive\n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" bltz %0, 1f \n"
|
|
" scd %0, %2 \n"
|
|
" .set noreorder \n"
|
|
" beqz %0, 1b \n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" .set reorder \n"
|
|
"1: \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp), "+m" (v->counter)
|
|
: "Ir" (i));
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
raw_local_irq_save(flags);
|
|
result = v->counter;
|
|
result -= i;
|
|
if (result >= 0)
|
|
v->counter = result;
|
|
raw_local_irq_restore(flags);
|
|
}
|
|
|
|
smp_llsc_mb();
|
|
|
|
return result;
|
|
}
|
|
|
|
#define atomic64_cmpxchg(v, o, n) \
|
|
((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
|
|
#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
|
|
|
|
/**
|
|
* atomic64_add_unless - add unless the number is a given value
|
|
* @v: pointer of type atomic64_t
|
|
* @a: the amount to add to v...
|
|
* @u: ...unless v is equal to u.
|
|
*
|
|
* Atomically adds @a to @v, so long as it was not @u.
|
|
* Returns the old value of @v.
|
|
*/
|
|
static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
|
|
{
|
|
long c, old;
|
|
c = atomic64_read(v);
|
|
for (;;) {
|
|
if (unlikely(c == (u)))
|
|
break;
|
|
old = atomic64_cmpxchg((v), c, c + (a));
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
return c != (u);
|
|
}
|
|
|
|
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
|
|
|
|
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
|
|
#define atomic64_inc_return(v) atomic64_add_return(1, (v))
|
|
|
|
/*
|
|
* atomic64_sub_and_test - subtract value from variable and test result
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically subtracts @i from @v and returns
|
|
* true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
|
|
|
|
/*
|
|
* atomic64_inc_and_test - increment and test
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically increments @v by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
|
|
|
|
/*
|
|
* atomic64_dec_and_test - decrement by 1 and test
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically decrements @v by 1 and
|
|
* returns true if the result is 0, or false for all other
|
|
* cases.
|
|
*/
|
|
#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
|
|
|
|
/*
|
|
* atomic64_dec_if_positive - decrement by 1 if old value positive
|
|
* @v: pointer of type atomic64_t
|
|
*/
|
|
#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
|
|
|
|
/*
|
|
* atomic64_inc - increment atomic variable
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically increments @v by 1.
|
|
*/
|
|
#define atomic64_inc(v) atomic64_add(1, (v))
|
|
|
|
/*
|
|
* atomic64_dec - decrement and test
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically decrements @v by 1.
|
|
*/
|
|
#define atomic64_dec(v) atomic64_sub(1, (v))
|
|
|
|
/*
|
|
* atomic64_add_negative - add and test if negative
|
|
* @v: pointer of type atomic64_t
|
|
* @i: integer value to add
|
|
*
|
|
* Atomically adds @i to @v and returns true
|
|
* if the result is negative, or false when
|
|
* result is greater than or equal to zero.
|
|
*/
|
|
#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
|
|
|
|
#endif /* CONFIG_64BIT */
|
|
|
|
#endif /* _ASM_ATOMIC_H */
|