[PATCH] i386: Clean up spin/rwlocks
- Inline spinlock strings into their inline functions - Convert macros to typesafe inlines - Replace some leftover __asm__ __volatile__s with asm volatile Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
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8b059d2373
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fb2e284856
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@ -20,18 +20,6 @@
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#define RW_LOCK_BIAS 0x01000000
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#define RW_LOCK_BIAS 0x01000000
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#define RW_LOCK_BIAS_STR "0x01000000"
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#define RW_LOCK_BIAS_STR "0x01000000"
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#define __build_read_lock(rw, helper) \
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/* Code is in asm-i386/spinlock.h */
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asm volatile(LOCK_PREFIX " subl $1,(%0)\n\t" \
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"jns 1f\n" \
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"call " helper "\n\t" \
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"1:\n" \
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::"a" (rw) : "memory")
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#define __build_write_lock(rw, helper) \
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asm volatile(LOCK_PREFIX " subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
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"jz 1f\n" \
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"call " helper "\n\t" \
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"1:\n" \
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::"a" (rw) : "memory")
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#endif
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#endif
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@ -4,6 +4,7 @@
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#include <asm/atomic.h>
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#include <asm/atomic.h>
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#include <asm/rwlock.h>
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#include <asm/rwlock.h>
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#include <asm/page.h>
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#include <asm/page.h>
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#include <asm/processor.h>
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#include <linux/compiler.h>
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#include <linux/compiler.h>
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/*
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/*
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@ -17,67 +18,64 @@
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* (the type definitions are in asm/spinlock_types.h)
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* (the type definitions are in asm/spinlock_types.h)
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*/
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*/
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#define __raw_spin_is_locked(x) \
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static inline int __raw_spin_is_locked(raw_spinlock_t *x)
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(*(volatile signed char *)(&(x)->slock) <= 0)
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{
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return *(volatile signed char *)(&(x)->slock) <= 0;
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#define __raw_spin_lock_string \
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}
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"\n1:\t" \
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LOCK_PREFIX " ; decb %0\n\t" \
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"jns 3f\n" \
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"2:\t" \
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"rep;nop\n\t" \
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"cmpb $0,%0\n\t" \
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"jle 2b\n\t" \
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"jmp 1b\n" \
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"3:\n\t"
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/*
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* NOTE: there's an irqs-on section here, which normally would have to be
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* irq-traced, but on CONFIG_TRACE_IRQFLAGS we never use
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* __raw_spin_lock_string_flags().
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*/
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#define __raw_spin_lock_string_flags \
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"\n1:\t" \
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LOCK_PREFIX " ; decb %0\n\t" \
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"jns 5f\n" \
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"2:\t" \
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"testl $0x200, %1\n\t" \
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"jz 4f\n\t" \
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"sti\n" \
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"3:\t" \
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"rep;nop\n\t" \
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"cmpb $0, %0\n\t" \
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"jle 3b\n\t" \
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"cli\n\t" \
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"jmp 1b\n" \
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"4:\t" \
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"rep;nop\n\t" \
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"cmpb $0, %0\n\t" \
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"jg 1b\n\t" \
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"jmp 4b\n" \
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"5:\n\t"
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static inline void __raw_spin_lock(raw_spinlock_t *lock)
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static inline void __raw_spin_lock(raw_spinlock_t *lock)
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{
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{
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asm(__raw_spin_lock_string : "+m" (lock->slock) : : "memory");
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asm volatile("\n1:\t"
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LOCK_PREFIX " ; decb %0\n\t"
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"jns 3f\n"
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"2:\t"
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"rep;nop\n\t"
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"cmpb $0,%0\n\t"
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"jle 2b\n\t"
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"jmp 1b\n"
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"3:\n\t"
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: "+m" (lock->slock) : : "memory");
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}
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}
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/*
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/*
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* It is easier for the lock validator if interrupts are not re-enabled
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* It is easier for the lock validator if interrupts are not re-enabled
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* in the middle of a lock-acquire. This is a performance feature anyway
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* in the middle of a lock-acquire. This is a performance feature anyway
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* so we turn it off:
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* so we turn it off:
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*
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* NOTE: there's an irqs-on section here, which normally would have to be
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* irq-traced, but on CONFIG_TRACE_IRQFLAGS we never use this variant.
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*/
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*/
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#ifndef CONFIG_PROVE_LOCKING
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#ifndef CONFIG_PROVE_LOCKING
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static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
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static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
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{
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{
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asm(__raw_spin_lock_string_flags : "+m" (lock->slock) : "r" (flags) : "memory");
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asm volatile(
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"\n1:\t"
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LOCK_PREFIX " ; decb %0\n\t"
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"jns 5f\n"
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"2:\t"
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"testl $0x200, %1\n\t"
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"jz 4f\n\t"
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"sti\n"
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"3:\t"
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"rep;nop\n\t"
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"cmpb $0, %0\n\t"
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"jle 3b\n\t"
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"cli\n\t"
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"jmp 1b\n"
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"4:\t"
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"rep;nop\n\t"
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"cmpb $0, %0\n\t"
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"jg 1b\n\t"
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"jmp 4b\n"
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"5:\n\t"
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: "+m" (lock->slock) : "r" (flags) : "memory");
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}
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}
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#endif
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#endif
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static inline int __raw_spin_trylock(raw_spinlock_t *lock)
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static inline int __raw_spin_trylock(raw_spinlock_t *lock)
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{
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{
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char oldval;
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char oldval;
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__asm__ __volatile__(
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asm volatile(
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"xchgb %b0,%1"
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"xchgb %b0,%1"
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:"=q" (oldval), "+m" (lock->slock)
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:"=q" (oldval), "+m" (lock->slock)
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:"0" (0) : "memory");
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:"0" (0) : "memory");
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@ -93,38 +91,29 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock)
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#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE)
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#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE)
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#define __raw_spin_unlock_string \
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"movb $1,%0" \
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:"+m" (lock->slock) : : "memory"
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static inline void __raw_spin_unlock(raw_spinlock_t *lock)
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static inline void __raw_spin_unlock(raw_spinlock_t *lock)
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{
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{
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__asm__ __volatile__(
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asm volatile("movb $1,%0" : "+m" (lock->slock) :: "memory");
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__raw_spin_unlock_string
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);
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}
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}
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#else
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#else
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#define __raw_spin_unlock_string \
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"xchgb %b0, %1" \
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:"=q" (oldval), "+m" (lock->slock) \
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:"0" (oldval) : "memory"
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static inline void __raw_spin_unlock(raw_spinlock_t *lock)
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static inline void __raw_spin_unlock(raw_spinlock_t *lock)
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{
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{
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char oldval = 1;
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char oldval = 1;
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__asm__ __volatile__(
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asm volatile("xchgb %b0, %1"
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__raw_spin_unlock_string
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: "=q" (oldval), "+m" (lock->slock)
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);
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: "0" (oldval) : "memory");
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}
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}
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#endif
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#endif
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#define __raw_spin_unlock_wait(lock) \
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static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
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do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0)
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{
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while (__raw_spin_is_locked(lock))
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cpu_relax();
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}
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/*
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/*
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* Read-write spinlocks, allowing multiple readers
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* Read-write spinlocks, allowing multiple readers
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@ -151,22 +140,36 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock)
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* read_can_lock - would read_trylock() succeed?
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* read_can_lock - would read_trylock() succeed?
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* @lock: the rwlock in question.
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* @lock: the rwlock in question.
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*/
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*/
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#define __raw_read_can_lock(x) ((int)(x)->lock > 0)
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static inline int __raw_read_can_lock(raw_rwlock_t *x)
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{
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return (int)(x)->lock > 0;
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}
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/**
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/**
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* write_can_lock - would write_trylock() succeed?
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* write_can_lock - would write_trylock() succeed?
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* @lock: the rwlock in question.
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* @lock: the rwlock in question.
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*/
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*/
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#define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS)
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static inline int __raw_write_can_lock(raw_rwlock_t *x)
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{
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return (x)->lock == RW_LOCK_BIAS;
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}
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static inline void __raw_read_lock(raw_rwlock_t *rw)
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static inline void __raw_read_lock(raw_rwlock_t *rw)
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{
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{
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__build_read_lock(rw, "__read_lock_failed");
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asm volatile(LOCK_PREFIX " subl $1,(%0)\n\t"
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"jns 1f\n"
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"call __read_lock_failed\n\t"
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"1:\n"
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::"a" (rw) : "memory");
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}
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}
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static inline void __raw_write_lock(raw_rwlock_t *rw)
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static inline void __raw_write_lock(raw_rwlock_t *rw)
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{
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{
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__build_write_lock(rw, "__write_lock_failed");
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asm volatile(LOCK_PREFIX " subl $" RW_LOCK_BIAS_STR ",(%0)\n\t"
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"jz 1f\n"
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"call __write_lock_failed\n\t"
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"1:\n"
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::"a" (rw) : "memory");
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}
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}
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static inline int __raw_read_trylock(raw_rwlock_t *lock)
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static inline int __raw_read_trylock(raw_rwlock_t *lock)
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