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Merge branches 'x86/asm', 'x86/cleanups', 'x86/cpudetect', 'x86/debug', 'x86/doc', 'x86/header-fixes', 'x86/mm', 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess' and 'x86/urgent' into x86/core

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This commit is contained in:
Ingo Molnar
2009-01-28 23:13:53 +01:00
parent 6a385db5ce 2d4d57db69 8f6d86dc41 b38b066590 d5e397cb49 e56d0cfe77 dbca1df48e fb746d0e13 6522869c34 d639bab8da 042cbaf88a 5662a2f8e7 3b4b75700a 30a0fb947a
commit 74b6eb6b93
36 changed files with 604 additions and 879 deletions
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69
arch/x86/include/asm/spinlock.h
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@ -172,70 +172,8 @@ static inline int __ticket_spin_is_contended(raw_spinlock_t *lock)
return (((tmp >> TICKET_SHIFT) - tmp) & ((1 << TICKET_SHIFT) - 1)) > 1;
}
#ifdef CONFIG_PARAVIRT
/*
* Define virtualization-friendly old-style lock byte lock, for use in
* pv_lock_ops if desired.
*
* This differs from the pre-2.6.24 spinlock by always using xchgb
* rather than decb to take the lock; this allows it to use a
* zero-initialized lock structure. It also maintains a 1-byte
* contention counter, so that we can implement
* __byte_spin_is_contended.
*/
struct __byte_spinlock {
s8 lock;
s8 spinners;
};
#ifndef CONFIG_PARAVIRT
static inline int __byte_spin_is_locked(raw_spinlock_t *lock)
{
struct __byte_spinlock *bl = (struct __byte_spinlock *)lock;
return bl->lock != 0;
}
static inline int __byte_spin_is_contended(raw_spinlock_t *lock)
{
struct __byte_spinlock *bl = (struct __byte_spinlock *)lock;
return bl->spinners != 0;
}
static inline void __byte_spin_lock(raw_spinlock_t *lock)
{
struct __byte_spinlock *bl = (struct __byte_spinlock *)lock;
s8 val = 1;
asm("1: xchgb %1, %0\n"
" test %1,%1\n"
" jz 3f\n"
" " LOCK_PREFIX "incb %2\n"
"2: rep;nop\n"
" cmpb $1, %0\n"
" je 2b\n"
" " LOCK_PREFIX "decb %2\n"
" jmp 1b\n"
"3:"
: "+m" (bl->lock), "+q" (val), "+m" (bl->spinners): : "memory");
}
static inline int __byte_spin_trylock(raw_spinlock_t *lock)
{
struct __byte_spinlock *bl = (struct __byte_spinlock *)lock;
u8 old = 1;
asm("xchgb %1,%0"
: "+m" (bl->lock), "+q" (old) : : "memory");
return old == 0;
}
static inline void __byte_spin_unlock(raw_spinlock_t *lock)
{
struct __byte_spinlock *bl = (struct __byte_spinlock *)lock;
smp_wmb();
bl->lock = 0;
}
#else /* !CONFIG_PARAVIRT */
static inline int __raw_spin_is_locked(raw_spinlock_t *lock)
{
return __ticket_spin_is_locked(lock);
@ -267,7 +205,7 @@ static __always_inline void __raw_spin_lock_flags(raw_spinlock_t *lock,
__raw_spin_lock(lock);
}
#endif /* CONFIG_PARAVIRT */
#endif
static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
{
@ -329,8 +267,7 @@ static inline int __raw_read_trylock(raw_rwlock_t *lock)
{
atomic_t *count = (atomic_t *)lock;
atomic_dec(count);
if (atomic_read(count) >= 0)
if (atomic_dec_return(count) >= 0)
return 1;
atomic_inc(count);
return 0;