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-rw-r--r--include/asm-generic/mutex-xchg.h120
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diff --git a/include/asm-generic/mutex-xchg.h b/include/asm-generic/mutex-xchg.h
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index 3269ec4e195f..000000000000
--- a/include/asm-generic/mutex-xchg.h
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@@ -1,120 +0,0 @@
-/*
- * include/asm-generic/mutex-xchg.h
- *
- * Generic implementation of the mutex fastpath, based on xchg().
- *
- * NOTE: An xchg based implementation might be less optimal than an atomic
- * decrement/increment based implementation. If your architecture
- * has a reasonable atomic dec/inc then you should probably use
- * asm-generic/mutex-dec.h instead, or you could open-code an
- * optimized version in asm/mutex.h.
- */
-#ifndef _ASM_GENERIC_MUTEX_XCHG_H
-#define _ASM_GENERIC_MUTEX_XCHG_H
-
-/**
- * __mutex_fastpath_lock - try to take the lock by moving the count
- * from 1 to a 0 value
- * @count: pointer of type atomic_t
- * @fail_fn: function to call if the original value was not 1
- *
- * Change the count from 1 to a value lower than 1, and call <fail_fn> if it
- * wasn't 1 originally. This function MUST leave the value lower than 1
- * even when the "1" assertion wasn't true.
- */
-static inline void
-__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
-{
- if (unlikely(atomic_xchg(count, 0) != 1))
- /*
- * We failed to acquire the lock, so mark it contended
- * to ensure that any waiting tasks are woken up by the
- * unlock slow path.
- */
- if (likely(atomic_xchg_acquire(count, -1) != 1))
- fail_fn(count);
-}
-
-/**
- * __mutex_fastpath_lock_retval - try to take the lock by moving the count
- * from 1 to a 0 value
- * @count: pointer of type atomic_t
- *
- * Change the count from 1 to a value lower than 1. This function returns 0
- * if the fastpath succeeds, or -1 otherwise.
- */
-static inline int
-__mutex_fastpath_lock_retval(atomic_t *count)
-{
- if (unlikely(atomic_xchg_acquire(count, 0) != 1))
- if (likely(atomic_xchg(count, -1) != 1))
- return -1;
- return 0;
-}
-
-/**
- * __mutex_fastpath_unlock - try to promote the mutex from 0 to 1
- * @count: pointer of type atomic_t
- * @fail_fn: function to call if the original value was not 0
- *
- * try to promote the mutex from 0 to 1. if it wasn't 0, call <function>
- * In the failure case, this function is allowed to either set the value to
- * 1, or to set it to a value lower than one.
- * If the implementation sets it to a value of lower than one, the
- * __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs
- * to return 0 otherwise.
- */
-static inline void
-__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
-{
- if (unlikely(atomic_xchg_release(count, 1) != 0))
- fail_fn(count);
-}
-
-#define __mutex_slowpath_needs_to_unlock() 0
-
-/**
- * __mutex_fastpath_trylock - try to acquire the mutex, without waiting
- *
- * @count: pointer of type atomic_t
- * @fail_fn: spinlock based trylock implementation
- *
- * Change the count from 1 to a value lower than 1, and return 0 (failure)
- * if it wasn't 1 originally, or return 1 (success) otherwise. This function
- * MUST leave the value lower than 1 even when the "1" assertion wasn't true.
- * Additionally, if the value was < 0 originally, this function must not leave
- * it to 0 on failure.
- *
- * If the architecture has no effective trylock variant, it should call the
- * <fail_fn> spinlock-based trylock variant unconditionally.
- */
-static inline int
-__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *))
-{
- int prev;
-
- if (atomic_read(count) != 1)
- return 0;
-
- prev = atomic_xchg_acquire(count, 0);
- if (unlikely(prev < 0)) {
- /*
- * The lock was marked contended so we must restore that
- * state. If while doing so we get back a prev value of 1
- * then we just own it.
- *
- * [ In the rare case of the mutex going to 1, to 0, to -1
- * and then back to 0 in this few-instructions window,
- * this has the potential to trigger the slowpath for the
- * owner's unlock path needlessly, but that's not a problem
- * in practice. ]
- */
- prev = atomic_xchg_acquire(count, prev);
- if (prev < 0)
- prev = 0;
- }
-
- return prev;
-}
-
-#endif