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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/powerpc/include/asm/mutex.h | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/powerpc/include/asm/mutex.h')
-rw-r--r-- | kernel/arch/powerpc/include/asm/mutex.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/include/asm/mutex.h b/kernel/arch/powerpc/include/asm/mutex.h new file mode 100644 index 000000000..127ab23e1 --- /dev/null +++ b/kernel/arch/powerpc/include/asm/mutex.h @@ -0,0 +1,132 @@ +/* + * Optimised mutex implementation of include/asm-generic/mutex-dec.h algorithm + */ +#ifndef _ASM_POWERPC_MUTEX_H +#define _ASM_POWERPC_MUTEX_H + +static inline int __mutex_cmpxchg_lock(atomic_t *v, int old, int new) +{ + int t; + + __asm__ __volatile__ ( +"1: lwarx %0,0,%1 # mutex trylock\n\ + cmpw 0,%0,%2\n\ + bne- 2f\n" + PPC405_ERR77(0,%1) +" stwcx. %3,0,%1\n\ + bne- 1b" + PPC_ACQUIRE_BARRIER + "\n\ +2:" + : "=&r" (t) + : "r" (&v->counter), "r" (old), "r" (new) + : "cc", "memory"); + + return t; +} + +static inline int __mutex_dec_return_lock(atomic_t *v) +{ + int t; + + __asm__ __volatile__( +"1: lwarx %0,0,%1 # mutex lock\n\ + addic %0,%0,-1\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1\n\ + bne- 1b" + PPC_ACQUIRE_BARRIER + : "=&r" (t) + : "r" (&v->counter) + : "cc", "memory"); + + return t; +} + +static inline int __mutex_inc_return_unlock(atomic_t *v) +{ + int t; + + __asm__ __volatile__( + PPC_RELEASE_BARRIER +"1: lwarx %0,0,%1 # mutex unlock\n\ + addic %0,%0,1\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1 \n\ + bne- 1b" + : "=&r" (t) + : "r" (&v->counter) + : "cc", "memory"); + + return t; +} + +/** + * __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(__mutex_dec_return_lock(count) < 0)) + 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(__mutex_dec_return_lock(count) < 0)) + return -1; + return 0; +} + +/** + * __mutex_fastpath_unlock - try to promote the count 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 count from 0 to 1. If it wasn't 0, call <fail_fn>. + * In the failure case, this function is allowed to either set the value to + * 1, or to set it to a value lower than 1. + */ +static inline void +__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + if (unlikely(__mutex_inc_return_unlock(count) <= 0)) + fail_fn(count); +} + +#define __mutex_slowpath_needs_to_unlock() 1 + +/** + * __mutex_fastpath_trylock - try to acquire the mutex, without waiting + * + * @count: pointer of type atomic_t + * @fail_fn: fallback function + * + * Change the count from 1 to 0, and return 1 (success), or if the count + * was not 1, then return 0 (failure). + */ +static inline int +__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) +{ + if (likely(__mutex_cmpxchg_lock(count, 1, 0) == 1)) + return 1; + return 0; +} + +#endif |