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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/alpha/include/asm/rwsem.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/alpha/include/asm/rwsem.h')
-rw-r--r-- | kernel/arch/alpha/include/asm/rwsem.h | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/kernel/arch/alpha/include/asm/rwsem.h b/kernel/arch/alpha/include/asm/rwsem.h new file mode 100644 index 000000000..a83bbea62 --- /dev/null +++ b/kernel/arch/alpha/include/asm/rwsem.h @@ -0,0 +1,223 @@ +#ifndef _ALPHA_RWSEM_H +#define _ALPHA_RWSEM_H + +/* + * Written by Ivan Kokshaysky <ink@jurassic.park.msu.ru>, 2001. + * Based on asm-alpha/semaphore.h and asm-i386/rwsem.h + */ + +#ifndef _LINUX_RWSEM_H +#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead" +#endif + +#ifdef __KERNEL__ + +#include <linux/compiler.h> + +#define RWSEM_UNLOCKED_VALUE 0x0000000000000000L +#define RWSEM_ACTIVE_BIAS 0x0000000000000001L +#define RWSEM_ACTIVE_MASK 0x00000000ffffffffL +#define RWSEM_WAITING_BIAS (-0x0000000100000000L) +#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS +#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) + +static inline void __down_read(struct rw_semaphore *sem) +{ + long oldcount; +#ifndef CONFIG_SMP + oldcount = sem->count; + sem->count += RWSEM_ACTIVE_READ_BIAS; +#else + long temp; + __asm__ __volatile__( + "1: ldq_l %0,%1\n" + " addq %0,%3,%2\n" + " stq_c %2,%1\n" + " beq %2,2f\n" + " mb\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) + :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory"); +#endif + if (unlikely(oldcount < 0)) + rwsem_down_read_failed(sem); +} + +/* + * trylock for reading -- returns 1 if successful, 0 if contention + */ +static inline int __down_read_trylock(struct rw_semaphore *sem) +{ + long old, new, res; + + res = sem->count; + do { + new = res + RWSEM_ACTIVE_READ_BIAS; + if (new <= 0) + break; + old = res; + res = cmpxchg(&sem->count, old, new); + } while (res != old); + return res >= 0 ? 1 : 0; +} + +static inline void __down_write(struct rw_semaphore *sem) +{ + long oldcount; +#ifndef CONFIG_SMP + oldcount = sem->count; + sem->count += RWSEM_ACTIVE_WRITE_BIAS; +#else + long temp; + __asm__ __volatile__( + "1: ldq_l %0,%1\n" + " addq %0,%3,%2\n" + " stq_c %2,%1\n" + " beq %2,2f\n" + " mb\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) + :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory"); +#endif + if (unlikely(oldcount)) + rwsem_down_write_failed(sem); +} + +/* + * trylock for writing -- returns 1 if successful, 0 if contention + */ +static inline int __down_write_trylock(struct rw_semaphore *sem) +{ + long ret = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE, + RWSEM_ACTIVE_WRITE_BIAS); + if (ret == RWSEM_UNLOCKED_VALUE) + return 1; + return 0; +} + +static inline void __up_read(struct rw_semaphore *sem) +{ + long oldcount; +#ifndef CONFIG_SMP + oldcount = sem->count; + sem->count -= RWSEM_ACTIVE_READ_BIAS; +#else + long temp; + __asm__ __volatile__( + " mb\n" + "1: ldq_l %0,%1\n" + " subq %0,%3,%2\n" + " stq_c %2,%1\n" + " beq %2,2f\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) + :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory"); +#endif + if (unlikely(oldcount < 0)) + if ((int)oldcount - RWSEM_ACTIVE_READ_BIAS == 0) + rwsem_wake(sem); +} + +static inline void __up_write(struct rw_semaphore *sem) +{ + long count; +#ifndef CONFIG_SMP + sem->count -= RWSEM_ACTIVE_WRITE_BIAS; + count = sem->count; +#else + long temp; + __asm__ __volatile__( + " mb\n" + "1: ldq_l %0,%1\n" + " subq %0,%3,%2\n" + " stq_c %2,%1\n" + " beq %2,2f\n" + " subq %0,%3,%0\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (count), "=m" (sem->count), "=&r" (temp) + :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory"); +#endif + if (unlikely(count)) + if ((int)count == 0) + rwsem_wake(sem); +} + +/* + * downgrade write lock to read lock + */ +static inline void __downgrade_write(struct rw_semaphore *sem) +{ + long oldcount; +#ifndef CONFIG_SMP + oldcount = sem->count; + sem->count -= RWSEM_WAITING_BIAS; +#else + long temp; + __asm__ __volatile__( + "1: ldq_l %0,%1\n" + " addq %0,%3,%2\n" + " stq_c %2,%1\n" + " beq %2,2f\n" + " mb\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) + :"Ir" (-RWSEM_WAITING_BIAS), "m" (sem->count) : "memory"); +#endif + if (unlikely(oldcount < 0)) + rwsem_downgrade_wake(sem); +} + +static inline void rwsem_atomic_add(long val, struct rw_semaphore *sem) +{ +#ifndef CONFIG_SMP + sem->count += val; +#else + long temp; + __asm__ __volatile__( + "1: ldq_l %0,%1\n" + " addq %0,%2,%0\n" + " stq_c %0,%1\n" + " beq %0,2f\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (temp), "=m" (sem->count) + :"Ir" (val), "m" (sem->count)); +#endif +} + +static inline long rwsem_atomic_update(long val, struct rw_semaphore *sem) +{ +#ifndef CONFIG_SMP + sem->count += val; + return sem->count; +#else + long ret, temp; + __asm__ __volatile__( + "1: ldq_l %0,%1\n" + " addq %0,%3,%2\n" + " addq %0,%3,%0\n" + " stq_c %2,%1\n" + " beq %2,2f\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (ret), "=m" (sem->count), "=&r" (temp) + :"Ir" (val), "m" (sem->count)); + + return ret; +#endif +} + +#endif /* __KERNEL__ */ +#endif /* _ALPHA_RWSEM_H */ |