From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: 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 Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior 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 --- kernel/arch/sh/include/asm/mutex-llsc.h | 109 ++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 kernel/arch/sh/include/asm/mutex-llsc.h (limited to 'kernel/arch/sh/include/asm/mutex-llsc.h') diff --git a/kernel/arch/sh/include/asm/mutex-llsc.h b/kernel/arch/sh/include/asm/mutex-llsc.h new file mode 100644 index 000000000..dad29b687 --- /dev/null +++ b/kernel/arch/sh/include/asm/mutex-llsc.h @@ -0,0 +1,109 @@ +/* + * arch/sh/include/asm/mutex-llsc.h + * + * SH-4A optimized mutex locking primitives + * + * Please look into asm-generic/mutex-xchg.h for a formal definition. + */ +#ifndef __ASM_SH_MUTEX_LLSC_H +#define __ASM_SH_MUTEX_LLSC_H + +/* + * Attempting to lock a mutex on SH4A is done like in ARMv6+ architecure. + * with a bastardized atomic decrement (it is not a reliable atomic decrement + * but it satisfies the defined semantics for our purpose, while being + * smaller and faster than a real atomic decrement or atomic swap. + * The idea is to attempt decrementing the lock value only once. If once + * decremented it isn't zero, or if its store-back fails due to a dispute + * on the exclusive store, we simply bail out immediately through the slow + * path where the lock will be reattempted until it succeeds. + */ +static inline void +__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + int __done, __res; + + __asm__ __volatile__ ( + "movli.l @%2, %0 \n" + "add #-1, %0 \n" + "movco.l %0, @%2 \n" + "movt %1 \n" + : "=&z" (__res), "=&r" (__done) + : "r" (&(count)->counter) + : "t"); + + if (unlikely(!__done || __res != 0)) + fail_fn(count); +} + +static inline int +__mutex_fastpath_lock_retval(atomic_t *count) +{ + int __done, __res; + + __asm__ __volatile__ ( + "movli.l @%2, %0 \n" + "add #-1, %0 \n" + "movco.l %0, @%2 \n" + "movt %1 \n" + : "=&z" (__res), "=&r" (__done) + : "r" (&(count)->counter) + : "t"); + + if (unlikely(!__done || __res != 0)) + __res = -1; + + return __res; +} + +static inline void +__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + int __done, __res; + + __asm__ __volatile__ ( + "movli.l @%2, %0 \n\t" + "add #1, %0 \n\t" + "movco.l %0, @%2 \n\t" + "movt %1 \n\t" + : "=&z" (__res), "=&r" (__done) + : "r" (&(count)->counter) + : "t"); + + if (unlikely(!__done || __res <= 0)) + fail_fn(count); +} + +/* + * If the unlock was done on a contended lock, or if the unlock simply fails + * then the mutex remains locked. + */ +#define __mutex_slowpath_needs_to_unlock() 1 + +/* + * For __mutex_fastpath_trylock we do an atomic decrement and check the + * result and put it in the __res variable. + */ +static inline int +__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) +{ + int __res, __orig; + + __asm__ __volatile__ ( + "1: movli.l @%2, %0 \n\t" + "dt %0 \n\t" + "movco.l %0,@%2 \n\t" + "bf 1b \n\t" + "cmp/eq #0,%0 \n\t" + "bt 2f \n\t" + "mov #0, %1 \n\t" + "bf 3f \n\t" + "2: mov #1, %1 \n\t" + "3: " + : "=&z" (__orig), "=&r" (__res) + : "r" (&count->counter) + : "t"); + + return __res; +} +#endif /* __ASM_SH_MUTEX_LLSC_H */ -- cgit 1.2.3-korg