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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/spinlock.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/spinlock.h')
-rw-r--r-- | kernel/arch/powerpc/include/asm/spinlock.h | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/include/asm/spinlock.h b/kernel/arch/powerpc/include/asm/spinlock.h new file mode 100644 index 000000000..4dbe072ee --- /dev/null +++ b/kernel/arch/powerpc/include/asm/spinlock.h @@ -0,0 +1,314 @@ +#ifndef __ASM_SPINLOCK_H +#define __ASM_SPINLOCK_H +#ifdef __KERNEL__ + +/* + * Simple spin lock operations. + * + * Copyright (C) 2001-2004 Paul Mackerras <paulus@au.ibm.com>, IBM + * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM + * Copyright (C) 2002 Dave Engebretsen <engebret@us.ibm.com>, IBM + * Rework to support virtual processors + * + * Type of int is used as a full 64b word is not necessary. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * (the type definitions are in asm/spinlock_types.h) + */ +#include <linux/irqflags.h> +#ifdef CONFIG_PPC64 +#include <asm/paca.h> +#include <asm/hvcall.h> +#endif +#include <asm/asm-compat.h> +#include <asm/synch.h> +#include <asm/ppc-opcode.h> + +#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */ + +#ifdef CONFIG_PPC64 +/* use 0x800000yy when locked, where yy == CPU number */ +#ifdef __BIG_ENDIAN__ +#define LOCK_TOKEN (*(u32 *)(&get_paca()->lock_token)) +#else +#define LOCK_TOKEN (*(u32 *)(&get_paca()->paca_index)) +#endif +#else +#define LOCK_TOKEN 1 +#endif + +#if defined(CONFIG_PPC64) && defined(CONFIG_SMP) +#define CLEAR_IO_SYNC (get_paca()->io_sync = 0) +#define SYNC_IO do { \ + if (unlikely(get_paca()->io_sync)) { \ + mb(); \ + get_paca()->io_sync = 0; \ + } \ + } while (0) +#else +#define CLEAR_IO_SYNC +#define SYNC_IO +#endif + +static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock) +{ + return lock.slock == 0; +} + +static inline int arch_spin_is_locked(arch_spinlock_t *lock) +{ + smp_mb(); + return !arch_spin_value_unlocked(*lock); +} + +/* + * This returns the old value in the lock, so we succeeded + * in getting the lock if the return value is 0. + */ +static inline unsigned long __arch_spin_trylock(arch_spinlock_t *lock) +{ + unsigned long tmp, token; + + token = LOCK_TOKEN; + __asm__ __volatile__( +"1: " PPC_LWARX(%0,0,%2,1) "\n\ + cmpwi 0,%0,0\n\ + bne- 2f\n\ + stwcx. %1,0,%2\n\ + bne- 1b\n" + PPC_ACQUIRE_BARRIER +"2:" + : "=&r" (tmp) + : "r" (token), "r" (&lock->slock) + : "cr0", "memory"); + + return tmp; +} + +static inline int arch_spin_trylock(arch_spinlock_t *lock) +{ + CLEAR_IO_SYNC; + return __arch_spin_trylock(lock) == 0; +} + +/* + * On a system with shared processors (that is, where a physical + * processor is multiplexed between several virtual processors), + * there is no point spinning on a lock if the holder of the lock + * isn't currently scheduled on a physical processor. Instead + * we detect this situation and ask the hypervisor to give the + * rest of our timeslice to the lock holder. + * + * So that we can tell which virtual processor is holding a lock, + * we put 0x80000000 | smp_processor_id() in the lock when it is + * held. Conveniently, we have a word in the paca that holds this + * value. + */ + +#if defined(CONFIG_PPC_SPLPAR) +/* We only yield to the hypervisor if we are in shared processor mode */ +#define SHARED_PROCESSOR (lppaca_shared_proc(local_paca->lppaca_ptr)) +extern void __spin_yield(arch_spinlock_t *lock); +extern void __rw_yield(arch_rwlock_t *lock); +#else /* SPLPAR */ +#define __spin_yield(x) barrier() +#define __rw_yield(x) barrier() +#define SHARED_PROCESSOR 0 +#endif + +static inline void arch_spin_lock(arch_spinlock_t *lock) +{ + CLEAR_IO_SYNC; + while (1) { + if (likely(__arch_spin_trylock(lock) == 0)) + break; + do { + HMT_low(); + if (SHARED_PROCESSOR) + __spin_yield(lock); + } while (unlikely(lock->slock != 0)); + HMT_medium(); + } +} + +static inline +void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags) +{ + unsigned long flags_dis; + + CLEAR_IO_SYNC; + while (1) { + if (likely(__arch_spin_trylock(lock) == 0)) + break; + local_save_flags(flags_dis); + local_irq_restore(flags); + do { + HMT_low(); + if (SHARED_PROCESSOR) + __spin_yield(lock); + } while (unlikely(lock->slock != 0)); + HMT_medium(); + local_irq_restore(flags_dis); + } +} + +static inline void arch_spin_unlock(arch_spinlock_t *lock) +{ + SYNC_IO; + __asm__ __volatile__("# arch_spin_unlock\n\t" + PPC_RELEASE_BARRIER: : :"memory"); + lock->slock = 0; +} + +#ifdef CONFIG_PPC64 +extern void arch_spin_unlock_wait(arch_spinlock_t *lock); +#else +#define arch_spin_unlock_wait(lock) \ + do { while (arch_spin_is_locked(lock)) cpu_relax(); } while (0) +#endif + +/* + * Read-write spinlocks, allowing multiple readers + * but only one writer. + * + * NOTE! it is quite common to have readers in interrupts + * but no interrupt writers. For those circumstances we + * can "mix" irq-safe locks - any writer needs to get a + * irq-safe write-lock, but readers can get non-irqsafe + * read-locks. + */ + +#define arch_read_can_lock(rw) ((rw)->lock >= 0) +#define arch_write_can_lock(rw) (!(rw)->lock) + +#ifdef CONFIG_PPC64 +#define __DO_SIGN_EXTEND "extsw %0,%0\n" +#define WRLOCK_TOKEN LOCK_TOKEN /* it's negative */ +#else +#define __DO_SIGN_EXTEND +#define WRLOCK_TOKEN (-1) +#endif + +/* + * This returns the old value in the lock + 1, + * so we got a read lock if the return value is > 0. + */ +static inline long __arch_read_trylock(arch_rwlock_t *rw) +{ + long tmp; + + __asm__ __volatile__( +"1: " PPC_LWARX(%0,0,%1,1) "\n" + __DO_SIGN_EXTEND +" addic. %0,%0,1\n\ + ble- 2f\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1\n\ + bne- 1b\n" + PPC_ACQUIRE_BARRIER +"2:" : "=&r" (tmp) + : "r" (&rw->lock) + : "cr0", "xer", "memory"); + + return tmp; +} + +/* + * This returns the old value in the lock, + * so we got the write lock if the return value is 0. + */ +static inline long __arch_write_trylock(arch_rwlock_t *rw) +{ + long tmp, token; + + token = WRLOCK_TOKEN; + __asm__ __volatile__( +"1: " PPC_LWARX(%0,0,%2,1) "\n\ + cmpwi 0,%0,0\n\ + bne- 2f\n" + PPC405_ERR77(0,%1) +" stwcx. %1,0,%2\n\ + bne- 1b\n" + PPC_ACQUIRE_BARRIER +"2:" : "=&r" (tmp) + : "r" (token), "r" (&rw->lock) + : "cr0", "memory"); + + return tmp; +} + +static inline void arch_read_lock(arch_rwlock_t *rw) +{ + while (1) { + if (likely(__arch_read_trylock(rw) > 0)) + break; + do { + HMT_low(); + if (SHARED_PROCESSOR) + __rw_yield(rw); + } while (unlikely(rw->lock < 0)); + HMT_medium(); + } +} + +static inline void arch_write_lock(arch_rwlock_t *rw) +{ + while (1) { + if (likely(__arch_write_trylock(rw) == 0)) + break; + do { + HMT_low(); + if (SHARED_PROCESSOR) + __rw_yield(rw); + } while (unlikely(rw->lock != 0)); + HMT_medium(); + } +} + +static inline int arch_read_trylock(arch_rwlock_t *rw) +{ + return __arch_read_trylock(rw) > 0; +} + +static inline int arch_write_trylock(arch_rwlock_t *rw) +{ + return __arch_write_trylock(rw) == 0; +} + +static inline void arch_read_unlock(arch_rwlock_t *rw) +{ + long tmp; + + __asm__ __volatile__( + "# read_unlock\n\t" + PPC_RELEASE_BARRIER +"1: lwarx %0,0,%1\n\ + addic %0,%0,-1\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1\n\ + bne- 1b" + : "=&r"(tmp) + : "r"(&rw->lock) + : "cr0", "xer", "memory"); +} + +static inline void arch_write_unlock(arch_rwlock_t *rw) +{ + __asm__ __volatile__("# write_unlock\n\t" + PPC_RELEASE_BARRIER: : :"memory"); + rw->lock = 0; +} + +#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) +#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) + +#define arch_spin_relax(lock) __spin_yield(lock) +#define arch_read_relax(lock) __rw_yield(lock) +#define arch_write_relax(lock) __rw_yield(lock) + +#endif /* __KERNEL__ */ +#endif /* __ASM_SPINLOCK_H */ |