Release 4.10 arch/powerpc/include/asm/spinlock.h
#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>
#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
#ifdef CONFIG_PPC_PSERIES
#define vcpu_is_preempted vcpu_is_preempted
static inline bool vcpu_is_preempted(int cpu)
{
return !!(be32_to_cpu(lppaca_of(cpu).yield_count) & 1);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| pan xinhui | pan xinhui | 27 | 100.00% | 1 | 100.00% |
| Total | 27 | 100.00% | 1 | 100.00% |
#endif
static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
{
return lock.slock == 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| michael ellerman | michael ellerman | 17 | 100.00% | 1 | 100.00% |
| Total | 17 | 100.00% | 1 | 100.00% |
static inline int arch_spin_is_locked(arch_spinlock_t *lock)
{
smp_mb();
return !arch_spin_value_unlocked(*lock);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| michael ellerman | michael ellerman | 22 | 100.00% | 2 | 100.00% |
| Total | 22 | 100.00% | 2 | 100.00% |
/*
* 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 11 | 39.29% | 1 | 14.29% |
| andrew morton | andrew morton | 8 | 28.57% | 1 | 14.29% |
| paul mackerras | paul mackerras | 5 | 17.86% | 1 | 14.29% |
| thomas gleixner | thomas gleixner | 2 | 7.14% | 2 | 28.57% |
| bart van assche | bart van assche | 1 | 3.57% | 1 | 14.29% |
| anton blanchard | anton blanchard | 1 | 3.57% | 1 | 14.29% |
| Total | 28 | 100.00% | 7 | 100.00% |
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
CLEAR_IO_SYNC;
return __arch_spin_trylock(lock) == 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 11 | 52.38% | 1 | 16.67% |
| andrew morton | andrew morton | 4 | 19.05% | 1 | 16.67% |
| thomas gleixner | thomas gleixner | 3 | 14.29% | 2 | 33.33% |
| paul mackerras | paul mackerras | 2 | 9.52% | 1 | 16.67% |
| bart van assche | bart van assche | 1 | 4.76% | 1 | 16.67% |
| Total | 21 | 100.00% | 6 | 100.00% |
/*
* 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();
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| zwane mwaikambo | zwane mwaikambo | 46 | 74.19% | 1 | 12.50% |
| anton blanchard | anton blanchard | 8 | 12.90% | 1 | 12.50% |
| thomas gleixner | thomas gleixner | 3 | 4.84% | 2 | 25.00% |
| paul mackerras | paul mackerras | 2 | 3.23% | 1 | 12.50% |
| jake moilanen | jake moilanen | 1 | 1.61% | 1 | 12.50% |
| ingo molnar | ingo molnar | 1 | 1.61% | 1 | 12.50% |
| bart van assche | bart van assche | 1 | 1.61% | 1 | 12.50% |
| Total | 62 | 100.00% | 8 | 100.00% |
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);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| zwane mwaikambo | zwane mwaikambo | 62 | 72.94% | 1 | 11.11% |
| anton blanchard | anton blanchard | 8 | 9.41% | 1 | 11.11% |
| andrew morton | andrew morton | 7 | 8.24% | 1 | 11.11% |
| thomas gleixner | thomas gleixner | 3 | 3.53% | 2 | 22.22% |
| paul mackerras | paul mackerras | 2 | 2.35% | 1 | 11.11% |
| ingo molnar | ingo molnar | 1 | 1.18% | 1 | 11.11% |
| jake moilanen | jake moilanen | 1 | 1.18% | 1 | 11.11% |
| bart van assche | bart van assche | 1 | 1.18% | 1 | 11.11% |
| Total | 85 | 100.00% | 9 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 16 | 72.73% | 1 | 16.67% |
| thomas gleixner | thomas gleixner | 2 | 9.09% | 2 | 33.33% |
| paul mackerras | paul mackerras | 2 | 9.09% | 1 | 16.67% |
| anton blanchard | anton blanchard | 1 | 4.55% | 1 | 16.67% |
| bart van assche | bart van assche | 1 | 4.55% | 1 | 16.67% |
| Total | 22 | 100.00% | 6 | 100.00% |
static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
{
arch_spinlock_t lock_val;
smp_mb();
/*
* Atomically load and store back the lock value (unchanged). This
* ensures that our observation of the lock value is ordered with
* respect to other lock operations.
*/
__asm__ __volatile__(
"1: " PPC_LWARX(%0, 0, %2, 0) "\n"
" stwcx. %0, 0, %2\n"
" bne- 1b\n"
: "=&r" (lock_val), "+m" (*lock)
: "r" (lock)
: "cr0", "xer");
if (arch_spin_value_unlocked(lock_val))
goto out;
while (lock->slock) {
HMT_low();
if (SHARED_PROCESSOR)
__spin_yield(lock);
}
HMT_medium();
out:
smp_mb();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| boqun feng | boqun feng | 51 | 86.44% | 1 | 20.00% |
| ingo molnar | ingo molnar | 5 | 8.47% | 1 | 20.00% |
| thomas gleixner | thomas gleixner | 2 | 3.39% | 2 | 40.00% |
| paul mackerras | paul mackerras | 1 | 1.69% | 1 | 20.00% |
| Total | 59 | 100.00% | 5 | 100.00% |
/*
* 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| zwane mwaikambo | zwane mwaikambo | 12 | 60.00% | 1 | 16.67% |
| andrew morton | andrew morton | 4 | 20.00% | 1 | 16.67% |
| thomas gleixner | thomas gleixner | 2 | 10.00% | 2 | 33.33% |
| bart van assche | bart van assche | 1 | 5.00% | 1 | 16.67% |
| anton blanchard | anton blanchard | 1 | 5.00% | 1 | 16.67% |
| Total | 20 | 100.00% | 6 | 100.00% |
/*
* 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 8 | 30.77% | 1 | 12.50% |
| paul mackerras | paul mackerras | 5 | 19.23% | 1 | 12.50% |
| zwane mwaikambo | zwane mwaikambo | 5 | 19.23% | 1 | 12.50% |
| andrew morton | andrew morton | 4 | 15.38% | 1 | 12.50% |
| thomas gleixner | thomas gleixner | 2 | 7.69% | 2 | 25.00% |
| bart van assche | bart van assche | 1 | 3.85% | 1 | 12.50% |
| anton blanchard | anton blanchard | 1 | 3.85% | 1 | 12.50% |
| Total | 26 | 100.00% | 8 | 100.00% |
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();
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| zwane mwaikambo | zwane mwaikambo | 48 | 80.00% | 1 | 16.67% |
| anton blanchard | anton blanchard | 7 | 11.67% | 1 | 16.67% |
| thomas gleixner | thomas gleixner | 3 | 5.00% | 2 | 33.33% |
| jake moilanen | jake moilanen | 1 | 1.67% | 1 | 16.67% |
| bart van assche | bart van assche | 1 | 1.67% | 1 | 16.67% |
| Total | 60 | 100.00% | 6 | 100.00% |
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();
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| zwane mwaikambo | zwane mwaikambo | 47 | 78.33% | 1 | 14.29% |
| anton blanchard | anton blanchard | 7 | 11.67% | 1 | 14.29% |
| thomas gleixner | thomas gleixner | 3 | 5.00% | 2 | 28.57% |
| jake moilanen | jake moilanen | 1 | 1.67% | 1 | 14.29% |
| bart van assche | bart van assche | 1 | 1.67% | 1 | 14.29% |
| andrew morton | andrew morton | 1 | 1.67% | 1 | 14.29% |
| Total | 60 | 100.00% | 7 | 100.00% |
static inline int arch_read_trylock(arch_rwlock_t *rw)
{
return __arch_read_trylock(rw) > 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 15 | 78.95% | 1 | 25.00% |
| thomas gleixner | thomas gleixner | 3 | 15.79% | 2 | 50.00% |
| bart van assche | bart van assche | 1 | 5.26% | 1 | 25.00% |
| Total | 19 | 100.00% | 4 | 100.00% |
static inline int arch_write_trylock(arch_rwlock_t *rw)
{
return __arch_write_trylock(rw) == 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 15 | 78.95% | 1 | 25.00% |
| thomas gleixner | thomas gleixner | 3 | 15.79% | 2 | 50.00% |
| bart van assche | bart van assche | 1 | 5.26% | 1 | 25.00% |
| Total | 19 | 100.00% | 4 | 100.00% |
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");
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 13 | 76.47% | 1 | 20.00% |
| thomas gleixner | thomas gleixner | 2 | 11.76% | 2 | 40.00% |
| anton blanchard | anton blanchard | 1 | 5.88% | 1 | 20.00% |
| bart van assche | bart van assche | 1 | 5.88% | 1 | 20.00% |
| Total | 17 | 100.00% | 5 | 100.00% |
static inline void arch_write_unlock(arch_rwlock_t *rw)
{
__asm__ __volatile__("# write_unlock\n\t"
PPC_RELEASE_BARRIER: : :"memory");
rw->lock = 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 16 | 80.00% | 1 | 20.00% |
| thomas gleixner | thomas gleixner | 2 | 10.00% | 2 | 40.00% |
| anton blanchard | anton blanchard | 1 | 5.00% | 1 | 20.00% |
| bart van assche | bart van assche | 1 | 5.00% | 1 | 20.00% |
| Total | 20 | 100.00% | 5 | 100.00% |
#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 */
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| zwane mwaikambo | zwane mwaikambo | 257 | 31.30% | 1 | 3.33% |
| ingo molnar | ingo molnar | 115 | 14.01% | 1 | 3.33% |
| paul mackerras | paul mackerras | 98 | 11.94% | 2 | 6.67% |
| anton blanchard | anton blanchard | 69 | 8.40% | 5 | 16.67% |
| boqun feng | boqun feng | 51 | 6.21% | 1 | 3.33% |
| thomas gleixner | thomas gleixner | 46 | 5.60% | 4 | 13.33% |
| andrew morton | andrew morton | 45 | 5.48% | 2 | 6.67% |
| michael ellerman | michael ellerman | 39 | 4.75% | 3 | 10.00% |
| pan xinhui | pan xinhui | 36 | 4.38% | 1 | 3.33% |
| martin schwidefsky | martin schwidefsky | 18 | 2.19% | 2 | 6.67% |
| robin holt | robin holt | 14 | 1.71% | 1 | 3.33% |
| bart van assche | bart van assche | 13 | 1.58% | 1 | 3.33% |
| arnd bergmann | arnd bergmann | 6 | 0.73% | 1 | 3.33% |
| jake moilanen | jake moilanen | 4 | 0.49% | 1 | 3.33% |
| linus torvalds | linus torvalds | 4 | 0.49% | 1 | 3.33% |
| benjamin herrenschmidt | benjamin herrenschmidt | 3 | 0.37% | 1 | 3.33% |
| david gibson | david gibson | 2 | 0.24% | 1 | 3.33% |
| stephen rothwell | stephen rothwell | 1 | 0.12% | 1 | 3.33% |
| Total | 821 | 100.00% | 30 | 100.00% |
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