From 2b47d54ed41c33baf5825185168b493317c5572f Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 28 Jul 2016 19:21:10 +0000 Subject: [PATCH] sh: add J2 atomics using the cas.l instruction Signed-off-by: Rich Felker --- arch/sh/include/asm/atomic.h | 8 + arch/sh/include/asm/barrier.h | 5 + arch/sh/include/asm/bitops-cas.h | 93 ++++++++++++ arch/sh/include/asm/bitops.h | 2 + arch/sh/include/asm/cmpxchg-cas.h | 24 +++ arch/sh/include/asm/cmpxchg.h | 2 + arch/sh/include/asm/spinlock-cas.h | 117 +++++++++++++++ arch/sh/include/asm/spinlock-llsc.h | 224 ++++++++++++++++++++++++++++ arch/sh/include/asm/spinlock.h | 222 +-------------------------- 9 files changed, 481 insertions(+), 216 deletions(-) create mode 100644 arch/sh/include/asm/bitops-cas.h create mode 100644 arch/sh/include/asm/cmpxchg-cas.h create mode 100644 arch/sh/include/asm/spinlock-cas.h create mode 100644 arch/sh/include/asm/spinlock-llsc.h diff --git a/arch/sh/include/asm/atomic.h b/arch/sh/include/asm/atomic.h index c399e1c55685..8a7bd80c8b33 100644 --- a/arch/sh/include/asm/atomic.h +++ b/arch/sh/include/asm/atomic.h @@ -1,6 +1,12 @@ #ifndef __ASM_SH_ATOMIC_H #define __ASM_SH_ATOMIC_H +#if defined(CONFIG_CPU_J2) + +#include + +#else + /* * Atomic operations that C can't guarantee us. Useful for * resource counting etc.. @@ -63,4 +69,6 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) return c; } +#endif /* CONFIG_CPU_J2 */ + #endif /* __ASM_SH_ATOMIC_H */ diff --git a/arch/sh/include/asm/barrier.h b/arch/sh/include/asm/barrier.h index 8a84e05adb2e..3c30b6e166b6 100644 --- a/arch/sh/include/asm/barrier.h +++ b/arch/sh/include/asm/barrier.h @@ -29,6 +29,11 @@ #define wmb() mb() #define ctrl_barrier() __icbi(PAGE_OFFSET) #else +#if defined(CONFIG_CPU_J2) && defined(CONFIG_SMP) +#define __smp_mb() do { int tmp = 0; __asm__ __volatile__ ("cas.l %0,%0,@%1" : "+r"(tmp) : "z"(&tmp) : "memory", "t"); } while(0) +#define __smp_rmb() __smp_mb() +#define __smp_wmb() __smp_mb() +#endif #define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop") #endif diff --git a/arch/sh/include/asm/bitops-cas.h b/arch/sh/include/asm/bitops-cas.h new file mode 100644 index 000000000000..88f793c04d3c --- /dev/null +++ b/arch/sh/include/asm/bitops-cas.h @@ -0,0 +1,93 @@ +#ifndef __ASM_SH_BITOPS_CAS_H +#define __ASM_SH_BITOPS_CAS_H + +static inline unsigned __bo_cas(volatile unsigned *p, unsigned old, unsigned new) +{ + __asm__ __volatile__("cas.l %1,%0,@r0" + : "+r"(new) + : "r"(old), "z"(p) + : "t", "memory" ); + return new; +} + +static inline void set_bit(int nr, volatile void *addr) +{ + unsigned mask, old; + volatile unsigned *a = addr; + + a += nr >> 5; + mask = 1U << (nr & 0x1f); + + do old = *a; + while (__bo_cas(a, old, old|mask) != old); +} + +static inline void clear_bit(int nr, volatile void *addr) +{ + unsigned mask, old; + volatile unsigned *a = addr; + + a += nr >> 5; + mask = 1U << (nr & 0x1f); + + do old = *a; + while (__bo_cas(a, old, old&~mask) != old); +} + +static inline void change_bit(int nr, volatile void *addr) +{ + unsigned mask, old; + volatile unsigned *a = addr; + + a += nr >> 5; + mask = 1U << (nr & 0x1f); + + do old = *a; + while (__bo_cas(a, old, old^mask) != old); +} + +static inline int test_and_set_bit(int nr, volatile void *addr) +{ + unsigned mask, old; + volatile unsigned *a = addr; + + a += nr >> 5; + mask = 1U << (nr & 0x1f); + + do old = *a; + while (__bo_cas(a, old, old|mask) != old); + + return !!(old & mask); +} + +static inline int test_and_clear_bit(int nr, volatile void *addr) +{ + unsigned mask, old; + volatile unsigned *a = addr; + + a += nr >> 5; + mask = 1U << (nr & 0x1f); + + do old = *a; + while (__bo_cas(a, old, old&~mask) != old); + + return !!(old & mask); +} + +static inline int test_and_change_bit(int nr, volatile void *addr) +{ + unsigned mask, old; + volatile unsigned *a = addr; + + a += nr >> 5; + mask = 1U << (nr & 0x1f); + + do old = *a; + while (__bo_cas(a, old, old^mask) != old); + + return !!(old & mask); +} + +#include + +#endif /* __ASM_SH_BITOPS_CAS_H */ diff --git a/arch/sh/include/asm/bitops.h b/arch/sh/include/asm/bitops.h index fc8e652cf173..a8699d60a8c4 100644 --- a/arch/sh/include/asm/bitops.h +++ b/arch/sh/include/asm/bitops.h @@ -18,6 +18,8 @@ #include #elif defined(CONFIG_CPU_SH4A) #include +#elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP) +#include #else #include #include diff --git a/arch/sh/include/asm/cmpxchg-cas.h b/arch/sh/include/asm/cmpxchg-cas.h new file mode 100644 index 000000000000..d0d86649e8c1 --- /dev/null +++ b/arch/sh/include/asm/cmpxchg-cas.h @@ -0,0 +1,24 @@ +#ifndef __ASM_SH_CMPXCHG_CAS_H +#define __ASM_SH_CMPXCHG_CAS_H + +static inline unsigned long +__cmpxchg_u32(volatile u32 *m, unsigned long old, unsigned long new) +{ + __asm__ __volatile__("cas.l %1,%0,@r0" + : "+r"(new) + : "r"(old), "z"(m) + : "t", "memory" ); + return new; +} + +static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val) +{ + unsigned long old; + do old = *m; + while (__cmpxchg_u32(m, old, val) != old); + return old; +} + +#include + +#endif /* __ASM_SH_CMPXCHG_CAS_H */ diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h index 5225916c1057..3dfe0467a773 100644 --- a/arch/sh/include/asm/cmpxchg.h +++ b/arch/sh/include/asm/cmpxchg.h @@ -13,6 +13,8 @@ #include #elif defined(CONFIG_CPU_SH4A) #include +#elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP) +#include #else #include #endif diff --git a/arch/sh/include/asm/spinlock-cas.h b/arch/sh/include/asm/spinlock-cas.h new file mode 100644 index 000000000000..c46e8cc7b515 --- /dev/null +++ b/arch/sh/include/asm/spinlock-cas.h @@ -0,0 +1,117 @@ +/* + * include/asm-sh/spinlock-cas.h + * + * Copyright (C) 2015 SEI + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#ifndef __ASM_SH_SPINLOCK_CAS_H +#define __ASM_SH_SPINLOCK_CAS_H + +#include +#include + +static inline unsigned __sl_cas(volatile unsigned *p, unsigned old, unsigned new) +{ + __asm__ __volatile__("cas.l %1,%0,@r0" + : "+r"(new) + : "r"(old), "z"(p) + : "t", "memory" ); + return new; +} + +/* + * Your basic SMP spinlocks, allowing only a single CPU anywhere + */ + +#define arch_spin_is_locked(x) ((x)->lock <= 0) +#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) + +static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) +{ + smp_cond_load_acquire(&lock->lock, VAL > 0); +} + +static inline void arch_spin_lock(arch_spinlock_t *lock) +{ + while (!__sl_cas(&lock->lock, 1, 0)); +} + +static inline void arch_spin_unlock(arch_spinlock_t *lock) +{ + __sl_cas(&lock->lock, 0, 1); +} + +static inline int arch_spin_trylock(arch_spinlock_t *lock) +{ + return __sl_cas(&lock->lock, 1, 0); +} + +/* + * 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. + */ + +/** + * read_can_lock - would read_trylock() succeed? + * @lock: the rwlock in question. + */ +#define arch_read_can_lock(x) ((x)->lock > 0) + +/** + * write_can_lock - would write_trylock() succeed? + * @lock: the rwlock in question. + */ +#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) + +static inline void arch_read_lock(arch_rwlock_t *rw) +{ + unsigned old; + do old = rw->lock; + while (!old || __sl_cas(&rw->lock, old, old-1) != old); +} + +static inline void arch_read_unlock(arch_rwlock_t *rw) +{ + unsigned old; + do old = rw->lock; + while (__sl_cas(&rw->lock, old, old+1) != old); +} + +static inline void arch_write_lock(arch_rwlock_t *rw) +{ + while (__sl_cas(&rw->lock, RW_LOCK_BIAS, 0) != RW_LOCK_BIAS); +} + +static inline void arch_write_unlock(arch_rwlock_t *rw) +{ + __sl_cas(&rw->lock, 0, RW_LOCK_BIAS); +} + +static inline int arch_read_trylock(arch_rwlock_t *rw) +{ + unsigned old; + do old = rw->lock; + while (old && __sl_cas(&rw->lock, old, old-1) != old); + return !!old; +} + +static inline int arch_write_trylock(arch_rwlock_t *rw) +{ + return __sl_cas(&rw->lock, RW_LOCK_BIAS, 0) == RW_LOCK_BIAS; +} + +#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) cpu_relax() +#define arch_read_relax(lock) cpu_relax() +#define arch_write_relax(lock) cpu_relax() + +#endif /* __ASM_SH_SPINLOCK_CAS_H */ diff --git a/arch/sh/include/asm/spinlock-llsc.h b/arch/sh/include/asm/spinlock-llsc.h new file mode 100644 index 000000000000..cec78143fa83 --- /dev/null +++ b/arch/sh/include/asm/spinlock-llsc.h @@ -0,0 +1,224 @@ +/* + * include/asm-sh/spinlock-llsc.h + * + * Copyright (C) 2002, 2003 Paul Mundt + * Copyright (C) 2006, 2007 Akio Idehara + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#ifndef __ASM_SH_SPINLOCK_LLSC_H +#define __ASM_SH_SPINLOCK_LLSC_H + +#include +#include + +/* + * Your basic SMP spinlocks, allowing only a single CPU anywhere + */ + +#define arch_spin_is_locked(x) ((x)->lock <= 0) +#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) + +static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) +{ + smp_cond_load_acquire(&lock->lock, VAL > 0); +} + +/* + * Simple spin lock operations. There are two variants, one clears IRQ's + * on the local processor, one does not. + * + * We make no fairness assumptions. They have a cost. + */ +static inline void arch_spin_lock(arch_spinlock_t *lock) +{ + unsigned long tmp; + unsigned long oldval; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%2, %0 ! arch_spin_lock \n\t" + "mov %0, %1 \n\t" + "mov #0, %0 \n\t" + "movco.l %0, @%2 \n\t" + "bf 1b \n\t" + "cmp/pl %1 \n\t" + "bf 1b \n\t" + : "=&z" (tmp), "=&r" (oldval) + : "r" (&lock->lock) + : "t", "memory" + ); +} + +static inline void arch_spin_unlock(arch_spinlock_t *lock) +{ + unsigned long tmp; + + __asm__ __volatile__ ( + "mov #1, %0 ! arch_spin_unlock \n\t" + "mov.l %0, @%1 \n\t" + : "=&z" (tmp) + : "r" (&lock->lock) + : "t", "memory" + ); +} + +static inline int arch_spin_trylock(arch_spinlock_t *lock) +{ + unsigned long tmp, oldval; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%2, %0 ! arch_spin_trylock \n\t" + "mov %0, %1 \n\t" + "mov #0, %0 \n\t" + "movco.l %0, @%2 \n\t" + "bf 1b \n\t" + "synco \n\t" + : "=&z" (tmp), "=&r" (oldval) + : "r" (&lock->lock) + : "t", "memory" + ); + + return oldval; +} + +/* + * 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. + */ + +/** + * read_can_lock - would read_trylock() succeed? + * @lock: the rwlock in question. + */ +#define arch_read_can_lock(x) ((x)->lock > 0) + +/** + * write_can_lock - would write_trylock() succeed? + * @lock: the rwlock in question. + */ +#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) + +static inline void arch_read_lock(arch_rwlock_t *rw) +{ + unsigned long tmp; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%1, %0 ! arch_read_lock \n\t" + "cmp/pl %0 \n\t" + "bf 1b \n\t" + "add #-1, %0 \n\t" + "movco.l %0, @%1 \n\t" + "bf 1b \n\t" + : "=&z" (tmp) + : "r" (&rw->lock) + : "t", "memory" + ); +} + +static inline void arch_read_unlock(arch_rwlock_t *rw) +{ + unsigned long tmp; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%1, %0 ! arch_read_unlock \n\t" + "add #1, %0 \n\t" + "movco.l %0, @%1 \n\t" + "bf 1b \n\t" + : "=&z" (tmp) + : "r" (&rw->lock) + : "t", "memory" + ); +} + +static inline void arch_write_lock(arch_rwlock_t *rw) +{ + unsigned long tmp; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%1, %0 ! arch_write_lock \n\t" + "cmp/hs %2, %0 \n\t" + "bf 1b \n\t" + "sub %2, %0 \n\t" + "movco.l %0, @%1 \n\t" + "bf 1b \n\t" + : "=&z" (tmp) + : "r" (&rw->lock), "r" (RW_LOCK_BIAS) + : "t", "memory" + ); +} + +static inline void arch_write_unlock(arch_rwlock_t *rw) +{ + __asm__ __volatile__ ( + "mov.l %1, @%0 ! arch_write_unlock \n\t" + : + : "r" (&rw->lock), "r" (RW_LOCK_BIAS) + : "t", "memory" + ); +} + +static inline int arch_read_trylock(arch_rwlock_t *rw) +{ + unsigned long tmp, oldval; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%2, %0 ! arch_read_trylock \n\t" + "mov %0, %1 \n\t" + "cmp/pl %0 \n\t" + "bf 2f \n\t" + "add #-1, %0 \n\t" + "movco.l %0, @%2 \n\t" + "bf 1b \n\t" + "2: \n\t" + "synco \n\t" + : "=&z" (tmp), "=&r" (oldval) + : "r" (&rw->lock) + : "t", "memory" + ); + + return (oldval > 0); +} + +static inline int arch_write_trylock(arch_rwlock_t *rw) +{ + unsigned long tmp, oldval; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%2, %0 ! arch_write_trylock \n\t" + "mov %0, %1 \n\t" + "cmp/hs %3, %0 \n\t" + "bf 2f \n\t" + "sub %3, %0 \n\t" + "2: \n\t" + "movco.l %0, @%2 \n\t" + "bf 1b \n\t" + "synco \n\t" + : "=&z" (tmp), "=&r" (oldval) + : "r" (&rw->lock), "r" (RW_LOCK_BIAS) + : "t", "memory" + ); + + return (oldval > (RW_LOCK_BIAS - 1)); +} + +#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) cpu_relax() +#define arch_read_relax(lock) cpu_relax() +#define arch_write_relax(lock) cpu_relax() + +#endif /* __ASM_SH_SPINLOCK_LLSC_H */ diff --git a/arch/sh/include/asm/spinlock.h b/arch/sh/include/asm/spinlock.h index 416834b60ad0..c2c61ea6a8e2 100644 --- a/arch/sh/include/asm/spinlock.h +++ b/arch/sh/include/asm/spinlock.h @@ -11,222 +11,12 @@ #ifndef __ASM_SH_SPINLOCK_H #define __ASM_SH_SPINLOCK_H -/* - * The only locking implemented here uses SH-4A opcodes. For others, - * split this out as per atomic-*.h. - */ -#ifndef CONFIG_CPU_SH4A -#error "Need movli.l/movco.l for spinlocks" +#if defined(CONFIG_CPU_SH4A) +#include +#elif defined(CONFIG_CPU_J2) +#include +#else +#error "The configured cpu type does not support spinlocks" #endif -#include -#include - -/* - * Your basic SMP spinlocks, allowing only a single CPU anywhere - */ - -#define arch_spin_is_locked(x) ((x)->lock <= 0) -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - -static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) -{ - smp_cond_load_acquire(&lock->lock, VAL > 0); -} - -/* - * Simple spin lock operations. There are two variants, one clears IRQ's - * on the local processor, one does not. - * - * We make no fairness assumptions. They have a cost. - */ -static inline void arch_spin_lock(arch_spinlock_t *lock) -{ - unsigned long tmp; - unsigned long oldval; - - __asm__ __volatile__ ( - "1: \n\t" - "movli.l @%2, %0 ! arch_spin_lock \n\t" - "mov %0, %1 \n\t" - "mov #0, %0 \n\t" - "movco.l %0, @%2 \n\t" - "bf 1b \n\t" - "cmp/pl %1 \n\t" - "bf 1b \n\t" - : "=&z" (tmp), "=&r" (oldval) - : "r" (&lock->lock) - : "t", "memory" - ); -} - -static inline void arch_spin_unlock(arch_spinlock_t *lock) -{ - unsigned long tmp; - - __asm__ __volatile__ ( - "mov #1, %0 ! arch_spin_unlock \n\t" - "mov.l %0, @%1 \n\t" - : "=&z" (tmp) - : "r" (&lock->lock) - : "t", "memory" - ); -} - -static inline int arch_spin_trylock(arch_spinlock_t *lock) -{ - unsigned long tmp, oldval; - - __asm__ __volatile__ ( - "1: \n\t" - "movli.l @%2, %0 ! arch_spin_trylock \n\t" - "mov %0, %1 \n\t" - "mov #0, %0 \n\t" - "movco.l %0, @%2 \n\t" - "bf 1b \n\t" - "synco \n\t" - : "=&z" (tmp), "=&r" (oldval) - : "r" (&lock->lock) - : "t", "memory" - ); - - return oldval; -} - -/* - * 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. - */ - -/** - * read_can_lock - would read_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_read_can_lock(x) ((x)->lock > 0) - -/** - * write_can_lock - would write_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) - -static inline void arch_read_lock(arch_rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__ ( - "1: \n\t" - "movli.l @%1, %0 ! arch_read_lock \n\t" - "cmp/pl %0 \n\t" - "bf 1b \n\t" - "add #-1, %0 \n\t" - "movco.l %0, @%1 \n\t" - "bf 1b \n\t" - : "=&z" (tmp) - : "r" (&rw->lock) - : "t", "memory" - ); -} - -static inline void arch_read_unlock(arch_rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__ ( - "1: \n\t" - "movli.l @%1, %0 ! arch_read_unlock \n\t" - "add #1, %0 \n\t" - "movco.l %0, @%1 \n\t" - "bf 1b \n\t" - : "=&z" (tmp) - : "r" (&rw->lock) - : "t", "memory" - ); -} - -static inline void arch_write_lock(arch_rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__ ( - "1: \n\t" - "movli.l @%1, %0 ! arch_write_lock \n\t" - "cmp/hs %2, %0 \n\t" - "bf 1b \n\t" - "sub %2, %0 \n\t" - "movco.l %0, @%1 \n\t" - "bf 1b \n\t" - : "=&z" (tmp) - : "r" (&rw->lock), "r" (RW_LOCK_BIAS) - : "t", "memory" - ); -} - -static inline void arch_write_unlock(arch_rwlock_t *rw) -{ - __asm__ __volatile__ ( - "mov.l %1, @%0 ! arch_write_unlock \n\t" - : - : "r" (&rw->lock), "r" (RW_LOCK_BIAS) - : "t", "memory" - ); -} - -static inline int arch_read_trylock(arch_rwlock_t *rw) -{ - unsigned long tmp, oldval; - - __asm__ __volatile__ ( - "1: \n\t" - "movli.l @%2, %0 ! arch_read_trylock \n\t" - "mov %0, %1 \n\t" - "cmp/pl %0 \n\t" - "bf 2f \n\t" - "add #-1, %0 \n\t" - "movco.l %0, @%2 \n\t" - "bf 1b \n\t" - "2: \n\t" - "synco \n\t" - : "=&z" (tmp), "=&r" (oldval) - : "r" (&rw->lock) - : "t", "memory" - ); - - return (oldval > 0); -} - -static inline int arch_write_trylock(arch_rwlock_t *rw) -{ - unsigned long tmp, oldval; - - __asm__ __volatile__ ( - "1: \n\t" - "movli.l @%2, %0 ! arch_write_trylock \n\t" - "mov %0, %1 \n\t" - "cmp/hs %3, %0 \n\t" - "bf 2f \n\t" - "sub %3, %0 \n\t" - "2: \n\t" - "movco.l %0, @%2 \n\t" - "bf 1b \n\t" - "synco \n\t" - : "=&z" (tmp), "=&r" (oldval) - : "r" (&rw->lock), "r" (RW_LOCK_BIAS) - : "t", "memory" - ); - - return (oldval > (RW_LOCK_BIAS - 1)); -} - -#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) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* __ASM_SH_SPINLOCK_H */ -- 2.20.1