[MIPS] Cleanup memory barriers for weakly ordered systems.

Also the R4000 / R4600 LL/SC instructions imply a sync so no explicit sync
needed.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle 2006-10-31 03:45:07 +00:00
parent 08f57f7ffe
commit 0004a9dfea
8 changed files with 225 additions and 212 deletions

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@ -1277,6 +1277,7 @@ config CPU_RM9000
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select WEAK_ORDERING
config CPU_SB1
bool "SB1"
@ -1285,6 +1286,7 @@ config CPU_SB1
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select WEAK_ORDERING
endchoice
@ -1345,6 +1347,8 @@ config SYS_HAS_CPU_RM9000
config SYS_HAS_CPU_SB1
bool
config WEAK_ORDERING
bool
endmenu
#

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@ -172,7 +172,7 @@ int smp_call_function (void (*func) (void *info), void *info, int retry,
spin_lock(&smp_call_lock);
call_data = &data;
mb();
smp_mb();
/* Send a message to all other CPUs and wait for them to respond */
for_each_online_cpu(i)
@ -204,7 +204,7 @@ void smp_call_function_interrupt(void)
* Notify initiating CPU that I've grabbed the data and am
* about to execute the function.
*/
mb();
smp_mb();
atomic_inc(&call_data->started);
/*
@ -215,7 +215,7 @@ void smp_call_function_interrupt(void)
irq_exit();
if (wait) {
mb();
smp_mb();
atomic_inc(&call_data->finished);
}
}

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@ -15,6 +15,7 @@
#define _ASM_ATOMIC_H
#include <linux/irqflags.h>
#include <asm/barrier.h>
#include <asm/cpu-features.h>
#include <asm/war.h>
@ -130,6 +131,8 @@ static __inline__ int atomic_add_return(int i, atomic_t * v)
{
unsigned long result;
smp_mb();
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
@ -140,7 +143,6 @@ static __inline__ int atomic_add_return(int i, atomic_t * v)
" sc %0, %2 \n"
" beqzl %0, 1b \n"
" addu %0, %1, %3 \n"
" sync \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
@ -155,7 +157,6 @@ static __inline__ int atomic_add_return(int i, atomic_t * v)
" sc %0, %2 \n"
" beqz %0, 1b \n"
" addu %0, %1, %3 \n"
" sync \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
@ -170,6 +171,8 @@ static __inline__ int atomic_add_return(int i, atomic_t * v)
local_irq_restore(flags);
}
smp_mb();
return result;
}
@ -177,6 +180,8 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v)
{
unsigned long result;
smp_mb();
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
@ -187,7 +192,6 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v)
" sc %0, %2 \n"
" beqzl %0, 1b \n"
" subu %0, %1, %3 \n"
" sync \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
@ -202,7 +206,6 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v)
" sc %0, %2 \n"
" beqz %0, 1b \n"
" subu %0, %1, %3 \n"
" sync \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
@ -217,6 +220,8 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v)
local_irq_restore(flags);
}
smp_mb();
return result;
}
@ -232,6 +237,8 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
{
unsigned long result;
smp_mb();
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
@ -245,7 +252,6 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
" beqzl %0, 1b \n"
" subu %0, %1, %3 \n"
" .set reorder \n"
" sync \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
@ -264,7 +270,6 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
" beqz %0, 1b \n"
" subu %0, %1, %3 \n"
" .set reorder \n"
" sync \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
@ -281,6 +286,8 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
local_irq_restore(flags);
}
smp_mb();
return result;
}
@ -484,6 +491,8 @@ static __inline__ long atomic64_add_return(long i, atomic64_t * v)
{
unsigned long result;
smp_mb();
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
@ -494,7 +503,6 @@ static __inline__ long atomic64_add_return(long i, atomic64_t * v)
" scd %0, %2 \n"
" beqzl %0, 1b \n"
" addu %0, %1, %3 \n"
" sync \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
@ -509,7 +517,6 @@ static __inline__ long atomic64_add_return(long i, atomic64_t * v)
" scd %0, %2 \n"
" beqz %0, 1b \n"
" addu %0, %1, %3 \n"
" sync \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
@ -524,6 +531,8 @@ static __inline__ long atomic64_add_return(long i, atomic64_t * v)
local_irq_restore(flags);
}
smp_mb();
return result;
}
@ -531,6 +540,8 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
{
unsigned long result;
smp_mb();
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
@ -541,7 +552,6 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
" scd %0, %2 \n"
" beqzl %0, 1b \n"
" subu %0, %1, %3 \n"
" sync \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
@ -556,7 +566,6 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
" scd %0, %2 \n"
" beqz %0, 1b \n"
" subu %0, %1, %3 \n"
" sync \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
@ -571,6 +580,8 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
local_irq_restore(flags);
}
smp_mb();
return result;
}
@ -586,6 +597,8 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
{
unsigned long result;
smp_mb();
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
@ -599,7 +612,6 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
" beqzl %0, 1b \n"
" dsubu %0, %1, %3 \n"
" .set reorder \n"
" sync \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
@ -618,7 +630,6 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
" beqz %0, 1b \n"
" dsubu %0, %1, %3 \n"
" .set reorder \n"
" sync \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
@ -635,6 +646,8 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
local_irq_restore(flags);
}
smp_mb();
return result;
}

132
include/asm-mips/barrier.h Normal file
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@ -0,0 +1,132 @@
/*
* 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.
*
* Copyright (C) 2006 by Ralf Baechle (ralf@linux-mips.org)
*/
#ifndef __ASM_BARRIER_H
#define __ASM_BARRIER_H
/*
* read_barrier_depends - Flush all pending reads that subsequents reads
* depend on.
*
* No data-dependent reads from memory-like regions are ever reordered
* over this barrier. All reads preceding this primitive are guaranteed
* to access memory (but not necessarily other CPUs' caches) before any
* reads following this primitive that depend on the data return by
* any of the preceding reads. This primitive is much lighter weight than
* rmb() on most CPUs, and is never heavier weight than is
* rmb().
*
* These ordering constraints are respected by both the local CPU
* and the compiler.
*
* Ordering is not guaranteed by anything other than these primitives,
* not even by data dependencies. See the documentation for
* memory_barrier() for examples and URLs to more information.
*
* For example, the following code would force ordering (the initial
* value of "a" is zero, "b" is one, and "p" is "&a"):
*
* <programlisting>
* CPU 0 CPU 1
*
* b = 2;
* memory_barrier();
* p = &b; q = p;
* read_barrier_depends();
* d = *q;
* </programlisting>
*
* because the read of "*q" depends on the read of "p" and these
* two reads are separated by a read_barrier_depends(). However,
* the following code, with the same initial values for "a" and "b":
*
* <programlisting>
* CPU 0 CPU 1
*
* a = 2;
* memory_barrier();
* b = 3; y = b;
* read_barrier_depends();
* x = a;
* </programlisting>
*
* does not enforce ordering, since there is no data dependency between
* the read of "a" and the read of "b". Therefore, on some CPUs, such
* as Alpha, "y" could be set to 3 and "x" to 0. Use rmb()
* in cases like this where there are no data dependencies.
*/
#define read_barrier_depends() do { } while(0)
#define smp_read_barrier_depends() do { } while(0)
#ifdef CONFIG_CPU_HAS_SYNC
#define __sync() \
__asm__ __volatile__( \
".set push\n\t" \
".set noreorder\n\t" \
".set mips2\n\t" \
"sync\n\t" \
".set pop" \
: /* no output */ \
: /* no input */ \
: "memory")
#else
#define __sync() do { } while(0)
#endif
#define __fast_iob() \
__asm__ __volatile__( \
".set push\n\t" \
".set noreorder\n\t" \
"lw $0,%0\n\t" \
"nop\n\t" \
".set pop" \
: /* no output */ \
: "m" (*(int *)CKSEG1) \
: "memory")
#define fast_wmb() __sync()
#define fast_rmb() __sync()
#define fast_mb() __sync()
#define fast_iob() \
do { \
__sync(); \
__fast_iob(); \
} while (0)
#ifdef CONFIG_CPU_HAS_WB
#include <asm/wbflush.h>
#define wmb() fast_wmb()
#define rmb() fast_rmb()
#define mb() wbflush()
#define iob() wbflush()
#else /* !CONFIG_CPU_HAS_WB */
#define wmb() fast_wmb()
#define rmb() fast_rmb()
#define mb() fast_mb()
#define iob() fast_iob()
#endif /* !CONFIG_CPU_HAS_WB */
#if defined(CONFIG_WEAK_ORDERING) && defined(CONFIG_SMP)
#define __WEAK_ORDERING_MB " sync \n"
#else
#define __WEAK_ORDERING_MB " \n"
#endif
#define smp_mb() __asm__ __volatile__(__WEAK_ORDERING_MB : : :"memory")
#define smp_rmb() __asm__ __volatile__(__WEAK_ORDERING_MB : : :"memory")
#define smp_wmb() __asm__ __volatile__(__WEAK_ORDERING_MB : : :"memory")
#define set_mb(var, value) \
do { var = value; smp_mb(); } while (0)
#endif /* __ASM_BARRIER_H */

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@ -3,7 +3,7 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1994 - 1997, 1999, 2000 Ralf Baechle (ralf@gnu.org)
* Copyright (c) 1994 - 1997, 1999, 2000, 06 Ralf Baechle (ralf@linux-mips.org)
* Copyright (c) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_BITOPS_H
@ -12,6 +12,7 @@
#include <linux/compiler.h>
#include <linux/irqflags.h>
#include <linux/types.h>
#include <asm/barrier.h>
#include <asm/bug.h>
#include <asm/byteorder.h> /* sigh ... */
#include <asm/cpu-features.h>
@ -204,9 +205,6 @@ static inline int test_and_set_bit(unsigned long nr,
" " __SC "%2, %1 \n"
" beqzl %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
@ -226,9 +224,6 @@ static inline int test_and_set_bit(unsigned long nr,
" " __SC "%2, %1 \n"
" beqz %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set pop \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
@ -250,6 +245,8 @@ static inline int test_and_set_bit(unsigned long nr,
return retval;
}
smp_mb();
}
/*
@ -275,9 +272,6 @@ static inline int test_and_clear_bit(unsigned long nr,
" " __SC "%2, %1 \n"
" beqzl %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
@ -298,9 +292,6 @@ static inline int test_and_clear_bit(unsigned long nr,
" " __SC "%2, %1 \n"
" beqz %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set pop \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
@ -322,6 +313,8 @@ static inline int test_and_clear_bit(unsigned long nr,
return retval;
}
smp_mb();
}
/*
@ -346,9 +339,6 @@ static inline int test_and_change_bit(unsigned long nr,
" " __SC "%2, %1 \n"
" beqzl %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
@ -368,9 +358,6 @@ static inline int test_and_change_bit(unsigned long nr,
" " __SC "\t%2, %1 \n"
" beqz %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set pop \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
@ -391,6 +378,8 @@ static inline int test_and_change_bit(unsigned long nr,
return retval;
}
smp_mb();
}
#include <asm-generic/bitops/non-atomic.h>

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@ -1,19 +1,21 @@
/*
* 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.
*
* Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org)
*/
#ifndef _ASM_FUTEX_H
#define _ASM_FUTEX_H
#ifdef __KERNEL__
#include <linux/futex.h>
#include <asm/barrier.h>
#include <asm/errno.h>
#include <asm/uaccess.h>
#include <asm/war.h>
#ifdef CONFIG_SMP
#define __FUTEX_SMP_SYNC " sync \n"
#else
#define __FUTEX_SMP_SYNC
#endif
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
{ \
if (cpu_has_llsc && R10000_LLSC_WAR) { \
@ -27,7 +29,7 @@
" .set mips3 \n" \
"2: sc $1, %2 \n" \
" beqzl $1, 1b \n" \
__FUTEX_SMP_SYNC \
__WEAK_ORDERING_MB \
"3: \n" \
" .set pop \n" \
" .set mips0 \n" \
@ -53,7 +55,7 @@
" .set mips3 \n" \
"2: sc $1, %2 \n" \
" beqz $1, 1b \n" \
__FUTEX_SMP_SYNC \
__WEAK_ORDERING_MB \
"3: \n" \
" .set pop \n" \
" .set mips0 \n" \
@ -150,7 +152,7 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
" .set mips3 \n"
"2: sc $1, %1 \n"
" beqzl $1, 1b \n"
__FUTEX_SMP_SYNC
__WEAK_ORDERING_MB
"3: \n"
" .set pop \n"
" .section .fixup,\"ax\" \n"
@ -177,7 +179,7 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
" .set mips3 \n"
"2: sc $1, %1 \n"
" beqz $1, 1b \n"
__FUTEX_SMP_SYNC
__WEAK_ORDERING_MB
"3: \n"
" .set pop \n"
" .section .fixup,\"ax\" \n"

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@ -3,12 +3,13 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1999, 2000 by Ralf Baechle
* Copyright (C) 1999, 2000, 06 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_SPINLOCK_H
#define _ASM_SPINLOCK_H
#include <asm/barrier.h>
#include <asm/war.h>
/*
@ -40,7 +41,6 @@ static inline void __raw_spin_lock(raw_spinlock_t *lock)
" sc %1, %0 \n"
" beqzl %1, 1b \n"
" nop \n"
" sync \n"
" .set reorder \n"
: "=m" (lock->lock), "=&r" (tmp)
: "m" (lock->lock)
@ -53,19 +53,22 @@ static inline void __raw_spin_lock(raw_spinlock_t *lock)
" li %1, 1 \n"
" sc %1, %0 \n"
" beqz %1, 1b \n"
" sync \n"
" nop \n"
" .set reorder \n"
: "=m" (lock->lock), "=&r" (tmp)
: "m" (lock->lock)
: "memory");
}
smp_mb();
}
static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
smp_mb();
__asm__ __volatile__(
" .set noreorder # __raw_spin_unlock \n"
" sync \n"
" sw $0, %0 \n"
" .set\treorder \n"
: "=m" (lock->lock)
@ -86,7 +89,6 @@ static inline unsigned int __raw_spin_trylock(raw_spinlock_t *lock)
" beqzl %2, 1b \n"
" nop \n"
" andi %2, %0, 1 \n"
" sync \n"
" .set reorder"
: "=&r" (temp), "=m" (lock->lock), "=&r" (res)
: "m" (lock->lock)
@ -99,13 +101,14 @@ static inline unsigned int __raw_spin_trylock(raw_spinlock_t *lock)
" sc %2, %1 \n"
" beqz %2, 1b \n"
" andi %2, %0, 1 \n"
" sync \n"
" .set reorder"
: "=&r" (temp), "=m" (lock->lock), "=&r" (res)
: "m" (lock->lock)
: "memory");
}
smp_mb();
return res == 0;
}
@ -143,7 +146,6 @@ static inline void __raw_read_lock(raw_rwlock_t *rw)
" sc %1, %0 \n"
" beqzl %1, 1b \n"
" nop \n"
" sync \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
@ -156,12 +158,14 @@ static inline void __raw_read_lock(raw_rwlock_t *rw)
" addu %1, 1 \n"
" sc %1, %0 \n"
" beqz %1, 1b \n"
" sync \n"
" nop \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
}
smp_mb();
}
/* Note the use of sub, not subu which will make the kernel die with an
@ -171,13 +175,14 @@ static inline void __raw_read_unlock(raw_rwlock_t *rw)
{
unsigned int tmp;
smp_mb();
if (R10000_LLSC_WAR) {
__asm__ __volatile__(
"1: ll %1, %2 # __raw_read_unlock \n"
" sub %1, 1 \n"
" sc %1, %0 \n"
" beqzl %1, 1b \n"
" sync \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
@ -188,7 +193,7 @@ static inline void __raw_read_unlock(raw_rwlock_t *rw)
" sub %1, 1 \n"
" sc %1, %0 \n"
" beqz %1, 1b \n"
" sync \n"
" nop \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
@ -208,7 +213,7 @@ static inline void __raw_write_lock(raw_rwlock_t *rw)
" lui %1, 0x8000 \n"
" sc %1, %0 \n"
" beqzl %1, 1b \n"
" sync \n"
" nop \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
@ -221,18 +226,22 @@ static inline void __raw_write_lock(raw_rwlock_t *rw)
" lui %1, 0x8000 \n"
" sc %1, %0 \n"
" beqz %1, 1b \n"
" sync \n"
" nop \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
}
smp_mb();
}
static inline void __raw_write_unlock(raw_rwlock_t *rw)
{
smp_mb();
__asm__ __volatile__(
" sync # __raw_write_unlock \n"
" # __raw_write_unlock \n"
" sw $0, %0 \n"
: "=m" (rw->lock)
: "m" (rw->lock)
@ -252,11 +261,10 @@ static inline int __raw_read_trylock(raw_rwlock_t *rw)
" bnez %1, 2f \n"
" addu %1, 1 \n"
" sc %1, %0 \n"
" beqzl %1, 1b \n"
" .set reorder \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" beqzl %1, 1b \n"
" nop \n"
__WEAK_ORDERING_MB
" li %2, 1 \n"
"2: \n"
: "=m" (rw->lock), "=&r" (tmp), "=&r" (ret)
@ -271,10 +279,9 @@ static inline int __raw_read_trylock(raw_rwlock_t *rw)
" addu %1, 1 \n"
" sc %1, %0 \n"
" beqz %1, 1b \n"
" nop \n"
" .set reorder \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
__WEAK_ORDERING_MB
" li %2, 1 \n"
"2: \n"
: "=m" (rw->lock), "=&r" (tmp), "=&r" (ret)
@ -299,7 +306,8 @@ static inline int __raw_write_trylock(raw_rwlock_t *rw)
" lui %1, 0x8000 \n"
" sc %1, %0 \n"
" beqzl %1, 1b \n"
" sync \n"
" nop \n"
__WEAK_ORDERING_MB
" li %2, 1 \n"
" .set reorder \n"
"2: \n"
@ -315,7 +323,8 @@ static inline int __raw_write_trylock(raw_rwlock_t *rw)
" lui %1, 0x8000 \n"
" sc %1, %0 \n"
" beqz %1, 1b \n"
" sync \n"
" nop \n"
__WEAK_ORDERING_MB
" li %2, 1 \n"
" .set reorder \n"
"2: \n"

View File

@ -3,7 +3,7 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle
* Copyright (C) 1994, 95, 96, 97, 98, 99, 2003, 06 by Ralf Baechle
* Copyright (C) 1996 by Paul M. Antoine
* Copyright (C) 1999 Silicon Graphics
* Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
@ -16,132 +16,12 @@
#include <linux/irqflags.h>
#include <asm/addrspace.h>
#include <asm/barrier.h>
#include <asm/cpu-features.h>
#include <asm/dsp.h>
#include <asm/ptrace.h>
#include <asm/war.h>
/*
* read_barrier_depends - Flush all pending reads that subsequents reads
* depend on.
*
* No data-dependent reads from memory-like regions are ever reordered
* over this barrier. All reads preceding this primitive are guaranteed
* to access memory (but not necessarily other CPUs' caches) before any
* reads following this primitive that depend on the data return by
* any of the preceding reads. This primitive is much lighter weight than
* rmb() on most CPUs, and is never heavier weight than is
* rmb().
*
* These ordering constraints are respected by both the local CPU
* and the compiler.
*
* Ordering is not guaranteed by anything other than these primitives,
* not even by data dependencies. See the documentation for
* memory_barrier() for examples and URLs to more information.
*
* For example, the following code would force ordering (the initial
* value of "a" is zero, "b" is one, and "p" is "&a"):
*
* <programlisting>
* CPU 0 CPU 1
*
* b = 2;
* memory_barrier();
* p = &b; q = p;
* read_barrier_depends();
* d = *q;
* </programlisting>
*
* because the read of "*q" depends on the read of "p" and these
* two reads are separated by a read_barrier_depends(). However,
* the following code, with the same initial values for "a" and "b":
*
* <programlisting>
* CPU 0 CPU 1
*
* a = 2;
* memory_barrier();
* b = 3; y = b;
* read_barrier_depends();
* x = a;
* </programlisting>
*
* does not enforce ordering, since there is no data dependency between
* the read of "a" and the read of "b". Therefore, on some CPUs, such
* as Alpha, "y" could be set to 3 and "x" to 0. Use rmb()
* in cases like this where there are no data dependencies.
*/
#define read_barrier_depends() do { } while(0)
#ifdef CONFIG_CPU_HAS_SYNC
#define __sync() \
__asm__ __volatile__( \
".set push\n\t" \
".set noreorder\n\t" \
".set mips2\n\t" \
"sync\n\t" \
".set pop" \
: /* no output */ \
: /* no input */ \
: "memory")
#else
#define __sync() do { } while(0)
#endif
#define __fast_iob() \
__asm__ __volatile__( \
".set push\n\t" \
".set noreorder\n\t" \
"lw $0,%0\n\t" \
"nop\n\t" \
".set pop" \
: /* no output */ \
: "m" (*(int *)CKSEG1) \
: "memory")
#define fast_wmb() __sync()
#define fast_rmb() __sync()
#define fast_mb() __sync()
#define fast_iob() \
do { \
__sync(); \
__fast_iob(); \
} while (0)
#ifdef CONFIG_CPU_HAS_WB
#include <asm/wbflush.h>
#define wmb() fast_wmb()
#define rmb() fast_rmb()
#define mb() wbflush()
#define iob() wbflush()
#else /* !CONFIG_CPU_HAS_WB */
#define wmb() fast_wmb()
#define rmb() fast_rmb()
#define mb() fast_mb()
#define iob() fast_iob()
#endif /* !CONFIG_CPU_HAS_WB */
#ifdef CONFIG_SMP
#define smp_mb() mb()
#define smp_rmb() rmb()
#define smp_wmb() wmb()
#define smp_read_barrier_depends() read_barrier_depends()
#else
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
#define smp_read_barrier_depends() do { } while(0)
#endif
#define set_mb(var, value) \
do { var = value; mb(); } while (0)
/*
* switch_to(n) should switch tasks to task nr n, first
@ -217,9 +97,6 @@ static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
" .set mips3 \n"
" sc %2, %1 \n"
" beqzl %2, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
@ -235,9 +112,6 @@ static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
" .set mips3 \n"
" sc %2, %1 \n"
" beqz %2, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
@ -251,6 +125,8 @@ static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
local_irq_restore(flags); /* implies memory barrier */
}
smp_mb();
return retval;
}
@ -268,9 +144,6 @@ static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
" move %2, %z4 \n"
" scd %2, %1 \n"
" beqzl %2, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
@ -284,9 +157,6 @@ static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
" move %2, %z4 \n"
" scd %2, %1 \n"
" beqz %2, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
@ -300,6 +170,8 @@ static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
local_irq_restore(flags); /* implies memory barrier */
}
smp_mb();
return retval;
}
#else
@ -345,9 +217,6 @@ static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
" .set mips3 \n"
" sc $1, %1 \n"
" beqzl $1, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
"2: \n"
" .set pop \n"
: "=&r" (retval), "=R" (*m)
@ -365,9 +234,6 @@ static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
" .set mips3 \n"
" sc $1, %1 \n"
" beqz $1, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
"2: \n"
" .set pop \n"
: "=&r" (retval), "=R" (*m)
@ -383,6 +249,8 @@ static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
local_irq_restore(flags); /* implies memory barrier */
}
smp_mb();
return retval;
}
@ -402,9 +270,6 @@ static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
" move $1, %z4 \n"
" scd $1, %1 \n"
" beqzl $1, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
"2: \n"
" .set pop \n"
: "=&r" (retval), "=R" (*m)
@ -420,9 +285,6 @@ static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
" move $1, %z4 \n"
" scd $1, %1 \n"
" beqz $1, 1b \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
"2: \n"
" .set pop \n"
: "=&r" (retval), "=R" (*m)
@ -438,6 +300,8 @@ static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
local_irq_restore(flags); /* implies memory barrier */
}
smp_mb();
return retval;
}
#else