Commit 0004a9df authored by Ralf Baechle's avatar Ralf Baechle
Browse files

[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: default avatarRalf Baechle <ralf@linux-mips.org>
parent 08f57f7f
......@@ -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
#
......
......@@ -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);
}
}
......
......@@ -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;
}
......
/*
* 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 */
......@@ -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>
......
/*
* 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"
......
......@@ -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"