mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 12:42:02 +00:00
af79420654
atomic_read() needs to ensure that it emits a load (which it can do by using ACCESS_ONCE()). Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: David Howells <dhowells@redhat.com>
352 lines
8.0 KiB
C
352 lines
8.0 KiB
C
/* MN10300 Atomic counter operations
|
|
*
|
|
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public Licence
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the Licence, or (at your option) any later version.
|
|
*/
|
|
#ifndef _ASM_ATOMIC_H
|
|
#define _ASM_ATOMIC_H
|
|
|
|
#include <asm/irqflags.h>
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#ifdef CONFIG_SMP
|
|
#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
|
|
static inline
|
|
unsigned long __xchg(volatile unsigned long *m, unsigned long val)
|
|
{
|
|
unsigned long status;
|
|
unsigned long oldval;
|
|
|
|
asm volatile(
|
|
"1: mov %4,(_AAR,%3) \n"
|
|
" mov (_ADR,%3),%1 \n"
|
|
" mov %5,(_ADR,%3) \n"
|
|
" mov (_ADR,%3),%0 \n" /* flush */
|
|
" mov (_ASR,%3),%0 \n"
|
|
" or %0,%0 \n"
|
|
" bne 1b \n"
|
|
: "=&r"(status), "=&r"(oldval), "=m"(*m)
|
|
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(m), "r"(val)
|
|
: "memory", "cc");
|
|
|
|
return oldval;
|
|
}
|
|
|
|
static inline unsigned long __cmpxchg(volatile unsigned long *m,
|
|
unsigned long old, unsigned long new)
|
|
{
|
|
unsigned long status;
|
|
unsigned long oldval;
|
|
|
|
asm volatile(
|
|
"1: mov %4,(_AAR,%3) \n"
|
|
" mov (_ADR,%3),%1 \n"
|
|
" cmp %5,%1 \n"
|
|
" bne 2f \n"
|
|
" mov %6,(_ADR,%3) \n"
|
|
"2: mov (_ADR,%3),%0 \n" /* flush */
|
|
" mov (_ASR,%3),%0 \n"
|
|
" or %0,%0 \n"
|
|
" bne 1b \n"
|
|
: "=&r"(status), "=&r"(oldval), "=m"(*m)
|
|
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(m),
|
|
"r"(old), "r"(new)
|
|
: "memory", "cc");
|
|
|
|
return oldval;
|
|
}
|
|
#else /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */
|
|
#error "No SMP atomic operation support!"
|
|
#endif /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */
|
|
|
|
#else /* CONFIG_SMP */
|
|
|
|
/*
|
|
* Emulate xchg for non-SMP MN10300
|
|
*/
|
|
struct __xchg_dummy { unsigned long a[100]; };
|
|
#define __xg(x) ((struct __xchg_dummy *)(x))
|
|
|
|
static inline
|
|
unsigned long __xchg(volatile unsigned long *m, unsigned long val)
|
|
{
|
|
unsigned long oldval;
|
|
unsigned long flags;
|
|
|
|
flags = arch_local_cli_save();
|
|
oldval = *m;
|
|
*m = val;
|
|
arch_local_irq_restore(flags);
|
|
return oldval;
|
|
}
|
|
|
|
/*
|
|
* Emulate cmpxchg for non-SMP MN10300
|
|
*/
|
|
static inline unsigned long __cmpxchg(volatile unsigned long *m,
|
|
unsigned long old, unsigned long new)
|
|
{
|
|
unsigned long oldval;
|
|
unsigned long flags;
|
|
|
|
flags = arch_local_cli_save();
|
|
oldval = *m;
|
|
if (oldval == old)
|
|
*m = new;
|
|
arch_local_irq_restore(flags);
|
|
return oldval;
|
|
}
|
|
|
|
#endif /* CONFIG_SMP */
|
|
|
|
#define xchg(ptr, v) \
|
|
((__typeof__(*(ptr))) __xchg((unsigned long *)(ptr), \
|
|
(unsigned long)(v)))
|
|
|
|
#define cmpxchg(ptr, o, n) \
|
|
((__typeof__(*(ptr))) __cmpxchg((unsigned long *)(ptr), \
|
|
(unsigned long)(o), \
|
|
(unsigned long)(n)))
|
|
|
|
#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
|
|
#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#ifndef CONFIG_SMP
|
|
#include <asm-generic/atomic.h>
|
|
#else
|
|
|
|
/*
|
|
* Atomic operations that C can't guarantee us. Useful for
|
|
* resource counting etc..
|
|
*/
|
|
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
/**
|
|
* atomic_read - read atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically reads the value of @v. Note that the guaranteed
|
|
* useful range of an atomic_t is only 24 bits.
|
|
*/
|
|
#define atomic_read(v) (ACCESS_ONCE((v)->counter))
|
|
|
|
/**
|
|
* atomic_set - set atomic variable
|
|
* @v: pointer of type atomic_t
|
|
* @i: required value
|
|
*
|
|
* Atomically sets the value of @v to @i. Note that the guaranteed
|
|
* useful range of an atomic_t is only 24 bits.
|
|
*/
|
|
#define atomic_set(v, i) (((v)->counter) = (i))
|
|
|
|
/**
|
|
* atomic_add_return - add integer to atomic variable
|
|
* @i: integer value to add
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically adds @i to @v and returns the result
|
|
* Note that the guaranteed useful range of an atomic_t is only 24 bits.
|
|
*/
|
|
static inline int atomic_add_return(int i, atomic_t *v)
|
|
{
|
|
int retval;
|
|
#ifdef CONFIG_SMP
|
|
int status;
|
|
|
|
asm volatile(
|
|
"1: mov %4,(_AAR,%3) \n"
|
|
" mov (_ADR,%3),%1 \n"
|
|
" add %5,%1 \n"
|
|
" mov %1,(_ADR,%3) \n"
|
|
" mov (_ADR,%3),%0 \n" /* flush */
|
|
" mov (_ASR,%3),%0 \n"
|
|
" or %0,%0 \n"
|
|
" bne 1b \n"
|
|
: "=&r"(status), "=&r"(retval), "=m"(v->counter)
|
|
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)
|
|
: "memory", "cc");
|
|
|
|
#else
|
|
unsigned long flags;
|
|
|
|
flags = arch_local_cli_save();
|
|
retval = v->counter;
|
|
retval += i;
|
|
v->counter = retval;
|
|
arch_local_irq_restore(flags);
|
|
#endif
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* atomic_sub_return - subtract integer from atomic variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically subtracts @i from @v and returns the result
|
|
* Note that the guaranteed useful range of an atomic_t is only 24 bits.
|
|
*/
|
|
static inline int atomic_sub_return(int i, atomic_t *v)
|
|
{
|
|
int retval;
|
|
#ifdef CONFIG_SMP
|
|
int status;
|
|
|
|
asm volatile(
|
|
"1: mov %4,(_AAR,%3) \n"
|
|
" mov (_ADR,%3),%1 \n"
|
|
" sub %5,%1 \n"
|
|
" mov %1,(_ADR,%3) \n"
|
|
" mov (_ADR,%3),%0 \n" /* flush */
|
|
" mov (_ASR,%3),%0 \n"
|
|
" or %0,%0 \n"
|
|
" bne 1b \n"
|
|
: "=&r"(status), "=&r"(retval), "=m"(v->counter)
|
|
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)
|
|
: "memory", "cc");
|
|
|
|
#else
|
|
unsigned long flags;
|
|
flags = arch_local_cli_save();
|
|
retval = v->counter;
|
|
retval -= i;
|
|
v->counter = retval;
|
|
arch_local_irq_restore(flags);
|
|
#endif
|
|
return retval;
|
|
}
|
|
|
|
static inline int atomic_add_negative(int i, atomic_t *v)
|
|
{
|
|
return atomic_add_return(i, v) < 0;
|
|
}
|
|
|
|
static inline void atomic_add(int i, atomic_t *v)
|
|
{
|
|
atomic_add_return(i, v);
|
|
}
|
|
|
|
static inline void atomic_sub(int i, atomic_t *v)
|
|
{
|
|
atomic_sub_return(i, v);
|
|
}
|
|
|
|
static inline void atomic_inc(atomic_t *v)
|
|
{
|
|
atomic_add_return(1, v);
|
|
}
|
|
|
|
static inline void atomic_dec(atomic_t *v)
|
|
{
|
|
atomic_sub_return(1, v);
|
|
}
|
|
|
|
#define atomic_dec_return(v) atomic_sub_return(1, (v))
|
|
#define atomic_inc_return(v) atomic_add_return(1, (v))
|
|
|
|
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
|
|
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
|
|
#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
|
|
|
|
#define atomic_add_unless(v, a, u) \
|
|
({ \
|
|
int c, old; \
|
|
c = atomic_read(v); \
|
|
while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
|
|
c = old; \
|
|
c != (u); \
|
|
})
|
|
|
|
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
|
|
|
|
/**
|
|
* atomic_clear_mask - Atomically clear bits in memory
|
|
* @mask: Mask of the bits to be cleared
|
|
* @v: pointer to word in memory
|
|
*
|
|
* Atomically clears the bits set in mask from the memory word specified.
|
|
*/
|
|
static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
int status;
|
|
|
|
asm volatile(
|
|
"1: mov %3,(_AAR,%2) \n"
|
|
" mov (_ADR,%2),%0 \n"
|
|
" and %4,%0 \n"
|
|
" mov %0,(_ADR,%2) \n"
|
|
" mov (_ADR,%2),%0 \n" /* flush */
|
|
" mov (_ASR,%2),%0 \n"
|
|
" or %0,%0 \n"
|
|
" bne 1b \n"
|
|
: "=&r"(status), "=m"(*addr)
|
|
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(addr), "r"(~mask)
|
|
: "memory", "cc");
|
|
#else
|
|
unsigned long flags;
|
|
|
|
mask = ~mask;
|
|
flags = arch_local_cli_save();
|
|
*addr &= mask;
|
|
arch_local_irq_restore(flags);
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* atomic_set_mask - Atomically set bits in memory
|
|
* @mask: Mask of the bits to be set
|
|
* @v: pointer to word in memory
|
|
*
|
|
* Atomically sets the bits set in mask from the memory word specified.
|
|
*/
|
|
static inline void atomic_set_mask(unsigned long mask, unsigned long *addr)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
int status;
|
|
|
|
asm volatile(
|
|
"1: mov %3,(_AAR,%2) \n"
|
|
" mov (_ADR,%2),%0 \n"
|
|
" or %4,%0 \n"
|
|
" mov %0,(_ADR,%2) \n"
|
|
" mov (_ADR,%2),%0 \n" /* flush */
|
|
" mov (_ASR,%2),%0 \n"
|
|
" or %0,%0 \n"
|
|
" bne 1b \n"
|
|
: "=&r"(status), "=m"(*addr)
|
|
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(addr), "r"(mask)
|
|
: "memory", "cc");
|
|
#else
|
|
unsigned long flags;
|
|
|
|
flags = arch_local_cli_save();
|
|
*addr |= mask;
|
|
arch_local_irq_restore(flags);
|
|
#endif
|
|
}
|
|
|
|
/* Atomic operations are already serializing on MN10300??? */
|
|
#define smp_mb__before_atomic_dec() barrier()
|
|
#define smp_mb__after_atomic_dec() barrier()
|
|
#define smp_mb__before_atomic_inc() barrier()
|
|
#define smp_mb__after_atomic_inc() barrier()
|
|
|
|
#include <asm-generic/atomic-long.h>
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* CONFIG_SMP */
|
|
#endif /* _ASM_ATOMIC_H */
|