mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 10:56:40 +00:00
52fefcec97
* git://git.kernel.org/pub/scm/linux/kernel/git/czankel/xtensa-2.6: xtensa: Update platform files to reflect new location of the header files. xtensa: switch to packed struct unaligned access implementation xtensa: Add xt2000 support files. xtensa: move headers files to arch/xtensa/include xtensa: use the new byteorder headers
300 lines
7.2 KiB
C
300 lines
7.2 KiB
C
/*
|
|
* include/asm-xtensa/atomic.h
|
|
*
|
|
* Atomic operations that C can't guarantee us. Useful for resource counting..
|
|
*
|
|
* 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) 2001 - 2005 Tensilica Inc.
|
|
*/
|
|
|
|
#ifndef _XTENSA_ATOMIC_H
|
|
#define _XTENSA_ATOMIC_H
|
|
|
|
#include <linux/stringify.h>
|
|
#include <linux/types.h>
|
|
|
|
#ifdef __KERNEL__
|
|
#include <asm/processor.h>
|
|
#include <asm/system.h>
|
|
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
/*
|
|
* This Xtensa implementation assumes that the right mechanism
|
|
* for exclusion is for locking interrupts to level 1.
|
|
*
|
|
* Locking interrupts looks like this:
|
|
*
|
|
* rsil a15, 1
|
|
* <code>
|
|
* wsr a15, PS
|
|
* rsync
|
|
*
|
|
* Note that a15 is used here because the register allocation
|
|
* done by the compiler is not guaranteed and a window overflow
|
|
* may not occur between the rsil and wsr instructions. By using
|
|
* a15 in the rsil, the machine is guaranteed to be in a state
|
|
* where no register reference will cause an overflow.
|
|
*/
|
|
|
|
/**
|
|
* atomic_read - read atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically reads the value of @v.
|
|
*/
|
|
#define atomic_read(v) ((v)->counter)
|
|
|
|
/**
|
|
* atomic_set - set atomic variable
|
|
* @v: pointer of type atomic_t
|
|
* @i: required value
|
|
*
|
|
* Atomically sets the value of @v to @i.
|
|
*/
|
|
#define atomic_set(v,i) ((v)->counter = (i))
|
|
|
|
/**
|
|
* atomic_add - add integer to atomic variable
|
|
* @i: integer value to add
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically adds @i to @v.
|
|
*/
|
|
static inline void atomic_add(int i, atomic_t * v)
|
|
{
|
|
unsigned int vval;
|
|
|
|
__asm__ __volatile__(
|
|
"rsil a15, "__stringify(LOCKLEVEL)"\n\t"
|
|
"l32i %0, %2, 0 \n\t"
|
|
"add %0, %0, %1 \n\t"
|
|
"s32i %0, %2, 0 \n\t"
|
|
"wsr a15, "__stringify(PS)" \n\t"
|
|
"rsync \n"
|
|
: "=&a" (vval)
|
|
: "a" (i), "a" (v)
|
|
: "a15", "memory"
|
|
);
|
|
}
|
|
|
|
/**
|
|
* atomic_sub - subtract the atomic variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically subtracts @i from @v.
|
|
*/
|
|
static inline void atomic_sub(int i, atomic_t *v)
|
|
{
|
|
unsigned int vval;
|
|
|
|
__asm__ __volatile__(
|
|
"rsil a15, "__stringify(LOCKLEVEL)"\n\t"
|
|
"l32i %0, %2, 0 \n\t"
|
|
"sub %0, %0, %1 \n\t"
|
|
"s32i %0, %2, 0 \n\t"
|
|
"wsr a15, "__stringify(PS)" \n\t"
|
|
"rsync \n"
|
|
: "=&a" (vval)
|
|
: "a" (i), "a" (v)
|
|
: "a15", "memory"
|
|
);
|
|
}
|
|
|
|
/*
|
|
* We use atomic_{add|sub}_return to define other functions.
|
|
*/
|
|
|
|
static inline int atomic_add_return(int i, atomic_t * v)
|
|
{
|
|
unsigned int vval;
|
|
|
|
__asm__ __volatile__(
|
|
"rsil a15,"__stringify(LOCKLEVEL)"\n\t"
|
|
"l32i %0, %2, 0 \n\t"
|
|
"add %0, %0, %1 \n\t"
|
|
"s32i %0, %2, 0 \n\t"
|
|
"wsr a15, "__stringify(PS)" \n\t"
|
|
"rsync \n"
|
|
: "=&a" (vval)
|
|
: "a" (i), "a" (v)
|
|
: "a15", "memory"
|
|
);
|
|
|
|
return vval;
|
|
}
|
|
|
|
static inline int atomic_sub_return(int i, atomic_t * v)
|
|
{
|
|
unsigned int vval;
|
|
|
|
__asm__ __volatile__(
|
|
"rsil a15,"__stringify(LOCKLEVEL)"\n\t"
|
|
"l32i %0, %2, 0 \n\t"
|
|
"sub %0, %0, %1 \n\t"
|
|
"s32i %0, %2, 0 \n\t"
|
|
"wsr a15, "__stringify(PS)" \n\t"
|
|
"rsync \n"
|
|
: "=&a" (vval)
|
|
: "a" (i), "a" (v)
|
|
: "a15", "memory"
|
|
);
|
|
|
|
return vval;
|
|
}
|
|
|
|
/**
|
|
* atomic_sub_and_test - subtract value from variable and test result
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically subtracts @i from @v and returns
|
|
* true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
#define atomic_sub_and_test(i,v) (atomic_sub_return((i),(v)) == 0)
|
|
|
|
/**
|
|
* atomic_inc - increment atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1.
|
|
*/
|
|
#define atomic_inc(v) atomic_add(1,(v))
|
|
|
|
/**
|
|
* atomic_inc - increment atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1.
|
|
*/
|
|
#define atomic_inc_return(v) atomic_add_return(1,(v))
|
|
|
|
/**
|
|
* atomic_dec - decrement atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically decrements @v by 1.
|
|
*/
|
|
#define atomic_dec(v) atomic_sub(1,(v))
|
|
|
|
/**
|
|
* atomic_dec_return - decrement atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically decrements @v by 1.
|
|
*/
|
|
#define atomic_dec_return(v) atomic_sub_return(1,(v))
|
|
|
|
/**
|
|
* atomic_dec_and_test - decrement and test
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically decrements @v by 1 and
|
|
* returns true if the result is 0, or false for all other
|
|
* cases.
|
|
*/
|
|
#define atomic_dec_and_test(v) (atomic_sub_return(1,(v)) == 0)
|
|
|
|
/**
|
|
* atomic_inc_and_test - increment and test
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
#define atomic_inc_and_test(v) (atomic_add_return(1,(v)) == 0)
|
|
|
|
/**
|
|
* atomic_add_negative - add and test if negative
|
|
* @v: pointer of type atomic_t
|
|
* @i: integer value to add
|
|
*
|
|
* Atomically adds @i to @v and returns true
|
|
* if the result is negative, or false when
|
|
* result is greater than or equal to zero.
|
|
*/
|
|
#define atomic_add_negative(i,v) (atomic_add_return((i),(v)) < 0)
|
|
|
|
#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
|
|
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
|
|
|
|
/**
|
|
* atomic_add_unless - add unless the number is a given value
|
|
* @v: pointer of type atomic_t
|
|
* @a: the amount to add to v...
|
|
* @u: ...unless v is equal to u.
|
|
*
|
|
* Atomically adds @a to @v, so long as it was not @u.
|
|
* Returns non-zero if @v was not @u, and zero otherwise.
|
|
*/
|
|
static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
|
|
{
|
|
int c, old;
|
|
c = atomic_read(v);
|
|
for (;;) {
|
|
if (unlikely(c == (u)))
|
|
break;
|
|
old = atomic_cmpxchg((v), c, c + (a));
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
return c != (u);
|
|
}
|
|
|
|
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
|
|
|
|
static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
|
|
{
|
|
unsigned int all_f = -1;
|
|
unsigned int vval;
|
|
|
|
__asm__ __volatile__(
|
|
"rsil a15,"__stringify(LOCKLEVEL)"\n\t"
|
|
"l32i %0, %2, 0 \n\t"
|
|
"xor %1, %4, %3 \n\t"
|
|
"and %0, %0, %4 \n\t"
|
|
"s32i %0, %2, 0 \n\t"
|
|
"wsr a15, "__stringify(PS)" \n\t"
|
|
"rsync \n"
|
|
: "=&a" (vval), "=a" (mask)
|
|
: "a" (v), "a" (all_f), "1" (mask)
|
|
: "a15", "memory"
|
|
);
|
|
}
|
|
|
|
static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
|
|
{
|
|
unsigned int vval;
|
|
|
|
__asm__ __volatile__(
|
|
"rsil a15,"__stringify(LOCKLEVEL)"\n\t"
|
|
"l32i %0, %2, 0 \n\t"
|
|
"or %0, %0, %1 \n\t"
|
|
"s32i %0, %2, 0 \n\t"
|
|
"wsr a15, "__stringify(PS)" \n\t"
|
|
"rsync \n"
|
|
: "=&a" (vval)
|
|
: "a" (mask), "a" (v)
|
|
: "a15", "memory"
|
|
);
|
|
}
|
|
|
|
/* Atomic operations are already serializing */
|
|
#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.h>
|
|
#endif /* __KERNEL__ */
|
|
|
|
#endif /* _XTENSA_ATOMIC_H */
|
|
|