/*
* Copyright (C) 2006 iptelorg GmbH
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/**
* @file
* @brief Atomic operations and memory barriers implemented using locks
*
* Atomic operations and memory barriers implemented using locks
* (for architectures not yet supported via inline assembler).
*
* \warning atomic ops do not include memory barriers, see atomic_ops.h
* for more details
*
* Config defines:
* - NOSMP (membars are null in this case)
* - HAVE_ASM_INLINE_MEMBAR (membars already defined => use them)
* - HAVE_ASM_INLINE_ATOMIC_OPS (atomic ops already defined => don't
* redefine them)
* @ingroup atomic
*/
/*
* History:
* --------
* 2006-03-08 created by andrei
* 2007-05-11 added atomic_add and atomic_cmpxchg
* use lock_set if lock economy is not needed (andrei)
* 2007-05-29 added membar_depends(), membar_*_atomic_op and
* membar_*_atomic_setget (andrei)
*/
#ifndef _atomic_unknown_h
#define _atomic_unknown_h
#include "../lock_ops.h"
#ifndef HAVE_ASM_INLINE_MEMBAR
#ifdef NOSMP
#define membar() do {} while(0)
#else /* SMP */
#warning no native memory barrier implementations, falling back to slow lock \
based workarround
#define MEMBAR_USES_LOCK
extern gen_lock_t* __membar_lock; /* init in atomic_ops.c */
#define _membar_lock lock_get(__membar_lock)
#define _membar_unlock lock_release(__membar_lock)
/* memory barriers
* not a known cpu -> fall back unlock/lock: safe but costly (it should
* include a memory barrier effect)
* lock/unlock does not imply a full memory barrier effect (it allows mixing
* operations from before the lock with operations after the lock _inside_
* the lock & unlock block; however in most implementations it is equivalent
* with at least membar StoreStore | StoreLoad | LoadStore => only LoadLoad
* is missing). On the other hand and unlock/lock will always be equivalent
* with a full memory barrier
* => to be safe we must use either unlock; lock or lock; unlock; lock; unlock
* --andrei*/
#define membar() \
do{\
_membar_unlock; \
_membar_lock; \
} while(0)
#endif /* NOSMP */
#define membar_write() membar()
#define membar_read() membar()
#ifndef __CPU_alpha
#define membar_depends() do {} while(0) /* really empty, not even a cc bar. */
#else
/* really slow */
#define membar_depends() membar_read()
#endif
#define membar_enter_lock() do {} while(0)
#define membar_leave_lock() do {} while(0)
/* membars after or before atomic_ops or atomic_setget -> use these or
* mb_<atomic_op_name>() if you need a memory barrier in one of these
* situations (on some archs where the atomic operations imply memory
* barriers is better to use atomic_op_x(); membar_atomic_op() then
* atomic_op_x(); membar()) */
#define membar_atomic_op() membar()
#define membar_atomic_setget() membar()
#define membar_write_atomic_op() membar_write()
#define membar_write_atomic_setget() membar_write()
#define membar_read_atomic_op() membar_read()
#define membar_read_atomic_setget() membar_read()
#endif /* HAVE_ASM_INLINE_MEMBAR */
#ifndef HAVE_ASM_INLINE_ATOMIC_OPS
#ifdef GEN_LOCK_SET_T_UNLIMITED
#ifndef ATOMIC_OPS_USE_LOCK_SET
#define ATOMIC_OPS_USE_LOCK_SET
#endif
#else
#ifndef ATOMIC_OPS_USE_LOCK
#define ATOMIC_OPS_USE_LOCK
#endif
#endif /* GEN_LOCK_SET_T_UNLIMITED */
#ifdef ATOMIC_OPS_USE_LOCK_SET
#define _ATOMIC_LS_SIZE 256
/* hash after the variable address: ignore first 4 bits since
* vars are generally alloc'ed at at least 16 bytes multiples */
#define _atomic_ls_hash(v) ((((unsigned long)(v))>>4)&(_ATOMIC_LS_SIZE-1))
extern gen_lock_set_t* _atomic_lock_set;
#define atomic_lock(v) lock_set_get(_atomic_lock_set, _atomic_ls_hash(v))
#define atomic_unlock(v) lock_set_release(_atomic_lock_set, _atomic_ls_hash(v))
#else
extern gen_lock_t* _atomic_lock; /* declared and init in ../atomic_ops.c */
#define atomic_lock(v) lock_get(_atomic_lock)
#define atomic_unlock(v) lock_release(_atomic_lock)
#endif /* ATOMIC_OPS_USE_LOCK_SET */
/* atomic ops */
/* OP can include var (function param), no other var. is declared */
#define ATOMIC_FUNC_DECL(NAME, OP, P_TYPE, RET_TYPE, RET_EXPR) \
inline static RET_TYPE atomic_##NAME##_##P_TYPE (volatile P_TYPE *var) \
{ \
atomic_lock(var); \
OP ; \
atomic_unlock(var); \
return RET_EXPR; \
}
/* like above, but takes an extra param: v =>
* OP can use var and v (function params) */
#define ATOMIC_FUNC_DECL1(NAME, OP, P_TYPE, RET_TYPE, RET_EXPR) \
inline static RET_TYPE atomic_##NAME##_##P_TYPE (volatile P_TYPE *var, \
P_TYPE v) \
{ \
atomic_lock(var); \
OP ; \
atomic_unlock(var); \
return RET_EXPR; \
}
/* OP can include var (function param), and ret (return)
* ( like ATOMIC_FUNC_DECL, but includes ret) */
#define ATOMIC_FUNC_DECL_RET(NAME, OP, P_TYPE, RET_TYPE, RET_EXPR) \
inline static RET_TYPE atomic_##NAME##_##P_TYPE (volatile P_TYPE *var) \
{ \
P_TYPE ret; \
atomic_lock(var); \
OP ; \
atomic_unlock(var); \
return RET_EXPR; \
}
/* like ATOMIC_FUNC_DECL1, but declares an extra variable: P_TYPE ret */
#define ATOMIC_FUNC_DECL1_RET(NAME, OP, P_TYPE, RET_TYPE, RET_EXPR) \
inline static RET_TYPE atomic_##NAME##_##P_TYPE (volatile P_TYPE *var, \
P_TYPE v) \
{ \
P_TYPE ret; \
atomic_lock(var); \
OP ; \
atomic_unlock(var); \
return RET_EXPR; \
}
/* like ATOMIC_FUNC_DECL1_RET, but takes an extra param */
#define ATOMIC_FUNC_DECL2_RET(NAME, OP, P_TYPE, RET_TYPE, RET_EXPR) \
inline static RET_TYPE atomic_##NAME##_##P_TYPE (volatile P_TYPE *var, \
P_TYPE v1, P_TYPE v2)\
{ \
P_TYPE ret; \
atomic_lock(var); \
OP ; \
atomic_unlock(var); \
return RET_EXPR; \
}
ATOMIC_FUNC_DECL(inc, (*var)++, int, void, /* no return */ )
ATOMIC_FUNC_DECL(dec, (*var)--, int, void, /* no return */ )
ATOMIC_FUNC_DECL1(and, *var&=v, int, void, /* no return */ )
ATOMIC_FUNC_DECL1(or, *var|=v, int, void, /* no return */ )
ATOMIC_FUNC_DECL_RET(inc_and_test, ret=++(*var), int, int, (ret==0) )
ATOMIC_FUNC_DECL_RET(dec_and_test, ret=--(*var), int, int, (ret==0) )
ATOMIC_FUNC_DECL1_RET(get_and_set, ret=*var;*var=v , int, int, ret)
ATOMIC_FUNC_DECL2_RET(cmpxchg, ret=*var;\
*var=(((ret!=v1)-1)&v2)+(~((ret!=v1)-1)&ret),\
int, int, ret)
ATOMIC_FUNC_DECL1_RET(add, *var+=v;ret=*var, int, int, ret )
ATOMIC_FUNC_DECL(inc, (*var)++, long, void, /* no return */ )
ATOMIC_FUNC_DECL(dec, (*var)--, long, void, /* no return */ )
ATOMIC_FUNC_DECL1(and, *var&=v, long, void, /* no return */ )
ATOMIC_FUNC_DECL1(or, *var|=v, long, void, /* no return */ )
ATOMIC_FUNC_DECL_RET(inc_and_test, ret=++(*var), long, long, (ret==0) )
ATOMIC_FUNC_DECL_RET(dec_and_test, ret=--(*var), long, long, (ret==0) )
ATOMIC_FUNC_DECL1_RET(get_and_set, ret=*var;*var=v , long, long, ret)
ATOMIC_FUNC_DECL2_RET(cmpxchg, ret=*var;\
*var=(((ret!=v1)-1)&v2)+(~((ret!=v1)-1)&ret),\
long, long, ret)
ATOMIC_FUNC_DECL1_RET(add, *var+=v;ret=*var, long, long, ret )
#define atomic_inc(var) atomic_inc_int(&(var)->val)
#define atomic_dec(var) atomic_dec_int(&(var)->val)
#define atomic_and(var, mask) atomic_and_int(&(var)->val, (mask))
#define atomic_or(var, mask) atomic_or_int(&(var)->val, (mask))
#define atomic_dec_and_test(var) atomic_dec_and_test_int(&(var)->val)
#define atomic_inc_and_test(var) atomic_inc_and_test_int(&(var)->val)
#define atomic_get_and_set(var, i) atomic_get_and_set_int(&(var)->val, i)
#define atomic_cmpxchg(var, old, new_v) \
atomic_cmpxchg_int(&(var)->val, old, new_v)
#define atomic_add(var, v) atomic_add_int(&(var)->val, v)
/* memory barrier versions, the same as "normal" versions (since the
* locks act as membars), * except fot * the set/get
*/
/* mb_atomic_{set,get} use membar() : if we're lucky we have membars
* for the arch. (e.g. sparc32) => membar() might be cheaper then lock/unlock */
#define mb_atomic_set_int(v, i) \
do{ \
membar(); \
atomic_set_int(v, i); \
}while(0)
inline static int mb_atomic_get_int(volatile int* v)
{
membar();
return atomic_get_int(v);
}
#define mb_atomic_set_long(v, i) \
do{ \
membar(); \
atomic_set_long(v, i); \
}while(0)
inline static long mb_atomic_get_long(volatile long* v)
{
membar();
return atomic_get_long(v);
}
/* the rest are the same as the non membar version (the locks have a membar
* effect) */
#define mb_atomic_inc_int(v) atomic_inc_int(v)
#define mb_atomic_dec_int(v) atomic_dec_int(v)
#define mb_atomic_or_int(v, m) atomic_or_int(v, m)
#define mb_atomic_and_int(v, m) atomic_and_int(v, m)
#define mb_atomic_inc_and_test_int(v) atomic_inc_and_test_int(v)
#define mb_atomic_dec_and_test_int(v) atomic_dec_and_test_int(v)
#define mb_atomic_get_and_set_int(v, i) atomic_get_and_set_int(v, i)
#define mb_atomic_cmpxchg_int(v, o, n) atomic_cmpxchg_int(v, o, n)
#define mb_atomic_add_int(v, i) atomic_add_int(v, i)
#define mb_atomic_inc_long(v) atomic_inc_long(v)
#define mb_atomic_dec_long(v) atomic_dec_long(v)
#define mb_atomic_or_long(v, m) atomic_or_long(v, m)
#define mb_atomic_and_long(v, m) atomic_and_long(v, m)
#define mb_atomic_inc_and_test_long(v) atomic_inc_and_test_long(v)
#define mb_atomic_dec_and_test_long(v) atomic_dec_and_test_long(v)
#define mb_atomic_get_and_set_long(v, i) atomic_get_and_set_long(v, i)
#define mb_atomic_cmpxchg_long(v, o, n) atomic_cmpxchg_long(v, o, n)
#define mb_atomic_add_long(v, i) atomic_add_long(v, i)
#define mb_atomic_inc(var) mb_atomic_inc_int(&(var)->val)
#define mb_atomic_dec(var) mb_atomic_dec_int(&(var)->val)
#define mb_atomic_and(var, mask) mb_atomic_and_int(&(var)->val, (mask))
#define mb_atomic_or(var, mask) mb_atomic_or_int(&(var)->val, (mask))
#define mb_atomic_dec_and_test(var) mb_atomic_dec_and_test_int(&(var)->val)
#define mb_atomic_inc_and_test(var) mb_atomic_inc_and_test_int(&(var)->val)
#define mb_atomic_get_and_set(var, i) mb_atomic_get_and_set_int(&(var)->val, i)
#define mb_atomic_cmpxchg(v, o, n) atomic_cmpxchg_int(&(v)->val, o, n)
#define mb_atomic_add(v, i) atomic_add_int(&(v)->val, i)
#define mb_atomic_get(var) mb_atomic_get_int(&(var)->val)
#define mb_atomic_set(var, i) mb_atomic_set_int(&(var)->val, i)
#endif /* if HAVE_ASM_INLINE_ATOMIC_OPS */
#endif