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/*-
* Copyright (c) 2009-2010 Brad Penoff
* Copyright (c) 2009-2010 Humaira Kamal
* Copyright (c) 2011-2012 Irene Ruengeler
* Copyright (c) 2011-2012 Michael Tuexen
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _USER_ATOMIC_H_
#define _USER_ATOMIC_H_
/* __Userspace__ version of sys/i386/include/atomic.h goes here */
/* TODO In the future, might want to not use i386 specific assembly.
* The options include:
* - implement them generically (but maybe not truly atomic?) in userspace
* - have ifdef's for __Userspace_arch_ perhaps (OS isn't enough...)
*/
#include <stdio.h>
#include <sys/types.h>
#if defined(__Userspace_os_Darwin) || defined (__Userspace_os_Windows)
#if defined (__Userspace_os_Windows)
#define atomic_add_int(addr, val) InterlockedExchangeAdd((LPLONG)addr, (LONG)val)
#define atomic_fetchadd_int(addr, val) InterlockedExchangeAdd((LPLONG)addr, (LONG)val)
#define atomic_subtract_int(addr, val) InterlockedExchangeAdd((LPLONG)addr,-((LONG)val))
#define atomic_cmpset_int(dst, exp, src) InterlockedCompareExchange((LPLONG)dst, src, exp)
#define SCTP_DECREMENT_AND_CHECK_REFCOUNT(addr) (InterlockedExchangeAdd((LPLONG)addr, (-1L)) == 1)
#else
#include <libkern/OSAtomic.h>
#define atomic_add_int(addr, val) OSAtomicAdd32Barrier(val, (int32_t *)addr)
#define atomic_fetchadd_int(addr, val) OSAtomicAdd32Barrier(val, (int32_t *)addr)
#define atomic_subtract_int(addr, val) OSAtomicAdd32Barrier(-val, (int32_t *)addr)
#define atomic_cmpset_int(dst, exp, src) OSAtomicCompareAndSwapIntBarrier(exp, src, (int *)dst)
#define SCTP_DECREMENT_AND_CHECK_REFCOUNT(addr) (atomic_fetchadd_int(addr, -1) == 0)
#endif
#if defined(INVARIANTS)
#define SCTP_SAVE_ATOMIC_DECREMENT(addr, val) \
{ \
int32_t newval; \
newval = atomic_fetchadd_int(addr, -val); \
if (newval < 0) { \
panic("Counter goes negative"); \
} \
}
#else
#define SCTP_SAVE_ATOMIC_DECREMENT(addr, val) \
{ \
int32_t newval; \
newval = atomic_fetchadd_int(addr, -val); \
if (newval < 0) { \
*addr = 0; \
} \
}
#if defined(__Userspace_os_Windows)
static void atomic_init() {} /* empty when we are not using atomic_mtx */
#else
static inline void atomic_init() {} /* empty when we are not using atomic_mtx */
#endif
#endif
#else
/* Using gcc built-in functions for atomic memory operations
Reference: http://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html
Requires gcc version 4.1.0
compile with -march=i486
*/
/*Atomically add V to *P.*/
#define atomic_add_int(P, V) (void) __sync_fetch_and_add(P, V)
/*Atomically subtrace V from *P.*/
#define atomic_subtract_int(P, V) (void) __sync_fetch_and_sub(P, V)
/*
* Atomically add the value of v to the integer pointed to by p and return
* the previous value of *p.
*/
#define atomic_fetchadd_int(p, v) __sync_fetch_and_add(p, v)
/* Following explanation from src/sys/i386/include/atomic.h,
* for atomic compare and set
*
* if (*dst == exp) *dst = src (all 32 bit words)
*
* Returns 0 on failure, non-zero on success
*/
#define atomic_cmpset_int(dst, exp, src) __sync_bool_compare_and_swap(dst, exp, src)
#define SCTP_DECREMENT_AND_CHECK_REFCOUNT(addr) (atomic_fetchadd_int(addr, -1) == 1)
#if defined(INVARIANTS)
#define SCTP_SAVE_ATOMIC_DECREMENT(addr, val) \
{ \
int32_t oldval; \
oldval = atomic_fetchadd_int(addr, -val); \
if (oldval < val) { \
panic("Counter goes negative"); \
} \
}
#else
#define SCTP_SAVE_ATOMIC_DECREMENT(addr, val) \
{ \
int32_t oldval; \
oldval = atomic_fetchadd_int(addr, -val); \
if (oldval < val) { \
*addr = 0; \
} \
}
#endif
static inline void atomic_init() {} /* empty when we are not using atomic_mtx */
#endif
#if 0 /* using libatomic_ops */
#include "user_include/atomic_ops.h"
/*Atomically add incr to *P, and return the original value of *P.*/
#define atomic_add_int(P, V) AO_fetch_and_add((AO_t*)P, V)
#define atomic_subtract_int(P, V) AO_fetch_and_add((AO_t*)P, -(V))
/*
* Atomically add the value of v to the integer pointed to by p and return
* the previous value of *p.
*/
#define atomic_fetchadd_int(p, v) AO_fetch_and_add((AO_t*)p, v)
/* Atomically compare *addr to old_val, and replace *addr by new_val
if the first comparison succeeds. Returns nonzero if the comparison
succeeded and *addr was updated.
*/
/* Following Explanation from src/sys/i386/include/atomic.h, which
matches that of AO_compare_and_swap above.
* Atomic compare and set, used by the mutex functions
*
* if (*dst == exp) *dst = src (all 32 bit words)
*
* Returns 0 on failure, non-zero on success
*/
#define atomic_cmpset_int(dst, exp, src) AO_compare_and_swap((AO_t*)dst, exp, src)
static inline void atomic_init() {} /* empty when we are not using atomic_mtx */
#endif /* closing #if for libatomic */
#if 0 /* using atomic_mtx */
#include <pthread.h>
extern userland_mutex_t atomic_mtx;
#if defined (__Userspace_os_Windows)
static inline void atomic_init() {
InitializeCriticalSection(&atomic_mtx);
}
static inline void atomic_destroy() {
DeleteCriticalSection(&atomic_mtx);
}
static inline void atomic_lock() {
EnterCriticalSection(&atomic_mtx);
}
static inline void atomic_unlock() {
LeaveCriticalSection(&atomic_mtx);
}
#else
static inline void atomic_init() {
(void)pthread_mutex_init(&atomic_mtx, NULL);
}
static inline void atomic_destroy() {
(void)pthread_mutex_destroy(&atomic_mtx);
}
static inline void atomic_lock() {
(void)pthread_mutex_lock(&atomic_mtx);
}
static inline void atomic_unlock() {
(void)pthread_mutex_unlock(&atomic_mtx);
}
#endif
/*
* For userland, always use lock prefixes so that the binaries will run
* on both SMP and !SMP systems.
*/
#define MPLOCKED "lock ; "
/*
* Atomically add the value of v to the integer pointed to by p and return
* the previous value of *p.
*/
static __inline u_int
atomic_fetchadd_int(volatile void *n, u_int v)
{
int *p = (int *) n;
atomic_lock();
__asm __volatile(
" " MPLOCKED " "
" xaddl %0, %1 ; "
"# atomic_fetchadd_int"
: "+r" (v), /* 0 (result) */
"=m" (*p) /* 1 */
: "m" (*p)); /* 2 */
atomic_unlock();
return (v);
}
#ifdef CPU_DISABLE_CMPXCHG
static __inline int
atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
{
u_char res;
atomic_lock();
__asm __volatile(
" pushfl ; "
" cli ; "
" cmpl %3,%4 ; "
" jne 1f ; "
" movl %2,%1 ; "
"1: "
" sete %0 ; "
" popfl ; "
"# atomic_cmpset_int"
: "=q" (res), /* 0 */
"=m" (*dst) /* 1 */
: "r" (src), /* 2 */
"r" (exp), /* 3 */
"m" (*dst) /* 4 */
: "memory");
atomic_unlock();
return (res);
}
#else /* !CPU_DISABLE_CMPXCHG */
static __inline int
atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
{
atomic_lock();
u_char res;
__asm __volatile(
" " MPLOCKED " "
" cmpxchgl %2,%1 ; "
" sete %0 ; "
"1: "
"# atomic_cmpset_int"
: "=a" (res), /* 0 */
"=m" (*dst) /* 1 */
: "r" (src), /* 2 */
"a" (exp), /* 3 */
"m" (*dst) /* 4 */
: "memory");
atomic_unlock();
return (res);
}
#endif /* CPU_DISABLE_CMPXCHG */
#define atomic_add_int(P, V) do { \
atomic_lock(); \
(*(u_int *)(P) += (V)); \
atomic_unlock(); \
} while(0)
#define atomic_subtract_int(P, V) do { \
atomic_lock(); \
(*(u_int *)(P) -= (V)); \
atomic_unlock(); \
} while(0)
#endif
#endif
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