Use a back-to-back pair of pthread_mutex_lock acquisitions and releases to stand in for a memory barrier, given that ARM doesn't seem to do the right thing with __sync_synchronize(). Tested on ARM and on x86. The x86 testing was performed by removing all of the x86-specific tests from configure.ac and then building from scratch.
Signed-off-by: Paul E. McKenney <[email protected]> --- configure.ac | 9 +--- urcu/arch_unknown.h | 87 +++++++++++++++++++++++++++++++++++++++++++ urcu/uatomic_arch_unknown.h | 57 ++++++++++++++++++++++++++++ 3 files changed, 146 insertions(+), 7 deletions(-) create mode 100644 urcu/arch_unknown.h create mode 100644 urcu/uatomic_arch_unknown.h diff --git a/configure.ac b/configure.ac index 1b1ca65..9274337 100644 --- a/configure.ac +++ b/configure.ac @@ -54,13 +54,8 @@ case $host_cpu in *) ARCHTYPE="unknown";; esac -if test "$ARCHTYPE" != "unknown"; then - UATOMICSRC=urcu/uatomic_arch_$ARCHTYPE.h - ARCHSRC=urcu/arch_$ARCHTYPE.h -else - UATOMICSRC=urcu/uatomic_generic.h - ARCHSRC=urcu/arch_generic.h -fi +UATOMICSRC=urcu/uatomic_arch_$ARCHTYPE.h +ARCHSRC=urcu/arch_$ARCHTYPE.h if test "x$ARCHTYPE" != xx86 -a "x$ARCHTYPE" != xppc; then APISRC=tests/api_gcc.h else diff --git a/urcu/arch_unknown.h b/urcu/arch_unknown.h new file mode 100644 index 0000000..3f78310 --- /dev/null +++ b/urcu/arch_unknown.h @@ -0,0 +1,87 @@ +#ifndef _URCU_ARCH_ARMV7_H +#define _URCU_ARCH_ARMV7_H + +/* + * arch_armv7.h: trivial definitions for the ARMv7-A/R architecture. + * + * Copyright (c) 2010 Paul E. McKenney, IBM Corporation. + * Copyright (c) 2009 Mathieu Desnoyers <[email protected]> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. +* + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <urcu/compiler.h> +#include <urcu/config.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/* We don't know, so guess!!! */ +#define CACHE_LINE_SIZE 64 + +#define mb() \ + do { \ + pthread_mutex_t __mb_fake_mutex; \ + \ + pthread_mutex_init(&__mb_fake_mutex, NULL); \ + if (pthread_mutex_lock(&__mb_fake_mutex) != 0) { \ + perror("pthread_mutex_lock"); \ + abort(); \ + } \ + if (pthread_mutex_unlock(&__mb_fake_mutex) != 0) { \ + perror("pthread_mutex_lock"); \ + abort(); \ + } \ + if (pthread_mutex_lock(&__mb_fake_mutex) != 0) { \ + perror("pthread_mutex_lock"); \ + abort(); \ + } \ + if (pthread_mutex_unlock(&__mb_fake_mutex) != 0) { \ + perror("pthread_mutex_lock"); \ + abort(); \ + } \ + } while (0) + +/* + * Serialize core instruction execution. Also acts as a compiler barrier. + */ +#define sync_core() asm volatile("isb" : : : "memory") + +#include <stdlib.h> +#include <sys/time.h> + +typedef unsigned long long cycles_t; + +static inline cycles_t get_cycles (void) +{ + long long thetime; + struct timeval tv; + + if (gettimeofday(&tv, NULL) != 0) { + perror("gettimeofday"); + abort(); + } + thetime = ((long long)tv.tv_sec) * 1000000ULL + ((long long)tv.tv_usec); + return (cycles_t)thetime; +} + +#ifdef __cplusplus +} +#endif + +#include <urcu/arch_generic.h> + +#endif /* _URCU_ARCH_ARMV7_H */ diff --git a/urcu/uatomic_arch_unknown.h b/urcu/uatomic_arch_unknown.h new file mode 100644 index 0000000..d1cf93e --- /dev/null +++ b/urcu/uatomic_arch_unknown.h @@ -0,0 +1,57 @@ +#ifndef _URCU_ARCH_UATOMIC_ARMV7_H +#define _URCU_ARCH_UATOMIC_ARMV7_H + +/* + * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved. + * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved. + * Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P. + * Copyright (c) 2009 Mathieu Desnoyers + * Copyright (c) 2010 Paul E. McKenney, IBM Corporation + * (Adapted from uatomic_arch_ppc.h) + * + * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED + * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. + * + * Permission is hereby granted to use or copy this program + * for any purpose, provided the above notices are retained on all copies. + * Permission to modify the code and to distribute modified code is granted, + * provided the above notices are retained, and a notice that the code was + * modified is included with the above copyright notice. + * + * Code inspired from libuatomic_ops-1.2, inherited in part from the + * Boehm-Demers-Weiser conservative garbage collector. + */ + +#include <urcu/compiler.h> +#include <urcu/system.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#define ILLEGAL_INSTR ".long 0xd00d00" /* @@@FIXME from ppc to ARM. */ + +/* + * Using a isync as second barrier for exchange to provide acquire semantic. + * According to uatomic_ops/sysdeps/gcc/powerpc.h, the documentation is "fairly + * explicit that this also has acquire semantics." + * Derived from AO_compare_and_swap(), but removed the comparison. + */ + +/* xchg */ +#define uatomic_xchg(addr, v) __sync_lock_test_and_set(addr, v); + +/* cmpxchg */ +#define uatomic_cmpxchg(addr, old, _new) \ + __sync_val_compare_and_swap(addr, old, _new) + +/* uatomic_add_return */ +#define uatomic_add_return(addr, v) __sync_add_and_fetch(addr, v) + +#ifdef __cplusplus +} +#endif + +#include <urcu/uatomic_generic.h> + +#endif /* _URCU_ARCH_UATOMIC_ARMV7_H */ -- 1.7.0.6 _______________________________________________ ltt-dev mailing list [email protected] http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
