From 22cd0f19b170394ac98ca3984e8f5b119fa32c7e Mon Sep 17 00:00:00 2001 From: "Ricardo M. Correia" Date: Tue, 20 Jul 2010 13:47:37 -0700 Subject: [PATCH] Fix compilation error due to undefined ACCESS_ONCE macro. When CONFIG_DEBUG_MUTEXES is turned on in RHEL5's kernel config, the mutexes store the owner for debugging purposes, therefore the SPL will enable HAVE_MUTEX_OWNER. However, the SPL code uses ACCESS_ONCE() to access the owner, and this macro is not defined in the RHEL5 kernel, therefore we define it ourselves in include/linux/compiler_compat.h. Signed-off-by: Ricardo M. Correia Signed-off-by: Brian Behlendorf --- include/linux/compiler_compat.h | 47 +++++++++++++++++++++++++++++++++ include/sys/mutex.h | 1 + 2 files changed, 48 insertions(+) create mode 100644 include/linux/compiler_compat.h diff --git a/include/linux/compiler_compat.h b/include/linux/compiler_compat.h new file mode 100644 index 0000000000..de3b3c3917 --- /dev/null +++ b/include/linux/compiler_compat.h @@ -0,0 +1,47 @@ +/*****************************************************************************\ + * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC. + * Copyright (C) 2007 The Regents of the University of California. + * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). + * Written by Brian Behlendorf . + * UCRL-CODE-235197 + * + * This file is part of the SPL, Solaris Porting Layer. + * For details, see . + * + * The SPL is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * The SPL 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 General Public License + * for more details. + * + * You should have received a copy of the GNU General Public License along + * with the SPL. If not, see . +\*****************************************************************************/ + +#ifndef _SPL_COMPILER_COMPAT_H +#define _SPL_COMPILER_COMPAT_H + +#include + +#ifndef ACCESS_ONCE +/* + * Prevent the compiler from merging or refetching accesses. The compiler + * is also forbidden from reordering successive instances of ACCESS_ONCE(), + * but only when the compiler is aware of some particular ordering. One way + * to make the compiler aware of ordering is to put the two invocations of + * ACCESS_ONCE() in different C statements. + * + * This macro does absolutely -nothing- to prevent the CPU from reordering, + * merging, or refetching absolutely anything at any time. Its main intended + * use is to mediate communication between process-level code and irq/NMI + * handlers, all running on the same CPU. + */ +/* Taken from 2.6.33.2 */ +# define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) +#endif + +#endif /* _SPL_COMPILER_COMPAT_H */ diff --git a/include/sys/mutex.h b/include/sys/mutex.h index d33694766d..ce8c0f4e91 100644 --- a/include/sys/mutex.h +++ b/include/sys/mutex.h @@ -27,6 +27,7 @@ #include #include +#include typedef enum { MUTEX_DEFAULT = 0,