add urcu/arch_generic.h

[urcu.git] / urcu / arch_generic.h

diff --git a/urcu/arch_generic.h b/urcu/arch_generic.h
new file mode 100644 (file)
index 0000000..e9b1b82
--- /dev/null
+++ b/urcu/arch_generic.h
@@ -0,0 +1,132 @@
+#ifndef _URCU_ARCH_GENERIC_H
+#define _URCU_ARCH_GENERIC_H
+
+/*
+ * arch_generic.h: common definitions for multiple architectures.
+ *
+ * Copyright (c) 2010 Paolo Bonzini <pbonzini@redhat.com>
+ *
+ * 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
+
+#ifndef CACHE_LINE_SIZE
+#define CACHE_LINE_SIZE        64
+#endif
+
+#if !defined(mc) && !defined(rmc) && !defined(wmc)
+#define CONFIG_HAVE_MEM_COHERENCY
+/*
+ * Architectures with cache coherency must _not_ define mc/rmc/wmc.
+ *
+ * For them, mc/rmc/wmc are implemented with a * simple compiler barrier;
+ * in addition, we provide defaults for mb (using GCC builtins) as well as
+ * rmb and wmb (defaulting to mb).
+ */
+
+#ifndef mb
+#define mb()    __sync_synchronize()
+#endif
+
+#ifndef rmb
+#define rmb()    mb()
+#endif
+
+#ifndef wmb
+#define wmb()    mb()
+#endif
+
+#define mc()    barrier()
+#define rmc()   barrier()
+#define wmc()   barrier()
+#else
+/*
+ * Architectures without cache coherency need something like the following:
+ *
+ * #define mc()                arch_cache_flush() 
+ * #define rmc()       arch_cache_flush_read()
+ * #define wmc()       arch_cache_flush_write()
+ *
+ * Of these, only mc is mandatory.  rmc and wmc default to mc.  mb/rmb/wmb
+ * use these definitions by default:
+ *
+ * #define mb()                mc()
+ * #define rmb()       rmc()
+ * #define wmb()       wmc()
+ */
+
+#ifndef mb
+#define mb()    mc()
+#endif
+
+#ifndef rmb
+#define rmb()    rmc()
+#endif
+
+#ifndef wmb
+#define wmb()    wmc()
+#endif
+
+#ifndef rmc
+#define rmc()    mc()
+#endif
+
+#ifndef wmc
+#define wmc()    mc()
+#endif
+#endif
+
+/* Nop everywhere except on alpha. */
+#ifndef read_barrier_depends
+#define read_barrier_depends()
+#endif
+
+#ifdef CONFIG_RCU_SMP
+#define smp_mb()       mb()
+#define smp_rmb()      rmb()
+#define smp_wmb()      wmb()
+#define smp_mc()       mc()
+#define smp_rmc()      rmc()
+#define smp_wmc()      wmc()
+#define smp_read_barrier_depends()     read_barrier_depends()
+#else
+#define smp_mb()       barrier()
+#define smp_rmb()      barrier()
+#define smp_wmb()      barrier()
+#define smp_mc()       barrier()
+#define smp_rmc()      barrier()
+#define smp_wmc()      barrier()
+#define smp_read_barrier_depends()
+#endif
+
+#ifndef cpu_relax
+#define cpu_relax()     barrier()
+#endif
+
+#ifndef sync_core
+#define sync_core()     mb()
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _URCU_ARCH_GENERIC_H */