fix: warning 'noreturn' function does return on ppc

[userspace-rcu.git] / include / urcu / arch / generic.h

#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>
#include <urcu/syscall-compat.h>

#ifdef __cplusplus
extern "C" {
#endif

#ifndef CAA_CACHE_LINE_SIZE
#define CAA_CACHE_LINE_SIZE	64
#endif

#if !defined(cmm_mc) && !defined(cmm_rmc) && !defined(cmm_wmc)
#define CONFIG_HAVE_MEM_COHERENCY
/*
 * Architectures with cache coherency must _not_ define cmm_mc/cmm_rmc/cmm_wmc.
 *
 * For them, cmm_mc/cmm_rmc/cmm_wmc are implemented with a simple
 * compiler barrier; in addition, we provide defaults for cmm_mb (using
 * GCC builtins) as well as cmm_rmb and cmm_wmb (defaulting to cmm_mb).
 */

#ifndef cmm_mb
#define cmm_mb()    __sync_synchronize()
#endif

#ifndef cmm_rmb
#define cmm_rmb()	cmm_mb()
#endif

#ifndef cmm_wmb
#define cmm_wmb()	cmm_mb()
#endif

#define cmm_mc()	cmm_barrier()
#define cmm_rmc()	cmm_barrier()
#define cmm_wmc()	cmm_barrier()
#else
/*
 * Architectures without cache coherency need something like the following:
 *
 * #define cmm_mc()	arch_cache_flush()
 * #define cmm_rmc()	arch_cache_flush_read()
 * #define cmm_wmc()	arch_cache_flush_write()
 *
 * Of these, only cmm_mc is mandatory. cmm_rmc and cmm_wmc default to
 * cmm_mc. cmm_mb/cmm_rmb/cmm_wmb use these definitions by default:
 *
 * #define cmm_mb()	cmm_mc()
 * #define cmm_rmb()	cmm_rmc()
 * #define cmm_wmb()	cmm_wmc()
 */

#ifndef cmm_mb
#define cmm_mb()	cmm_mc()
#endif

#ifndef cmm_rmb
#define cmm_rmb()	cmm_rmc()
#endif

#ifndef cmm_wmb
#define cmm_wmb()	cmm_wmc()
#endif

#ifndef cmm_rmc
#define cmm_rmc()	cmm_mc()
#endif

#ifndef cmm_wmc
#define cmm_wmc()	cmm_mc()
#endif
#endif

/* Nop everywhere except on alpha. */
#ifndef cmm_read_barrier_depends
#define cmm_read_barrier_depends()
#endif

#ifdef CONFIG_RCU_SMP
#ifndef cmm_smp_mb
#define cmm_smp_mb()	cmm_mb()
#endif
#ifndef cmm_smp_rmb
#define cmm_smp_rmb()	cmm_rmb()
#endif
#ifndef cmm_smp_wmb
#define cmm_smp_wmb()	cmm_wmb()
#endif
#ifndef cmm_smp_mc
#define cmm_smp_mc()	cmm_mc()
#endif
#ifndef cmm_smp_rmc
#define cmm_smp_rmc()	cmm_rmc()
#endif
#ifndef cmm_smp_wmc
#define cmm_smp_wmc()	cmm_wmc()
#endif
#ifndef cmm_smp_read_barrier_depends
#define cmm_smp_read_barrier_depends()	cmm_read_barrier_depends()
#endif
#else
#ifndef cmm_smp_mb
#define cmm_smp_mb()	cmm_barrier()
#endif
#ifndef cmm_smp_rmb
#define cmm_smp_rmb()	cmm_barrier()
#endif
#ifndef cmm_smp_wmb
#define cmm_smp_wmb()	cmm_barrier()
#endif
#ifndef cmm_smp_mc
#define cmm_smp_mc()	cmm_barrier()
#endif
#ifndef cmm_smp_rmc
#define cmm_smp_rmc()	cmm_barrier()
#endif
#ifndef cmm_smp_wmc
#define cmm_smp_wmc()	cmm_barrier()
#endif
#ifndef cmm_smp_read_barrier_depends
#define cmm_smp_read_barrier_depends()
#endif
#endif

#ifndef caa_cpu_relax
#define caa_cpu_relax()		cmm_barrier()
#endif

#ifndef HAS_CAA_GET_CYCLES
#define HAS_CAA_GET_CYCLES

#if defined(__APPLE__)

#include <mach/mach.h>
#include <mach/clock.h>
#include <mach/mach_time.h>
#include <time.h>
#include <stdint.h>

typedef uint64_t caa_cycles_t;

static inline caa_cycles_t caa_get_cycles (void)
{
	mach_timespec_t ts = { 0, 0 };
	static clock_serv_t clock_service;

	if (caa_unlikely(!clock_service)) {
		if (host_get_clock_service(mach_host_self(),
				SYSTEM_CLOCK, &clock_service))
			return -1ULL;
	}
	if (caa_unlikely(clock_get_time(clock_service, &ts)))
		return -1ULL;
	return ((uint64_t) ts.tv_sec * 1000000000ULL) + ts.tv_nsec;
}

#elif defined(CONFIG_RCU_HAVE_CLOCK_GETTIME)

#include <time.h>
#include <stdint.h>

typedef uint64_t caa_cycles_t;

static inline caa_cycles_t caa_get_cycles (void)
{
	struct timespec ts;

	if (caa_unlikely(clock_gettime(CLOCK_MONOTONIC, &ts)))
		return -1ULL;
	return ((uint64_t) ts.tv_sec * 1000000000ULL) + ts.tv_nsec;
}

#else

#error caa_get_cycles() not implemented for this platform.

#endif

#endif /* HAS_CAA_GET_CYCLES */

#ifdef __cplusplus
}
#endif

#endif /* _URCU_ARCH_GENERIC_H */