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NetBSD/sys/arch/i386/include/rnd.h

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Use #if defined(FOO_CPU) instead of #if FOO_CPU just to be picky. Spotted by Thomas Klausner.
2001-12-06 04:56:19 +03:00
/* $NetBSD: rnd.h,v 1.4 2001/12/06 01:56:19 sommerfeld Exp $ */
Let rnd(4) know how to read the (pentium and higher) cycle counter: If __HAVE_CPU_TIMESTAMP is defined, <machine/rnd.h> exists and defines two functions: 1) u_int32_t cpu_timestamp(void); returns the 32 low order bits of a reasonably high frequency counter. 2) int cpu_havetimestamp(void); returns non-zero if cpu_timestamp() actually works. The timestamp counter should run at a frequency greater than 1 MHz (otherwise, microtime would be sufficient); other than that, the exact frequency and origin of the counter are unspecified.
2000-06-06 01:15:22 +04:00
/*-
* Copyright (c) 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Bill Sommerfeld.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 _I386_RND_H_
#define _I386_RND_H_
/*
* Machine-specific support for rnd(4)
*/
#include <machine/cpufunc.h>
#include <machine/specialreg.h>
#include "opt_cputype.h"
#ifdef _KERNEL
static __inline int
Replace "timestamp" with "counter" in previous change, to avoid any possible confusion that it has anything to do with accurate measurement of time. New names: __HAVE_CPU_COUNTER cpu_counter() cpu_hascounter()
2000-06-06 05:33:15 +04:00
cpu_hascounter(void)
Let rnd(4) know how to read the (pentium and higher) cycle counter: If __HAVE_CPU_TIMESTAMP is defined, <machine/rnd.h> exists and defines two functions: 1) u_int32_t cpu_timestamp(void); returns the 32 low order bits of a reasonably high frequency counter. 2) int cpu_havetimestamp(void); returns non-zero if cpu_timestamp() actually works. The timestamp counter should run at a frequency greater than 1 MHz (otherwise, microtime would be sufficient); other than that, the exact frequency and origin of the counter are unspecified.
2000-06-06 01:15:22 +04:00
{
Use #if defined(FOO_CPU) instead of #if FOO_CPU just to be picky. Spotted by Thomas Klausner.
2001-12-06 04:56:19 +03:00
#if defined(I586_CPU) || defined(I686_CPU)
Let rnd(4) know how to read the (pentium and higher) cycle counter: If __HAVE_CPU_TIMESTAMP is defined, <machine/rnd.h> exists and defines two functions: 1) u_int32_t cpu_timestamp(void); returns the 32 low order bits of a reasonably high frequency counter. 2) int cpu_havetimestamp(void); returns non-zero if cpu_timestamp() actually works. The timestamp counter should run at a frequency greater than 1 MHz (otherwise, microtime would be sufficient); other than that, the exact frequency and origin of the counter are unspecified.
2000-06-06 01:15:22 +04:00
/*
* Note that:
* 1) Intel documentation is very specific that code *must* test
* the CPU feature flag, even if you "know" that a particular
* rev of the hardware supports it.
* 2) We know that the TSC is busted on some Cyrix CPU's..
*/
return (cpu_feature & CPUID_TSC) != 0;
#else
return 0;
#endif
}
Return the full width of the counter here.
2000-07-03 01:05:14 +04:00
static __inline u_int64_t
Replace "timestamp" with "counter" in previous change, to avoid any possible confusion that it has anything to do with accurate measurement of time. New names: __HAVE_CPU_COUNTER cpu_counter() cpu_hascounter()
2000-06-06 05:33:15 +04:00
cpu_counter(void)
Let rnd(4) know how to read the (pentium and higher) cycle counter: If __HAVE_CPU_TIMESTAMP is defined, <machine/rnd.h> exists and defines two functions: 1) u_int32_t cpu_timestamp(void); returns the 32 low order bits of a reasonably high frequency counter. 2) int cpu_havetimestamp(void); returns non-zero if cpu_timestamp() actually works. The timestamp counter should run at a frequency greater than 1 MHz (otherwise, microtime would be sufficient); other than that, the exact frequency and origin of the counter are unspecified.
2000-06-06 01:15:22 +04:00
{
return rdtsc();
}
#endif /* _KERNEL */
#endif /* !_I386_RND_H_ */
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