1 /* $NetBSD: cpu_counter.h,v 1.6 2007/10/17 19:54:56 garbled Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Bill Sommerfeld. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #ifndef _I386_CPU_COUNTER_H_ 40 #define _I386_CPU_COUNTER_H_ 41 42 /* 43 * Machine-specific support for CPU counter. 44 */ 45 46 #include <machine/cpu.h> 47 #include <machine/cpufunc.h> 48 #include <machine/specialreg.h> 49 50 #include "opt_cputype.h" 51 52 #ifdef _KERNEL 53 54 #include <x86/cpu_counter.h> 55 56 static __inline int 57 cpu_hascounter(void) 58 { 59 60 #if defined(I586_CPU) || defined(I686_CPU) 61 /* 62 * Note that: 63 * 1) Intel documentation is very specific that code *must* test 64 * the CPU feature flag, even if you "know" that a particular 65 * rev of the hardware supports it. 66 * 2) We know that the TSC is busted on some Cyrix CPU in that if 67 * you execute "hlt" when in powersave mode, TSC stops counting, 68 * even though the CPU clock crystal is still ticking (it always has to). 69 */ 70 return (cpu_feature & CPUID_TSC) != 0; 71 #else 72 return 0; 73 #endif 74 } 75 76 #endif /* _KERNEL */ 77 78 #endif /* !_I386_CPU_COUNTER_H_ */ 79