[dragonfly.git] / sys / cpu / amd64 / include / param.h

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * Copyright (c) 2008 The DragonFly Project.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * 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 University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *	from: @(#)param.h	5.8 (Berkeley) 6/28/91
 * $FreeBSD: src/sys/i386/include/param.h,v 1.54.2.8 2002/08/31 21:15:55 dillon Exp $
 * $DragonFly: src/sys/cpu/amd64/include/param.h,v 1.4 2008/08/29 17:07:06 dillon Exp $
 */

#ifndef _CPU_PARAM_H_

/*
 * Do not prevent re-includes of <machine/param.h> if the file was included
 * with NO_NAMESPACE_POLLUTION, or expected macros will not exist.
 */
#ifndef _NO_NAMESPACE_POLLUTION
#define _CPU_PARAM_H_
#endif

/*
 * Machine dependent constants for x86_64.
 */
#ifndef _CPU_PARAM_H1_
#define _CPU_PARAM_H1_

/*
 * Round p (pointer or byte index) up to a correctly-aligned value
 * for all data types (int, long, ...).   The result is unsigned int
 * and must be cast to any desired pointer type.
 */
#ifndef _ALIGNBYTES
#define _ALIGNBYTES	(sizeof(long) - 1)
#endif
#ifndef _ALIGN
#define _ALIGN(p)	(((unsigned long)(p) + _ALIGNBYTES) & ~_ALIGNBYTES)
#endif

#ifndef _MACHINE
#define	_MACHINE	amd64
#endif
#ifndef _MACHINE_ARCH
#define	_MACHINE_ARCH	amd64
#endif

#endif	/* _CPU_PARAM_H1_ */

#ifndef _NO_NAMESPACE_POLLUTION

#ifndef MACHINE
#define MACHINE		"amd64"
#endif
#ifndef MACHINE_ARCH
#define	MACHINE_ARCH	"amd64"
#endif

/*
 * Use SMP_MAXCPU instead of MAXCPU for structures that are intended to
 * remain compatible between UP and SMP builds.
 */
#define SMP_MAXCPU	16
#ifdef SMP
#define MAXCPU		SMP_MAXCPU
#else
#define MAXCPU		1
#endif /* SMP */

#define ALIGNBYTES	_ALIGNBYTES
#define ALIGN(p)	_ALIGN(p)

/* JG license? from fbsd/src/sys/amd64/include/param.h */
/* level 1 == page table */
#define	NPTEPGSHIFT	9		/* LOG2(NPTEPG) */
#define PAGE_SHIFT	12		/* LOG2(PAGE_SIZE) */
#define PAGE_SIZE	(1<<PAGE_SHIFT)	/* bytes/page */
#define PAGE_MASK	(PAGE_SIZE-1)
#define NPTEPG		(PAGE_SIZE/(sizeof (pt_entry_t)))

/* level 2 == page directory */
#define	NPDEPGSHIFT	9		/* LOG2(NPDEPG) */
#define PDRSHIFT	21		/* LOG2(NBPDR) */
#define NBPDR		(1<<PDRSHIFT)	/* bytes/page dir */
#define PDRMASK		(NBPDR-1)
#define NPDEPG		(PAGE_SIZE/(sizeof (pd_entry_t)))

/* level 3 == page directory pointer table */
#define	NPDPEPGSHIFT	9		/* LOG2(NPDPEPG) */
#define PDPSHIFT	30		/* LOG2(NBPDP) */
#define NBPDP		(1<<PDPSHIFT)	/* bytes/page dir ptr table */
#define PDPMASK		(NBPDP-1)
#define NPDPEPG		(PAGE_SIZE/(sizeof (pdp_entry_t)))

/* level 4 */
#define	NPML4EPGSHIFT	9		/* LOG2(NPML4EPG) */
#define PML4SHIFT	39		/* LOG2(NPML4) */
#define NPML4		(1UL<<PML4SHIFT)/* bytes/page map level4 table */
#define	NBPML4		(1ul<<PML4SHIFT)/* bytes/page map lev4 table */
#define PML4MASK	(NPML4-1)
#define NPML4EPG	(PAGE_SIZE/(sizeof (pml4_entry_t)))

#define DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
#define DEV_BSIZE	(1<<DEV_BSHIFT)
#define DEV_BMASK	(DEV_BSIZE - 1)

#ifndef BLKDEV_IOSIZE
#define BLKDEV_IOSIZE	PAGE_SIZE	/* default block device I/O size */
#endif
#define DFLTPHYS	(64 * 1024)	/* default max raw I/O transfer size */
#define MAXPHYS		(128 * 1024)	/* max raw I/O transfer size */
#define MAXDUMPPGS	(DFLTPHYS/PAGE_SIZE)

#define IOPAGES	2		/* pages of i/o permission bitmap */
#define UPAGES	3		/* pages of u-area */

/*
 * Ceiling on amount of swblock kva space, can be changed via
 * kern.maxswzone /boot/loader.conf variable.
 */
#ifndef VM_SWZONE_SIZE_MAX
#define VM_SWZONE_SIZE_MAX	(32 * 1024 * 1024)
#endif

/*
 * Ceiling on size of buffer cache (really only effects write queueing,
 * the VM page cache is not effected), can be changed via
 * kern.maxbcache /boot/loader.conf variable.
 */
#ifndef VM_BCACHE_SIZE_MAX
#define VM_BCACHE_SIZE_MAX	(200 * 1024 * 1024)
#endif


/*
 * Constants related to network buffer management.
 * MCLBYTES must be no larger than CLBYTES (the software page size), and,
 * on machines that exchange pages of input or output buffers with mbuf
 * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
 * of the hardware page size.
 */
#ifndef	MSIZE
#define MSIZE		512		/* size of an mbuf */
#endif	/* MSIZE */

#ifndef	MCLSHIFT
#define MCLSHIFT	11		/* convert bytes to m_buf clusters */
#endif	/* MCLSHIFT */
#define MCLBYTES	(1 << MCLSHIFT)	/* size of an m_buf cluster */
#define MCLOFSET	(MCLBYTES - 1)	/* offset within an m_buf cluster */

/*
 * Some macros for units conversion
 */

/* clicks to bytes */
#define ctob(x)	((x)<<PAGE_SHIFT)

/* bytes to clicks */
#define btoc(x)	(((unsigned)(x)+PAGE_MASK)>>PAGE_SHIFT)

/*
 * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
 * want to shift an unsigned type to avoid sign extension and we don't
 * want to widen `bytes' unnecessarily.  Assume that the result fits in
 * a daddr_t.
 */
#define btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
	(sizeof (bytes) > sizeof(long) \
	 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
	 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))

#define dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
	((off_t)(db) << DEV_BSHIFT)

/*
 * Mach derived conversion macros
 */
#define	round_page(x)	((((unsigned long)(x)) + PAGE_MASK) & ~(unsigned long)(PAGE_MASK))
#define	trunc_page(x)	((unsigned long)(x) & ~(unsigned long)(PAGE_MASK))
#define trunc_2mpage(x)	((unsigned long)(x) & ~(unsigned long)PDRMASK)
#define round_2mpage(x)	((((unsigned long)(x)) + PDRMASK) & ~(unsigned long)PDRMASK)

#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
#define	atop(x)		((vm_pindex_t)((x) >> PAGE_SHIFT))
#endif
#define	ptoa(x)		((vm_paddr_t)(x) << PAGE_SHIFT)

#define	amd64_btop(x)	((vm_pindex_t)((x) >> PAGE_SHIFT))
#define	amd64_ptob(x)	((vm_paddr_t)(x) << PAGE_SHIFT)

#define	pgtok(x)		((x) * (PAGE_SIZE / 1024))

#ifdef _KERNEL

/*
 * We put here the definition of two debugging macros/function which
 * are very convenient to have available.
 * The macro is called TSTMP() and is used to timestamp events in the
 * kernel using the TSC register, and export them to userland through
 * the sysctl variable debug.timestamp, which is a circular buffer
 * holding pairs of u_int32_t variables <timestamp, argument> .
 * They can be retrieved with something like
 *
 *	sysctl -b debug.timestamp | hexdump -e '"%15u %15u\n"'
 *
 * The function _TSTMP() is defined in i386/isa/clock.c. It does not
 * try to grab any locks or block interrupts or identify which CPU it
 * is running on. You are supposed to know what to do if you use it.
 *
 * The macros must be enabled with "options KERN_TIMESTAMP" in the kernel
 * config file, otherwise they default to an empty block.
 */

#ifdef KERN_TIMESTAMP
extern void _TSTMP(u_int32_t argument);
#define TSTMP(class, unit, event, par)	_TSTMP(	\
	(((class) &   0x0f) << 28 ) |		\
	(((unit)  &   0x0f) << 24 ) |		\
	(((event) &   0xff) << 16 ) |		\
	(((par)   & 0xffff)       )   )

#else /* !KERN_TIMESTAMP */
#define        _TSTMP(x)                       {}
#define        TSTMP(class, unit, event, par)  _TSTMP(0)
#endif /* !KERN_TIMESTAMP */
#endif /* _KERNEL */

#endif /* !_NO_NAMESPACE_POLLUTION */
#endif /* !_CPU_PARAM_H_ */
Commit	Line	Data
fc3f9779 SS	1	/*-
fc3f9779 SS	2	* Copyright (c) 1990 The Regents of the University of California.
c8fe38ae	3	* Copyright (c) 2008 The DragonFly Project.
fc3f9779 SS	4	* All rights reserved.
	5	*
	6	* This code is derived from software contributed to Berkeley by
	7	* William Jolitz.
	8	*
	9	* Redistribution and use in source and binary forms, with or without
	10	* modification, are permitted provided that the following conditions
	11	* are met:
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	* 2. Redistributions in binary form must reproduce the above copyright
	15	* notice, this list of conditions and the following disclaimer in the
	16	* documentation and/or other materials provided with the distribution.
	17	* 3. All advertising materials mentioning features or use of this software
	18	* must display the following acknowledgement:
	19	* This product includes software developed by the University of
	20	* California, Berkeley and its contributors.
	21	* 4. Neither the name of the University nor the names of its contributors
	22	* may be used to endorse or promote products derived from this software
	23	* without specific prior written permission.
	24	*
	25	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	26	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	27	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	28	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	29	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	30	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	31	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	32	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	33	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	34	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	35	* SUCH DAMAGE.
	36	*
	37	* from: @(#)param.h 5.8 (Berkeley) 6/28/91
	38	* $FreeBSD: src/sys/i386/include/param.h,v 1.54.2.8 2002/08/31 21:15:55 dillon Exp $
c8fe38ae	39	* $DragonFly: src/sys/cpu/amd64/include/param.h,v 1.4 2008/08/29 17:07:06 dillon Exp $
fc3f9779 SS	40	*/
	41
	42	#ifndef _CPU_PARAM_H_
	43
	44	/*
	45	* Do not prevent re-includes of <machine/param.h> if the file was included
	46	* with NO_NAMESPACE_POLLUTION, or expected macros will not exist.
	47	*/
	48	#ifndef _NO_NAMESPACE_POLLUTION
	49	#define _CPU_PARAM_H_
	50	#endif
	51
	52	/*
02fc0ba7	53	* Machine dependent constants for x86_64.
fc3f9779 SS	54	*/
	55	#ifndef _CPU_PARAM_H1_
	56	#define _CPU_PARAM_H1_
	57
	58	/*
	59	* Round p (pointer or byte index) up to a correctly-aligned value
	60	* for all data types (int, long, ...). The result is unsigned int
	61	* and must be cast to any desired pointer type.
	62	*/
	63	#ifndef _ALIGNBYTES
	64	#define _ALIGNBYTES (sizeof(long) - 1)
	65	#endif
	66	#ifndef _ALIGN
	67	#define _ALIGN(p) (((unsigned long)(p) + _ALIGNBYTES) & ~_ALIGNBYTES)
	68	#endif
	69
02fc0ba7 SS	70	#ifndef _MACHINE
02fc0ba7 SS	71	#define _MACHINE amd64
fc3f9779	72	#endif
02fc0ba7 SS	73	#ifndef _MACHINE_ARCH
02fc0ba7 SS	74	#define _MACHINE_ARCH amd64
fc3f9779 SS	75	#endif
fc3f9779 SS	76
fc3f9779 SS	77	#endif /* _CPU_PARAM_H1_ */
	78
	79	#ifndef _NO_NAMESPACE_POLLUTION
	80
02fc0ba7 SS	81	#ifndef MACHINE
02fc0ba7 SS	82	#define MACHINE "amd64"
fc3f9779	83	#endif
02fc0ba7 SS	84	#ifndef MACHINE_ARCH
02fc0ba7 SS	85	#define MACHINE_ARCH "amd64"
fc3f9779 SS	86	#endif
	87
	88	/*
	89	* Use SMP_MAXCPU instead of MAXCPU for structures that are intended to
	90	* remain compatible between UP and SMP builds.
	91	*/
	92	#define SMP_MAXCPU 16
	93	#ifdef SMP
	94	#define MAXCPU SMP_MAXCPU
	95	#else
	96	#define MAXCPU 1
	97	#endif /* SMP */
	98
	99	#define ALIGNBYTES _ALIGNBYTES
	100	#define ALIGN(p) _ALIGN(p)
	101
c8fe38ae	102	/* JG license? from fbsd/src/sys/amd64/include/param.h */
fc3f9779	103	/* level 1 == page table */
c8fe38ae	104	#define NPTEPGSHIFT 9 /* LOG2(NPTEPG) */
fc3f9779 SS	105	#define PAGE_SHIFT 12 /* LOG2(PAGE_SIZE) */
	106	#define PAGE_SIZE (1<<PAGE_SHIFT) /* bytes/page */
	107	#define PAGE_MASK (PAGE_SIZE-1)
	108	#define NPTEPG (PAGE_SIZE/(sizeof (pt_entry_t)))
	109
	110	/* level 2 == page directory */
c8fe38ae	111	#define NPDEPGSHIFT 9 /* LOG2(NPDEPG) */
fc3f9779 SS	112	#define PDRSHIFT 21 /* LOG2(NBPDR) */
	113	#define NBPDR (1<<PDRSHIFT) /* bytes/page dir */
	114	#define PDRMASK (NBPDR-1)
	115	#define NPDEPG (PAGE_SIZE/(sizeof (pd_entry_t)))
	116
	117	/* level 3 == page directory pointer table */
c8fe38ae	118	#define NPDPEPGSHIFT 9 /* LOG2(NPDPEPG) */
fc3f9779 SS	119	#define PDPSHIFT 30 /* LOG2(NBPDP) */
	120	#define NBPDP (1<<PDPSHIFT) /* bytes/page dir ptr table */
	121	#define PDPMASK (NBPDP-1)
	122	#define NPDPEPG (PAGE_SIZE/(sizeof (pdp_entry_t)))
	123
	124	/* level 4 */
c8fe38ae	125	#define NPML4EPGSHIFT 9 /* LOG2(NPML4EPG) */
fc3f9779 SS	126	#define PML4SHIFT 39 /* LOG2(NPML4) */
fc3f9779 SS	127	#define NPML4 (1UL<<PML4SHIFT)/* bytes/page map level4 table */
c8fe38ae	128	#define NBPML4 (1ul<<PML4SHIFT)/* bytes/page map lev4 table */
fc3f9779 SS	129	#define PML4MASK (NPML4-1)
	130	#define NPML4EPG (PAGE_SIZE/(sizeof (pml4_entry_t)))
	131
fc3f9779 SS	132	#define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
	133	#define DEV_BSIZE (1<<DEV_BSHIFT)
	134	#define DEV_BMASK (DEV_BSIZE - 1)
	135
	136	#ifndef BLKDEV_IOSIZE
	137	#define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
	138	#endif
	139	#define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
	140	#define MAXPHYS (128 * 1024) /* max raw I/O transfer size */
	141	#define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
	142
	143	#define IOPAGES 2 /* pages of i/o permission bitmap */
	144	#define UPAGES 3 /* pages of u-area */
	145
	146	/*
	147	* Ceiling on amount of swblock kva space, can be changed via
	148	* kern.maxswzone /boot/loader.conf variable.
	149	*/
	150	#ifndef VM_SWZONE_SIZE_MAX
	151	#define VM_SWZONE_SIZE_MAX (32 * 1024 * 1024)
	152	#endif
	153
	154	/*
	155	* Ceiling on size of buffer cache (really only effects write queueing,
	156	* the VM page cache is not effected), can be changed via
	157	* kern.maxbcache /boot/loader.conf variable.
	158	*/
	159	#ifndef VM_BCACHE_SIZE_MAX
	160	#define VM_BCACHE_SIZE_MAX (200 * 1024 * 1024)
	161	#endif
	162
	163
	164	/*
	165	* Constants related to network buffer management.
	166	* MCLBYTES must be no larger than CLBYTES (the software page size), and,
	167	* on machines that exchange pages of input or output buffers with mbuf
	168	* clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
	169	* of the hardware page size.
	170	*/
	171	#ifndef MSIZE
c8fe38ae	172	#define MSIZE 512 /* size of an mbuf */
fc3f9779 SS	173	#endif /* MSIZE */
	174
	175	#ifndef MCLSHIFT
	176	#define MCLSHIFT 11 /* convert bytes to m_buf clusters */
	177	#endif /* MCLSHIFT */
	178	#define MCLBYTES (1 << MCLSHIFT) /* size of an m_buf cluster */
	179	#define MCLOFSET (MCLBYTES - 1) /* offset within an m_buf cluster */
	180
	181	/*
	182	* Some macros for units conversion
	183	*/
	184
	185	/* clicks to bytes */
	186	#define ctob(x) ((x)<<PAGE_SHIFT)
	187
	188	/* bytes to clicks */
	189	#define btoc(x) (((unsigned)(x)+PAGE_MASK)>>PAGE_SHIFT)
	190
	191	/*
	192	* btodb() is messy and perhaps slow because `bytes' may be an off_t. We
	193	* want to shift an unsigned type to avoid sign extension and we don't
	194	* want to widen `bytes' unnecessarily. Assume that the result fits in
	195	* a daddr_t.
	196	*/
	197	#define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
	198	(sizeof (bytes) > sizeof(long) \
	199	? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
	200	: (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
	201
	202	#define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
	203	((off_t)(db) << DEV_BSHIFT)
	204
	205	/*
	206	* Mach derived conversion macros
	207	*/
89ffa1cf SS	208	#define round_page(x) ((((unsigned long)(x)) + PAGE_MASK) & ~(unsigned long)(PAGE_MASK))
	209	#define trunc_page(x) ((unsigned long)(x) & ~(unsigned long)(PAGE_MASK))
	210	#define trunc_2mpage(x) ((unsigned long)(x) & ~(unsigned long)PDRMASK)
	211	#define round_2mpage(x) ((((unsigned long)(x)) + PDRMASK) & ~(unsigned long)PDRMASK)
fc3f9779 SS	212
fc3f9779 SS	213	#if defined(_KERNEL) \|\| defined(_KERNEL_STRUCTURES)
c8fe38ae	214	#define atop(x) ((vm_pindex_t)((x) >> PAGE_SHIFT))
fc3f9779	215	#endif
c8fe38ae	216	#define ptoa(x) ((vm_paddr_t)(x) << PAGE_SHIFT)
fc3f9779	217
c8fe38ae MD	218	#define amd64_btop(x) ((vm_pindex_t)((x) >> PAGE_SHIFT))
c8fe38ae MD	219	#define amd64_ptob(x) ((vm_paddr_t)(x) << PAGE_SHIFT)
fc3f9779 SS	220
	221	#define pgtok(x) ((x) * (PAGE_SIZE / 1024))
	222
	223	#ifdef _KERNEL
	224
	225	/*
	226	* We put here the definition of two debugging macros/function which
	227	* are very convenient to have available.
	228	* The macro is called TSTMP() and is used to timestamp events in the
	229	* kernel using the TSC register, and export them to userland through
	230	* the sysctl variable debug.timestamp, which is a circular buffer
	231	* holding pairs of u_int32_t variables <timestamp, argument> .
	232	* They can be retrieved with something like
	233	*
	234	* sysctl -b debug.timestamp \| hexdump -e '"%15u %15u\n"'
	235	*
	236	* The function _TSTMP() is defined in i386/isa/clock.c. It does not
	237	* try to grab any locks or block interrupts or identify which CPU it
	238	* is running on. You are supposed to know what to do if you use it.
	239	*
	240	* The macros must be enabled with "options KERN_TIMESTAMP" in the kernel
	241	* config file, otherwise they default to an empty block.
	242	*/
	243
	244	#ifdef KERN_TIMESTAMP
	245	extern void _TSTMP(u_int32_t argument);
	246	#define TSTMP(class, unit, event, par) _TSTMP( \
	247	(((class) & 0x0f) << 28 ) \| \
	248	(((unit) & 0x0f) << 24 ) \| \
	249	(((event) & 0xff) << 16 ) \| \
	250	(((par) & 0xffff) ) )
	251
	252	#else /* !KERN_TIMESTAMP */
	253	#define _TSTMP(x) {}
	254	#define TSTMP(class, unit, event, par) _TSTMP(0)
	255	#endif /* !KERN_TIMESTAMP */
	256	#endif /* _KERNEL */
	257
	258	#endif /* !_NO_NAMESPACE_POLLUTION */
	259	#endif /* !_CPU_PARAM_H_ */