NetBSD/sys/arch/pmax/pmax/machdep.c

/*	$NetBSD: machdep.c,v 1.171 2000/04/12 04:40:50 nisimura Exp $	*/

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department, The Mach Operating System project at
 * Carnegie-Mellon University and Ralph Campbell.
 *
 * 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.
 *
 *	@(#)machdep.c	8.3 (Berkeley) 1/12/94
 * 	from: Utah Hdr: machdep.c 1.63 91/04/24
 */

#include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.171 2000/04/12 04:40:50 nisimura Exp $");

#include "fs_mfs.h"
#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/buf.h>
#include <sys/reboot.h>
#include <sys/user.h>
#include <sys/mount.h>
#include <sys/kcore.h>

#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <sys/sysctl.h>			/* XXX after <vm/vm.h> */

#include <dev/cons.h>

#include <ufs/mfs/mfs_extern.h>		/* mfs_initminiroot() */

#include <machine/psl.h>
#include <machine/autoconf.h>
#include <machine/dec_prom.h>
#include <machine/sysconf.h>
#include <machine/bootinfo.h>
#include <machine/locore.h>
#include <pmax/pmax/machdep.h>

#ifdef DDB
#include <sys/exec_aout.h>		/* XXX backwards compatilbity for DDB */
#include <machine/db_machdep.h>
#include <ddb/db_extern.h>
#endif

#include "opt_dec_3min.h"
#include "opt_dec_maxine.h"
#include "opt_dec_3maxplus.h"

/* the following is used externally (sysctl_hw) */
char	machine[] = MACHINE;		/* from <machine/param.h> */
char	machine_arch[] = MACHINE_ARCH;	/* from <machine/param.h> */
char	cpu_model[40];
unsigned ssir;				/* simulated interrupt register */

/* maps for VM objects */
vm_map_t exec_map = NULL;
vm_map_t mb_map = NULL;
vm_map_t phys_map = NULL;

int		systype;		/* mother board type */
char		*bootinfo = NULL;	/* pointer to bootinfo structure */
int		cpuspeed = 30;		/* approx # instr per usec. */
int		physmem;		/* max supported memory, changes to actual */
int		physmem_boardmax;	/* {model,SIMM}-specific bound on physmem */
int		mem_cluster_cnt;
phys_ram_seg_t	mem_clusters[VM_PHYSSEG_MAX];

/*      
 * During autoconfiguration or after a panic, a sleep will simply
 * lower the priority briefly to allow interrupts, then return.
 * The priority to be used (safepri) is machine-dependent, thus this
 * value is initialized and maintained in the machine-dependent layers.
 * This priority will typically be 0, or the lowest priority
 * that is safe for use on the interrupt stack; it can be made
 * higher to block network software interrupts after panics.
 */
/*
 * safepri is a safe priority for sleep to set for a spin-wait
 * during autoconfiguration or after a panic.
 * Used as an argument to splx().
 * XXX disables interrupt 5 to disable mips3 on-chip clock, which also
 * disables mips1 FPU interrupts.
 */
int	safepri = MIPS3_PSL_LOWIPL;	/* XXX */

struct splvec	splvec;			/* XXX will go XXX */

void	mach_init __P((int, char *[], int, int, u_int, char *)); /* XXX */
void	cpu_intr  __P((u_int32_t, u_int32_t, u_int32_t, u_int32_t));

/* Motherboard or system-specific initialization vector */
static void	unimpl_bus_reset __P((void));
static void	unimpl_cons_init __P((void));
static int	unimpl_iointr __P((unsigned, unsigned, unsigned, unsigned));
static void	unimpl_intr_establish __P((struct device *, void *, int,
		    int (*)(void *), void *));
static int	unimpl_memsize __P((caddr_t));
static unsigned	nullwork __P((void));

struct platform platform = {
	"iobus not set",
	unimpl_bus_reset,
	unimpl_cons_init,
	unimpl_iointr,
	unimpl_intr_establish,
	unimpl_memsize,
	(void *)nullwork,
};

extern caddr_t esym;			/* XXX */
extern struct user *proc0paddr;		/* XXX */
extern struct consdev promcd;		/* XXX */

/*
 * Do all the stuff that locore normally does before calling main().
 * The first 4 argments are passed by PROM monitor, and remaining two
 * are built on temporary stack by our boot loader.
 */
void
mach_init(argc, argv, code, cv, bim, bip)
	int argc;
	char *argv[];
	int code, cv;
	u_int bim;
	char *bip;
{
	char *cp, *bootinfo_msg;
	u_long first, last;
	int i;
	caddr_t kernend, v;
	unsigned size;
#ifdef DDB
	int nsym = 0;
	caddr_t ssym = 0;
	struct btinfo_symtab *bi_syms;
	struct exec *aout;		/* XXX backwards compatilbity for DDB */
#endif
	extern char edata[], end[];	/* XXX */

	/* Initialize callv so we can do PROM output... */
	callv = (code == DEC_PROM_MAGIC) ? (void *)cv : &callvec;

	/* Use PROM console output until we initialize a console driver. */
	cn_tab = &promcd;

	/* Set up bootinfo structure looking at stack. */
	if (bim == BOOTINFO_MAGIC) {
		struct btinfo_magic *bi_magic;

		bootinfo = bip;
		bi_magic = lookup_bootinfo(BTINFO_MAGIC);
		if (bi_magic == NULL || bi_magic->magic != BOOTINFO_MAGIC)
			bootinfo_msg =
			    "invalid magic number in bootinfo structure.\n";
		else
			bootinfo_msg = NULL;
	}
	else
		bootinfo_msg = "invalid bootinfo pointer (old bootblocks?)\n";
#if 0
	if (bootinfo_msg != NULL)
		printf(bootinfo_msg);
#endif

	/* clear the BSS segment */
#ifdef DDB
	bi_syms = lookup_bootinfo(BTINFO_SYMTAB);
	aout = (struct exec *)edata;

	/* Was it a valid bootinfo symtab info? */
	if (bi_syms != NULL) {
		nsym = bi_syms->nsym;
		ssym = (caddr_t)bi_syms->ssym;
		esym = (caddr_t)bi_syms->esym;
		kernend = (caddr_t)mips_round_page(esym);
		memset(edata, 0, end - edata);
	}
	/* XXX: Backwards compatibility with old bootblocks - this should
	 * go soon...
	 */
	/* Exec header and symbols? */
	else if (aout->a_midmag == 0x07018b00 && (i = aout->a_syms) != 0) {
		nsym = *(long *)end = i;
		ssym = end;
		i += (*(long *)(end + i + 4) + 3) & ~3;		/* strings */
		esym = end + i + 4;
		kernend = (caddr_t)mips_round_page(esym);
		memset(edata, 0, end - edata);
	} else
#endif
	{
		kernend = (caddr_t)mips_round_page(end);
		memset(edata, 0, kernend - edata);
	}

	/*
	 * Set the VM page size.
	 */
	uvm_setpagesize();

	/*
	 * Copy exception-dispatch code down to exception vector.
	 * Initialize locore-function vector.
	 * Clear out the I and D caches.
	 */
	mips_vector_init();

	/* Check for direct boot from DS5000 REX monitor */
	if (argc > 0 && strcmp(argv[0], "boot") == 0) {
		argc--;
		argv++;
	}

	/* Look at argv[0] and compute bootdev */
	makebootdev(argv[0]);

	/*
	 * Look at arguments passed to us and compute boothowto.
	 */
	boothowto = RB_SINGLE;
#ifdef KADB
	boothowto |= RB_KDB;
#endif
	for (i = 1; i < argc; i++) {
		for (cp = argv[i]; *cp; cp++) {
			switch (*cp) {
			case 'a': /* autoboot */
				boothowto &= ~RB_SINGLE;
				break;

			case 'd': /* break into the kernel debugger ASAP */
				boothowto |= RB_KDB;
				break;

			case 'm': /* mini root present in memory */
				boothowto |= RB_MINIROOT;
				break;

			case 'n': /* ask for names */
				boothowto |= RB_ASKNAME;
				break;

			case 'N': /* don't ask for names */
				boothowto &= ~RB_ASKNAME;
			}
		}
	}

#ifdef MFS
	/*
	 * Check to see if a mini-root was loaded into memory. It resides
	 * at the start of the next page just after the end of BSS.
	 */
	if (boothowto & RB_MINIROOT) {
		boothowto |= RB_DFLTROOT;
		kernend += round_page(mfs_initminiroot(kernend));
	}
#endif

#ifdef DDB
	/*
	 * Initialize machine-dependent DDB commands, in case of early panic.
	 */
	db_machine_init();
	/* init symbols if present */
	if (esym)
		ddb_init(esym - ssym, ssym, esym);
	if (boothowto & RB_KDB)
		Debugger();
#endif

	/*
	 * Alloc u pages for proc0 stealing KSEG0 memory.
	 */
	proc0.p_addr = proc0paddr = (struct user *)kernend;
	proc0.p_md.md_regs = (struct frame *)(kernend + USPACE) - 1;
	memset(proc0.p_addr, 0, USPACE);
	curpcb = &proc0.p_addr->u_pcb;
	curpcb->pcb_context[11] = MIPS_INT_MASK | MIPS_SR_INT_IE; /* SR */

	kernend += USPACE;

	/*
	 * Initialize physmem_boardmax; assume no SIMM-bank limits.
	 * Adjust later in model-specific code if necessary.
	 */
	physmem_boardmax = MIPS_MAX_MEM_ADDR;

	/*
	 * Determine what model of computer we are running on.
	 */
	systype = ((prom_systype() >> 16) & 0xff);
	if (systype >= nsysinit) {
		platform_not_supported();
		/* NOTREACHED */
	}

	/* Machine specific initialization. */
	(*sysinit[systype].init)();

	/* Find out how much memory is available. */
	physmem = (*platform.memsize)(kernend);

	/*
	 * Now that we know how much memory we have, initialize the
	 * mem cluster array.
	 */
	mem_clusters[0].start = 0;		/* XXX is this correct? */
	mem_clusters[0].size  = ctob(physmem);
	mem_cluster_cnt = 1;

	/*
	 * Load the rest of the available pages into the VM system.
	 * Put the first 8M of RAM onto a lower-priority free list, since
	 * some TC boards (e.g. PixelStamp boards) are only able to DMA
	 * into this region, and we want them to have a fighting chance of
	 * allocating their DMA memory during autoconfiguration.
	 */
	first = round_page(MIPS_KSEG0_TO_PHYS(kernend));
	last = mem_clusters[0].start + mem_clusters[0].size;
	if (last <= (8 * 1024 * 1024)) {
		uvm_page_physload(atop(first), atop(last), atop(first),
		    atop(last), VM_FREELIST_DEFAULT);
	} else {
		uvm_page_physload(atop(first), atop(8 * 1024 * 1024),
		    atop(first), atop(8 * 1024 * 1024), VM_FREELIST_FIRST8);
		uvm_page_physload(atop(8 * 1024 * 1024), atop(last),
		    atop(8 * 1024 * 1024), atop(last), VM_FREELIST_DEFAULT);
	}

	/*
	 * Initialize error message buffer (at end of core).
	 */
	mips_init_msgbuf();

	/*
	 * Allocate space for system data structures.  These data structures
	 * are allocated here instead of cpu_startup() because physical memory
	 * is directly addressable.  We don't have to map these into virtual
	 * address space.
	 */
	size = (unsigned)allocsys(NULL, NULL);
	v = (caddr_t)pmap_steal_memory(size, NULL, NULL);
	if ((allocsys(v, NULL) - v) != size)
		panic("mach_init: table size inconsistency");

	/*
	 * Initialize the virtual memory system.
	 */
	pmap_bootstrap();
}

void
consinit()
{

	(*platform.cons_init)();
}

/*
 * Machine-dependent startup code: allocate memory for variable-sized
 * tables.
 */
void
cpu_startup()
{
	unsigned i;
	int base, residual;
	vaddr_t minaddr, maxaddr;
	vsize_t size;
	char pbuf[9];
#ifdef DEBUG
	extern int pmapdebug;		/* XXX */
	int opmapdebug = pmapdebug;

	pmapdebug = 0;
#endif

	/*
	 * Good {morning,afternoon,evening,night}.
	 */
	printf(version);
	printf("%s\n", cpu_model);
	format_bytes(pbuf, sizeof(pbuf), ctob(physmem));
	printf("total memory = %s\n", pbuf);

	/*
	 * Allocate virtual address space for file I/O buffers.
	 * Note they are different than the array of headers, 'buf',
	 * and usually occupy more virtual memory than physical.
	 */
	size = MAXBSIZE * nbuf;
	if (uvm_map(kernel_map, (vaddr_t *)&buffers, round_page(size),
		    NULL, UVM_UNKNOWN_OFFSET,
		    UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE,
				UVM_ADV_NORMAL, 0)) != KERN_SUCCESS)
		panic("cpu_startup: cannot allocate VM for buffers");

	minaddr = (vaddr_t)buffers;
	if ((bufpages / nbuf) >= btoc(MAXBSIZE)) {
		bufpages = btoc(MAXBSIZE) * nbuf; /* do not overallocate RAM */
	}
	base = bufpages / nbuf;
	residual = bufpages % nbuf;

	/* now allocate RAM for buffers */
	for (i = 0; i < nbuf; i++) {
		vsize_t curbufsize;
		vaddr_t curbuf;
		struct vm_page *pg;

		/*
		 * Each buffer has MAXBSIZE bytes of VM space allocated.  Of
		 * that MAXBSIZE space, we allocate and map (base+1) pages
		 * for the first "residual" buffers, and then we allocate
		 * "base" pages for the rest.
		 */
		curbuf = (vaddr_t)buffers + (i * MAXBSIZE);
		curbufsize = NBPG * ((i < residual) ? (base+1) : base);

		while (curbufsize) {
			pg = uvm_pagealloc(NULL, 0, NULL, 0);
			if (pg == NULL)
				panic("cpu_startup: not enough memory for "
				    "buffer cache");
			pmap_kenter_pa(curbuf, VM_PAGE_TO_PHYS(pg),
				       VM_PROT_READ|VM_PROT_WRITE);
			curbuf += PAGE_SIZE;
			curbufsize -= PAGE_SIZE;
		}
	}
	/*
	 * Allocate a submap for exec arguments.  This map effectively
	 * limits the number of processes exec'ing at any time.
	 */
	exec_map = uvm_km_suballoc(kernel_map, &minaddr, &maxaddr,
				   16 * NCARGS, VM_MAP_PAGEABLE, FALSE, NULL);

	/*
	 * Allocate a submap for physio
	 */
	phys_map = uvm_km_suballoc(kernel_map, &minaddr, &maxaddr,
				   VM_PHYS_SIZE, 0, FALSE, NULL);

	/*
	 * No need to allocate an mbuf cluster submap.  Mbuf clusters
	 * are allocated via the pool allocator, and we use KSEG to
	 * map those pages.
	 */

#ifdef DEBUG
	pmapdebug = opmapdebug;
#endif
	format_bytes(pbuf, sizeof(pbuf), ptoa(uvmexp.free));
	printf("avail memory = %s\n", pbuf);
	format_bytes(pbuf, sizeof(pbuf), bufpages * NBPG);
	printf("using %d buffers containing %s of memory\n", nbuf, pbuf);

	/*
	 * Set up buffers, so they can be used to read disk labels.
	 */
	bufinit();
}

/*
 * Machine dependent system variables.
 */
int
cpu_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
	int *name;
	u_int namelen;
	void *oldp;
	size_t *oldlenp;
	void *newp;
	size_t newlen;
	struct proc *p;
{
	struct btinfo_bootpath *bibp;

	/* all sysctl names at this level are terminal */
	if (namelen != 1)
		return (ENOTDIR);		/* overloaded */

	switch (name[0]) {
	case CPU_CONSDEV:
		return (sysctl_rdstruct(oldp, oldlenp, newp, &cn_tab->cn_dev,
		    sizeof cn_tab->cn_dev));
	case CPU_BOOTED_KERNEL:
	        bibp = lookup_bootinfo(BTINFO_BOOTPATH);
	        if(!bibp)
			return (ENOENT); /* ??? */
		return (sysctl_rdstring(oldp, oldlenp, newp, bibp->bootpath));
	default:
		return (EOPNOTSUPP);
	}
	/* NOTREACHED */
}

/*
 * Look up information in bootinfo of boot loader.
 */
void *
lookup_bootinfo(type)
	int type;
{
	struct btinfo_common *bt;
	char *help = bootinfo;

	/* Check for a bootinfo record first. */
	if (help == NULL)
		return (NULL);

	do {
		bt = (struct btinfo_common *)help;
		if (bt->type == type)
			return ((void *)help);
		help += bt->next;
	} while (bt->next != 0 &&
		(size_t)help < (size_t)bootinfo + BOOTINFO_SIZE);

	return (NULL);
}

void
cpu_reboot(howto, bootstr)
	volatile int howto;	/* XXX volatile to keep gcc happy */
	char *bootstr;
{

	/* take a snap shot before clobbering any registers */
	if (curproc)
		savectx((struct user *)curpcb);

#ifdef DEBUG
	if (panicstr)
		stacktrace();
#endif

	/* If system is cold, just halt. */
	if (cold) {
		howto |= RB_HALT;
		goto haltsys;
	}

	/* If "always halt" was specified as a boot flag, obey. */
	if ((boothowto & RB_HALT) != 0)
		howto |= RB_HALT;

	boothowto = howto;
	if ((howto & RB_NOSYNC) == 0) {
		/*
		 * Synchronize the disks....
		 */
		vfs_shutdown();

		/*
		 * If we've been adjusting the clock, the todr
		 * will be out of synch; adjust it now.
		 */
		resettodr();
	}

	/* Disable interrupts. */
	splhigh();

	/* If rebooting and a dump is requested do it. */
#if 0
	if ((howto & (RB_DUMP | RB_HALT)) == RB_DUMP)
#else
	if ((howto & RB_DUMP) != 0)
#endif
		dumpsys();

haltsys:

	/* run any shutdown hooks */
	doshutdownhooks();

	/* Finally, halt/reboot the system. */
	printf("%s\n\n", ((howto & RB_HALT) != 0) ? "halted." : "rebooting...");
	prom_halt(howto & RB_HALT, bootstr);
	/*NOTREACHED*/
}

/*
 * Find out how much memory is available by testing memory.
 * Be careful to save and restore the original contents for msgbuf.
 */
int
memsize_scan(first)
	caddr_t first;
{
	int i, mem;
	char *cp;

	mem = btoc((paddr_t)first - MIPS_KSEG0_START);
	cp = (char *)MIPS_PHYS_TO_KSEG1(mem << PGSHIFT);
	while (cp < (char *)physmem_boardmax) {
	  	int j;
		if (badaddr(cp, 4))
			break;
		i = *(int *)cp;
		j = ((int *)cp)[4];
		*(int *)cp = 0xa5a5a5a5;
		/*
		 * Data will persist on the bus if we read it right away.
		 * Have to be tricky here.
		 */
		((int *)cp)[4] = 0x5a5a5a5a;
		wbflush();
		if (*(int *)cp != 0xa5a5a5a5)
			break;
		*(int *)cp = i;
		((int *)cp)[4] = j;
		cp += NBPG;
		mem++;
	}

	/* clear any memory error conditions possibly caused by probe */
	(*platform.bus_reset)();
	return (mem);
}

/*
 * Find out how much memory is available by using the PROM bitmap.
 */
int
memsize_bitmap(first)
	caddr_t first;
{

	panic("memsize_bitmap not implemented");
}

/*
 *  Ensure all platform vectors are always initialized.
 */
static void
unimpl_bus_reset()
{

	panic("sysconf.init didn't set bus_reset");
}

static void
unimpl_cons_init()
{

	panic("sysconf.init didn't set cons_init");
}

static int
unimpl_iointr(mask, pc, statusreg, causereg)
	u_int mask;
	u_int pc;
	u_int statusreg;
	u_int causereg;
{

	panic("sysconf.init didn't set intr");
}

static void
unimpl_intr_establish(dev, cookie, level, handler, arg)
	struct device *dev;
	void *cookie;
	int level;
	int (*handler) __P((void *));
	void *arg;
{
	panic("sysconf.init didn't set intr_establish");
}

static int
unimpl_memsize(first)
caddr_t first;
{

	panic("sysconf.init didn't set memsize");
}

static unsigned
nullwork()
{

	return (0);
}

/*
 * pmax uses standard mips1 convention, wiring FPU to hard interupt 5.
 */
#define INT_MASK_FPU	MIPS_INT_MASK_5
#define	INT_MASK_DEV	(MIPS_HARD_INT_MASK &~ MIPS_INT_MASK_5)

void
cpu_intr(status, cause, pc, ipending)
	u_int32_t status;
	u_int32_t cause;
	u_int32_t pc;
	u_int32_t ipending;
{
	extern void MachFPInterrupt __P((unsigned, unsigned, unsigned, struct frame *));

	uvmexp.intrs++;

	/* device interrupts */
	if (ipending & INT_MASK_DEV) {
		(*platform.iointr)(status, cause, pc, ipending);
	}
	/* FPU nofiticaition */
	if (ipending & INT_MASK_FPU) {
		if (!USERMODE(status))
			goto kerneltouchedFPU;
		intrcnt[FPU_INTR]++;
		/* dealfpu(status, cause, pc); */
		MachFPInterrupt(status, cause, pc, curproc->p_md.md_regs);
	}

	/* software simulated interrupt */
	if ((ipending & MIPS_SOFT_INT_MASK_1)
		    || (ssir && (status & MIPS_SOFT_INT_MASK_1))) {

#define DO_SIR(bit, fn)						\
	do {							\
		if (n & (bit)) {				\
			uvmexp.softs++;				\
			fn;					\
		}						\
	} while (0)

		unsigned n;
		n = ssir; ssir = 0;
		_clrsoftintr(MIPS_SOFT_INT_MASK_1);

		DO_SIR(SIR_NET, netintr());
#undef DO_SIR
	}

	/* 'softclock' interrupt */
	if (ipending & MIPS_SOFT_INT_MASK_0) {
		_clrsoftintr(MIPS_SOFT_INT_MASK_0);
		uvmexp.softs++;
		intrcnt[SOFTCLOCK_INTR]++;
		softclock();
	}
	return;

kerneltouchedFPU:
	panic("kernel used FPU: PC %x, CR %x, SR %x", pc, cause, status);
}

/*
 * Return the best possible estimate of the time in the timeval to
 * which tvp points.  We guarantee that the time will be greater than
 * the value obtained by a previous call.  Some models of DECstations
 * provide a high resolution timer circuit.
 */
void
microtime(tvp)
	struct timeval *tvp;
{
	int s = splclock();
	static struct timeval lasttime;

	*tvp = time;
#if (DEC_3MIN + DEC_MAXINE + DEC_3MAXPLUS) > 0
	tvp->tv_usec += (*platform.clkread)();
#endif
	if (tvp->tv_usec >= 1000000) {
		tvp->tv_usec -= 1000000;
		tvp->tv_sec++;
	}

	if (tvp->tv_sec == lasttime.tv_sec &&
	    tvp->tv_usec <= lasttime.tv_usec &&
	    (tvp->tv_usec = lasttime.tv_usec + 1) >= 1000000) {
		tvp->tv_sec++;
		tvp->tv_usec -= 1000000;
	}
	lasttime = *tvp;
	splx(s);
}

/*
 * Wait "n" microseconds. (scsi code needs this).
 */
void
delay(n)
        int n;
{

        DELAY(n);
}