machdep.c

早期freebsd实现

/*
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * 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, Lawrence Berkeley Laboratory.
 *
 * 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	8.6 (Berkeley) 1/14/94
 *
 * from: $Header: machdep.c,v 1.44 93/10/31 05:28:36 torek Exp $
 */

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/map.h>
#include <sys/buf.h>
#include <sys/device.h>
#include <sys/reboot.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/clist.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/msgbuf.h>
#ifdef SYSVSHM
#include <sys/shm.h>
#endif
#include <sys/exec.h>
#include <sys/sysctl.h>

#include <machine/autoconf.h>
#include <machine/frame.h>
#include <machine/cpu.h>

#include <vm/vm_kern.h>
#include <vm/vm_page.h>

#include <sparc/sparc/asm.h>
#include <sparc/sparc/cache.h>
#include <sparc/sparc/vaddrs.h>

vm_map_t buffer_map;
extern vm_offset_t avail_end;

/*
 * Declare these as initialized data so we can patch them.
 */
int	nswbuf = 0;
#ifdef	NBUF
int	nbuf = NBUF;
#else
int	nbuf = 0;
#endif
#ifdef	BUFPAGES
int	bufpages = BUFPAGES;
#else
int	bufpages = 0;
#endif

int	physmem;

extern struct msgbuf msgbuf;
struct	msgbuf *msgbufp = &msgbuf;
int	msgbufmapped = 1;	/* message buffer is always mapped */

/*
 * safepri is a safe priority for sleep to set for a spin-wait
 * during autoconfiguration or after a panic.
 */
int   safepri = 0;

caddr_t allocsys();

/*
 * Machine-dependent startup code
 */
cpu_startup()
{
	register unsigned i;
	register caddr_t v;
	register int sz;
	int base, residual;
#ifdef DEBUG
	extern int pmapdebug;
	int opmapdebug = pmapdebug;
#endif
	vm_offset_t minaddr, maxaddr;
	vm_size_t size;

#ifdef DEBUG
	pmapdebug = 0;
#endif

	/*
	 * Good {morning,afternoon,evening,night}.
	 */
	printf(version);
	/*identifycpu();*/
	physmem = btoc(avail_end);
	printf("real mem = %d\n", avail_end);

	/*
	 * Find out how much space we need, allocate it,
	 * and then give everything true virtual addresses.
	 */
	sz = (int)allocsys((caddr_t)0);
	if ((v = (caddr_t)kmem_alloc(kernel_map, round_page(sz))) == 0)
		panic("startup: no room for tables");
	if (allocsys(v) - v != sz)
		panic("startup: table size inconsistency");

	/*
	 * Now allocate buffers proper.  They are different than the above
	 * in that they usually occupy more virtual memory than physical.
	 */
	size = MAXBSIZE * nbuf;
	buffer_map = kmem_suballoc(kernel_map, (vm_offset_t *)&buffers,
	    &maxaddr, size, TRUE);
	minaddr = (vm_offset_t)buffers;
	if (vm_map_find(buffer_map, vm_object_allocate(size), (vm_offset_t)0,
			&minaddr, size, FALSE) != KERN_SUCCESS)
		panic("startup: cannot allocate buffers");
	base = bufpages / nbuf;
	residual = bufpages % nbuf;
	for (i = 0; i < nbuf; i++) {
		vm_size_t curbufsize;
		vm_offset_t curbuf;

		/*
		 * First <residual> buffers get (base+1) physical pages
		 * allocated for them.  The rest get (base) physical pages.
		 *
		 * The rest of each buffer occupies virtual space,
		 * but has no physical memory allocated for it.
		 */
		curbuf = (vm_offset_t)buffers + i * MAXBSIZE;
		curbufsize = CLBYTES * (i < residual ? base+1 : base);
		vm_map_pageable(buffer_map, curbuf, curbuf+curbufsize, FALSE);
		vm_map_simplify(buffer_map, curbuf);
	}
	/*
	 * Allocate a submap for exec arguments.  This map effectively
	 * limits the number of processes exec'ing at any time.
	 */
	exec_map = kmem_suballoc(kernel_map, &minaddr, &maxaddr,
	    16*NCARGS, TRUE);
	/*
	 * Allocate a map for physio.  Others use a submap of the kernel
	 * map, but we want one completely separate, even though it uses
	 * the same pmap.
	 */
	phys_map = vm_map_create(kernel_pmap, DVMA_BASE, DVMA_END, 1);
	if (phys_map == NULL)
		panic("unable to create DVMA map");

	/*
	 * Finally, allocate mbuf pool.  Since mclrefcnt is an off-size
	 * we use the more space efficient malloc in place of kmem_alloc.
	 */
	mclrefcnt = (char *)malloc(NMBCLUSTERS+CLBYTES/MCLBYTES,
				   M_MBUF, M_NOWAIT);
	bzero(mclrefcnt, NMBCLUSTERS+CLBYTES/MCLBYTES);
	mb_map = kmem_suballoc(kernel_map, (vm_offset_t *)&mbutl, &maxaddr,
			       VM_MBUF_SIZE, FALSE);
	/*
	 * Initialize callouts
	 */
	callfree = callout;
	for (i = 1; i < ncallout; i++)
		callout[i-1].c_next = &callout[i];
	callout[i-1].c_next = NULL;

#ifdef DEBUG
	pmapdebug = opmapdebug;
#endif
	printf("avail mem = %d\n", ptoa(cnt.v_free_count));
	printf("using %d buffers containing %d bytes of memory\n",
		nbuf, bufpages * CLBYTES);

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

	/*
	 * Configure the system, then turn on the cache.  Should be able
	 * to do this earlier, but then esp.c fails on SS1+ boxes (??).
	 */
	configure();
	cache_enable();
}

/*
 * Allocate space for system data structures.  We are given
 * a starting virtual address and we return a final virtual
 * address; along the way we set each data structure pointer.
 *
 * You call allocsys() with 0 to find out how much space we want,
 * allocate that much and fill it with zeroes, and then call
 * allocsys() again with the correct base virtual address.
 */
caddr_t
allocsys(v)
	register caddr_t v;
{

#define	valloc(name, type, num) \
	    v = (caddr_t)(((name) = (type *)v) + (num))
	valloc(cfree, struct cblock, nclist);
	valloc(callout, struct callout, ncallout);
	valloc(swapmap, struct map, nswapmap = maxproc * 2);
#ifdef SYSVSHM
	valloc(shmsegs, struct shmid_ds, shminfo.shmmni);
#endif
	
	/*
	 * Determine how many buffers to allocate (enough to
	 * hold 5% of total physical memory, but at least 16).
	 * Allocate 1/2 as many swap buffer headers as file i/o buffers.
	 */
	if (bufpages == 0)
		bufpages = (physmem / 20) / CLSIZE;
	if (nbuf == 0) {
		nbuf = bufpages;
		if (nbuf < 16)
			nbuf = 16;
	}
	if (nswbuf == 0) {
		nswbuf = (nbuf / 2) &~ 1;	/* force even */
		if (nswbuf > 256)
			nswbuf = 256;		/* sanity */
	}
	valloc(swbuf, struct buf, nswbuf);
	valloc(buf, struct buf, nbuf);
	return (v);
}

/*
 * Set up registers on exec.
 *
 * XXX this entire mess must be fixed
 */
/* ARGSUSED */
setregs(p, entry, retval)
	register struct proc *p;
	u_long entry;
	int retval[2];
{
	register struct trapframe *tf = p->p_md.md_tf;
	register struct fpstate *fs;
	register int psr, sp;

	/*
	 * The syscall will ``return'' to npc or %g7 or %g2; set them all.
	 * Set the rest of the registers to 0 except for %o6 (stack pointer,
	 * built in exec()) and psr (retain CWP and PSR_S bits).
	 */
	psr = tf->tf_psr & (PSR_S | PSR_CWP);
	sp = tf->tf_out[6];
	if ((fs = p->p_md.md_fpstate) != NULL) {
		/*
		 * We hold an FPU state.  If we own *the* FPU chip state
		 * we must get rid of it, and the only way to do that is
		 * to save it.  In any case, get rid of our FPU state.
		 */
		if (p == fpproc) {
			savefpstate(fs);
			fpproc = NULL;
		}
		free((void *)fs, M_SUBPROC);
		p->p_md.md_fpstate = NULL;
	}
	bzero((caddr_t)tf, sizeof *tf);
	tf->tf_psr = psr;
	tf->tf_global[2] = tf->tf_global[7] = tf->tf_npc = entry & ~3;
	tf->tf_out[6] = sp;
	retval[1] = 0;
}

#ifdef DEBUG
int sigdebug = 0;
int sigpid = 0;
#define SDB_FOLLOW	0x01
#define SDB_KSTACK	0x02
#define SDB_FPSTATE	0x04
#endif

struct sigframe {
	int	sf_signo;		/* signal number */
	int	sf_code;		/* code */
#ifdef COMPAT_SUNOS
	struct	sigcontext *sf_scp;	/* points to user addr of sigcontext */
#else
	int	sf_xxx;			/* placeholder */
#endif
	int	sf_addr;		/* SunOS compat, always 0 for now */
	struct	sigcontext sf_sc;	/* actual sigcontext */
};

/*
 * machine dependent system variables.
 */
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;
{

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

	switch (name[0]) {
	default:
		return (EOPNOTSUPP);
	}
	/* NOTREACHED */
}

/*
 * Send an interrupt to process.
 */
void
sendsig(catcher, sig, mask, code)
	sig_t catcher;
	int sig, mask;
	unsigned code;
{
	register struct proc *p = curproc;
	register struct sigacts *psp = p->p_sigacts;
	register struct sigframe *fp;
	register struct trapframe *tf;
	register int addr, oonstack, oldsp, newsp;
	struct sigframe sf;
	extern char sigcode[], esigcode[];
#define	szsigcode	(esigcode - sigcode)

	tf = p->p_md.md_tf;
	oldsp = tf->tf_out[6];
	oonstack = psp->ps_sigstk.ss_flags & SA_ONSTACK;
	/*
	 * Compute new user stack addresses, subtract off
	 * one signal frame, and align.
	 */
	if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
	    (psp->ps_sigonstack & sigmask(sig))) {
		fp = (struct sigframe *)(psp->ps_sigstk.ss_base +
					 psp->ps_sigstk.ss_size);
		psp->ps_sigstk.ss_flags |= SA_ONSTACK;
	} else
		fp = (struct sigframe *)oldsp;
	fp = (struct sigframe *)((int)(fp - 1) & ~7);

#ifdef DEBUG
	if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
		printf("sendsig: %s[%d] sig %d newusp %x scp %x\n",
		    p->p_comm, p->p_pid, sig, fp, &fp->sf_sc);
#endif
	/* 
	 * Now set up the signal frame.  We build it in kernel space
	 * and then copy it out.  We probably ought to just build it
	 * directly in user space....
	 */
	sf.sf_signo = sig;
	sf.sf_code = code;
#ifdef COMPAT_SUNOS
	sf.sf_scp = &fp->sf_sc;
#endif
	sf.sf_addr = 0;			/* XXX */

	/*
	 * Build the signal context to be used by sigreturn.
	 */
	sf.sf_sc.sc_onstack = oonstack;
	sf.sf_sc.sc_mask = mask;
	sf.sf_sc.sc_sp = oldsp;
	sf.sf_sc.sc_pc = tf->tf_pc;
	sf.sf_sc.sc_npc = tf->tf_npc;
	sf.sf_sc.sc_psr = tf->tf_psr;
	sf.sf_sc.sc_g1 = tf->tf_global[1];
	sf.sf_sc.sc_o0 = tf->tf_out[0];

	/*
	 * Put the stack in a consistent state before we whack away
	 * at it.  Note that write_user_windows may just dump the
	 * registers into the pcb; we need them in the process's memory.
	 * We also need to make sure that when we start the signal handler,
	 * its %i6 (%fp), which is loaded from the newly allocated stack area,
	 * joins seamlessly with the frame it was in when the signal occurred,
	 * so that the debugger and _longjmp code can back up through it.
	 */
	newsp = (int)fp - sizeof(struct rwindow);
	write_user_windows();