machdep.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)machdep.c	4.12    ULTRIX  3/6/91";
#endif	lint
/************************************************************************
 *									*
 *			Copyright (c) 1990 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
/* ------------------------------------------------------------------ */
/* | Copyright Unpublished, MIPS Computer Systems, Inc.  All Rights | */
/* | Reserved.  This software contains proprietary and confidential | */
/* | information of MIPS and its suppliers.  Use, disclosure or     | */
/* | reproduction is prohibited without the prior express written   | */
/* | consent of MIPS.                                               | */
/* ------------------------------------------------------------------ */
/************************************************************************
 *
 *	Modification History: machdep.c
 *
 * 06-Mar-91	jaw
 *	3min ipl opt...
 *
 * 06-Nov-90 	Joe Szczypek
 *	Created char array which where bootpath will be saved.  This
 *	will be used by the network dump code during crashdumping.
 *	Also added check for tftp to getbootctlr().
 *
 * 13-Sep-90	Joe Szczypek
 *	Added support for 3max/3min TURBOchannel console callbacks.  Use
 *	rex_rex() to reboot, restart, and autoboot.  Use argv to get 
 *	bootdev if new console ROMs are present, and modified code getting
 *	"lnx" and "fzax" to use slot number instead of controller number to
 *	fetch appropriate entry from tc_slot structure.  Also added
 *	routine which will load up bootctlr for getsysinfo.
 *
 * 04-Sep-90	sekhar
 *	changes for memory mapped devices:
 *	modified useracc to disallow access to virtual addresses which 
 *	map I/O space.
 *
 * 31-Aug-90	Jim Paradis
 *	On sigreturn(), only restore the fp context if it had been
 * 	previously saved by sendsig().
 *
 * 04-Aug-90	Randall Brown
 *	Added getspl() and whatspl() routines that call the system specific
 *	routines through the cpu switch.  Added the spl_init() routine that
 *	loads the spl pointers with values from the cpu switch .
 *
 * 18-June-90 Fred L. Templin
 *	Added FZA for DS_5000. Code is running in compatibility mode.
 *
 * 15-June-90 Mark A. Parenti
 *      Moved stray() and passive_release here from vec_intr.c because
 *      vec_intr.c now gets built as Notbinary and we don't want to ship
 *      these sources.
 *
 * 6-June-90 Fred L. Templin
 *	Fixed "netbootchk()" for all LANCE and SGEC platforms
 *
 * 2-May-90 chc
 * 	Added the "ne" device for supporting the network boot 
 *
 * 24-Aprl-90 robin
 * fixed a bug in the R3000 that causes the cache isolate to fail if the 
 * write buffers are full is worked around via wbflush.  The fix is in the
 * clear_cache routines; we need to make sure the write buffers are NOT
 * full when we TRY to isolate the cache.  If the write buffer is
 * full the cache REALY is NOT isolated and every word get a zero low
 * order byte.... not good.
 *
 *
 * 29-Mar-90 gmm
 *	Changed some splhigh() to splextreme() since splhigh() now same
 *	as splclock()
 *
 * 06-Mar-90 gmm
 *	Added the routine alert_cpu() to update whichqs to ALLCPU under 
 *	lk_rq.
 *
 * 03-Mar-90 jaw
 *	primitive change to optimize mips.
 *
 * 14-Feb-90 -- gmm
 *	Avoid a race condition when starting more than one secondary 
 *	processor by switching affinity of the idle_proc to boot cpu.
 *
 * 05-Feb-90 -- dws
 *	Fixed handling of SIGCONT in sigreturn() for POSIX mode.
 *
 * 08-Dec-89 -- gmm
 *	Change the parent of the secondary's idle process to proc 0. When the
 *	idle process comes up on the secondary, it goes and removes itself 
 *	from the current parent's child queue and puts itself on proc 0's
 *	child queue.
 *
 * 14-Nov-89 -- gmm
 *	Changes to secondary_startup(), new routine init_idleproc() to start
 *	the idle process for the secondary, etc. Stop_secondary_cpu() now
 *	dumps the tlbs in core for debugging purposes.
 *
 * 09-Nov-89 -- jaw
 *	change references to maxcpu to smp.
 *
 * 26-Oct-89 -- afd
 *	for network boot, pick up network device unit number if its not 0.
 *
 * 19-Oct-89 -- jmartin
 *	Use PROT_{URKR|UW} instead of PG_{URKR|UW} as they are no longer
 *	the same thing.
 *
 * 13-Oct 89 -- gmm
 *	All MIPS specific smp changes. Changes to release_uarea_noreturn(),
 *	stop_secondary_cpu(), sig_parent_swtch(), new rotutines like intrcpu(),
 *	cpuident(), is_cpu(), secondary_startup() etc.
 *
 * 03-Oct-89 -- Joe Szczypek
 *	Changed set_lock, clear_lock, set_bit_atomic, and clear_bit_atomic
 *      to use interlocked operations if system is MP.
 *
 * 25 Jul 89 -- chet
 *	Change unmount and cache flushing code in boot()
 *
 * 24-July-89 -- Alan Frechette
 *	Moved all the crashdump code to a new file. The new file
 *	containing the crashdump code is "/sys/sys/crashdump.c".
 *
 * 18-July-89	kong
 *	Rewrote the routine useracc.  The original routine was
 *	located in usercopy.s and checks user access by reading
 *	and writing the page.  If the cache is incoherent at the
 *	time, or if DMA is going on, the contents of the buffer
 *	being probed gets corrupted.  The original routine also
 *	has the side-effect of causing paging in of pages.
 *	The new routine simply checks the protection field of the
 *	PTE to determine if access is allowed.  This is similar
 *	to the implementation on a VAX which uses the PROBEr/w instruction
 *	to check access.  
 *
 * 10-July-89	burns
 *	Added emulation for Vax crc instruction (from pmk).
 *	Added cpu switch routines for mips specific cache routines to
 *		clean_icache, clean_dcache, page_iflush and page_dflush.
 * 
 * 21-Jul-89 -- Fred Canter
 *	Conditionally include devio.h (errlog.h includes devio.h).
 *
 * 19-Jun-89 -- condylis
 *	Tightened up unmounting of file systems in boot().
 *
 * 15-Jun-1989  afd
 * 	Added cpu_initialize routine to call system specific initialization
 *	routine (for splm, intr vectors, hz, etc).
 *
 * 15-June-1989 kong
 *	Changed code in boot to work around (not fix) a panic hang,
 *	see the comments in "boot".
 *
 * 12-Jun-1989 -- gg
 *	In dumpsys() added a check for the presence dumpdev.
 *
 * 09-Jun-1989  gmm
 *	Call switch_to_idle_stack() in release_uarea_noreturn() before
 *	releasing the process's memory resources.
 *
 * 06-June-1989 robin
 *	Changed gendump to dump to the device specified in the config
 *	file as the bump device.  This applies to devices on non-boot
 *	controllers.  I also put in a routine to convert an integer to
 *	an ascii string (didn't know where to put it; its used here so 
 *	here it lives?).
 *
 * 20-Apr-1989	afd
 * 	In dumpsys(), if console is a graphics device, force printf messages
 *	directly to screen.  This is needed here for the case when we
 *	manually start the dump routine from console mode.
 *
 * 07-Apr-1989	afd
 *	Call wbflush, flush_cache, microdelay, & clock routines thru
 *	 cpu switch.
 *
 * 06-Apr-89 -- prs
 *      Added SMP accounting lock in boot().
 *
 * 28-Feb-1989  Kong
 *	Added routine "startrtclock", "ackrtclock", and "stopclocks".
 *	These routines are machine dependent and should eventually
 *	go through the  cpu switch table.
 *
 * 24-Feb-1989  Kong
 *	Added variable "Physmem" to keep track of the size of
 *	physical memory actually in the system.  This variable
 *	is used by "sizer" to generate the proper config file.
 *
 * 20-Feb-1989  Kong
 *	Added routine "badaddr".  As in VAXen, "badaddr" needs to
 *	be machine dependent because of the differences in I/O buses
 *	used.
 *
 * 13-Jan-1989	Kong
 *	Add the use of a system switch table.  From the variable "cpu"
 *	index into the system switch table to determine what system
 *	specific routine to call.
 *
 * 29-Dec-1988  afd
 *	In dumpsys(), set dumpsize BEFORE calling netdump().
 *	Otherwise, dumpsize is zero and savecore saves zero bytes.
 *
 *************************************************************************/


#include "../machine/pte.h"
#include "../machine/entrypt.h"

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/kernel.h"
#include "../h/map.h"
#include "../h/vm.h"
#include "../h/proc.h"
#include "../h/buf.h"
#include "../h/reboot.h"
#include "../h/conf.h"
#include "../h/gnode.h"
#include "../h/file.h"
#include "../h/text.h"
#include "../h/clist.h"
#include "../h/callout.h"
#include "../h/cmap.h"
#include "../h/mbuf.h"
#include "../h/mount.h"
#include "../h/errlog.h"
#ifdef QUOTA
#include "../h/quota.h"
#endif QUOTA
#include "../h/exec.h"
#include "../h/signal.h"
#include "../h/fs_types.h"
#include "../h/dump.h"

#include "../io/uba/ubavar.h"
#include "../io/tc/tc.h"

#include "../machine/cpu.h"
#include "../machine/fpu.h"
#include "../machine/reg.h"
#include "../../machine/common/cpuconf.h"

#include "../net/net/netisr.h"
#include "../h/ioctl.h"
#ifndef	DEVIO_INCLUDE
#include "../h/devio.h"
#endif	DEVIO_INCLUDE
#include "../fs/ufs/fs.h"
#include "../sas/mop.h"
#include "../h/cpudata.h"
#include "../h/ipc.h"
#include "../h/shm.h"


extern int cpu;		/* System type, value defined in system.h */
extern struct cpusw *cpup;	/* Pointer to cpusw entry for this machine*/
extern int console_magic; /* magic number of console */
char netdevice[80];

#ifdef PGINPROF
/* NOT ported to MIPS yet! */
/*
 * Return the difference (in microseconds)
 * between the  current time and a previous
 * time as represented  by the arguments.
 * If there is a pending clock interrupt
 * which has not been serviced due to high
 * ipl, return error code.
 */
vmtime(otime, olbolt, oicr)
	register int otime, olbolt, oicr;
{

	if (mfpr(ICCS)&ICCS_INT)
		return(-1);
	else
		return(((time.tv_sec-otime)*60 + lbolt-olbolt)*16667 + mfpr(ICR)-oicr);
}
#endif

/*
 * Clear registers on exec
 */
setregs(entry)
	long entry;
{
	register int i;
	register struct proc *p = u.u_procp;
	register int *rp;

	for (rp = &u.u_ar0[EF_AT]; rp < &u.u_ar0[EF_GP];)
		*rp++ = 0;
	u.u_ar0[EF_S8] = 0;
	u.u_ar0[EF_RA] = 0;
	u.u_ar0[EF_MDLO] = 0;
	u.u_ar0[EF_MDHI] = 0;
	u.u_ar0[EF_EPC] = (int)entry;
	for (rp = u.u_pcb.pcb_fpregs; rp < &u.u_pcb.pcb_fpregs[32];)
		*rp++ = 0;
	u.u_pcb.pcb_fpc_csr = 0;
	u.u_pcb.pcb_fpc_eir = 0;
	u.u_pcb.pcb_ownedfp = 0;
	u.u_pcb.pcb_sstep = 0;
	u.u_pcb.pcb_ssi.ssi_cnt = 0;
}

#define	R_ZERO	0
#define	R_AT	1
#define	R_V0	2
#define	R_A0	4
#define	R_A1	5
#define	R_A2	6
#define	R_A3	7
#define	R_SP	29

/*
 * Send an interrupt to process.
 *
 * Stack is set up to allow sigcode in libc
 * to call user signal handling routine, followed by syscall
 * to sigreturn routine below.  After sigreturn
 * restores critcal registers, resets the signal mask and the
 * stack, it returns to user mode.
 */

#define	STACK_ALIGN(x)	((unsigned)(x) &~ ((4*sizeof(int))-1))

sendsig(p, sig, signalmask)
int (*p)(), sig, signalmask;
{
	register struct sigcontext *scp;
	register int *srp;
	register u_int *urp;
	register int *frp;
	int oonstack;

	XPRINTF(XPR_SIGNAL,"enter sendsig %d, 0x%x",sig,signalmask,0,0);
	oonstack = u.u_onstack;

	/*
	 * decide which stack signal is to be taken on, and make
	 * sure its aligned and accessable.
	 */
	if (!u.u_onstack && (u.u_sigonstack & sigmask(sig))) {
		scp = (struct sigcontext *)STACK_ALIGN(u.u_sigsp) - 1;
		u.u_onstack = 1;
	} else
		scp = (struct sigcontext *)STACK_ALIGN(USER_REG(EF_SP)) - 1;

	if (!u.u_onstack && (int)scp <= USRSTACK - ctob(u.u_ssize))
		grow((unsigned)scp);
	if (!useracc((caddr_t)scp, sizeof (struct sigcontext), B_WRITE))
		goto bad;

	/*
	 * Save into the sigcontext the signal state and that portion
	 * of process state that we trash in order to transfer control
	 * to the signal trampoline code.
	 * The remainder of the process state is preserved by
	 * signal trampoline code that runs in user mode.
	 */
	scp->sc_onstack = oonstack;
	scp->sc_mask = signalmask;
	scp->sc_pc = USER_REG(EF_EPC);
	scp->sc_regs[R_V0] = USER_REG(EF_V0);
	scp->sc_regs[R_A0] = USER_REG(EF_A0);
	scp->sc_regs[R_A1] = USER_REG(EF_A1);
	scp->sc_regs[R_A2] = USER_REG(EF_A2);
	scp->sc_regs[R_A3] = USER_REG(EF_A3);
	scp->sc_regs[R_SP] = USER_REG(EF_SP);

	/*
	 * if this process has ever used the fp coprocessor, save
	 * its state into the sigcontext
	 */
	scp->sc_ownedfp = u.u_pcb.pcb_ownedfp;
	if (u.u_pcb.pcb_ownedfp) {
		checkfp(u.u_procp, 0);	/* dump fp to pcb */
		for (srp = &scp->sc_fpregs[0], frp = u.u_pcb.pcb_fpregs;
		    frp < &u.u_pcb.pcb_fpregs[32]; srp++, frp++)
			*srp = *frp;
		scp->sc_fpc_csr = u.u_pcb.pcb_fpc_csr;
		scp->sc_fpc_eir = u.u_pcb.pcb_fpc_eir;
		u.u_pcb.pcb_fpc_csr &= ~FPCSR_EXCEPTIONS;
	}
	scp->sc_cause = USER_REG(EF_CAUSE);
	scp->sc_badvaddr = USER_REG(EF_BADVADDR);

	/*
	 * setup registers to enter signal handler
	 * when resuming user process
	 */
	USER_REG(EF_A0) = sig;
	if (sig == SIGFPE || sig == SIGSEGV || sig == SIGILL ||
	    sig == SIGBUS || sig == SIGTRAP) {
		USER_REG(EF_A1) = u.u_code;
		u.u_code = 0;
	} else
		USER_REG(EF_A1) = 0;
	USER_REG(EF_A2) = (unsigned)scp;
	USER_REG(EF_A3) = (unsigned)p;
	USER_REG(EF_SP) = STACK_ALIGN(scp);
	USER_REG(EF_EPC) = (unsigned)u.u_sigtramp;
	XPRINTF(XPR_SIGNAL,"exit sendsig %d, 0x%x",sig,signalmask,0,0);
	return;

bad:
	uprintf("sendsig: can't grow stack, pid %d, proc %s\n", 
		u.u_procp->p_pid, u.u_comm);
	/*
	 * Process has trashed its stack; give it an illegal
	 * instruction to halt it in its tracks.
	 */
	u.u_signal[SIGILL] = SIG_DFL;
	sig = sigmask(SIGILL);
	u.u_procp->p_sigignore &= ~sig;
	u.u_procp->p_sigcatch &= ~sig;
	u.u_procp->p_sigmask &= ~sig;
	psignal(u.u_procp, SIGILL);
}

/*
 * Routine to cleanup state after a signal
 * has been taken.  Reset signal mask and
 * stack state from context left by sendsig (above).
 */
sigreturn()
{
	register int *srp;
	register u_int *urp;
	register int *frp;
	struct a {
		struct sigcontext *sigcontextp;
	} *uap = (struct a *)u.u_ap;
	register struct sigcontext *scp;

	scp = uap->sigcontextp;
	if (!useracc((caddr_t)scp, sizeof (*scp), B_READ))
		return;
	u.u_eosys = FULLRESTORE;
	u.u_onstack = scp->sc_onstack & 01;
	if (u.u_procp->p_progenv == A_POSIX) u.u_procp->p_sigmask = 
		scp->sc_mask &~ (sigmask(SIGKILL)|sigmask(SIGSTOP));
	else	u.u_procp->p_sigmask = 
		scp->sc_mask &~ (sigmask(SIGKILL)|sigmask(SIGCONT)|sigmask(SIGSTOP));
	/*
	 * copy entire user process state from sigcontext into
	 * exception frame, a special exit from syscall insures
	 * that the entire exception frame gets restored
	 */