Subversion Repositories planix.SVN

#include	"u.h"

#include	"../port/lib.h"

#include	"mem.h"

#include	"dat.h"

#include	"fns.h"

#include	"io.h"

#include	"ureg.h"

#include	"init.h"

#include	"pool.h"

#include	"reboot.h"

#include	"mp.h"

#include	<tos.h>

Mach *m;

/*

 * Where configuration info is left for the loaded programme.

 * This will turn into a structure as more is done by the boot loader

 * (e.g. why parse the .ini file twice?).

 * There are 3584 bytes available at CONFADDR.

 */

#define BOOTLINE	((char*)CONFADDR)

#define BOOTLINELEN	64

#define BOOTARGS	((char*)(CONFADDR+BOOTLINELEN))

#define	BOOTARGSLEN	(4096-0x200-BOOTLINELEN)

#define	MAXCONF		64

enum {

	/* space for syscall args, return PC, top-of-stack struct */

	Ustkheadroom	= sizeof(Sargs) + sizeof(uintptr) + sizeof(Tos),

};

char bootdisk[KNAMELEN];

Conf conf;

char *confname[MAXCONF];

char *confval[MAXCONF];

int nconf;

uchar *sp;	/* user stack of init proc */

int delaylink;

int idle_spin, idle_if_nproc;

static void

options(void)

{

	long i, n;

	char *cp, *line[MAXCONF], *p, *q;

	/*

	 *  parse configuration args from dos file plan9.ini

	 */

	cp = BOOTARGS;	/* where b.com leaves its config */

	cp[BOOTARGSLEN-1] = 0;

	/*

	 * Strip out '\r', change '\t' -> ' '.

	 */

	p = cp;

	for(q = cp; *q; q++){

		if(*q == '\r')

			continue;

		if(*q == '\t')

			*q = ' ';

		*p++ = *q;

	}

	*p = 0;

	n = getfields(cp, line, MAXCONF, 1, "\n");

	for(i = 0; i < n; i++){

		if(*line[i] == '#')

			continue;

		cp = strchr(line[i], '=');

		if(cp == nil)

			continue;

		*cp++ = '\0';

		confname[nconf] = line[i];

		confval[nconf] = cp;

		nconf++;

	}

}

extern void mmuinit0(void);

extern void (*i8237alloc)(void);

void

fpsavealloc(void)

{

	m->fpsavalign = mallocalign(sizeof(FPssestate), FPalign, 0, 0);

	if (m->fpsavalign == nil)

		panic("cpu%d: can't allocate fpsavalign", m->machno);

}

static int

isa20on(void)

{

	int r;

	ulong o;

	ulong *zp, *mb1p;

	zp = (ulong *)KZERO;

	mb1p = (ulong *)(KZERO|MB);

	o = *zp;

	*zp = 0x1234;

	*mb1p = 0x8765;

	coherence();

	wbinvd();

	r = *zp != *mb1p;

	*zp = o;

	return r;

}

void

main(void)

{

	cgapost(0);

	mach0init();

	options();

	ioinit();

	i8250console();

	quotefmtinstall();

	screeninit();

	print("\nPlan 9\n");

	trapinit0();

	mmuinit0();

	kbdinit();

	i8253init();

	cpuidentify();

	meminit();

	confinit();

	archinit();

	if(!isa20on())

		panic("bootstrap didn't leave a20 address line enabled");

	xinit();

	if(i8237alloc != nil)

		i8237alloc();

	trapinit();

	printinit();

	cpuidprint();

	mmuinit();

	fpsavealloc();

	if(arch->intrinit)	/* launches other processors on an mp */

		arch->intrinit();

	timersinit();

	mathinit();

	kbdenable();

	if(arch->clockenable)

		arch->clockenable();

	procinit0();

	initseg();

	if(delaylink){

		bootlinks();

		pcimatch(0, 0, 0);

	}else

		links();

	conf.monitor = 1;

	chandevreset();

	cgapost(0xcd);

	pageinit();

	i8253link();

	swapinit();

	userinit();

	active.thunderbirdsarego = 1;

	cgapost(0x99);

	schedinit();

}

void

mach0init(void)

{

	conf.nmach = 1;

	MACHP(0) = (Mach*)CPU0MACH;

	m->pdb = (ulong*)CPU0PDB;

	m->gdt = (Segdesc*)CPU0GDT;

	machinit();

	active.machs = 1;

	active.exiting = 0;

}

void

machinit(void)

{

	int machno;

	ulong *pdb;

	Segdesc *gdt;

	machno = m->machno;

	pdb = m->pdb;

	gdt = m->gdt;

	memset(m, 0, sizeof(Mach));

	m->machno = machno;

	m->pdb = pdb;

	m->gdt = gdt;

	m->perf.period = 1;

	/*

	 * For polled uart output at boot, need

	 * a default delay constant. 100000 should

	 * be enough for a while. Cpuidentify will

	 * calculate the real value later.

	 */

	m->loopconst = 100000;

}

void

init0(void)

{

	int i;

	char buf[2*KNAMELEN];

	up->nerrlab = 0;

	spllo();

	/*

	 * These are o.k. because rootinit is null.

	 * Then early kproc's will have a root and dot.

	 */

	up->slash = namec("#/", Atodir, 0, 0);

	pathclose(up->slash->path);

	up->slash->path = newpath("/");

	up->dot = cclone(up->slash);

	chandevinit();

	if(!waserror()){

		snprint(buf, sizeof(buf), "%s %s", arch->id, conffile);

		ksetenv("terminal", buf, 0);

		ksetenv("cputype", "386", 0);

		if(cpuserver)

			ksetenv("service", "cpu", 0);

		else

			ksetenv("service", "terminal", 0);

		for(i = 0; i < nconf; i++){

			if(confname[i][0] != '*')

				ksetenv(confname[i], confval[i], 0);

			ksetenv(confname[i], confval[i], 1);

		}

		poperror();

	}

	kproc("alarm", alarmkproc, 0);

	cgapost(0x9);

	touser(sp);

}

void

userinit(void)

{

	void *v;

	Proc *p;

	Segment *s;

	Page *pg;

	p = newproc();

	p->pgrp = newpgrp();

	p->egrp = smalloc(sizeof(Egrp));

	p->egrp->ref = 1;

	p->fgrp = dupfgrp(nil);

	p->rgrp = newrgrp();

	p->procmode = 0640;

	kstrdup(&eve, "");

	kstrdup(&p->text, "*init*");

	kstrdup(&p->user, eve);

	p->fpstate = FPinit;

	fpoff();

	/*

	 * Kernel Stack

	 *

	 * N.B. make sure there's enough space for syscall to check

	 *	for valid args and 

	 *	4 bytes for gotolabel's return PC

	 */

	p->sched.pc = (ulong)init0;

	p->sched.sp = (ulong)p->kstack+KSTACK-(sizeof(Sargs)+BY2WD);

	/*

	 * User Stack

	 *

	 * N.B. cannot call newpage() with clear=1, because pc kmap

	 * requires up != nil.  use tmpmap instead.

	 */

	s = newseg(SG_STACK, USTKTOP-USTKSIZE, USTKSIZE/BY2PG);

	p->seg[SSEG] = s;

	pg = newpage(0, 0, USTKTOP-BY2PG);

	v = tmpmap(pg);

	memset(v, 0, BY2PG);

	segpage(s, pg);

	bootargs(v);

	tmpunmap(v);

	/*

	 * Text

	 */

	s = newseg(SG_TEXT, UTZERO, 1);

	s->flushme++;

	p->seg[TSEG] = s;

	pg = newpage(0, 0, UTZERO);

	memset(pg->cachectl, PG_TXTFLUSH, sizeof(pg->cachectl));

	segpage(s, pg);

	v = tmpmap(pg);

	memset(v, 0, BY2PG);

	memmove(v, initcode, sizeof initcode);

	tmpunmap(v);

	ready(p);

}

uchar *

pusharg(char *p)

{

	int n;

	n = strlen(p)+1;

	sp -= n;

	memmove(sp, p, n);

	return sp;

}

void

bootargs(void *base)

{

 	int i, ac;

	uchar *av[32];

	uchar **lsp;

	char *cp = BOOTLINE;

	char buf[64];

	sp = (uchar*)base + BY2PG - Ustkheadroom;

	ac = 0;

	av[ac++] = pusharg("/386/9dos");

	/* when boot is changed to only use rc, this code can go away */

	cp[BOOTLINELEN-1] = 0;

	buf[0] = 0;

	if(strncmp(cp, "fd", 2) == 0){

		snprint(buf, sizeof buf, "local!#f/fd%lddisk",

			strtol(cp+2, 0, 0));

		av[ac++] = pusharg(buf);

	} else if(strncmp(cp, "sd", 2) == 0){

		snprint(buf, sizeof buf, "local!#S/sd%c%c/fs", *(cp+2), *(cp+3));

		av[ac++] = pusharg(buf);

	} else if(strncmp(cp, "ether", 5) == 0)

		av[ac++] = pusharg("-n");

	/* 4 byte word align stack */

	sp = (uchar*)((ulong)sp & ~3);

	/* build argc, argv on stack */

	sp -= (ac+1)*sizeof(sp);

	lsp = (uchar**)sp;

	for(i = 0; i < ac; i++)

		*lsp++ = av[i] + ((USTKTOP - BY2PG) - (ulong)base);

	*lsp = 0;

	sp += (USTKTOP - BY2PG) - (ulong)base - sizeof(ulong);

}

char*

getconf(char *name)

{

	int i;

	for(i = 0; i < nconf; i++)

		if(cistrcmp(confname[i], name) == 0)

			return confval[i];

	return 0;

}

static void

writeconf(void)

{

	char *p, *q;

	int n;

	p = getconfenv();

	if(waserror()) {

		free(p);

		nexterror();

	}

	/* convert to name=value\n format */

	for(q=p; *q; q++) {

		q += strlen(q);

		*q = '=';

		q += strlen(q);

		*q = '\n';

	}

	n = q - p + 1;

	if(n >= BOOTARGSLEN)

		error("kernel configuration too large");

	memset(BOOTLINE, 0, BOOTLINELEN);

	memmove(BOOTARGS, p, n);

	poperror();

	free(p);

}

void

confinit(void)

{

	char *p;

	int i, userpcnt;

	unsigned mb;

	ulong kpages, ksize;

	if(p = getconf("*kernelpercent"))

		userpcnt = 100 - strtol(p, 0, 0);

	else

		userpcnt = 0;

	conf.npage = 0;

	for(i=0; i<nelem(conf.mem); i++)

		conf.npage += conf.mem[i].npage;

	conf.nproc = 100 + ((conf.npage*BY2PG)/MB)*5;

	if(cpuserver)

		conf.nproc *= 3;

	if(conf.nproc > 2000)

		conf.nproc = 2000;

	conf.nimage = 200;

	conf.nswap = conf.nproc*80;

	conf.nswppo = 4096;

	if(cpuserver) {

		if(userpcnt < 10)

			userpcnt = 70;

		kpages = conf.npage - (conf.npage*userpcnt)/100;

		/*

		 * Hack for the big boys. Only good while physmem < 4GB.

		 * Give the kernel fixed max + enough to allocate the

		 * page pool.

		 * This is an overestimate as conf.upages < conf.npages.

		 * The patch of nimage is a band-aid, scanning the whole

		 * page list in imagereclaim just takes too long.

		 */

		for (mb = 400; mb >= 100; mb /= 2) {

			ksize = mb*MB + conf.npage*sizeof(Page);

			if(kpages > ksize/BY2PG && cankaddr(ksize)) {

				kpages = ksize/BY2PG + (conf.nproc*KSTACK)/BY2PG;

				conf.nimage = 2000;

				break;

			}

		}

	} else {

		if(userpcnt < 10) {

			if(conf.npage*BY2PG < 16*MB)

				userpcnt = 40;

			else

				userpcnt = 60;

		}

		kpages = conf.npage - (conf.npage*userpcnt)/100;

		/*

		 * Make sure terminals with low memory get at least

		 * 4MB on the first Image chunk allocation.

		 */

		if(conf.npage*BY2PG < 16*MB)

			imagmem->minarena = 4*1024*1024;

	}

	/*

	 * can't go past the end of virtual memory

	 * (ulong)-KZERO is 2^32 - KZERO

	 */

	if(kpages > ((ulong)-KZERO)/BY2PG)

		kpages = ((ulong)-KZERO)/BY2PG;

	conf.upages = conf.npage - kpages;

	conf.ialloc = (kpages/2)*BY2PG;

	/*

	 * Guess how much is taken by the large permanent

	 * datastructures. Mntcache and Mntrpc are not accounted for

	 * (probably ~300KB).

	 */

	kpages *= BY2PG;

	kpages -= conf.upages*sizeof(Page)

		+ conf.nproc*sizeof(Proc)

		+ conf.nimage*sizeof(Image)

		+ conf.nswap

		+ conf.nswppo*sizeof(Page);

	mainmem->maxsize = kpages;

	if(!cpuserver){

		/*

		 * give terminals lots of image memory, too; the dynamic

		 * allocation will balance the load properly, hopefully.

		 * be careful with 32-bit overflow.

		 */

		imagmem->maxsize = kpages;

	}

}

static char* mathmsg[] =

{

	nil,	/* handled below */

	"denormalized operand",

	"division by zero",

	"numeric overflow",

	"numeric underflow",

	"precision loss",

};

static void

mathstate(ulong *stsp, ulong *pcp, ulong *ctlp)

{

	ulong sts, fpc, ctl;

	FPsave *f = &up->fpsave;

	if(fpsave == fpx87save){

		sts = f->status;

		fpc = f->pc;

		ctl = f->control;

	} else {

		sts = f->fsw;

		fpc = f->fpuip;

		ctl = f->fcw;

	}

	if(stsp)

		*stsp = sts;

	if(pcp)

		*pcp = fpc;

	if(ctlp)

		*ctlp = ctl;

}

static void

mathnote(void)

{

	int i;

	ulong status, pc;

	char *msg, note[ERRMAX];

	mathstate(&status, &pc, nil);

	/*

	 * Some attention should probably be paid here to the

	 * exception masks and error summary.

	 */

	msg = "unknown exception";

	for(i = 1; i <= 5; i++){

		if(!((1<<i) & status))

			continue;

		msg = mathmsg[i];

		break;

	}

	if(status & 0x01){

		if(status & 0x40){

			if(status & 0x200)

				msg = "stack overflow";

			else

				msg = "stack underflow";

		}else

			msg = "invalid operation";

	}

	snprint(note, sizeof note, "sys: fp: %s fppc=%#lux status=%#lux",

		msg, pc, status);

	postnote(up, 1, note, NDebug);

}

/*

 * sse fp save and restore buffers have to be 16-byte (FPalign) aligned,

 * so we shuffle the data down as needed or make copies.

 */

void

fpssesave(FPsave *fps)

{

	FPsave *afps;

	fps->magic = 0x1234;

	afps = (FPsave *)ROUND(((uintptr)fps), FPalign);

	fpssesave0(afps);

	if (fps != afps)  /* not aligned? shuffle down from aligned buffer */

		memmove(fps, afps, sizeof(FPssestate));

	if (fps->magic != 0x1234)

		print("fpssesave: magic corrupted\n");

}

void

fpsserestore(FPsave *fps)

{

	FPsave *afps;

	fps->magic = 0x4321;

	afps = (FPsave *)ROUND(((uintptr)fps), FPalign);

	if (fps != afps) {

		afps = m->fpsavalign;

		memmove(afps, fps, sizeof(FPssestate));	/* make aligned copy */

	}

	fpsserestore0(afps);

	if (fps->magic != 0x4321)

		print("fpsserestore: magic corrupted\n");

}

/*

 *  math coprocessor error

 */

static void

matherror(Ureg *ur, void*)

{

	ulong status, pc;

	/*

	 *  a write cycle to port 0xF0 clears the interrupt latch attached

	 *  to the error# line from the 387

	 */

	if(!(m->cpuiddx & Fpuonchip))

		outb(0xF0, 0xFF);

	/*

	 *  save floating point state to check out error

	 */

	fpenv(&up->fpsave);	/* result ignored, but masks fp exceptions */

	fpsave(&up->fpsave);		/* also turns fpu off */

	fpon();

	mathnote();

	if((ur->pc & 0xf0000000) == KZERO){

		mathstate(&status, &pc, nil);

		panic("fp: status %#lux fppc=%#lux pc=%#lux", status, pc, ur->pc);

	}

}

/*

 *  math coprocessor emulation fault

 */

static void

mathemu(Ureg *ureg, void*)

{

	ulong status, control;

	if(up->fpstate & FPillegal){

		/* someone did floating point in a note handler */

		postnote(up, 1, "sys: floating point in note handler", NDebug);

		return;

	}

	switch(up->fpstate){

	case FPinit:

		fpinit();

		up->fpstate = FPactive;

		break;

	case FPinactive:

		/*

		 * Before restoring the state, check for any pending

		 * exceptions, there's no way to restore the state without

		 * generating an unmasked exception.

		 * More attention should probably be paid here to the

		 * exception masks and error summary.

		 */

		mathstate(&status, nil, &control);

		if((status & ~control) & 0x07F){

			mathnote();

			break;

		}

		fprestore(&up->fpsave);

		up->fpstate = FPactive;

		break;

	case FPactive:

		panic("math emu pid %ld %s pc %#lux",

			up->pid, up->text, ureg->pc);

		break;

	}

}

/*

 *  math coprocessor segment overrun

 */

static void

mathover(Ureg*, void*)

{

	pexit("math overrun", 0);

}

void

mathinit(void)

{

	trapenable(VectorCERR, matherror, 0, "matherror");

	if(X86FAMILY(m->cpuidax) == 3)

		intrenable(IrqIRQ13, matherror, 0, BUSUNKNOWN, "matherror");

	trapenable(VectorCNA, mathemu, 0, "mathemu");

	trapenable(VectorCSO, mathover, 0, "mathover");

}

/*

 *  set up floating point for a new process

 */

void

procsetup(Proc*p)

{

	p->fpstate = FPinit;

	fpoff();

}

void

procrestore(Proc *p)

{

	uvlong t;

	if(p->kp)

		return;

	cycles(&t);

	p->pcycles -= t;

}

/*

 *  Save the mach dependent part of the process state.

 */

void

procsave(Proc *p)

{

	uvlong t;

	cycles(&t);

	p->pcycles += t;

	if(p->fpstate == FPactive){

		if(p->state == Moribund)

			fpclear();

		else{

			/*

			 * Fpsave() stores without handling pending

			 * unmasked exeptions. Postnote() can't be called

			 * here as sleep() already has up->rlock, so

			 * the handling of pending exceptions is delayed

			 * until the process runs again and generates an

			 * emulation fault to activate the FPU.

			 */

			fpsave(&p->fpsave);

		}

		p->fpstate = FPinactive;

	}

	/*

	 * While this processor is in the scheduler, the process could run

	 * on another processor and exit, returning the page tables to

	 * the free list where they could be reallocated and overwritten.

	 * When this processor eventually has to get an entry from the

	 * trashed page tables it will crash.

	 *

	 * If there's only one processor, this can't happen.

	 * You might think it would be a win not to do this in that case,

	 * especially on VMware, but it turns out not to matter.

	 */

	mmuflushtlb(PADDR(m->pdb));

}

static void

shutdown(int ispanic)

{

	int ms, once;

	lock(&active);

	if(ispanic)

		active.ispanic = ispanic;

	else if(m->machno == 0 && (active.machs & (1<<m->machno)) == 0)

		active.ispanic = 0;

	once = active.machs & (1<<m->machno);

	/*

	 * setting exiting will make hzclock() on each processor call exit(0),

	 * which calls shutdown(0) and arch->reset(), which on mp systems is

	 * mpshutdown, which idles non-bootstrap cpus and returns on bootstrap

	 * processors (to permit a reboot).  clearing our bit in machs avoids

	 * calling exit(0) from hzclock() on this processor.

	 */

	active.machs &= ~(1<<m->machno);

	active.exiting = 1;

	unlock(&active);

	if(once)

		iprint("cpu%d: exiting\n", m->machno);

	/* wait for any other processors to shutdown */

	spllo();

	for(ms = 5*1000; ms > 0; ms -= TK2MS(2)){

		delay(TK2MS(2));

		if(active.machs == 0 && consactive() == 0)

			break;

	}

	if(active.ispanic){

		if(!cpuserver)

			for(;;)

				halt();

		if(getconf("*debug"))

			delay(5*60*1000);

		else

			delay(10000);

	}else

		delay(1000);

}

void

reboot(void *entry, void *code, ulong size)

{

	void (*f)(ulong, ulong, ulong);

	ulong *pdb;

	writeconf();

	/*

	 * the boot processor is cpu0.  execute this function on it

	 * so that the new kernel has the same cpu0.  this only matters

	 * because the hardware has a notion of which processor was the

	 * boot processor and we look at it at start up.

	 */

	if (m->machno != 0) {

		procwired(up, 0);

		sched();

	}

	if(conf.nmach > 1) {

		/*

		 * the other cpus could be holding locks that will never get

		 * released (e.g., in the print path) if we put them into

		 * reset now, so force them to shutdown gracefully first.

		 */

		lock(&active);

		active.rebooting = 1;

		unlock(&active);

		shutdown(0);

		if(arch->resetothers)

			arch->resetothers();

		delay(20);

	}

	/*

	 * should be the only processor running now

	 */

	active.machs = 0;

	if (m->machno != 0)

		print("on cpu%d (not 0)!\n", m->machno);

	print("shutting down...\n");

	delay(200);

	splhi();

	/* turn off buffered serial console */

	serialoq = nil;

	/* shutdown devices */

	chandevshutdown();

	arch->introff();

	/*

	 * Modify the machine page table to directly map the low 4MB of memory

	 * This allows the reboot code to turn off the page mapping

	 */

	pdb = m->pdb;

	pdb[PDX(0)] = pdb[PDX(KZERO)];

	mmuflushtlb(PADDR(pdb));

	/* setup reboot trampoline function */

	f = (void*)REBOOTADDR;

	memmove(f, rebootcode, sizeof(rebootcode));

	print("rebooting...\n");

	/* off we go - never to return */

	coherence();

	(*f)(PADDR(entry), PADDR(code), size);

}