#include	"u.h"
#include	"../port/lib.h"
#include	"mem.h"
#include	"dat.h"
#include	"fns.h"
#include	"ureg.h"
#include	"io.h"
#include	"../port/error.h"

void	noted(Ureg*, Ureg**, ulong);
void	rfnote(Ureg**);
void	kernfault(Ureg*, int);
void	illegal(Ureg *);
void	fen(Ureg *);

char *regname[]={
	"type",	"a0",		"a1",
	"a2",		"R0",		"R1",
	"R2",		"R3",		"R4",
	"R5",		"R6",		"R7",
	"R8",		"R9",		"R10",
	"R11",	"R12",	"R13",
	"R14",	"R15",	"R19",
	"R20",	"R21",	"R22",
	"R23",	"R24",	"R25",
	"R26",	"R27",	"R28",
	"R30",	"status",	"PC",
	"R29",	"R16",	"R17",
	"R18",
};

void
intrenable(int irq, void (*f)(Ureg*, void*), void* a, int tbdf)
{
	arch->intrenable(irq, f, a, tbdf);
}

void
trap(Ureg *ur)
{
	char buf[ERRLEN];
	int user, x;

	user = ur->status&UMODE;

	if(user){
		up = m->proc;
		up->dbgreg = ur;
		if(up && up->fpstate == FPactive) {
			up->fpstate = FPinactive;
			savefpregs(&up->fpsave);
			fpenab(0);
		}
	}
	switch ((int)ur->type) {
	case 1:	/* arith */
		fptrap(ur);
		break;
	case 2:	/* bad instr or FEN */
		illegal(ur);
		break;
	case 3:	/* intr */
		intr(ur);
		break;
	case 4:	/* memory fault */
		if(up == 0)
			kernfault(ur, (ulong)ur->a1);

		x = up->insyscall;
		up->insyscall = 1;
		spllo();
		faultalpha(ur);
		up->insyscall = x;
		break;
	case 6:	/* alignment fault */
		ur->pc -= 4;
		sprint(buf, "trap: unaligned addr 0x%lux", (ulong)ur->a0);
		fataltrap(ur, buf);
		break;
	default:	/* cannot happen */
		panic("bad trap type %d", (int)ur->type);
		break;
	}

	splhi();
	if(!user)
		return;

	notify(ur);
	if(up->fpstate == FPinactive) {
		fpenab(1);
		restfpregs(&up->fpsave);
		up->fpstate = FPactive;
	}
}

typedef struct Mcheck Mcheck;
struct Mcheck
{
	ulong	len;
	ulong	inprogress;
	ulong	procoff;
	ulong	sysoff;
	ulong	code;
};

static char *
smcheck(ulong code)
{
	switch (code) {
	case 0x80: return "tag parity error";
	case 0x82: return "tag control parity error";
	case 0x84: return "generic hard error";
	case 0x86: return "correctable ECC error";
	case 0x88: return "uncorrectable ECC error";
	case 0x8a: return "OS-specific PAL bugcheck";
	case 0x90: return "callsys in kernel mode";
	case 0x96: return "i-cache read retryable error";
	case 0x98: return "processor detected hard error";

	case 0x203: return "system detected uncorrectable ECC error";
	case 0x205: return "parity error detected by CIA";
	case 0x207: return "non-existent memory error";
	case 0x209: return "PCI SERR detected";
	case 0x20b: return "PCI data parity error detected";
	case 0x20d: return "PCI address parity error detected";
	case 0x20f: return "PCI master abort error";
	case 0x211: return "PCI target abort error";
	case 0x213: return "scatter/gather PTE invalid error";
	case 0x215: return "flash ROM write error";
	case 0x217: return "IOA timeout detected";
	case 0x219: return "IOCHK#, EISA add-in board parity or other catastrophic error";
	case 0x21b: return "EISA fail-safe timer timeout";
	case 0x21d: return "EISA bus time-out";
	case 0x21f: return "EISA software generated NMI";
	case 0x221: return "unexpected ev5 IRQ[3] interrupt";
	default: return "unknown mcheck";
	}
}

void
mcheck(void *x)
{
	Mcheck *m;
	uvlong *data;
	int i, col;

	m = x;
	data = x;
	iprint("panic: Machine Check @%lux: %s (%lux) len %d\n",
			m, smcheck(m->code), m->code, m->len);
	iprint("proc offset %lux sys offset %lux\n", m->procoff, m->sysoff);
	for (i = 0, col = 0; i < m->len/8; i++) {
		iprint("%.3lux: %.16llux%s", 8*i, data[i], (col == 2) ? "\n" : "    ");
		if (col++ == 2)
			col = 0;
	}
	firmware();
}

void
intr(Ureg *ur)
{
	m->intr++;
	switch ((int)ur->a0) {
	case 0:	/* interprocessor */
		panic("interprocessor intr");
		break;
	case 1:	/* clock */
		clock(ur);
		break;
	case 2:	/* machine check */
		mcheck((void*)(KZERO|(ulong)ur->a2));
		break;
	case 3:	/* device */
		arch->intr(ur);
		break;
	case 4:	/* perf counter */
		panic("perf count");
		break;
	default:
		panic("bad intr");
		break;
	}

	/* preemptive scheduling */
	if(up && up->state == Running && anyhigher())
		sched();
}

void
trapinit(void)
{
	splhi();
	wrent(0, intr0);
	wrent(1, arith);
	wrent(2, fault0);
	wrent(3, illegal0);
	wrent(4, unaligned);
	wrent(5, syscall0);
}

void
fataltrap(Ureg *ur, char *reason)
{
	char buf[ERRLEN];

	if(ur->status&UMODE) {
		spllo();
		sprint(buf, "sys: %s", reason);
		postnote(up, 1, buf, NDebug);
		return;
	}
	print("kernel %s pc=%lux\n", reason, (ulong)ur->pc);
	dumpregs(ur);
	dumpstack();
	if(m->machno == 0)
		spllo();
	exit(1);
}

void
kernfault(Ureg *ur, int code)
{
	Label l;
	char *s;

	splhi();
	if (code == 0)
		s = "read";
	else if (code == 1)
		s = "write";
	else
		s = "ifetch";
	print("panic: kfault %s VA=0x%lux\n", s, (ulong)ur->a0);
	print("u=0x%lux status=0x%lux pc=0x%lux sp=0x%lux\n",
				up, (ulong)ur->status, (ulong)ur->pc, (ulong)ur->sp);
	dumpregs(ur);
	l.sp = ur->sp;
	l.pc = ur->pc;
	dumpstack();
	exit(1);
}

void
dumpstack(void)
{
	ulong l, sl, el, v, i, instr, op;
	extern ulong etext;

	l=(ulong)&l;
	if(l&4)
		l += 4;
	if(up == 0){
		el = (ulong)m+BY2PG;
		sl = el-KSTACK;
	}
	else{
		sl = (ulong)up->kstack;
		el = sl + KSTACK;
	}
	if(l > el || l < sl){
		el = (ulong)m+BY2PG;
		sl = el-KSTACK;
	}
	iprint("dumpstack: l %lux sl %lux el %lux m %lux\n", l, sl, el, m);
	if(l > el || l < sl){
		return;
	}

	i = 0;
	for(; l<el; l+=8){
		v = *(ulong*)l - 4;
		if(KTZERO < v && v < (ulong)&etext && (v&3) == 0){
			/*
			 * Check for JSR/BSR
			 */
			instr = *(ulong*)v;
			op = (instr>>26);
			if(op == 26 || op == 52){
				iprint("%lux ", v);
				i++;
			}
		}
		if(i == 8){
			i = 0;
			iprint("\n");
		}
	}
}

void
dumpregs(Ureg *ur)
{
	int i, col;
	uvlong *l;

	spllo();
	prflush(); 
	if(up)
		iprint("registers for %s %d\n", up->text, up->pid);
	else
		iprint("registers for kernel\n");

	l = &ur->type;
	col = 0;
	for (i = 0; i < sizeof regname/sizeof(char*); i++, l++) {
		iprint("%-7s%.16llux%s", regname[i], *l, col == 2 ? "\n" : "     ");
		if (col++ == 2)
			col = 0;
	}
	iprint("\n");
//	prflush();
}

int
notify(Ureg *ur)
{
	int l;
	ulong sp;
	Note *n;

	if(up->procctl)
		procctl(up);
	if(up->nnote == 0)
		return 0;

	spllo();
	qlock(&up->debug);
	up->notepending = 0;
	n = &up->note[0];
	if(strncmp(n->msg, "sys:", 4) == 0) {
		l = strlen(n->msg);
		if(l > ERRLEN-15)	/* " pc=0x12345678\0" */
			l = ERRLEN-15;

		sprint(n->msg+l, " pc=0x%lux", (ulong)ur->pc);
	}

	if(n->flag != NUser && (up->notified || up->notify==0)) {
		if(n->flag == NDebug)
			pprint("suicide: %s\n", n->msg);
		qunlock(&up->debug);
		pexit(n->msg, n->flag!=NDebug);
	}

	if(up->notified) {
		qunlock(&up->debug);
		splhi();
		return 0;
	}
		
	if(!up->notify) {
		qunlock(&up->debug);
		pexit(n->msg, n->flag!=NDebug);
	}
	sp = ur->usp & ~(BY2V-1);
	sp -= sizeof(Ureg);

	if(!okaddr((ulong)up->notify, BY2WD, 0)
	|| !okaddr(sp-ERRLEN-6*BY2WD, sizeof(Ureg)+ERRLEN-6*BY2WD, 1)) {
		pprint("suicide: bad address or sp in notify\n");
print("suicide: bad address or sp in notify\n");
		qunlock(&up->debug);
		pexit("Suicide", 0);
	}

	memmove((Ureg*)sp, ur, sizeof(Ureg));
	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */
	up->ureg = (void*)sp;
	sp -= 2*BY2WD+ERRLEN;
	memmove((char*)sp, up->note[0].msg, ERRLEN);
	sp -= 4*BY2WD;
	*(ulong*)(sp+3*BY2WD) = sp+4*BY2WD;	/* arg 2 is string */
	ur->r0 = (ulong)up->ureg;		/* arg 1 (R0) is ureg* */
	*(ulong*)(sp+2*BY2WD) = (ulong)up->ureg;	/* arg 1 0(FP) is ureg* */
	*(ulong*)(sp+0*BY2WD) = 0;		/* arg 0 is pc */
	ur->usp = sp;
	ur->pc = (ulong)up->notify;
	up->notified = 1;
	up->nnote--;
	memmove(&up->lastnote, &up->note[0], sizeof(Note));
	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

	qunlock(&up->debug);
	splhi();
	return 1;
}

/*
 * Check that status is OK to return from note.
 */
int
validstatus(ulong kstatus, ulong ustatus)
{
	if((kstatus & 7) != (ustatus & 7))
		return 0;
	if((ustatus&UMODE) != UMODE)
		return 0;
	return 1;
}

/*
 * Return user to state before notify()
 */
void
noted(Ureg *kur, Ureg **urp, ulong arg0)
{
	Ureg *nur;
	ulong oureg, sp;

	qlock(&up->debug);
	if(arg0!=NRSTR && !up->notified) {
		qunlock(&up->debug);
		pprint("call to noted() when not notified\n");
print("call to noted() when not notified\n");
		pexit("Suicide", 0);
	}
	up->notified = 0;

	nur = up->ureg;

	oureg = (ulong)nur;
	if((oureg & (BY2V-1))
	|| !okaddr((ulong)oureg-BY2WD, BY2WD+sizeof(Ureg), 0)){
		pprint("bad ureg in noted or call to noted() when not notified\n");
print("bad ureg in noted or call to noted() when not notified\n");
		qunlock(&up->debug);
		pexit("Suicide", 0);
	}

	if(!validstatus(kur->status, nur->status)) {
		qunlock(&up->debug);
		pprint("bad noted ureg status %lux\n", (ulong)nur->status);
print("bad noted ureg status %lux\n", (ulong)nur->status);
		pexit("Suicide", 0);
	}

	memmove(*urp, up->ureg, sizeof(Ureg));
	switch(arg0) {
	case NCONT:
	case NRSTR:
		if(!okaddr(nur->pc, BY2WD, 0) || !okaddr(nur->usp, BY2WD, 0)){
			pprint("suicide: trap in noted\n");
print("suicide: trap in noted\n");
			qunlock(&up->debug);
			pexit("Suicide", 0);
		}
		up->ureg = (Ureg*)(*(ulong*)(oureg-BY2WD));
		qunlock(&up->debug);
		splhi();
		rfnote(urp);
		break;

	case NSAVE:
		if(!okaddr(nur->pc, BY2WD, 0) || !okaddr(nur->usp, BY2WD, 0)){
			pprint("suicide: trap in noted\n");
print("suicide: trap in noted\n");
			qunlock(&up->debug);
			pexit("Suicide", 0);
		}
		qunlock(&up->debug);
		sp = oureg-4*BY2WD-ERRLEN;
		splhi();
		(*urp)->sp = sp;
		((ulong*)sp)[1] = oureg;	/* arg 1 0(FP) is ureg* */
		((ulong*)sp)[0] = 0;			/* arg 0 is pc */
		(*urp)->r0 = oureg;		/* arg 1 is ureg* */
		rfnote(urp);
		break;

	default:
		pprint("unknown noted arg 0x%lux\n", arg0);
print("unknown noted arg 0x%lux\n", arg0);
		up->lastnote.flag = NDebug;
		/* fall through */
		
	case NDFLT:
		if(up->lastnote.flag == NDebug)
			pprint("suicide: %s\n", up->lastnote.msg);
		qunlock(&up->debug);
		pexit(up->lastnote.msg, up->lastnote.flag!=NDebug);
	}
}

#include "../port/systab.h"

long
syscall(Ureg *aur)
{
	long ret;
	ulong sp;
	Ureg *ur;

	m->syscall++;
	up = m->proc;
	up->insyscall = 1;
	ur = aur;
	up->pc = ur->pc;
	up->dbgreg = aur;
	ur->type = 5;		/* for debugging */

	if(up->fpstate == FPactive) {
		up->fpsave.fpstatus = getfcr();
		up->fpstate = FPinit;
		fpenab(0);
	}
	spllo();

	if(up->procctl)
		procctl(up);

	up->scallnr = ur->r0;
	up->nerrlab = 0;
	sp = ur->sp;
	ret = -1;
	if(waserror())
		goto error;

	if(up->scallnr >= nsyscall){
		pprint("bad sys call %d pc %lux\n", up->scallnr, (ulong)ur->pc);
print("bad sys call %d pc %lux\n", up->scallnr, (ulong)ur->pc);
		postnote(up, 1, "sys: bad sys call", NDebug);
		error(Ebadarg);
	}

	if(sp & (BY2WD-1)){	/* XXX too weak? */
		pprint("odd sp in sys call pc %lux sp %lux\n", (ulong)ur->pc, (ulong)ur->sp);
		postnote(up, 1, "sys: odd stack", NDebug);
		error(Ebadarg);
	}

	if(sp<(USTKTOP-BY2PG) || sp>(USTKTOP-sizeof(Sargs)))
		validaddr(sp, sizeof(Sargs), 0);

	up->s = *((Sargs*)(sp+2*BY2WD));
	up->psstate = sysctab[up->scallnr];

	ret = (*systab[up->scallnr])(up->s.args);
	poperror();

error:
	up->nerrlab = 0;
	up->psstate = 0;
	up->insyscall = 0;
	if(up->scallnr == NOTED)				/* ugly hack */
		noted(ur, &aur, *(ulong*)(sp+2*BY2WD));	/* doesn't return */

	splhi();
	if(up->scallnr!=RFORK && (up->procctl || up->nnote)){
		ur->r0 = ret;				/* load up for noted() */
		if(notify(ur))
			return ur->r0;
	}

	if(up->fpstate == FPinactive)		/* due to race with intr */
		up->fpstate = FPinit;

	return ret;
}

void
forkchild(Proc *p, Ureg *ur)
{
	Ureg *cur;

	p->sched.sp = (ulong)p->kstack+KSTACK-(4*BY2WD+sizeof(Ureg));
	p->sched.pc = (ulong)forkret;

	cur = (Ureg*)(p->sched.sp+4*BY2WD);
	memmove(cur, ur, sizeof(Ureg));

	/* Things from bottom of syscall we never got to execute */
	p->psstate = 0;
	p->insyscall = 0;
}

static
void
linkproc(void)
{
	spllo();
	up->kpfun(up->kparg);
}

void
kprocchild(Proc *p, void (*func)(void*), void *arg)
{
	p->sched.pc = (ulong)linkproc;
	p->sched.sp = (ulong)p->kstack+KSTACK;

	p->kpfun = func;
	p->kparg = arg;
}

long
execregs(ulong entry, ulong ssize, ulong nargs)
{
	Ureg *ur;
	ulong *sp;

	sp = (ulong*)(USTKTOP - ssize);
	*--sp = nargs;

	ur = (Ureg*)up->dbgreg;
	ur->usp = (ulong)sp;
	ur->pc = entry;
	up->fpsave.fpstatus = initfp.fpstatus;
	return USTKTOP-BY2WD;			/* address of user-level clock */
}

ulong
userpc(void)
{
	Ureg *ur;

	ur = (Ureg*)up->dbgreg;
	return ur->pc;
}

/* This routine must save the values of registers the user is not permitted to write
 * from devproc and then restore the saved values before returning
 */
void
setregisters(Ureg *xp, char *pureg, char *uva, int n)
{
	ulong status;

	status = xp->status;
	memmove(pureg, uva, n);
	xp->status = status;
}

/* Give enough context in the ureg to produce a kernel stack for
 * a sleeping process
 */
void
setkernur(Ureg *xp, Proc *p)
{
	xp->pc = p->sched.pc;
	xp->sp = p->sched.sp;
	xp->r26 = (ulong)sched;
}

ulong
dbgpc(Proc *p)
{
	Ureg *ur;

	ur = p->dbgreg;
	if(ur == 0)
		return 0;

	return ur->pc;
}

void
illegal(Ureg *ur)
{
	switch ((int)ur->a0) {
	case 0:	/* breakpoint */
		ur->pc -= 4;
		fataltrap(ur, "breakpoint");
		break;
	case 1:	/* bugchk */
		fataltrap(ur, "trap: bugchk");
		break;
	case 2:	/* gentrap */
		fataltrap(ur, "trap: gentrap");
		break;
	case 3:	/* FEN */
		fen(ur);
		break;
	case 4:	/* opDEC */
		fataltrap(ur, "trap: illegal instruction");
		break;
	default:
		panic("illegal illegal %d", (int)ur->a0);
		break;
	}
}

void
fen(Ureg *ur)
{
	ulong fpcr;

	if ((ur->status&UMODE) && up) {
		if(up->fpstate == FPinit) {
			up->fpstate = FPactive;
			fpcr = up->fpsave.fpstatus;
			up->fpsave = initfp;
			up->fpsave.fpstatus = fpcr;
			fpenab(1);
			restfpregs(&up->fpsave);
			return;
		}
	}
	fataltrap(ur, "trap: floating enable");		/* should never happen */
}