ref: f0f2d452c873255dec4b3359b3f93e349be0f2c5
dir: /sys/src/9/mtx/trap.c/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "ureg.h"
#include "io.h"
#include "tos.h"
#include "../port/error.h"
static Lock vctllock;
static Vctl *vctl[256];
void
hwintrinit(void)
{
i8259init();
mpicenable(0, nil); /* 8259 interrupts are routed through MPIC intr 0 */
}
static int
hwintrenable(Vctl *v)
{
int vec, irq;
irq = v->irq;
if(BUSTYPE(v->tbdf) == BusPCI) { /* MPIC? */
if(irq > 15) {
print("intrenable: pci irq %d out of range\n", v->irq);
return -1;
}
vec = irq;
mpicenable(vec, v);
}
else {
if(irq > MaxIrqPIC) {
print("intrenable: irq %d out of range\n", v->irq);
return -1;
}
vec = irq+VectorPIC;
if(i8259enable(v) == -1)
return -1;
}
return vec;
}
static int
hwintrdisable(Vctl *v)
{
int vec, irq;
irq = v->irq;
if(BUSTYPE(v->tbdf) == BusPCI) { /* MPIC? */
if(irq > 15) {
print("intrdisable: pci irq %d out of range\n", v->irq);
return -1;
}
vec = irq;
mpicdisable(vec);
}
else {
if(irq > MaxIrqPIC) {
print("intrdisable: irq %d out of range\n", v->irq);
return -1;
}
vec = irq+VectorPIC;
if(i8259disable(irq) == -1)
return -1;
}
return vec;
}
static int
hwvecno(int irq, int tbdf)
{
if(BUSTYPE(tbdf) == BusPCI) /* MPIC? */
return irq;
else
return irq+VectorPIC;
}
void
intrenable(int irq, void (*f)(Ureg*, void*), void* a, int tbdf, char *name)
{
int vno;
Vctl *v;
if(f == nil){
print("intrenable: nil handler for %d, tbdf 0x%uX for %s\n",
irq, tbdf, name);
return;
}
v = xalloc(sizeof(Vctl));
v->isintr = 1;
v->irq = irq;
v->tbdf = tbdf;
v->f = f;
v->a = a;
strncpy(v->name, name, KNAMELEN-1);
v->name[KNAMELEN-1] = 0;
ilock(&vctllock);
vno = hwintrenable(v);
if(vno == -1){
iunlock(&vctllock);
print("intrenable: couldn't enable irq %d, tbdf 0x%uX for %s\n",
irq, tbdf, v->name);
xfree(v);
return;
}
if(vctl[vno]){
if(vctl[vno]->isr != v->isr || vctl[vno]->eoi != v->eoi)
panic("intrenable: handler: %s %s %#p %#p %#p %#p",
vctl[vno]->name, v->name,
vctl[vno]->isr, v->isr, vctl[vno]->eoi, v->eoi);
v->next = vctl[vno];
}
vctl[vno] = v;
iunlock(&vctllock);
}
void
intrdisable(int irq, void (*f)(Ureg *, void *), void *a, int tbdf, char *name)
{
Vctl **pv, *v;
int vno;
vno = hwvecno(irq, tbdf);
ilock(&vctllock);
pv = &vctl[vno];
while (*pv &&
((*pv)->irq != irq || (*pv)->tbdf != tbdf || (*pv)->f != f || (*pv)->a != a ||
strcmp((*pv)->name, name)))
pv = &((*pv)->next);
assert(*pv);
v = *pv;
*pv = (*pv)->next; /* Link out the entry */
if(vctl[vno] == nil)
hwintrdisable(v);
iunlock(&vctllock);
xfree(v);
}
void syscall(Ureg*);
void noted(Ureg*, ulong);
static void _dumpstack(Ureg*);
char *excname[] =
{
"reserved 0",
"system reset",
"machine check",
"data access",
"instruction access",
"external interrupt",
"alignment",
"program exception",
"floating-point unavailable",
"decrementer",
"reserved A",
"reserved B",
"system call",
"trace trap",
"floating point assist",
"reserved F",
"reserved 10",
"reserved 11",
"reserved 12",
"instruction address breakpoint",
"system management interrupt",
};
char *fpcause[] =
{
"inexact operation",
"division by zero",
"underflow",
"overflow",
"invalid operation",
};
char *fpexcname(Ureg*, ulong, char*);
#define FPEXPMASK 0xfff80300 /* Floating exception bits in fpscr */
char *regname[]={
"CAUSE", "SRR1",
"PC", "GOK",
"LR", "CR",
"XER", "CTR",
"R0", "R1",
"R2", "R3",
"R4", "R5",
"R6", "R7",
"R8", "R9",
"R10", "R11",
"R12", "R13",
"R14", "R15",
"R16", "R17",
"R18", "R19",
"R20", "R21",
"R22", "R23",
"R24", "R25",
"R26", "R27",
"R28", "R29",
"R30", "R31",
};
void
trap(Ureg *ureg)
{
ulong dsisr;
int ecode, user;
char buf[ERRMAX], *s;
user = kenter(ureg);
ecode = (ureg->cause >> 8) & 0xff;
if((ureg->status & MSR_RI) == 0)
print("double fault?: ecode = %d\n", ecode);
switch(ecode) {
case CEI:
intr(ureg);
preempted(0);
break;
case CDEC:
clockintr(ureg);
preempted(1);
break;
case CSYSCALL:
if(!user)
panic("syscall in kernel: srr1 0x%4.4luX", ureg->srr1);
syscall(ureg);
return; /* syscall() calls notify itself, don't do it again */
case CFPU:
if(!user || up == nil) {
dumpregs(ureg);
panic("floating point in kernel");
}
switch(up->fpstate){
case FPinit:
fprestore(&initfp);
up->fpstate = FPactive;
break;
case FPinactive:
fprestore(up->fpsave);
up->fpstate = FPactive;
break;
default:
panic("fpstate");
}
ureg->srr1 |= MSR_FP;
break;
case CISI:
faultpower(ureg, ureg->pc, 1);
break;
case CDSI:
dsisr = getdsisr();
if(dsisr & BIT(6))
faultpower(ureg, getdar(), 0);
else
faultpower(ureg, getdar(), 1);
break;
case CPROG:
if(ureg->status & (1<<19))
s = "floating point exception";
else if(ureg->status & (1<<18))
s = "illegal instruction";
else if(ureg->status & (1<<17))
s = "privileged instruction";
else
s = "undefined program exception";
if(user){
spllo();
sprint(buf, "sys: trap: %s", s);
postnote(up, 1, buf, NDebug);
break;
}
dumpregs(ureg);
panic(s);
break;
default:
if(ecode < nelem(excname) && user){
spllo();
sprint(buf, "sys: trap: %s", excname[ecode]);
postnote(up, 1, buf, NDebug);
break;
}
dumpregs(ureg);
if(ecode < nelem(excname))
panic("%s", excname[ecode]);
panic("unknown trap/intr: %d", ecode);
}
/* restoreureg must execute at high IPL */
splhi();
if(user) {
notify(ureg);
if(up->fpstate == FPinactive)
ureg->srr1 &= ~MSR_FP;
kexit(ureg);
}
}
void
faultpower(Ureg *ureg, ulong addr, int read)
{
int user, insyscall, n;
char buf[ERRMAX];
user = (ureg->srr1 & MSR_PR) != 0;
insyscall = up->insyscall;
up->insyscall = 1;
n = fault(addr, ureg->pc, read);
if(n < 0){
if(!user){
dumpregs(ureg);
panic("fault: 0x%lux", addr);
}
sprint(buf, "sys: trap: fault %s addr=0x%lux", read? "read" : "write", addr);
postnote(up, 1, buf, NDebug);
}
up->insyscall = insyscall;
}
void
sethvec(int v, void (*r)(void))
{
ulong *vp, pa, o;
vp = KADDR(v);
vp[0] = 0x7c1043a6; /* MOVW R0, SPR(SPRG0) */
vp[1] = 0x7c0802a6; /* MOVW LR, R0 */
vp[2] = 0x7c1243a6; /* MOVW R0, SPR(SPRG2) */
pa = PADDR(r);
o = pa >> 25;
if(o != 0 && o != 0x7F){
/* a branch too far */
vp[3] = (15<<26)|(pa>>16); /* MOVW $r&~0xFFFF, R0 */
vp[4] = (24<<26)|(pa&0xFFFF); /* OR $r&0xFFFF, R0 */
vp[5] = 0x7c0803a6; /* MOVW R0, LR */
vp[6] = 0x4e800021; /* BL (LR) */
}else
vp[3] = (18<<26)|(pa&0x3FFFFFC)|3; /* bla */
dcflush(vp, 8*sizeof(ulong));
}
void
trapinit(void)
{
int i;
/*
* set all exceptions to trap
*/
for(i = 0; i < 0x2000; i += 0x100)
sethvec(i, trapvec);
putmsr(getmsr() & ~MSR_IP);
}
void
intr(Ureg *ureg)
{
int vno;
Vctl *ctl, *v;
vno = mpicintack();
if(vno == 0) { /* 8259, wired through MPIC vec 0 */
vno = i8259intack();
mpiceoi(0);
}
if(vno > nelem(vctl) || (ctl = vctl[vno]) == 0) {
panic("spurious intr %d", vno);
return;
}
if(ctl->isr)
ctl->isr(vno);
for(v = ctl; v != nil; v = v->next){
if(v->f)
v->f(ureg, v->a);
}
if(ctl->eoi)
ctl->eoi(vno);
}
char*
fpexcname(Ureg *ur, ulong fpscr, char *buf)
{
int i;
char *s;
ulong fppc;
fppc = ur->pc;
s = 0;
fpscr >>= 3; /* trap enable bits */
fpscr &= (fpscr>>22); /* anded with exceptions */
for(i=0; i<5; i++)
if(fpscr & (1<<i))
s = fpcause[i];
if(s == 0)
return "no floating point exception";
sprint(buf, "%s fppc=0x%lux", s, fppc);
return buf;
}
/*
* Fill in enough of Ureg to get a stack trace, and call a function.
* Used by debugging interface rdb.
*/
static void
getpcsp(ulong *pc, ulong *sp)
{
*pc = getcallerpc(&pc);
*sp = (ulong)&pc-4;
}
void
callwithureg(void (*fn)(Ureg*))
{
Ureg ureg;
getpcsp((ulong*)&ureg.pc, (ulong*)&ureg.sp);
ureg.lr = getcallerpc(&fn);
fn(&ureg);
}
static void
_dumpstack(Ureg *ureg)
{
ulong l, sl, el, v;
int i;
l = (ulong)&l;
if(up == 0){
el = (ulong)m+BY2PG;
sl = el-KSTACK;
}
else{
el = (ulong)up;
sl = el-KSTACK;
}
if(l > el || l < sl){
el = (ulong)m+BY2PG;
sl = el-KSTACK;
}
if(l > el || l < sl)
return;
print("ktrace /kernel/path %.8lux %.8lux %.8lux\n", ureg->pc, ureg->sp, ureg->lr);
i = 0;
for(; l < el; l += 4){
v = *(ulong*)l;
if(KTZERO < v && v < (ulong)etext){
print("%.8lux=%.8lux ", l, v);
if(i++ == 4){
print("\n");
i = 0;
}
}
}
}
void
dumpstack(void)
{
callwithureg(_dumpstack);
}
void
dumpregs(Ureg *ur)
{
int i;
ulong *l;
if(up) {
print("registers for %s %ld\n", up->text, up->pid);
if((ur->srr1 & MSR_PR) == 0)
if(ur->usp < (ulong)up - KSTACK || ur->usp > (ulong)up)
print("invalid stack ptr\n");
}
else
print("registers for kernel\n");
print("dsisr\t%.8lux\tdar\t%.8lux\n", getdsisr(), getdar());
l = &ur->cause;
for(i=0; i<sizeof regname/sizeof(char*); i+=2, l+=2)
print("%s\t%.8lux\t%s\t%.8lux\n", regname[i], l[0], regname[i+1], l[1]);
}
void
kprocchild(Proc *p, void (*entry)(void))
{
p->sched.pc = (ulong)entry;
p->sched.sp = (ulong)p;
}
/*
* called in sysfile.c
*/
void
evenaddr(ulong addr)
{
if(addr & 3){
postnote(up, 1, "sys: odd address", NDebug);
error(Ebadarg);
}
}
uintptr
execregs(uintptr entry, ulong ssize, ulong nargs)
{
ulong *sp;
Ureg *ureg;
sp = (ulong*)(USTKTOP - ssize);
*--sp = nargs;
ureg = up->dbgreg;
ureg->usp = (ulong)sp;
ureg->pc = entry;
ureg->srr1 &= ~MSR_FP;
return USTKTOP-sizeof(Tos); /* address of kernel/user shared data */
}
void
forkchild(Proc *p, Ureg *ur)
{
Ureg *cur;
p->sched.sp = (ulong)p - UREGSIZE;
p->sched.pc = (ulong)forkret;
cur = (Ureg*)(p->sched.sp+2*BY2WD);
memmove(cur, ur, sizeof(Ureg));
cur->r3 = 0;
}
uintptr
userpc(void)
{
Ureg *ureg;
ureg = (Ureg*)up->dbgreg;
return ureg->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* ureg, Proc* p)
{
ureg->pc = p->sched.pc;
ureg->sp = p->sched.sp+4;
}
uintptr
dbgpc(Proc *p)
{
Ureg *ureg;
ureg = p->dbgreg;
if(ureg == 0)
return 0;
return ureg->pc;
}
/*
* system calls
*/
#include "../port/systab.h"
/* TODO: make this trap a separate asm entry point, like on other RISC architectures */
void
syscall(Ureg* ureg)
{
int i;
char *e;
long ret;
ulong sp, scallnr;
m->syscall++;
up->insyscall = 1;
up->pc = ureg->pc;
scallnr = ureg->r3;
up->scallnr = ureg->r3;
spllo();
sp = ureg->usp;
up->nerrlab = 0;
ret = -1;
if(!waserror()){
if(sp<(USTKTOP-BY2PG) || sp>(USTKTOP-sizeof(Sargs)-BY2WD))
validaddr(sp, sizeof(Sargs)+BY2WD, 0);
up->s = *((Sargs*)(sp+BY2WD));
if(scallnr >= nsyscall || systab[scallnr] == nil){
postnote(up, 1, "sys: bad sys call", NDebug);
error(Ebadarg);
}
up->psstate = sysctab[scallnr];
ret = systab[scallnr](up->s.args);
poperror();
}else{
/* failure: save the error buffer for errstr */
e = up->syserrstr;
up->syserrstr = up->errstr;
up->errstr = e;
}
if(up->nerrlab){
print("bad errstack [%uld]: %d extra\n", scallnr, up->nerrlab);
print("scall %s lr =%lux\n", sysctab[scallnr], ureg->lr);
for(i = 0; i < NERR; i++)
print("sp=%lux pc=%lux\n", up->errlab[i].sp, up->errlab[i].pc);
panic("error stack");
}
up->insyscall = 0;
up->psstate = 0;
/*
* Put return value in frame. On the x86 the syscall is
* just another trap and the return value from syscall is
* ignored. On other machines the return value is put into
* the results register by caller of syscall.
*/
ureg->r3 = ret;
if(scallnr == NOTED)
noted(ureg, *(ulong*)(sp+BY2WD));
/* restoreureg must execute at high IPL */
splhi();
if(scallnr!=RFORK)
notify(ureg);
if(up->fpstate == FPinactive)
ureg->srr1 &= ~MSR_FP;
}
/*
* Call user, if necessary, with note.
* Pass user the Ureg struct and the note on his stack.
*/
int
notify(Ureg* ur)
{
ulong s, sp;
char *msg;
if(up->procctl)
procctl();
if(up->nnote == 0)
return 0;
s = spllo();
qlock(&up->debug);
msg = popnote(ur);
if(msg == nil){
qunlock(&up->debug);
splhi();
return 0;
}
sp = ur->usp & ~(BY2V-1);
sp -= sizeof(Ureg);
if(!okaddr((uintptr)up->notify, BY2WD, 0) ||
!okaddr(sp-ERRMAX-4*BY2WD, sizeof(Ureg)+ERRMAX+4*BY2WD, 1)) {
qunlock(&up->debug);
pprint("suicide: bad address or sp in notify\n");
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 -= BY2WD+ERRMAX;
memmove((char*)sp, msg, ERRMAX);
sp -= 3*BY2WD;
*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD; /* arg 2 is string */
ur->r1 = (long)up->ureg; /* arg 1 is ureg* */
((ulong*)sp)[1] = (ulong)up->ureg; /* arg 1 0(FP) is ureg* */
((ulong*)sp)[0] = 0; /* arg 0 is pc */
ur->usp = sp;
ur->pc = (ulong)up->notify;
qunlock(&up->debug);
splx(s);
return 1;
}
/*
* Return user to state before notify()
*/
void
noted(Ureg* ureg, ulong arg0)
{
Ureg *nureg;
ulong oureg, sp;
qlock(&up->debug);
if(arg0!=NRSTR && !up->notified) {
qunlock(&up->debug);
pprint("call to noted() when not notified\n");
pexit("Suicide", 0);
}
up->notified = 0;
nureg = up->ureg; /* pointer to user returned Ureg struct */
/* sanity clause */
oureg = (ulong)nureg;
if(!okaddr(oureg-BY2WD, BY2WD+sizeof(Ureg), 0)){
qunlock(&up->debug);
pprint("bad ureg in noted or call to noted when not notified\n");
pexit("Suicide", 0);
}
memmove(ureg, nureg, sizeof(Ureg));
switch(arg0){
case NCONT:
case NRSTR:
if(!okaddr(nureg->pc, 1, 0) || !okaddr(nureg->usp, BY2WD, 0)){
qunlock(&up->debug);
pprint("suicide: trap in noted\n");
pexit("Suicide", 0);
}
up->ureg = (Ureg*)(*(ulong*)(oureg-BY2WD));
qunlock(&up->debug);
break;
case NSAVE:
if(!okaddr(nureg->pc, BY2WD, 0)
|| !okaddr(nureg->usp, BY2WD, 0)){
qunlock(&up->debug);
pprint("suicide: trap in noted\n");
pexit("Suicide", 0);
}
qunlock(&up->debug);
sp = oureg-4*BY2WD-ERRMAX;
splhi();
ureg->sp = sp;
((ulong*)sp)[1] = oureg; /* arg 1 0(FP) is ureg* */
((ulong*)sp)[0] = 0; /* arg 0 is pc */
break;
default:
up->lastnote->flag = NDebug;
/* fall through */
case NDFLT:
qunlock(&up->debug);
if(up->lastnote->flag == NDebug)
pprint("suicide: %s\n", up->lastnote->msg);
pexit(up->lastnote->msg, up->lastnote->flag!=NDebug);
}
}