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plan9fox/sys/src/9/xen/main.c

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#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 <tos.h>
Mach *m;
#define BOOTARGS (xenstart->cmd_line)
#define BOOTARGSLEN (sizeof xenstart->cmd_line)
#define MAXCONF 64
enum {
/* space for syscall args, return PC, top-of-stack struct */
Ustkheadroom = sizeof(Sargs) + sizeof(uintptr) + sizeof(Tos),
};
Conf conf;
char *confname[MAXCONF];
char *confval[MAXCONF];
int nconf;
uchar *sp; /* user stack of init proc */
int idle_spin;
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++;
}
}
void
main(void)
{
mach0init();
options();
ioinit();
xenconsinit();
quotefmtinstall();
//consdebug = rdb;
print("\nPlan 9 (%s)\n", xenstart->magic);
cpuidentify();
// meminit() is not for us
confinit();
archinit();
xinit();
trapinit();
printinit();
cpuidprint();
mmuinit();
if(arch->intrinit) /* launches other processors on an mp */
arch->intrinit();
timersinit();
mathinit();
kbdenable();
xengrantinit();
if(arch->clockenable)
arch->clockenable();
procinit0();
initseg();
links();
// conf.monitor = 1;
chandevreset();
pageinit();
swapinit();
userinit();
schedinit();
}
void
mach0init(void)
{
m = (Mach*)MACHADDR;
m->machno = 0;
conf.nmach = 1;
MACHP(0) = (Mach*)CPU0MACH;
m->pdb = (ulong*)xenstart->pt_base;
machinit();
active.machs[0] = 1;
active.exiting = 0;
}
void
machinit(void)
{
int machno;
ulong *pdb;
machno = m->machno;
pdb = m->pdb;
memset(m, 0, sizeof(Mach));
m->machno = machno;
m->pdb = pdb;
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;
m->cpumhz = 1000; // XXX!
HYPERVISOR_shared_info = (shared_info_t*)mmumapframe(XENSHARED, (xenstart->shared_info)>>PGSHIFT);
// XXX m->shared = &HYPERVISOR_shared_info->vcpu_data[m->machno];
}
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);
ksetenv("readparts", "1", 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);
touser(sp);
}
void
userinit(void)
{
Proc *p;
Segment *s;
KMap *k;
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
*/
s = newseg(SG_STACK, USTKTOP-USTKSIZE, USTKSIZE/BY2PG);
p->seg[SSEG] = s;
pg = newpage(1, 0, USTKTOP-BY2PG);
segpage(s, pg);
k = kmap(pg);
bootargs(VA(k));
kunmap(k);
/*
* Text
*/
s = newseg(SG_TEXT, UTZERO, 1);
s->flushme++;
p->seg[TSEG] = s;
pg = newpage(1, 0, UTZERO);
pg->txtflush = ~0;
segpage(s, pg);
k = kmap(s->map[0]->pages[0]);
memmove((ulong*)VA(k), initcode, sizeof initcode);
kunmap(k);
ready(p);
}
uchar *
pusharg(char *p)
{
int n;
n = strlen(p)+1;
sp -= n;
memmove(sp, p, n);
return sp;
}
void
bootargs(ulong base)
{
int i, ac;
uchar *av[32];
uchar **lsp;
sp = (uchar*)base + BY2PG - Ustkheadroom;
ac = 0;
av[ac++] = pusharg("boot");
av[ac++] = pusharg("-D");
/* 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) - base);
*lsp = 0;
sp += (USTKTOP - BY2PG) - 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");
memmove(BOOTARGS, p, n);
poperror();
free(p);
}
void
confinit(void)
{
char *p;
int i, userpcnt;
ulong kpages;
for(i = 0; i < nconf; i++)
print("%s=%s\n", confname[i], confval[i]);
/*
* all ram above xentop is free, but must be mappable
* to virt addrs less than VIRT_START.
*/
kpages = PADDR(hypervisor_virt_start)>>PGSHIFT;
if(xenstart->nr_pages <= kpages)
kpages = xenstart->nr_pages;
else
print("Warning: Plan 9 / Xen limitation - "
"using only %lud of %lud available RAM pages\n",
kpages, xenstart->nr_pages);
xentop = PGROUND(PADDR(xentop));
conf.mem[0].npage = kpages - (xentop>>PGSHIFT);
conf.mem[0].base = xentop;
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.
*/
if(kpages > (64*MB + conf.npage*sizeof(Page))/BY2PG){
kpages = (64*MB + conf.npage*sizeof(Page))/BY2PG;
conf.nimage = 2000;
kpages += (conf.nproc*KSTACK)/BY2PG;
}
} 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.
*/
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
mathnote(void)
{
int i;
ulong status;
char *msg, note[ERRMAX];
status = up->fpsave.status;
/*
* 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=0x%lux status=0x%lux",
msg, up->fpsave.pc, status);
postnote(up, 1, note, NDebug);
}
/*
* math coprocessor error
*/
static void
matherror(Ureg *ur, void*)
{
/*
* a write cycle to port 0xF0 clears the interrupt latch attached
* to the error# line from the 387
*/
if(!(m->cpuiddx & 0x01))
outb(0xF0, 0xFF);
/*
* save floating point state to check out error
*/
fpenv(&up->fpsave);
mathnote();
if(ur->pc & KZERO)
panic("fp: status %ux fppc=0x%lux pc=0x%lux",
up->fpsave.status, up->fpsave.pc, ur->pc);
}
/*
* math coprocessor emulation fault
*/
static void
mathemu(Ureg *ureg, void*)
{
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.
*/
if((up->fpsave.status & ~up->fpsave.control) & 0x07F){
mathnote();
break;
}
fprestore(&up->fpsave);
up->fpstate = FPactive;
break;
case FPactive:
panic("math emu pid %ld %s pc 0x%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
procfork(Proc *p)
{
int s;
p->kentry = up->kentry;
p->pcycles = -p->kentry;
/* save floating point state */
s = splhi();
switch(up->fpstate & ~FPillegal){
case FPactive:
fpsave(&up->fpsave);
up->fpstate = FPinactive;
case FPinactive:
p->fpsave = up->fpsave;
p->fpstate = FPinactive;
}
splx(s);
}
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(0);
}
void
reboot(void *entry, void *code, ulong size)
{
void (*f)(ulong, ulong, ulong);
writeconf();
cpushutdown();
splhi();
/* turn off buffered serial console */
serialoq = nil;
/* shutdown devices */
chandevshutdown();
/* reboot(0, ...) on Xen causes domU shutdown */
if(entry == 0)
HYPERVISOR_shutdown(0);
mmuflushtlb(0);
/* setup reboot trampoline function */
f = (void*)REBOOTADDR;
memmove(f, rebootcode, sizeof(rebootcode));
/* off we go - never to return */
(*f)(PADDR(entry), PADDR(code), size);
}
void
exit(int)
{
cpushutdown();
arch->reset();
}
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