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

#include "init.h"
#include <pool.h>
#include <tos.h>

#include "arm.h"
#include "reboot.h"

/*
 * 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 BOOTARGS        ((char*)CONFADDR)
#define BOOTARGSLEN     (16*KiB)                /* limit in devenv.c */
#define MAXCONF         64
#define MAXCONFLINE     160

enum {
        Minmem  = 256*MB,                       /* conservative default */

        /* space for syscall args, return PC, top-of-stack struct */
        Ustkheadroom    = sizeof(Sargs) + sizeof(uintptr) + sizeof(Tos),
};

#define isascii(c) ((uchar)(c) > 0 && (uchar)(c) < 0177)

extern char bdata[], edata[], end[], etext[];

uintptr kseg0 = KZERO;
Mach* machaddr[MAXMACH];
uchar *l2pages;

Memcache cachel[8];             /* arm arch v7 supports 1-7 */
/*
 * these are used by the cache.v7.s routines.
 */
Lowmemcache *cacheconf;

/*
 * Option arguments from the command line.
 * oargv[0] is the boot file.
 * Optionsinit() is called from multiboot()
 * or some other machine-dependent place
 * to set it all up.
 */
static int oargc;
static char* oargv[20];
static char oargb[128];
static int oargblen;
static char oenv[4096];

static uintptr sp;              /* XXX - must go - user stack of init proc */

int vflag;
int normalprint;
char debug[256];

static Lock testlock;

/* store plan9.ini contents here at least until we stash them in #ec */
static char confname[MAXCONF][KNAMELEN];
static char confval[MAXCONF][MAXCONFLINE];
static int nconf;

static int
findconf(char *name)
{
        int i;

        for(i = 0; i < nconf; i++)
                if(cistrcmp(confname[i], name) == 0)
                        return i;
        return -1;
}

char*
getconf(char *name)
{
        int i;

        i = findconf(name);
        if(i >= 0)
                return confval[i];
        return nil;
}

void
addconf(char *name, char *val)
{
        int i;

        i = findconf(name);
        if(i < 0){
                if(val == nil || nconf >= MAXCONF)
                        return;
                i = nconf++;
                strecpy(confname[i], confname[i]+sizeof(confname[i]), name);
        }
//      confval[i] = val;
        strecpy(confval[i], confval[i]+sizeof(confval[i]), val);
}

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);
        memset(BOOTARGS + n, '\n', BOOTARGSLEN - n);
        poperror();
        free(p);
}

/*
 * assumes that we have loaded our /cfg/pxe/mac file at CONFADDR
 * (usually 0x1000) with tftp in u-boot.  no longer uses malloc, so
 * can be called early.
 */
static void
plan9iniinit(void)
{
        char *k, *v, *next;

        k = (char *)CONFADDR;
        if(!isascii(*k))
                return;

        for(; k && *k != '\0'; k = next) {
                if (!isascii(*k))               /* sanity check */
                        break;
                next = strchr(k, '\n');
                if (next)
                        *next++ = '\0';

                if (*k == '\0' || *k == '\n' || *k == '#')
                        continue;
                v = strchr(k, '=');
                if(v == nil)
                        continue;               /* mal-formed line */
                *v++ = '\0';

                addconf(k, v);
        }
}

static void
optionsinit(char* s)
{
        char *o;

        strcpy(oenv, "");
        o = strecpy(oargb, oargb+sizeof(oargb), s)+1;
        if(getenv("bootargs", o, o - oargb) != nil)
                *(o-1) = ' ';

        oargblen = strlen(oargb);
        oargc = tokenize(oargb, oargv, nelem(oargv)-1);
        oargv[oargc] = nil;
}

char*
getenv(char* name, char* buf, int n)
{
        char *e, *p, *q;

        p = oenv;
        while(*p != 0){
                if((e = strchr(p, '=')) == nil)
                        break;
                for(q = name; p < e; p++){
                        if(*p != *q)
                                break;
                        q++;
                }
                if(p == e && *q == 0){
                        strecpy(buf, buf+n, e+1);
                        return buf;
                }
                p += strlen(p)+1;
        }

        return nil;
}

/* enable scheduling of this cpu */
void
machon(uint cpu)
{
        ulong cpubit;

        cpubit = 1 << cpu;
        lock(&active);
        if ((active.machs & cpubit) == 0) {     /* currently off? */
                conf.nmach++;
                active.machs |= cpubit;
        }
        unlock(&active);
}

/* disable scheduling of this cpu */
void
machoff(uint cpu)
{
        ulong cpubit;

        cpubit = 1 << cpu;
        lock(&active);
        if (active.machs & cpubit) {            /* currently on? */
                conf.nmach--;
                active.machs &= ~cpubit;
        }
        unlock(&active);
}

void
machinit(void)
{
        Mach *m0;

        if (m == 0) {
                serialputc('?');
                serialputc('m');
                serialputc('0');
        }
        if(machaddr[m->machno] != m) {
                serialputc('?');
                serialputc('m');
                serialputc('m');
        }

        if (canlock(&testlock)) {
                serialputc('?');
                serialputc('l');
                panic("cpu%d: locks don't work", m->machno);
        }

        m->ticks = 1;
        m->perf.period = 1;
        m0 = MACHP(0);
        if (m->machno != 0) {
                /* synchronise with cpu 0 */
                m->ticks = m0->ticks;
                m->fastclock = m0->fastclock;
                m->cpuhz = m0->cpuhz;
                m->delayloop = m0->delayloop;
        }
        if (m->machno != 0 &&
            (m->fastclock == 0 || m->cpuhz == 0 || m->delayloop == 0))
                panic("buggered cpu 0 Mach");

        machon(m->machno);
        fpoff();
}

/* l.s has already zeroed Mach, which now contains our stack. */
void
mach0init(void)
{
        if (m == 0) {
                serialputc('?');
                serialputc('m');
        }
        conf.nmach = 0;

        m->machno = 0;
        machaddr[0] = m;

        lock(&testlock);                /* hold this forever */
        machinit();

        active.exiting = 0;
        l1cache->wbse(&active, sizeof active);
        up = nil;
}

/*
 *  count CPU's, set up their mach structures and l1 ptes.
 *  we're running on cpu 0 and our data structures were
 *  statically allocated.
 */
void
launchinit(void)
{
        int mach;
        Mach *mm;
        PTE *l1;

        for(mach = 1; mach < MAXMACH; mach++){
                machaddr[mach] = mm = mallocalign(MACHSIZE, MACHSIZE, 0, 0);
                l1 = mallocalign(L1SIZE, L1SIZE, 0, 0);
                if(mm == nil || l1 == nil)
                        panic("launchinit");
                memset(mm, 0, MACHSIZE);
                mm->machno = mach;

                memmove(l1, (void *)L1, L1SIZE);  /* clone cpu0's l1 table */
                l1cache->wbse(l1, L1SIZE);

                mm->mmul1 = l1;
                l1cache->wbse(mm, MACHSIZE);
        }
        l1cache->wbse(machaddr, sizeof machaddr);
        conf.nmach = 1;
}

void
dump(void *vaddr, int words)
{
        ulong *addr;

        addr = vaddr;
        while (words-- > 0)
                iprint("%.8lux%c", *addr++, words % 8 == 0? '\n': ' ');
}

static void
cacheinit(void)
{
        allcacheinfo(cachel);
        cacheconf = (Lowmemcache *)CACHECONF;
        cacheconf->l1waysh = cachel[1].waysh;
        cacheconf->l1setsh = cachel[1].setsh;
        /* on the tegra 2, l2 is unarchitected */
        cacheconf->l2waysh = cachel[2].waysh;
        cacheconf->l2setsh = cachel[2].setsh;

        l2pl310init();
        allcacheson();
        allcache->wb();
}

void
l2pageinit(void)
{
        l2pages = KADDR(PHYSDRAM + DRAMSIZE - RESRVDHIMEM);
}

/*
 * at entry, l.s has set m for cpu0 and printed "Plan 9 from Be"
 * but has not zeroed bss.
 */
void
main(void)
{
        int cpu;
        static ulong vfy = 0xcafebabe;

        up = nil;
        if (vfy != 0xcafebabe) {
                serialputc('?');
                serialputc('d');
                panic("data segment misaligned");
        }

        memset(edata, 0, end - edata);

        /*
         * we can't lock until smpon has run, but we're supposed to wait
         * until l1 & l2 are on.  too bad.  l1 is on, l2 will soon be.
         */
        smpon();
        iprint("ll Labs ");
        cacheinit();

        /*
         * data segment is aligned, bss is zeroed, caches' characteristics
         * are known.  begin initialisation.
         */
        mach0init();
        l2pageinit();
        mmuinit();

        optionsinit("/boot/boot boot");
        quotefmtinstall();

        /* want plan9.ini to be able to affect memory sizing in confinit */
        plan9iniinit();         /* before we step on plan9.ini in low memory */

        /* l2 looks for *l2off= in plan9.ini */
        l2cache->on();          /* l2->on requires locks to work, thus smpon */
        l2cache->info(&cachel[2]);
        allcache->on();

        cortexa9cachecfg();

        trapinit();             /* so confinit can probe memory to size it */
        confinit();             /* figures out amount of memory */
        /* xinit prints (if it can), so finish up the banner here. */
        delay(100);
        navailcpus = getncpus();
        iprint("(mp arm; %d cpus)\n\n", navailcpus);
        delay(100);

        for (cpu = 1; cpu < navailcpus; cpu++)
                stopcpu(cpu);

        xinit();
        irqtooearly = 0;        /* now that xinit and trapinit have run */

        mainmem->flags |= POOL_ANTAGONISM /* | POOL_PARANOIA */ ;

        /*
         * Printinit will cause the first malloc call.
         * (printinit->qopen->malloc) unless any of the
         * above (like clockinit) do an irqenable, which
         * will call malloc.
         * If the system dies here it's probably due
         * to malloc(->xalloc) not being initialised
         * correctly, or the data segment is misaligned
         * (it's amazing how far you can get with
         * things like that completely broken).
         *
         * (Should be) boilerplate from here on.
         */

        archreset();                    /* cfg clock signals, print cache cfg */
        clockinit();                    /* start clocks */
        timersinit();

        delay(50);                      /* let uart catch up */
        printinit();
        kbdenable();

        cpuidprint();
        chkmissing();

        procinit0();
        initseg();

//      dmainit();
        links();
        conf.monitor = 1;
//      screeninit();

        iprint("pcireset...");
        pcireset();                     /* this tends to hang after a reboot */
        iprint("ok\n");

        chandevreset();                 /* most devices are discovered here */
//      i8250console();                 /* too early; see init0 */

        pageinit();                     /* prints "1020M memory: ⋯ */
        swapinit();
        userinit();

        /*
         * starting a cpu will eventually result in it calling schedinit,
         * so everything necessary to run user processes should be set up
         * before starting secondary cpus.
         */
        launchinit();
        /* SMP & FW are already on when we get here; u-boot set them? */
        for (cpu = 1; cpu < navailcpus; cpu++)
                if (startcpu(cpu) < 0)
                        panic("cpu%d didn't start", cpu);
        l1diag();

        schedinit();
        panic("cpu%d: schedinit returned", m->machno);
}

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 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) {
                delay(m->machno*1000);          /* stagger them */
                iprint("cpu%d: exiting\n", m->machno);
        }
        spllo();
        if (m->machno == 0)
                ms = 5*1000;
        else
                ms = 2*1000;
        for(; ms > 0; ms -= TK2MS(2)){
                delay(TK2MS(2));
                if(active.machs == 0 && consactive() == 0)
                        break;
        }
        delay(500);
}

/*
 *  exit kernel either on a panic or user request
 */
void
exit(int code)
{
        shutdown(code);
        splhi();
        if (m->machno == 0)
                archreboot();
        else {
                intrcpushutdown();
                stopcpu(m->machno);
                for (;;)
                        idlehands();
        }
}

int
isaconfig(char *class, int ctlrno, ISAConf *isa)
{
        char cc[32], *p;
        int i;

        snprint(cc, sizeof cc, "%s%d", class, ctlrno);
        p = getconf(cc);
        if(p == nil)
                return 0;

        isa->type = "";
        isa->nopt = tokenize(p, isa->opt, NISAOPT);
        for(i = 0; i < isa->nopt; i++){
                p = isa->opt[i];
                if(cistrncmp(p, "type=", 5) == 0)
                        isa->type = p + 5;
                else if(cistrncmp(p, "port=", 5) == 0)
                        isa->port = strtoul(p+5, &p, 0);
                else if(cistrncmp(p, "irq=", 4) == 0)
                        isa->irq = strtoul(p+4, &p, 0);
                else if(cistrncmp(p, "dma=", 4) == 0)
                        isa->dma = strtoul(p+4, &p, 0);
                else if(cistrncmp(p, "mem=", 4) == 0)
                        isa->mem = strtoul(p+4, &p, 0);
                else if(cistrncmp(p, "size=", 5) == 0)
                        isa->size = strtoul(p+5, &p, 0);
                else if(cistrncmp(p, "freq=", 5) == 0)
                        isa->freq = strtoul(p+5, &p, 0);
        }
        return 1;
}

/*
 * the new kernel is already loaded at address `code'
 * of size `size' and entry point `entry'.
 */
void
reboot(void *entry, void *code, ulong size)
{
        int cpu, nmach, want, ms;
        void (*f)(ulong, ulong, ulong);

        nmach = conf.nmach;
        writeconf();

        /*
         * the boot processor is cpu0.  execute this function on it
         * so that the new kernel has the same cpu0.
         */
        if (m->machno != 0) {
                procwired(up, 0);
                sched();
        }
        if (m->machno != 0)
                print("on cpu%d (not 0)!\n", m->machno);

        /*
         * 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.
         */
        for (want = 0, cpu = 1; cpu < navailcpus; cpu++)
                want |= 1 << cpu;
        active.stopped = 0;
        shutdown(0);
        for (ms = 15*1000; ms > 0 && active.stopped != want; ms -= 10)
                delay(10);
        delay(20);
        if (active.stopped != want) {
                for (cpu = 1; cpu < nmach; cpu++)
                        stopcpu(cpu);           /* make really sure */
                delay(20);
        }

        /*
         * should be the only processor running now
         */
        pcireset();
//      print("reboot entry %#lux code %#lux size %ld\n",
//              PADDR(entry), PADDR(code), size);

        /* turn off buffered serial console */
        serialoq = nil;
        kprintoq = nil;
        screenputs = nil;

        /* shutdown devices */
        chandevshutdown();

        /* call off the dog */
        clockshutdown();

        splhi();
        intrshutdown();

        /* setup reboot trampoline function */
        f = (void*)REBOOTADDR;
        memmove(f, rebootcode, sizeof(rebootcode));
        cachedwb();
        l2cache->wbinv();
        l2cache->off();
        cacheuwbinv();

        /* off we go - never to return */
        (*f)(PADDR(entry), PADDR(code), size);

        iprint("loaded kernel returned!\n");
        archreboot();
}

/*
 *  starting place for first process
 */
void
init0(void)
{
        int i;
        char buf[2*KNAMELEN];

        up->nerrlab = 0;
        coherence();
        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();
        i8250console();         /* might be redundant, but harmless */
        if(kbdq == nil)
                panic("init0: nil kbdq");
        if(serialoq == nil)
                panic("init0: nil serialoq");
        normalprint = 1;

        if(!waserror()){
                snprint(buf, sizeof(buf), "%s %s", "ARM", conffile);
                ksetenv("terminal", buf, 0);
                ksetenv("cputype", "arm", 0);
                if(cpuserver)
                        ksetenv("service", "cpu", 0);
                else
                        ksetenv("service", "terminal", 0);

                /* convert plan9.ini variables to #e and #ec */
                for(i = 0; i < nconf; i++) {
                        ksetenv(confname[i], confval[i], 0);
                        ksetenv(confname[i], confval[i], 1);
                }
                poperror();
        }
        kproc("alarm", alarmkproc, 0);
//      kproc("startcpusproc", startcpusproc, nil);

        touser(sp);
}

static void
bootargs(uintptr base)
{
        int i;
        ulong ssize;
        char **av, *p;

        /*
         * Push the boot args onto the stack.
         * The initial value of the user stack must be such
         * that the total used is larger than the maximum size
         * of the argument list checked in syscall.
         */
        i = oargblen+1;
        p = UINT2PTR(STACKALIGN(base + BY2PG - Ustkheadroom - i));
        memmove(p, oargb, i);

        /*
         * Now push argc and the argv pointers.
         * This isn't strictly correct as the code jumped to by
         * touser in init9.s calls startboot (port/initcode.c) which
         * expects arguments
         *      startboot(char *argv0, char **argv)
         * not the usual (int argc, char* argv[]), but argv0 is
         * unused so it doesn't matter (at the moment...).
         */
        av = (char**)(p - (oargc+2)*sizeof(char*));
        ssize = base + BY2PG - PTR2UINT(av);
        *av++ = (char*)oargc;
        for(i = 0; i < oargc; i++)
                *av++ = (oargv[i] - oargb) + (p - base) + (USTKTOP - BY2PG);
        *av = nil;

        /*
         * Leave space for the return PC of the
         * caller of initcode.
         */
        sp = USTKTOP - ssize - sizeof(void*);
}

/*
 *  create the first process
 */
void
userinit(void)
{
        Proc *p;
        Segment *s;
        KMap *k;
        Page *pg;

        /* no processes yet */
        up = nil;

        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);

        /*
         * Kernel Stack
         */
        p->sched.pc = PTR2UINT(init0);
        p->sched.sp = PTR2UINT(p->kstack+KSTACK-sizeof(up->s.args)-sizeof(uintptr));
        p->sched.sp = STACKALIGN(p->sched.sp);

        /*
         * User Stack
         *
         * Technically, newpage can't be called here because it
         * should only be called when in a user context as it may
         * try to sleep if there are no pages available, but that
         * shouldn't be the case here.
         */
        s = newseg(SG_STACK, USTKTOP-USTKSIZE, USTKSIZE/BY2PG);
        s->flushme++;
        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);
        p->seg[TSEG] = s;
        pg = newpage(1, 0, UTZERO);
        memset(pg->cachectl, PG_TXTFLUSH, sizeof(pg->cachectl));
        segpage(s, pg);
        k = kmap(s->map[0]->pages[0]);
        memmove(UINT2PTR(VA(k)), initcode, sizeof initcode);
        kunmap(k);

        ready(p);
}

Conf conf;                      /* XXX - must go - gag */

Confmem tsmem[nelem(conf.mem)] = {
        /*
         * Memory available to Plan 9:
         */
        { .base = PHYSDRAM, .limit = PHYSDRAM + Minmem, },
};
ulong memsize = DRAMSIZE;

static int
gotmem(uintptr sz)
{
        uintptr addr;

        /* back off a little from the end */
        addr = (uintptr)KADDR(PHYSDRAM + sz - BY2WD);
        if (probeaddr(addr) >= 0) {     /* didn't trap? memory present */
                memsize = sz;
                return 0;
        }
        return -1;
}

void
confinit(void)
{
        int i;
        ulong kpages;
        uintptr pa;
        char *p;

        /*
         * Copy the physical memory configuration to Conf.mem.
         */
        if(nelem(tsmem) > nelem(conf.mem)){
                iprint("memory configuration botch\n");
                exit(1);
        }
        if(0 && (p = getconf("*maxmem")) != nil) {
                memsize = strtoul(p, 0, 0) - PHYSDRAM;
                if (memsize < 16*MB)            /* sanity */
                        memsize = 16*MB;
        }

        /*
         * see if all that memory exists; if not, find out how much does.
         * trapinit must have been called first.
         */
        if (gotmem(memsize - RESRVDHIMEM) < 0)
                panic("can't find 1GB of memory");

        tsmem[0].limit = PHYSDRAM + memsize;
        memmove(conf.mem, tsmem, sizeof(tsmem));

        conf.npage = 0;
        pa = PADDR(PGROUND(PTR2UINT(end)));

        /*
         *  we assume that the kernel is at the beginning of one of the
         *  contiguous chunks of memory and fits therein.
         */
        for(i=0; i<nelem(conf.mem); i++){
                /* take kernel out of allocatable space */
                if(pa > conf.mem[i].base && pa < conf.mem[i].limit)
                        conf.mem[i].base = pa;

                conf.mem[i].npage = (conf.mem[i].limit - conf.mem[i].base)/BY2PG;
                conf.npage += conf.mem[i].npage;
        }

        conf.upages = (conf.npage*80)/100;
        conf.ialloc = ((conf.npage-conf.upages)/2)*BY2PG;

        /* set up other configuration parameters */
        conf.nproc = 100 + ((conf.npage*BY2PG)/MB)*5;
        if(cpuserver)
                conf.nproc *= 3;
        if(conf.nproc > 2000)
                conf.nproc = 2000;
        conf.nswap = conf.npage*3;
        conf.nswppo = 4096;
        conf.nimage = 200;

        /*
         * it's simpler on mp systems to take page-faults early,
         * on reference, rather than later, on write, which might
         * require tlb shootdowns.
         */
        conf.copymode = 1;              /* copy on reference */

        /*
         * Guess how much is taken by the large permanent
         * datastructures. Mntcache and Mntrpc are not accounted for
         * (probably ~300KB).
         */
        kpages = conf.npage - conf.upages;
        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;

//      archconfinit();
}

int
cmpswap(long *addr, long old, long new)
{
        return cas((int *)addr, old, new);
}

void
advertwfi(void)                 /* advertise my wfi status */
{
        ilock(&active);
        active.wfi |= 1 << m->machno;
        iunlock(&active);
}

void
unadvertwfi(void)               /* do not advertise my wfi status */
{
        ilock(&active);
        active.wfi &= ~(1 << m->machno);
        iunlock(&active);
}

void
idlehands(void)
{
#ifdef use_ipi
        int advertised;

        /* don't go into wfi until my local timer is ticking */
        if (m->ticks <= 1)
                return;

        advertised = 0;
        m->inidlehands++;
        /* avoid recursion via ilock, advertise iff this cpu is initialised */
        if (m->inidlehands == 1 && m->syscall > 0) {
                advertwfi();
                advertised = 1;
        }

        wfi();

        if (advertised)
                unadvertwfi();
        m->inidlehands--;
#endif
}

void
wakewfi(void)
{
#ifdef use_ipi
        uint cpu;

        /*
         * find any cpu other than me currently in wfi.
         * need not be exact.
         */
        cpu = BI2BY*BY2WD - 1 - clz(active.wfi & ~(1 << m->machno));
        if (cpu < MAXMACH)
                intrcpu(cpu);
#endif
}