void
sysziofree(Ar0 *ar0, ...)
{
	Mach *m = machp();
	Zio *io;
	int nio, i;
	Segment *s;
	va_list list;
	va_start(list, ar0);

	/*
	 * zfree(Zio io[], int nio);
	 */
	io = va_arg(list, Zio*);
	nio = va_arg(list, int);
	va_end(list);
	io = validaddr(io, sizeof io[0] * nio, 1);
	for(i = 0; i < nio; i++){
		s = seg(m->externup, PTR2UINT(io[i].data), 1);
		if(s == nil)
			error("invalid address in zio");
		if((s->type&SG_ZIO) == 0){
			qunlock(&s->lk);
			error("segment is not a zero-copy segment");
		}
		zputaddr(s, PTR2UINT(io[i].data));
		qunlock(&s->lk);
		io[i].data = nil;
		io[i].size = 0;
	}
}

void
syssemalt(Ar0 *ar0, ...)
{
	Proc *up = externup();
	int **sl;
	int i, *np, ns;
	Segment *sg;
	Sem *ksl[16];
	va_list list;
	va_start(list, ar0);

	/*
	 * void semalt(int*[], int);
	 */
	ar0->i = -1;
	sl = va_arg(list, int**);
	ns = va_arg(list, int);
	sl = validaddr(sl, ns * sizeof(int*), 1);
	if(ns > nelem(ksl))
		panic("syssemalt: bug: too many semaphores in alt");
	for(i = 0; i < ns; i++){
		np = sl[i];
		np = validaddr(np, sizeof(int), 1);
		evenaddr(PTR2UINT(np));
		if((sg = seg(up, PTR2UINT(np), 0)) == nil)
			error(Ebadarg);
		ksl[i] = segmksem(sg, np);
	}
	ar0->i = semalt(ksl, ns);
	va_end(list);
}

void
sysrforkchild(Proc* child, Proc* parent)
{
	Ureg *cureg;
// If STACKPAD is 1 things go very bad very quickly.
// But it is the right value ...
#define STACKPAD 1 /* for return PC? */
	/*
	 * Add STACKPAD*BY2SE to the stack to account for
	 *  - the return PC
	 *  (NOT NOW) - trap's arguments (syscallnr, ureg)
	 */
	child->sched.sp = PTR2UINT(child->kstack+KSTACK-((sizeof(Ureg)+STACKPAD*BY2SE)));
	child->sched.pc = PTR2UINT(sysrforkret);

	cureg = (Ureg*)(child->sched.sp+STACKPAD*BY2SE);
	memmove(cureg, parent->dbgreg, sizeof(Ureg));

	/* Things from bottom of syscall which were never executed */
	child->psstate = 0;
	child->insyscall = 0;
	//iprint("Child SP set tp %p\n", (void *)child->sched.sp);

	fpusysrforkchild(child, parent);
}

static void
_kproftimer(uintptr_t pc)
{
	if(kprof.time == 0)
		return;

	/*
	 * if the pc corresponds to the idle loop, don't consider it.
	if(m->inidle)
		return;
	 */
	/*
	 *  if the pc is coming out of spllo or splx,
	 *  use the pc saved when we went splhi.
	 */
	if(pc>=PTR2UINT(spllo) && pc<=PTR2UINT(spldone))
		pc = machp()->splpc;

	ilock(&kprof.l);
	kprof.buf[0] += TK2MS(1);
	if(kprof.minpc<=pc && pc<kprof.maxpc){
		pc -= kprof.minpc;
		pc >>= LRES;
		kprof.buf[pc] += TK2MS(1);
	}else

/*
 *  setup stack and initial PC for a new kernel proc.  This is architecture
 *  dependent because of the starting stack location
 */
void
kprocchild(Proc *p, void (*func)(void*), void *arg)
{
	p->sched.pc = PTR2UINT(linkproc);
	p->sched.sp = PTR2UINT(p->kstack+KSTACK);

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

void
kprocchild(Proc* p, void (*func)(void*), void* arg)
{
	/*
	 * gotolabel() needs a word on the stack in
	 * which to place the return PC used to jump
	 * to linkproc().
	 */
	p->sched.pc = PTR2UINT(linkproc);
	p->sched.sp = PTR2UINT(p->kstack+KSTACK-BY2SE);
	p->sched.sp = STACKALIGN(p->sched.sp);

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

void
xinit(void)
{
	int i, n, upages, kpages;
	ulong maxkpa;
	Confmem *m;
	Pallocmem *pm;
	Hole *h, *eh;

	eh = &xlists.hole[Nhole-1];
	for(h = xlists.hole; h < eh; h++)
		h->link = h+1;

	xlists.flist = xlists.hole;

	upages = conf.upages;
	kpages = conf.npage - upages;
	pm = palloc.mem;
	maxkpa = -KZERO;
	for(i=0; i<nelem(conf.mem); i++){
		m = &conf.mem[i];
		n = m->npage;
		if(n > kpages)
			n = kpages;
		if(m->base >= maxkpa)
			n = 0;
		else if(n > 0 && m->base+n*PGSZ >= maxkpa)
			n = (maxkpa - m->base)/PGSZ;
		/* first give to kernel */
		if(n > 0){
			m->kbase = PTR2UINT(KADDR(m->base));
			m->klimit = PTR2UINT(KADDR(m->base+n*PGSZ));
			xhole(m->base, n*PGSZ);
			kpages -= n;
		}
		/* if anything left over, give to user */
		if(n < m->npage){
			if(pm >= palloc.mem+nelem(palloc.mem)){
				print("xinit: losing %lud pages\n", m->npage-n);
				continue;
			}
			pm->base = m->base+n*PGSZ;
			pm->npage = m->npage - n;
			pm++;
		}
	}
	xsummary();
}

/*
 * This is the counterpart of devzread in some sense,
 * it reads in the traditional way from io[].
 */
int32_t
readzio(Kzio *io, int nio, void *a, int32_t count)
{
	int32_t tot, nr;
	char *p;

	p = a;
	tot = 0;
	while(nio-- > 0){
		if(tot < count){
			nr = io->size;
			if(tot + nr > count)
				nr = count - tot;
			DBG("readzio: copy %#p %Z\n", p+tot, io);
			memmove(p+tot, io->data, nr);
			tot += nr;
		}
		qlock(&io->seg->lk);
		zputaddr(io->seg, PTR2UINT(io->data));
		qunlock(&io->seg->lk);
		putseg(io->seg);
		io->seg = nil;
		io++;
	}
	return tot;
}

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 - sizeof(Tos) - i));
	memmove(p, oargb, i);

	/*
	 * Now push the argv pointers.
	 * The code jumped to by touser in lproc.s expects arguments
	 *	main(char* argv0, ...)
	 * and calls
	 * 	startboot("/boot/boot", &argv0)
	 * not the usual (int argc, char* argv[])
	 */
	av = (char**)(p - (oargc+1)*sizeof(char*));
	ssize = base + BY2PG - PTR2UINT(av);
	for(i = 0; i < oargc; i++)
		*av++ = (oargv[i] - oargb) + (p - base) + (USTKTOP - BY2PG);
	*av = nil;
	sp = USTKTOP - ssize;
}

/**
 * @param hl a hashlist.
 * @param key the key to look for.
 * @param bin if not NULL, it will be set to the bin number that is or would
 *        be used for the key. It is set regardless whether the key is in
 *        the hashlist.
 * @return NULL if the key is not in the hashlist. Otherwise, the item
 *         associated with the key is returned.
 */
static hash_item_t *
hashlist_find(hashlist_t *hl, const void *key, uint32_t *bin)
{
  hash_item_t *item;
  uint32_t hash, b;

  HASHLIST_CHECK(hl);

  hash = hl->hash ? hl->hash(key) : (uint32_t) PTR2UINT(key);
  b = (hash ^ hl->rnd) % hl->num_bins;
  item = hl->bins[b];
  if (bin) {
    *bin = b;
  }

  if (hl->cmp) {
    for (/* NOTHING */; item != NULL; item = item->bnext) {
      if (hl->cmp(key, item->node.ptr))
        return item;
    }
  } else {
    for (/* NOTHING */; item != NULL; item = item->bnext) {
      if (key == item->node.ptr)
        return item;
    }
  }

  return NULL;
}

void
vunmap(void* v, usize size)
{
	Proc *up = externup();
	uintptr_t va;

	DBG("vunmap(%#p, %lud)\n", v, size);

	if(machp()->machno != 0)
		panic("vunmap");

	/*
	 * See the comments above in vmap.
	 */
	va = PTR2UINT(v);
	if(va >= KZERO && va+size < KZERO+1ull*MiB)
		return;

	/*
	 * Here will have to deal with releasing any
	 * resources used for the allocation (e.g. page table
	 * pages).
	 */
	DBG("vunmap(%#p, %lud)\n", v, size);
}

static Block*
_allocb(int size)
{
	Block *b;
	uint8_t *p;
	int n;

	n = BLOCKALIGN + ROUNDUP(size+Hdrspc, BLOCKALIGN) + sizeof(Block);
	if((p = malloc(n)) == nil)
		return nil;

	b = (Block*)(p + n - sizeof(Block));	/* block at end of allocated space */
	b->base = p;
	b->next = nil;
	b->list = nil;
	b->free = 0;
	b->flag = 0;

	/* align base and bounds of data */
	b->lim = (uint8_t*)(PTR2UINT(b) & ~(BLOCKALIGN-1));

	/* align start of writable data, leaving space below for added headers */
	b->rp = b->lim - ROUNDUP(size, BLOCKALIGN);
	b->wp = b->rp;

	if(b->rp < b->base || b->lim - b->rp < size)
		panic("_allocb");

	return b;
}

void*
mmuuncache(void* v, usize size)
{
	int x;
	PTE *pte;
	uintptr va;

	/*
	 * Simple helper for ucalloc().
	 * Uncache a Section, must already be
	 * valid in the MMU.
	 */
	va = PTR2UINT(v);
	assert(!(va & (1*MiB-1)) && size == 1*MiB);

	x = L1X(va);
	pte = &m->mmul1[x];
	if((*pte & (Fine|Section|Coarse)) != Section)
		return nil;
	*pte &= ~(Cached|Buffered);
	mmuinvalidateaddr(va);
	cachedwbinvse(pte, 4);

	return v;
}

void
mmuswitch(Proc* proc)
{
    PTE *pte;
    Page *page;
    Mpl pl;

    pl = splhi();
    if(proc->newtlb) {
        /*
         * NIX: We cannot clear our page tables if they are going to
         * be used in the AC
         */
        if(proc->ac == nil)
            mmuptpfree(proc, 1);
        proc->newtlb = 0;
    }

    if(machp()->MMU.pml4->daddr) {
        memset(UINT2PTR(machp()->MMU.pml4->va), 0, machp()->MMU.pml4->daddr*sizeof(PTE));
        machp()->MMU.pml4->daddr = 0;
    }

    pte = UINT2PTR(machp()->MMU.pml4->va);
    for(page = proc->MMU.mmuptp[3]; page != nil; page = page->next) {
        pte[page->daddr] = PPN(page->pa)|PteU|PteRW|PteP;
        if(page->daddr >= machp()->MMU.pml4->daddr)
            machp()->MMU.pml4->daddr = page->daddr+1;
        page->prev = machp()->MMU.pml4;
    }

    tssrsp0(machp(), STACKALIGN(PTR2UINT(proc->kstack+KSTACK)));
    cr3put(machp()->MMU.pml4->pa);
    splx(pl);
}

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

	/*
	 * Push the boot args onto the stack.
	 * Make sure the validaddr check in syscall won't fail
	 * because there are fewer than the maximum number of
	 * args by subtracting sizeof(up->arg).
	 */
	i = oargblen+1;
	p = UINT2PTR(STACKALIGN(base + BIGPGSZ - sizeof(up->arg) - 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.[cs] 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 + BIGPGSZ - PTR2UINT(av);
	*av++ = (char*)oargc;
	for(i = 0; i < oargc; i++)
		*av++ = (oargv[i] - oargb) + (p - base) + (USTKTOP - BIGPGSZ);
	*av = nil;

	sp = USTKTOP - ssize;
}

void*
xspanalloc(ulong size, int align, ulong span)
{
	uintptr a, v, t;

	a = PTR2UINT(xalloc(size+align+span));
	if(a == 0)
		panic("xspanalloc: %lud %d %lux\n", size, align, span);

	if(span > 2) {
		v = (a + span) & ~(span-1);
		t = v - a;
		if(t > 0)
			xhole(PADDR(UINT2PTR(a)), t);
		t = a + span - v;
		if(t > 0)
			xhole(PADDR(UINT2PTR(v+size+align)), t);
	}
	else
		v = a;

	if(align > 1)
		v = (v + align) & ~(align-1);

	return (void*)v;
}

ushort
ptclbsum(uchar *addr, int len)
{
	ulong losum, hisum, mdsum, x;
	ulong t1, t2;

	losum = 0;
	hisum = 0;
	mdsum = 0;

	x = 0;
	if(PTR2UINT(addr) & 1) {
		if(len) {
			hisum += addr[0];
			len--;
			addr++;
		}
		x = 1;
	}
	while(len >= 16) {
		t1 = *(ushort*)(addr+0);
		t2 = *(ushort*)(addr+2);	mdsum += t1;
		t1 = *(ushort*)(addr+4);	mdsum += t2;
		t2 = *(ushort*)(addr+6);	mdsum += t1;
		t1 = *(ushort*)(addr+8);	mdsum += t2;
		t2 = *(ushort*)(addr+10);	mdsum += t1;
		t1 = *(ushort*)(addr+12);	mdsum += t2;
		t2 = *(ushort*)(addr+14);	mdsum += t1;
		mdsum += t2;
		len -= 16;
		addr += 16;
	}
	while(len >= 2) {
		mdsum += *(ushort*)addr;
		len -= 2;
		addr += 2;
	}
	if(x) {
		if(len)
			losum += addr[0];
		if(LITTLE)
			losum += mdsum;
		else
			hisum += mdsum;
	} else {
		if(len)
			hisum += addr[0];
		if(LITTLE)
			hisum += mdsum;
		else
			losum += mdsum;
	}

	losum += hisum >> 8;
	losum += (hisum & 0xff) << 8;
	while(hisum = losum>>16)
		losum = hisum + (losum & 0xffff);

	return losum & 0xffff;
}

/* 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;
	ureg->r14 = PTR2UINT(sched);
}

void*
sysexecregs(uintptr_t entry, uint32_t ssize, void *tos)
{
	Proc *up = externup();
	uintptr_t *sp;
	Ureg *ureg;

	// We made sure it was correctly aligned in sysexecstack, above.
	if (ssize & 0xf) {
		print("your stack is wrong: stacksize is not 16-byte aligned: %d\n", ssize);
		panic("misaligned stack in sysexecregs");
	}
	sp = (uintptr_t*)(USTKTOP - ssize);

	ureg = up->dbgreg;
	ureg->sp = PTR2UINT(sp);
	ureg->ip = entry;
	ureg->type = 64;			/* fiction for acid */
	ureg->dx = (uintptr_t)tos;

	/*
	 * return the address of kernel/user shared data
	 * (e.g. clock stuff)
	 */
	return UINT2PTR(USTKTOP-sizeof(Tos));
}

void
Tcl_DeleteHashEntry(
    Tcl_HashEntry *entryPtr)
{
    register Tcl_HashEntry *prevPtr;
    const Tcl_HashKeyType *typePtr;
    Tcl_HashTable *tablePtr;
    Tcl_HashEntry **bucketPtr;
#if TCL_HASH_KEY_STORE_HASH
    int index;
#endif

    tablePtr = entryPtr->tablePtr;

    if (tablePtr->keyType == TCL_STRING_KEYS) {
	typePtr = &tclStringHashKeyType;
    } else if (tablePtr->keyType == TCL_ONE_WORD_KEYS) {
	typePtr = &tclOneWordHashKeyType;
    } else if (tablePtr->keyType == TCL_CUSTOM_TYPE_KEYS
	    || tablePtr->keyType == TCL_CUSTOM_PTR_KEYS) {
	typePtr = tablePtr->typePtr;
    } else {
	typePtr = &tclArrayHashKeyType;
    }

#if TCL_HASH_KEY_STORE_HASH
    if (typePtr->hashKeyProc == NULL
	    || typePtr->flags & TCL_HASH_KEY_RANDOMIZE_HASH) {
	index = RANDOM_INDEX (tablePtr, entryPtr->hash);
    } else {
	index = PTR2UINT(entryPtr->hash) & tablePtr->mask;
    }

    bucketPtr = &(tablePtr->buckets[index]);
#else
    bucketPtr = entryPtr->bucketPtr;
#endif

    if (*bucketPtr == entryPtr) {
	*bucketPtr = entryPtr->nextPtr;
    } else {
	for (prevPtr = *bucketPtr; ; prevPtr = prevPtr->nextPtr) {
	    if (prevPtr == NULL) {
		Tcl_Panic("malformed bucket chain in Tcl_DeleteHashEntry");
	    }
	    if (prevPtr->nextPtr == entryPtr) {
		prevPtr->nextPtr = entryPtr->nextPtr;
		break;
	    }
	}
    }

    tablePtr->numEntries--;
    if (typePtr->freeEntryProc) {
	typePtr->freeEntryProc (entryPtr);
    } else {
	ckfree((char *) entryPtr);
    }
}