--- /sys/src/9k/k10/main.c
+++ /sys/src/9k/k10/main.c
@@ -392,7 +392,7 @@ userinit(void)
 	 */
 	s = newseg(SG_STACK, USTKTOP-USTKSIZE, USTKTOP);
 	p->seg[SSEG] = s;
-	pg = newpage(1, s, USTKTOP-(1<<s->lg2pgsize), 0);
+	pg = newpage(1, s, USTKTOP-segpgsize(s), 0);
 	segpage(s, pg);
 	k = kmap(pg);
 	bootargs(VA(k));
--- /sys/src/9k/port/devproc.c
+++ /sys/src/9k/port/devproc.c
@@ -1590,7 +1590,7 @@ procctlmemio(Proc *p, uintptr offset, int n, void *va, int read)
 	if(pagedout(pg))
 		panic("procctlmemio1");
 
-	pgsize = 1<<s->lg2pgsize;
+	pgsize = segpgsize(s);
 	l = pgsize - (offset&(pgsize-1));
 	if(n > l)
 		n = l;
--- /sys/src/9k/port/fault.c
+++ /sys/src/9k/port/fault.c
@@ -76,7 +76,7 @@ fixfault(Segment *s, uintptr addr, int read, int dommuput)
 	Page *(*fn)(Segment*, uintptr);
 	uintptr mmuphys, pgsize, soff;
 
-	pgsize = 1<<s->lg2pgsize;
+	pgsize = segpgsize(s);
 	addr &= ~(pgsize-1);
 	soff = addr-s->base;
 	p = &s->map[soff/s->ptemapmem];
@@ -201,7 +201,7 @@ pio(Segment *s, uintptr addr, uintptr soff, Page **p)
 	Page *loadrec;
 	uintptr pgsize;
 
-	pgsize = 1<<s->lg2pgsize;
+	pgsize = segpgsize(s);
 	loadrec = *p;
 	if(!pagedout(*p) || loadrec != nil)
 		return;
@@ -363,7 +363,7 @@ checkpages(void)
 		if(s == nil)
 			continue;
 		qlock(&s->lk);
-		pgsize = 1<<s->lg2pgsize;
+		pgsize = segpgsize(s);
 		for(addr=s->base; addr<s->top; addr+=pgsize){
 			off = addr - s->base;
 			p = s->map[off/s->ptemapmem];
--- /sys/src/9k/port/portdat.h
+++ /sys/src/9k/port/portdat.h
@@ -411,6 +411,8 @@ struct Segment
 	Sema	sema;
 };
 
+#define	segpgsize(s)	(1<<(s)->lg2pgsize)
+
 enum
 {
 	RENDLOG	=	5,
--- /sys/src/9k/port/sysseg.c
+++ /sys/src/9k/port/sysseg.c
@@ -84,7 +84,7 @@ ibrk(uintptr addr, int seg)
 		addr = s->base;
 	}
 
-	pgsize = 1<<s->lg2pgsize;
+	pgsize = segpgsize(s);
 	newtop = ROUNDUP(addr, pgsize);
 	newsize = (newtop-s->base)/pgsize;
 	if(newtop < s->top) {
@@ -400,7 +400,7 @@ syssegflush(Ar0* ar0, va_list list)
 			error(Ebadarg);
 
 		s->flushme = 1;
-		pgsize = 1<<s->lg2pgsize;
+		pgsize = segpgsize(s);
 	more:
 		l = len;
 		if(addr+l > s->top)