rewrite kseg2map in terms of mmumap as prep for reboot code.

Reference: /n/atom/patch/applied/mmumap
Date: Sat Mar 22 01:55:06 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/mmu.c	Sat Mar 22 01:54:06 2014
+++ /sys/src/nix/k10/mmu.c	Sat Mar 22 01:54:07 2014
@@ -540,17 +540,15 @@
 	return 0;
 }
 
-uintptr
-kseg2map(uintmem pa, uintmem len, uint basef)
+void
+mmumap(uintmem pa, uintptr va, u64int len, uint basef)
 {
 	int i, l;
-	uintptr va;
 	uintmem mem, nextmem;
 	PTE *pte, *pml4;
 
-	DBG("kseg2map: %#P %#P size %P\n", pa, pa+len, len);
+	DBG("map: %#P %#P size %P\n", pa, pa+len, len);
 	pml4 = UINT2PTR(m->pml4->va);
-	va = KSEG2+pa;
 	for(mem = pa; mem < pa+len; mem = nextmem){
 		nextmem = (mem + PGLSZ(0)) & ~m->pgszmask[0];
 		for(i = m->npgsz - 1; i >= 0; i--){
@@ -559,13 +557,19 @@
 			if(mem + PGLSZ(i) > pa+len)
 				continue;
 			if((l = mmuwalk(pml4, va, i, &pte, walkalloc)) < 0)
-				panic("mmu: kseg2map");
+				panic("mmu: map");
 			*pte = mem|memflagssz(basef, PGLSZ(l));
 			nextmem = mem + PGLSZ(i);
 			va += PGLSZ(i);
 			break;
 		}
 	}
+}
+
+uintptr
+kseg2map(uintmem pa, uintmem len, uint basef)
+{
+	mmumap(pa, KSEG2+pa, len, basef);
 	return KSEG2+pa;
 }
 
--- /sys/src/nix/k10/fns.h	Sat Mar 22 01:54:09 2014
+++ /sys/src/nix/k10/fns.h	Sat Mar 22 01:54:09 2014
@@ -77,6 +77,7 @@
 void	machinit(void);
 void	meminit(void);
 void	mfence(void);
+void	mmumap(uintmem, uintptr, u64int, uint);
 void	mmuflushtlb(uintmem);
 void	mmuinit(void);
 uintmem	mmuphysaddr(uintptr);