clean up page sizes & add my terminal to recognized amd machines.

there's no need to test for 2mb pages.  if a machine can do
64-bit, it can do 2mb pages.

Reference: /n/patches.lsub.org/patch/archk10clean
Date: Sun Oct 28 19:30:19 CET 2012
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/archk10.c	Tue Jul  3 10:42:54 2012
+++ /sys/src/nix/k10/archk10.c	Sun Oct 28 18:35:03 2012
@@ -127,6 +127,7 @@
 				return 0;
 			hz = (800 + 200*((msr>>1) & 0x1f)) * 1000000ll;
 			break;
+		case 0x00100f40:		/* phenom ii x4 */
 		case 0x00100f90:		/* K10 */
 		case 0x00000620:		/* QEMU64 */
 			msr = rdmsr(0xc0010064);
@@ -137,8 +138,7 @@
 		DBG("cpuidhz: %#llux hz %lld\n", msr, hz);
 	}
 	else
-		return 0;
-
+		hz = 0;
 	return hz;
 }
 
@@ -162,6 +162,18 @@
 	return i8254hz(info);
 }
 
+static void
+addmachpgsz(int bits)
+{
+	int i;
+
+	i = m->npgsz;
+	m->pgszlg2[i] = bits;
+	m->pgszmask[i] = (1<<bits)-1;
+	m->pgsz[i] = 1<<bits;
+	m->npgsz++;
+}
+
 int
 archmmu(void)
 {
@@ -170,46 +182,16 @@
 	/*
 	 * Should the check for m->machno != 0 be here
 	 * or in the caller (mmuinit)?
-	 *
-	 * To do here:
-	 * check and enable Pse;
-	 * Pge; Nxe.
 	 */
 
-	/*
-	 * How many page sizes are there?
-	 * Always have 4*KiB, but need to check
-	 * configured correctly.
-	 */
-	assert(PGSZ == 4*KiB);
-
-	m->pgszlg2[0] = 12;
-	m->pgszmask[0] = (1<<12)-1;
-	m->pgsz[0] = 1<<12;
-	m->npgsz = 1;
-	if(m->ncpuinfos == 0 && cpuidinit() == 0)
-		return 1;
-
-	/*
-	 * Check the Pse bit in function 1 DX for 2*MiB support;
-	 * if false, only 4*KiB is available.
-	 */
-	if(!(m->cpuinfo[1][3] & 0x00000008))
-		return 1;
-	m->pgszlg2[1] = 21;
-	m->pgszmask[1] = (1<<21)-1;
-	m->pgsz[1] = 1<<21;
-	m->npgsz = 2;
+	addmachpgsz(12);
+	addmachpgsz(21);
 
 	/*
 	 * Check the Page1GB bit in function 0x80000001 DX for 1*GiB support.
 	 */
-	if(cpuidinfo(0x80000001, 0, info) && (info[3] & 0x04000000)){
-		m->pgszlg2[2] = 30;
-		m->pgszmask[2] = (1<<30)-1;
-		m->pgsz[2] = 1<<30;
-		m->npgsz = 3;
-	}
+	if(cpuid(0x80000001, 0, info) && (info[3] & 0x04000000))
+		addmachpgsz(30);
 
 	return m->npgsz;
 }