also use the apic madt table to pick up processors and i/o apics.
this is important for many intel machines which have incomplete
mp tables.  (some are as bare as just mentioning the bsp and
interrupt routing.)

here's some output from my 4c/8t intel 1st generation i7

APIC lapic paddr 0xfee00000, flags 0x00000001
apic proc 0/0 apicid 0 (mp)
apic proc 1/1 apicid 2 (mp)
apic proc 2/2 apicid 4 (mp)
apic proc 3/3 apicid 6 (mp)
apic proc 4/4 apicid 1 
apic proc 5/5 apicid 3 
apic proc 6/6 apicid 5 
apic proc 7/7 apicid 7 

note that the odd apic ids (that is, the hyperthread partners)
were not in the mp table, but the even apic ids were.

changes:
- undid changes to devacpi prints

Reference: /n/patches.lsub.org/patch/mpacpi
Date: Fri Jul  6 00:51:18 CES 2012
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/mpacpi.c	Thu Jan  1 00:00:00 1970
+++ /sys/src/nix/k10/mpacpi.c	Thu Jul  5 23:25:04 2012
@@ -0,0 +1,57 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+#include "mp.h"
+#include "apic.h"
+#include "acpi.h"
+
+extern	Madt	*apics;
+
+int
+mpacpi(int maxcores)
+{
+	char *already;
+	int np, bp;
+	Apic *apic;
+	Apicst *st;
+
+	print("APIC lapic paddr %#.8llux, flags %#.8ux\n",
+		apics->lapicpa, apics->pcat);
+	np = 0;
+	for(st = apics->st; st != nil; st = st->next){
+		already = "";
+		switch(st->type){
+		case ASlapic:
+			if(st->lapic.id > Napic || np == maxcores)
+				break;
+			apic = xlapic + st->lapic.id;
+			bp = (np++ == 0);
+			if(apic->useable){
+				already = "(mp)";
+				goto pr;
+			}
+			apicinit(st->lapic.id, apics->lapicpa, bp);
+		pr:
+			print("apic proc %d/%d apicid %d %s\n", np-1, apic->machno, st->lapic.id, already);
+			break;
+		case ASioapic:
+			if(st->ioapic.id > Napic)
+				break;
+			apic = xioapic + st->ioapic.id;
+			if(apic->useable){
+				apic->ibase = st->ioapic.ibase;	/* gnarly */
+				already = "(mp)";
+				goto pr1;
+			}
+			ioapicinit(st->ioapic.id, st->ioapic.ibase, st->ioapic.addr);
+		pr1:
+			print("ioapic %d ", st->ioapic.id);
+			print("addr %p base %d %s\n", apic->paddr, apic->ibase, already);
+			break;
+		}
+	}
+	return maxcores - np;
+}
--- /sys/src/nix/k10/devacpi.c	Fri Jun 29 11:50:22 2012
+++ /sys/src/nix/k10/devacpi.c	Thu Jul  5 23:52:49 2012
@@ -64,7 +64,7 @@
 static Xsdt*	xsdt;	/* XSDT table */
 static Atable*	tfirst;	/* loaded DSDT/SSDT/... tables */
 static Atable*	tlast;	/* pointer to last table */
-static Madt*	apics;	/* APIC info */
+	Madt*	apics;	/* APIC info */
 static Srat*	srat;	/* System resource affinity, used by physalloc */
 static Slit*	slit;	/* System locality information table used by the scheduler */
 static Msct*	msct;	/* Maximum system characteristics table */
--- /sys/src/nix/k10/apic.h	Thu Apr 12 12:26:27 2012
+++ /sys/src/nix/k10/apic.h	Fri Jul  6 15:03:27 2012
@@ -10,16 +10,17 @@
 typedef	struct	Apic	Apic;
 
 struct Ioapic {
-	Lock;					/* IOAPIC: register access */
-	u32int*	addr;				/* IOAPIC: register base */
-	int	nrdt;				/* IOAPIC: size of RDT */
-	int	gsib;				/* IOAPIC: global RDT index */
+	Lock;					/* register access */
+	u32int*	addr;				/* register base */
+	uintmem	paddr;				/* register base */
+	int	nrdt;				/* size of RDT */
+	int	ibase;				/* global interrupt base */
 };
 
 struct Lapic {
 	int	machno;				/* APIC */
 
-	u32int	lvt[6];
+	u32int	lvt[7];
 	int	nlvt;
 	int	ver;
 
@@ -36,7 +37,7 @@
 };
 
 enum {
-	Nbus		= 256,
+	Nbus		= 256,			/* must be 256 */
 	Napic		= 254,			/* xAPIC architectural limit */
 	Nrdt		= 64,
 };
--- /sys/src/nix/k10/mp.c	Mon May 14 11:40:26 2012
+++ /sys/src/nix/k10/mp.c	Thu Jul  5 23:19:38 2012
@@ -173,7 +173,7 @@
 	return v;
 }
 
-static void
+static int
 mpparse(PCMP* pcmp, int maxcores)
 {
 	u32int lo;
@@ -245,7 +245,7 @@
 		 * p[1] is the APIC ID, p[4-7] is the memory mapped address.
 		 */
 		if(p[3] & 0x01)
-			ioapicinit(p[1], l32get(p+4));
+			ioapicinit(p[1], -1, l32get(p+4));
 
 		p += 8;
 		break;
@@ -348,6 +348,7 @@
 		p += p[1];
 		break;
 	}
+	return maxcores;
 }
 
 static int
@@ -476,7 +477,8 @@
 	 * for later interrupt enabling and application processor
 	 * startup.
 	 */
-	mpparse(pcmp, maxcores);
+	maxcores = mpparse(pcmp, maxcores);
+	mpacpi(maxcores);
 
 	apicdump();
 	ioapicdump();
--- /sys/src/nix/k10/ioapic.c	Thu Jun 14 09:36:22 2012
+++ /sys/src/nix/k10/ioapic.c	Thu Jul  5 23:22:36 2012
@@ -40,7 +40,6 @@
 
 static Rdt rdtarray[Nrdt];
 static int nrdtarray;
-static int gsib;
 static Rbus* rdtbus[Nbus];
 static Rdt* rdtvecno[IdtMAX+1];
 
@@ -121,9 +120,10 @@
 }
 
 void
-ioapicinit(int id, uintptr pa)
+ioapicinit(int id, int ibase, uintptr pa)
 {
 	Apic *apic;
+	static int base;
 
 	/*
 	 * Mark the IOAPIC useable if it has a good ID
@@ -136,6 +136,7 @@
 	if(apic->useable || (apic->addr = vmap(pa, 1024)) == nil)
 		return;
 	apic->useable = 1;
+	apic->paddr = pa;
 
 	/*
 	 * Initialise the I/O APIC.
@@ -145,9 +146,12 @@
 	lock(apic);
 	*(apic->addr+Ioregsel) = Ioapicver;
 	apic->nrdt = ((*(apic->addr+Iowin)>>16) & 0xff) + 1;
-	apic->gsib = gsib;
-	gsib += apic->nrdt;
-
+	if(ibase != -1)
+		apic->ibase = ibase;
+	else{
+		apic->ibase = base;
+		base += apic->nrdt;
+	}
 	*(apic->addr+Ioregsel) = Ioapicid;
 	*(apic->addr+Iowin) = id<<24;
 	unlock(apic);
@@ -168,8 +172,8 @@
 		apic = &xioapic[i];
 		if(!apic->useable || apic->addr == 0)
 			continue;
-		print("ioapic %d addr %#p nrdt %d gsib %d\n",
-			i, apic->addr, apic->nrdt, apic->gsib);
+		print("ioapic %d addr %#p nrdt %d ibase %d\n",
+			i, apic->addr, apic->nrdt, apic->ibase);
 		for(n = 0; n < apic->nrdt; n++){
 			lock(apic);
 			rtblget(apic, n, &hi, &lo);
@@ -367,19 +371,19 @@
 
 		busno = BUSBNO(v->tbdf);
 		if((pcidev = pcimatchtbdf(v->tbdf)) == nil)
-			panic("no PCI dev for tbdf %#8.8ux\n", v->tbdf);
+			panic("no PCI dev for tbdf %#8.8ux", v->tbdf);
 		if((vecno = intrenablemsi(v, pcidev)) != -1)
 			return vecno;
 		disablemsi(v, pcidev);
 		if((devno = pcicfgr8(pcidev, PciINTP)) == 0)
-			panic("no INTP for tbdf %#8.8ux\n", v->tbdf);
+			panic("no INTP for tbdf %#8.8ux", v->tbdf);
 		devno = BUSDNO(v->tbdf)<<2|(devno-1);
 		DBG("ioapicintrenable: tbdf %#8.8ux busno %d devno %d\n",
 			v->tbdf, busno, devno);
 	}
 	else{
 		SET(busno, devno);
-		panic("unknown tbdf %#8.8ux\n", v->tbdf);
+		panic("unknown tbdf %#8.8ux", v->tbdf);
 	}
 
 	rdt = nil;
--- /sys/src/nix/k10/k8cpu	Tue Apr 24 10:39:34 2012
+++ /sys/src/nix/k10/k8cpu	Thu Jul  5 23:34:40 2012
@@ -57,7 +57,7 @@
 
 misc +dev
 #	cache
-	mp		apic ioapic msi pci sipi
+	mp		mpacpi apic ioapic msi pci sipi
 
 #
 #boot cpu
--- /sys/src/nix/k10/fns.h	Tue Jul  3 10:40:23 2012
+++ /sys/src/nix/k10/fns.h	Thu Jul  5 23:35:38 2012
@@ -221,7 +221,7 @@
 extern void apicsipi(int, uintmem);
 void	apicnipi(int apicno);
 
-extern void ioapicinit(int, uintmem);
+extern void ioapicinit(int, int, uintmem);
 extern void ioapicintrinit(int, int, int, int, u32int);
 extern void ioapiconline(void);
 
@@ -243,6 +243,7 @@
  * mp.c
  */
 extern void mpsinit(int);
+extern int mpacpi(int);
 
 /*
  * sipi.c