From f0c9bb979fd6d8481462aed68828094e202916cd Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@gmx.de>
Date: Fri, 7 Jun 2013 18:03:44 +0200
Subject: [PATCH] archacpi: handle multiple SSDT tables

we cannot assume theres only one instance of an acpi table. some
bios have multiple SSDT tables and we would only find the first
one.

now, we keep a second array to record the physical address of
the table visited by maptable(). load all instances to the
SSDT.
---
 sys/src/9/pc/archacpi.c | 70 ++++++++++++++++++++++++++---------------
 1 file changed, 45 insertions(+), 25 deletions(-)

diff --git a/sys/src/9/pc/archacpi.c b/sys/src/9/pc/archacpi.c
index 9e40f452b..243b8996c 100644
--- a/sys/src/9/pc/archacpi.c
+++ b/sys/src/9/pc/archacpi.c
@@ -38,8 +38,14 @@ struct Tbl {
 };
 
 static Rsd *rsd;
-static int ntbltab;
-static Tbl *tbltab[64];
+
+/* physical addresses visited by maptable() */
+static int ntblpa;
+static uintptr tblpa[64];
+
+/* successfully mapped tables */
+static int ntblmap;
+static Tbl *tblmap[64];
 
 void*
 amlalloc(int n){
@@ -79,16 +85,6 @@ tbldlen(Tbl *t){
 	return get32(t->len) - sizeof(Tbl);
 }
 
-
-static Tbl*
-findtable(void *sig){
-	int i;
-	for(i=0; i<ntbltab; i++)
-		if(memcmp(tbltab[i]->sig, sig, 4) == 0)
-			return tbltab[i];
-	return nil;
-}
-
 static void
 maptable(uvlong xpa)
 {
@@ -96,16 +92,24 @@ maptable(uvlong xpa)
 	uintptr pa;
 	u32int l;
 	Tbl *t;
+	int i;
 
 	pa = xpa;
 	if((uvlong)pa != xpa || pa == 0)
 		return;
-	if(ntbltab >= nelem(tbltab))
+	if(ntblpa >= nelem(tblpa) || ntblmap >= nelem(tblmap))
 		return;
+
+	for(i=0; i<ntblpa; i++){
+		if(pa == tblpa[i])
+			return;
+	}
+	tblpa[ntblpa++] = pa;
+
 	if((t = vmap(pa, 8)) == nil)
 		return;
 	l = get32(t->len);
-	if(l < sizeof(Tbl) || findtable(t->sig)){
+	if(l < sizeof(Tbl)){
 		vunmap(t, 8);
 		return;
 	}
@@ -116,8 +120,7 @@ maptable(uvlong xpa)
 		vunmap(t, l);
 		return;
 	}
-
-	tbltab[ntbltab++] = t;
+	tblmap[ntblmap++] = t;
 
 	p = (uchar*)t;
 	e = p + l;
@@ -145,7 +148,7 @@ maptable(uvlong xpa)
 static void
 maptables(void)
 {
-	if(rsd == nil || ntbltab > 0)
+	if(rsd == nil || ntblmap > 0 || ntblpa > 0)
 		return;
 	if(!checksum(rsd, 20))
 		maptable(get32(rsd->raddr));
@@ -340,17 +343,34 @@ acpiinit(void)
 
 	amlinit();
 
-	if(t = findtable("DSDT"))
-		amlload(t->data, tbldlen(t));
-	if(t = findtable("SSDT"))
-		amlload(t->data, tbldlen(t));
+	/* load DSDT */
+	for(i=0; i<ntblmap; i++){
+		t = tblmap[i];
+		if(memcmp(t->sig, "DSDT", 4) == 0){
+			amlload(t->data, tbldlen(t));
+			break;
+		}
+	}
+
+	/* load SSDT, there can be multiple tables */
+	for(i=0; i<ntblmap; i++){
+		t = tblmap[i];
+		if(memcmp(t->sig, "SSDT", 4) == 0)
+			amlload(t->data, tbldlen(t));
+	}
 
 	/* set APIC mode */
 	amleval(amlwalk(amlroot, "_PIC"), "i", 1, nil);
 
-	if((t = findtable("APIC")) == nil)
-		panic("acpiinit: no MADT table");
+	for(i=0; i<ntblmap; i++){
+		t = tblmap[i];
+		if(memcmp(t->sig, "APIC", 4) == 0)
+			goto Foundapic;
+	}
+	panic("acpiinit: no MADT (APIC) table");
+	return;
 
+Foundapic:
 	p = t->data;
 	e = p + tbldlen(t);
 	lapicbase = get32(p); p += 8;
@@ -461,8 +481,8 @@ readtbls(Chan*, void *v, long n, vlong o)
 	maptables();
 
 	p = v;
-	for(i=0; n > 0 && i < ntbltab; i++){
-		t = tbltab[i];
+	for(i=0; n > 0 && i < ntblmap; i++){
+		t = tblmap[i];
 		l = get32(t->len);
 		if(o >= l){
 			o -= l;