From 5707b24a50b40582226618c56692af932db9fe02 Mon Sep 17 00:00:00 2001
From: Aristeu Rozanski <aris@redhat.com>
Date: Thu, 9 Jul 2009 22:21:13 -0300
Subject: [PATCH] pci: Add a probing code that seeks for an specific bus

This patch adds a probing code that seeks for an specific pci bus. It
still needs testing, but it is hoped that this will help to identify the
memory controller with Xeon 55xx series.

Signed-off-by: Aristeu Sergio <arozansk@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
 arch/x86/include/asm/pci_x86.h |  2 ++
 arch/x86/pci/legacy.c          | 42 ++++++++++++++++++++--------------
 2 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index 1a0422348d6d..ff5404b82fdc 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -53,6 +53,8 @@ extern int pcibios_last_bus;
 extern struct pci_bus *pci_root_bus;
 extern struct pci_ops pci_root_ops;
 
+void pcibios_scan_specific_bus(int busn);
+
 /* pci-irq.c */
 
 struct irq_info {
diff --git a/arch/x86/pci/legacy.c b/arch/x86/pci/legacy.c
index 0db5eaf54560..c734c277b116 100644
--- a/arch/x86/pci/legacy.c
+++ b/arch/x86/pci/legacy.c
@@ -11,28 +11,14 @@
  */
 static void __devinit pcibios_fixup_peer_bridges(void)
 {
-	int n, devfn;
-	long node;
+	int n;
 
 	if (pcibios_last_bus <= 0 || pcibios_last_bus > 0xff)
 		return;
 	DBG("PCI: Peer bridge fixup\n");
 
-	for (n=0; n <= pcibios_last_bus; n++) {
-		u32 l;
-		if (pci_find_bus(0, n))
-			continue;
-		node = get_mp_bus_to_node(n);
-		for (devfn = 0; devfn < 256; devfn += 8) {
-			if (!raw_pci_read(0, n, devfn, PCI_VENDOR_ID, 2, &l) &&
-			    l != 0x0000 && l != 0xffff) {
-				DBG("Found device at %02x:%02x [%04x]\n", n, devfn, l);
-				printk(KERN_INFO "PCI: Discovered peer bus %02x\n", n);
-				pci_scan_bus_on_node(n, &pci_root_ops, node);
-				break;
-			}
-		}
-	}
+	for (n=0; n <= pcibios_last_bus; n++)
+		pcibios_scan_specific_bus(n);
 }
 
 int __init pci_legacy_init(void)
@@ -49,6 +35,28 @@ int __init pci_legacy_init(void)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(pci_legacy_init);
+
+void pcibios_scan_specific_bus(int busn)
+{
+	int devfn;
+	long node;
+	u32 l;
+
+	if (pci_find_bus(0, busn))
+		return;
+
+	node = get_mp_bus_to_node(busn);
+	for (devfn = 0; devfn < 256; devfn += 8) {
+		if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) &&
+		    l != 0x0000 && l != 0xffff) {
+			DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l);
+			printk(KERN_INFO "PCI: Discovered peer bus %02x\n", busn);
+			pci_scan_bus_on_node(busn, &pci_root_ops, node);
+			return;
+		}
+	}
+}
 
 int __init pci_subsys_init(void)
 {