Date: Mon, 02 Oct 2006 23:13:12 -0400
From: Jim Paradis <jparadis@redhat.com>
Subject: [RHEL5] Disable PCI mmconf and segmentation on HP xw9300/9400

This patch is a stopgap to address Bug 207396.  The problem is that
HP xw9300 and xw9400 systems have problems with PCI mmconfig access
and with PCI bus segmentation.  We saw these problems in RHEL4 as
well.  jgarzik is working on a patch to support multiple PCI domains,
but it's not had enough soak time for us to slip it into a beta at
this stage.  This patch is a port of the patch I made for RHEL4.
It implements a pair of dmi quirks to turn turn off MMCONFIG and
collapse all PCI domains into domain 0 on these systems.  Tested
on a xw9300, works a champ.

--- linux-2.6.18.noarch/drivers/acpi/pci_root.c.orig	2006-10-02 18:41:55.000000000 -0400
+++ linux-2.6.18.noarch/drivers/acpi/pci_root.c	2006-10-02 18:43:56.000000000 -0400
@@ -67,6 +67,10 @@
 
 static struct acpi_pci_driver *sub_driver;
 
+#if defined(CONFIG_X86)
+extern int pci_noseg;
+#endif
+
 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
 {
 	int n = 0;
@@ -202,6 +206,13 @@
 		goto end;
 	}
 
+#if defined(CONFIG_X86)
+	if (root->id.segment && pci_noseg) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "pci=noseg enabled, forcing segment %d to 0\n", root->id.segment));
+		root->id.segment = 0;
+	}
+#endif
+
 	/* 
 	 * Bus
 	 * ---
--- linux-2.6.18.noarch/arch/i386/pci/mmconfig.c.orig	2006-09-19 23:42:06.000000000 -0400
+++ linux-2.6.18.noarch/arch/i386/pci/mmconfig.c	2006-10-02 18:07:59.000000000 -0400
@@ -12,6 +12,7 @@
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/acpi.h>
+#include <linux/dmi.h>
 #include <asm/e820.h>
 #include "pci.h"
 
@@ -187,8 +188,41 @@
 	}
 }
 
+static int __devinit disable_mmconf(struct dmi_system_id *d)
+{
+	pci_probe &= ~PCI_PROBE_MMCONF;
+	printk(KERN_INFO "%s detected: disabling PCI MMCONFIG\n", d->ident);
+	return 0;
+}
+
+
+/*
+ * Systems which cannot use PCI MMCONFIG at this time...
+ */
+static struct dmi_system_id __devinitdata nommconf_dmi_table[] = {
+	{
+		.callback = disable_mmconf,
+		.ident = "HP xw9300 Workstation",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9300 Workstation"),
+		},
+	},
+	{
+		.callback = disable_mmconf,
+		.ident = "HP xw9400 Workstation",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9400 Workstation"),
+		},
+	},
+
+	{}
+};
+
+
 void __init pci_mmcfg_init(void)
 {
+	dmi_check_system(nommconf_dmi_table);
+
 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
 		return;
 
--- linux-2.6.18.noarch/arch/i386/pci/common.c.orig	2006-10-02 18:46:28.000000000 -0400
+++ linux-2.6.18.noarch/arch/i386/pci/common.c	2006-10-02 18:48:53.000000000 -0400
@@ -26,6 +26,10 @@
 struct pci_bus *pci_root_bus;
 struct pci_raw_ops *raw_pci_ops;
 
+#ifdef CONFIG_X86
+int pci_noseg = 0;
+#endif;
+
 static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
 {
 	return raw_pci_ops->read(0, bus->number, devfn, where, size, value);
@@ -130,6 +134,16 @@
 }
 #endif
 
+#ifdef CONFIG_X86
+static int __devinit disable_pci_seg(struct dmi_system_id *d)
+{
+	pci_noseg = 1;
+	printk(KERN_INFO "%s detected: disabling PCI segments\n", d->ident);
+	return 0;
+}
+#endif
+
+
 /*
  * Laptops which need pci=assign-busses to see Cardbus cards
  */
@@ -144,6 +158,23 @@
 		},
 	},
 #endif		/* __i386__ */
+#ifdef CONFIG_X86
+	{
+		.callback = disable_pci_seg,
+		.ident = "HP xw9300 Workstation",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9300 Workstation"),
+		},
+	},
+	{
+		.callback = disable_pci_seg,
+		.ident = "HP xw9400 Workstation",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9400 Workstation"),
+		},
+	},
+#endif
+
 	{}
 };
 
@@ -238,6 +269,12 @@
 		return NULL;
 	}
 #endif
+#ifdef CONFIG_X86
+	else if (!strcmp(str, "noseg")) {
+		pci_noseg = 1;
+		return NULL;
+	}
+#endif
 	else if (!strcmp(str, "noacpi")) {
 		acpi_noirq_set();
 		return NULL;
--- linux-2.6.18.noarch/arch/x86_64/pci/mmconfig.c.orig	2006-09-19 23:42:06.000000000 -0400
+++ linux-2.6.18.noarch/arch/x86_64/pci/mmconfig.c	2006-10-02 18:07:59.000000000 -0400
@@ -9,6 +9,7 @@
 #include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/bitmap.h>
+#include <linux/dmi.h>
 #include <asm/e820.h>
 
 #include "pci.h"
@@ -164,10 +165,43 @@
 	}
 }
 
+static int __devinit disable_mmconf(struct dmi_system_id *d)
+{
+	pci_probe &= ~PCI_PROBE_MMCONF;
+	printk(KERN_INFO "%s detected: disabling PCI MMCONFIG\n", d->ident);
+	return 0;
+}
+
+
+/*
+ * Systems which cannot use PCI MMCONFIG at this time...
+ */
+static struct dmi_system_id __devinitdata nommconf_dmi_table[] = {
+	{
+		.callback = disable_mmconf,
+		.ident = "HP xw9300 Workstation",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9300 Workstation"),
+		},
+	},
+	{
+		.callback = disable_mmconf,
+		.ident = "HP xw9400 Workstation",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9400 Workstation"),
+		},
+	},
+
+	{}
+};
+
+
 void __init pci_mmcfg_init(void)
 {
 	int i;
 
+	dmi_check_system(nommconf_dmi_table);
+
 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
 		return;