[PATCH] x86: Disable MMCONFIG on Intel SDV using DMI blacklist

As a replacement for the earlier removal of the e820 MCFG check
we blacklist the Intel SDV with the original BIOS bug that
motivated that check. On those machines don't use MMCONFIG.

This also adds a new pci=mmconf parameter to override the blacklist.

Cc: Greg KH <gregkh@suse.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

5 files changed, 57 insertions, 3 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index b50595a0550f..7947cede8712 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1183,6 +1183,8 @@ running once the system is up.
                                 Mechanism 2.
                 nommconf        [IA-32,X86_64] Disable use of MMCONFIG for PCI
                                 Configuration
+                mmconf          [IA-32,X86_64] Force MMCONFIG. This is useful
+                                to override the builtin blacklist.
                 nomsi           [MSI] If the PCI_MSI kernel config parameter is
                                 enabled, this kernel boot option can be used to
                                 disable the use of MSI interrupts system-wide.
diff --git a/arch/i386/pci/common.c b/arch/i386/pci/common.c
index 0a362e3aeac5..1220dd828ce3 100644
--- a/arch/i386/pci/common.c
+++ b/arch/i386/pci/common.c
@@ -237,6 +237,11 @@ char * __devinit  pcibios_setup(char *str)
                 pci_probe &= ~PCI_PROBE_MMCONF;
                 return NULL;
         }
+        /* override DMI blacklist */
+        else if (!strcmp(str, "mmconf")) {
+                pci_probe |= PCI_PROBE_MMCONF_FORCE;
+                return NULL;
+        }
 #endif
         else if (!strcmp(str, "noacpi")) {
                 acpi_noirq_set();
diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c
index 5effb2e663ed..ef5a2faa7d82 100644
--- a/arch/i386/pci/mmconfig.c
+++ b/arch/i386/pci/mmconfig.c
@@ -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"
 
@@ -187,9 +188,31 @@ static __init void unreachable_devices(void)
         }
 }
 
+static int disable_mcfg(struct dmi_system_id *d)
+{
+        printk("PCI: %s detected. Disabling MCFG.\n", d->ident);
+        pci_probe &= ~PCI_PROBE_MMCONF;
+        return 0;
+}
+
+static struct dmi_system_id __initdata dmi_bad_mcfg[] = {
+        /* Has broken MCFG table that makes the system hang when used */
+        {
+         .callback = disable_mcfg,
+         .ident = "Intel D3C5105 SDV",
+         .matches = {
+                     DMI_MATCH(DMI_BIOS_VENDOR, "Intel"),
+                     DMI_MATCH(DMI_BOARD_NAME, "D26928"),
+                     },
+         },
+         {}
+};
+
 void __init pci_mmcfg_init(void)
 {
-        if ((pci_probe & PCI_PROBE_MMCONF) == 0)
+        dmi_check_system(dmi_bad_mcfg);
+
+        if ((pci_probe & (PCI_PROBE_MMCONF_FORCE|PCI_PROBE_MMCONF)) == 0)
                 return;
 
         acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);
diff --git a/arch/i386/pci/pci.h b/arch/i386/pci/pci.h
index bf4e79335388..49a849b3a241 100644
--- a/arch/i386/pci/pci.h
+++ b/arch/i386/pci/pci.h
@@ -16,7 +16,8 @@
 #define PCI_PROBE_CONF1         0x0002
 #define PCI_PROBE_CONF2         0x0004
 #define PCI_PROBE_MMCONF        0x0008
-#define PCI_PROBE_MASK          0x000f
+#define PCI_PROBE_MMCONF_FORCE  0x0010
+#define PCI_PROBE_MASK          0x00ff
 
 #define PCI_NO_SORT             0x0100
 #define PCI_BIOS_SORT           0x0200
diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c
index 8a4a0f9263ce..2d48a7941d48 100644
--- a/arch/x86_64/pci/mmconfig.c
+++ b/arch/x86_64/pci/mmconfig.c
@@ -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"
@@ -164,11 +165,33 @@ static __init void unreachable_devices(void)
         }
 }
 
+static int disable_mcfg(struct dmi_system_id *d)
+{
+        printk("PCI: %s detected. Disabling MCFG.\n", d->ident);
+        pci_probe &= ~PCI_PROBE_MMCONF;
+        return 0;
+}
+
+static struct dmi_system_id __initdata dmi_bad_mcfg[] = {
+        /* Has broken MCFG table that makes the system hang when used */
+        {
+         .callback = disable_mcfg,
+         .ident = "Intel D3C5105 SDV",
+         .matches = {
+                     DMI_MATCH(DMI_BIOS_VENDOR, "Intel"),
+                     DMI_MATCH(DMI_BOARD_NAME, "D26928"),
+                     },
+         },
+         {}
+};
+
 void __init pci_mmcfg_init(void)
 {
         int i;
 
-        if ((pci_probe & PCI_PROBE_MMCONF) == 0)
+        dmi_check_system(dmi_bad_mcfg);
+
+        if ((pci_probe & (PCI_PROBE_MMCONF|PCI_PROBE_MMCONF_FORCE)) == 0)
                 return;
 
         acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);