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);