x86: add pci=check_enable_amd_mmconf and dmi check

so will disable that feature by default, and only enable that via
pci=check_enable_amd_mmconf or for system match with dmi table.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

5 files changed, 51 insertions, 8 deletions

diff --git a/arch/x86/kernel/mmconf-fam10h_64.c b/arch/x86/kernel/mmconf-fam10h_64.c
index 37897920ec65..edc5fbfe85c0 100644
--- a/arch/x86/kernel/mmconf-fam10h_64.c
+++ b/arch/x86/kernel/mmconf-fam10h_64.c
@@ -6,12 +6,15 @@
 #include <linux/mm.h>
 #include <linux/string.h>
 #include <linux/pci.h>
+#include <linux/dmi.h>
 #include <asm/pci-direct.h>
 #include <linux/sort.h>
 #include <asm/io.h>
 #include <asm/msr.h>
 #include <asm/acpi.h>
 
+#include "../pci/pci.h"
+
 struct pci_hostbridge_probe {
         u32 bus;
         u32 slot;
@@ -176,6 +179,9 @@ void __cpuinit fam10h_check_enable_mmcfg(void)
         u64 val;
         u32 address;
 
+        if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
+                return;
+
         address = MSR_FAM10H_MMIO_CONF_BASE;
         rdmsrl(address, val);
 
@@ -213,3 +219,25 @@ void __cpuinit fam10h_check_enable_mmcfg(void)
                FAM10H_MMIO_CONF_ENABLE;
         wrmsrl(address, val);
 }
+
+static int __devinit set_check_enable_amd_mmconf(const struct dmi_system_id *d)
+{
+        pci_probe |= PCI_CHECK_ENABLE_AMD_MMCONF;
+        return 0;
+}
+
+static struct dmi_system_id __devinitdata mmconf_dmi_table[] = {
+        {
+                .callback = set_check_enable_amd_mmconf,
+                .ident = "Sun Microsystems Machine",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Sun Microsystems"),
+                },
+        },
+        {}
+};
+
+void __init check_enable_amd_mmconf_dmi(void)
+{
+        dmi_check_system(mmconf_dmi_table);
+}
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index d8a9ee752fb3..2f5c488aad0b 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -289,6 +289,18 @@ static void __init parse_setup_data(void)
         }
 }
 
+#ifdef CONFIG_PCI_MMCONFIG
+extern void __cpuinit fam10h_check_enable_mmcfg(void);
+extern void __init check_enable_amd_mmconf_dmi(void);
+#else
+void __cpuinit fam10h_check_enable_mmcfg(void)
+{
+}
+void __init check_enable_amd_mmconf_dmi(void)
+{
+}
+#endif
+
 /*
  * setup_arch - architecture-specific boot-time initializations
  *
@@ -510,6 +522,9 @@ void __init setup_arch(char **cmdline_p)
         conswitchp = &dummy_con;
 #endif
 #endif
+
+        /* do this before identify_cpu for boot cpu */
+        check_enable_amd_mmconf_dmi();
 }
 
 static int __cpuinit get_model_name(struct cpuinfo_x86 *c)
@@ -697,14 +712,6 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
                 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 }
 
-#ifdef CONFIG_PCI_MMCONFIG
-extern void __cpuinit fam10h_check_enable_mmcfg(void);
-#else
-void __cpuinit fam10h_check_enable_mmcfg(void)
-{
-}
-#endif
-
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 {
         unsigned level;
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 07d53184f7a4..2a4d751818b7 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -425,6 +425,10 @@ char * __devinit  pcibios_setup(char *str)
                 pci_probe &= ~PCI_PROBE_MMCONF;
                 return NULL;
         }
+        else if (!strcmp(str, "check_enable_amd_mmconf")) {
+                pci_probe |= PCI_CHECK_ENABLE_AMD_MMCONF;
+                return NULL;
+        }
 #endif
         else if (!strcmp(str, "noacpi")) {
                 acpi_noirq_set();
diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index bdf62243186a..0cfebecf2a8f 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -107,6 +107,9 @@ static const char __init *pci_mmcfg_amd_fam10h(void)
         int i;
         unsigned segnbits = 0, busnbits;
 
+        if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
+                return NULL;
+
         address = MSR_FAM10H_MMIO_CONF_BASE;
         if (rdmsr_safe(address, &low, &high))
                 return NULL;
diff --git a/arch/x86/pci/pci.h b/arch/x86/pci/pci.h
index c8b89a832c66..8ef86b5c37c8 100644
--- a/arch/x86/pci/pci.h
+++ b/arch/x86/pci/pci.h
@@ -26,6 +26,7 @@
 #define PCI_ASSIGN_ALL_BUSSES   0x4000
 #define PCI_CAN_SKIP_ISA_ALIGN  0x8000
 #define PCI_USE__CRS            0x10000
+#define PCI_CHECK_ENABLE_AMD_MMCONF     0x20000
 
 extern unsigned int pci_probe;
 extern unsigned long pirq_table_addr;