From 5f0b2976cb2b62668a076f54419c24b8ab677167 Mon Sep 17 00:00:00 2001
From: Yinghai Lu <yhlu.kernel@gmail.com>
Date: Mon, 14 Apr 2008 16:08:25 -0700
Subject: [PATCH] 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>
---
 arch/x86/kernel/mmconf-fam10h_64.c | 28 ++++++++++++++++++++++++++++
 arch/x86/kernel/setup_64.c         | 23 +++++++++++++++--------
 arch/x86/pci/common.c              |  4 ++++
 arch/x86/pci/mmconfig-shared.c     |  3 +++
 arch/x86/pci/pci.h                 |  1 +
 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 37897920ec..edc5fbfe85 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 d8a9ee752f..2f5c488aad 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 07d53184f7..2a4d751818 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 bdf6224318..0cfebecf2a 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 c8b89a832c..8ef86b5c37 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;
-- 
2.39.5