x86: add PCI extended config space access for AMD Barcelona

This patch implements PCI extended configuration space access for
AMD's Barcelona CPUs. It extends the method using CF8/CFC IO
addresses. An x86 capability bit has been introduced that is set for
CPUs supporting PCI extended config space accesses.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 48 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 24586682829..99221f9834e 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -6,6 +6,7 @@
 #include <asm/apic.h>
 
 #include <mach_apic.h>
+#include "../setup.h"
 #include "cpu.h"
 
 /*
@@ -308,6 +309,9 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 
 	if (cpu_has_xmm2)
 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
+
+	if (c->x86 == 0x10)
+		amd_enable_pci_ext_cfg(c);
 }
 
 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
diff --git a/arch/x86/kernel/cpu/amd_64.c b/arch/x86/kernel/cpu/amd_64.c
index c815c2c0484..180097e9921 100644
--- a/arch/x86/kernel/cpu/amd_64.c
+++ b/arch/x86/kernel/cpu/amd_64.c
@@ -217,6 +217,9 @@ void __cpuinit init_amd(struct cpuinfo_x86 *c)
 	if (c->x86 == 0x10)
 		fam10h_check_enable_mmcfg();
 
+	if (c->x86 == 0x10)
+		amd_enable_pci_ext_cfg(c);
+
 	if (amd_apic_timer_broken())
 		disable_apic_timer = 1;
 
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 6f80b852a19..d8f17123401 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -136,4 +136,17 @@ void __init setup_per_cpu_areas(void)
 	setup_cpumask_of_cpu();
 }
 
+#define ENABLE_CF8_EXT_CFG      (1ULL << 46)
+
+void __cpuinit amd_enable_pci_ext_cfg(struct cpuinfo_x86 *c)
+{
+	u64 reg;
+	rdmsrl(MSR_AMD64_NB_CFG, reg);
+	if (!(reg & ENABLE_CF8_EXT_CFG)) {
+		reg |= ENABLE_CF8_EXT_CFG;
+		wrmsrl(MSR_AMD64_NB_CFG, reg);
+	}
+	set_cpu_cap(c, X86_FEATURE_PCI_EXT_CFG);
+}
+
 #endif
diff --git a/arch/x86/kernel/setup.h b/arch/x86/kernel/setup.h
new file mode 100644
index 00000000000..66cc2c7f961
--- /dev/null
+++ b/arch/x86/kernel/setup.h
@@ -0,0 +1,26 @@
+/*
+ * Internal declarations for shared x86 setup code.
+ *
+ * Copyright (c) 2008 Advanced Micro Devices, Inc.
+ * Contributed by Robert Richter <robert.richter@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA
+ */
+
+#ifndef _ARCH_X86_KERNEL_SETUP_H
+
+extern void __cpuinit amd_enable_pci_ext_cfg(struct cpuinfo_x86 *c);
+
+#endif	/* _ARCH_X86_KERNEL_SETUP_H */
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 25afdd80a3c..215bd67e5b6 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -73,6 +73,8 @@
 #include <asm/pat.h>
 #include <asm/mmconfig.h>
 
+#include "setup.h"
+
 #include <mach_apic.h>
 #ifdef CONFIG_PARAVIRT
 #include <asm/paravirt.h>