From 0e152cd7c16832bd5cadee0c2e41d9959bc9b6f9 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@amd64.org>
Date: Fri, 12 Mar 2010 15:43:03 +0100
Subject: [PATCH] x86, k8 nb: Fix boot crash: enable k8_northbridges
unconditionally on AMD systems
de957628ce7c84764ff41331111036b3ae5bad0f changed setting of the
x86_init.iommu.iommu_init function ptr only when GART IOMMU is
found.
One side effect of it is that num_k8_northbridges
is not initialized anymore if not explicitly
called. This resulted in uninitialized pointers in
<arch/x86/kernel/cpu/intel_cacheinfo.c:amd_calc_l3_indices()>,
for example, which uses the num_k8_northbridges thing through
node_to_k8_nb_misc().
Fix that through an initcall that runs right after the PCI
subsystem and does all the scanning. Then, remove initialization
in gart_iommu_init() which is a rootfs_initcall and we're
running before that.
What is more, since num_k8_northbridges is being used in other
places beside GART IOMMU, include it whenever we add AMD CPU
support. The previous dependency chain in kconfig contained
K8_NB depends on AGP_AMD64|GART_IOMMU
which was clearly incorrect. The more natural way in terms of
hardware dependency should be
AGP_AMD64|GART_IOMMU depends on K8_NB depends on CPU_SUP_AMD &&
PCI. Make it so Number One!
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20100312144303.GA29262@aftab>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Joerg Roedel <joerg.roedel@amd.com>
---
arch/x86/Kconfig | 4 ++--
arch/x86/kernel/k8.c | 14 ++++++++++++++
arch/x86/kernel/pci-gart_64.c | 2 +-
drivers/char/agp/Kconfig | 2 +-
4 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index eb4092568f9e..ddb52b8d38a7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -627,7 +627,7 @@ config GART_IOMMU
bool "GART IOMMU support" if EMBEDDED
default y
select SWIOTLB
- depends on X86_64 && PCI
+ depends on X86_64 && PCI && K8_NB
---help---
Support for full DMA access of devices with 32bit memory access only
on systems with more than 3GB. This is usually needed for USB,
@@ -2026,7 +2026,7 @@ endif # X86_32
config K8_NB
def_bool y
- depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
+ depends on CPU_SUP_AMD && PCI
source "drivers/pcmcia/Kconfig"
diff --git a/arch/x86/kernel/k8.c b/arch/x86/kernel/k8.c
index cbc4332a77b2..9b895464dd03 100644
--- a/arch/x86/kernel/k8.c
+++ b/arch/x86/kernel/k8.c
@@ -121,3 +121,17 @@ void k8_flush_garts(void)
}
EXPORT_SYMBOL_GPL(k8_flush_garts);
+static __init int init_k8_nbs(void)
+{
+ int err = 0;
+
+ err = cache_k8_northbridges();
+
+ if (err < 0)
+ printk(KERN_NOTICE "K8 NB: Cannot enumerate AMD northbridges.\n");
+
+ return err;
+}
+
+/* This has to go after the PCI subsystem */
+fs_initcall(init_k8_nbs);
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 34de53b46f87..f3af115a573a 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -735,7 +735,7 @@ int __init gart_iommu_init(void)
unsigned long scratch;
long i;
- if (cache_k8_northbridges() < 0 || num_k8_northbridges == 0)
+ if (num_k8_northbridges == 0)
return 0;
#ifndef CONFIG_AGP_AMD64
diff --git a/drivers/char/agp/Kconfig b/drivers/char/agp/Kconfig
index 2fb3a480f6b0..4b66c69eaf57 100644
--- a/drivers/char/agp/Kconfig
+++ b/drivers/char/agp/Kconfig
@@ -57,7 +57,7 @@ config AGP_AMD
config AGP_AMD64
tristate "AMD Opteron/Athlon64 on-CPU GART support"
- depends on AGP && X86
+ depends on AGP && X86 && K8_NB
help
This option gives you AGP support for the GLX component of
X using the on-CPU northbridge of the AMD Athlon64/Opteron CPUs.