x86, k8 nb: Fix boot crash: enable k8_northbridges unconditionally on AMD systems
authorBorislav Petkov <bp@amd64.org>
Fri, 12 Mar 2010 14:43:03 +0000 (15:43 +0100)
committerIngo Molnar <mingo@elte.hu>
Sat, 13 Mar 2010 07:36:16 +0000 (08:36 +0100)
commit0e152cd7c16832bd5cadee0c2e41d9959bc9b6f9
treec84df0d86adf5347268939be88426394cd28e18e
parent8447b360a3897bdfb0677107564d1dd9ab6e63be
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
arch/x86/kernel/k8.c
arch/x86/kernel/pci-gart_64.c
drivers/char/agp/Kconfig