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authorNishanth Aravamudan <nacc@linux.vnet.ibm.com>2015-09-04 11:22:52 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-09-29 19:33:24 +0200
commit2561478bd278c61e6a349bf0b054ff562d3f3df7 (patch)
tree373253ca200d680a558ec93b28dce708abf1759a /arch
parent92b87ea1c17f438d85a29ba083259ee8c7fdb8c0 (diff)
powerpc/powernv/pci-ioda: fix kdump with non-power-of-2 crashkernel=
commit fa14486979b3a47307bcdb10f8b5baa875a5cf68 upstream. The 32-bit TCE table initialization relies on the DMA window having a size equal to a power of 2 (and checks for it explicitly). But crashkernel= has no constraint that requires a power-of-2 be specified. This causes the kdump kernel to fail to boot as none of the PCI devices (including the disk controller) are successfully initialized. After this change, the PCI devices successfully set up the 32-bit TCE table and kdump succeeds. Fixes: aca6913f5551 ("powerpc/powernv/ioda2: Introduce helpers to allocate TCE pages") Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Tested-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/platforms/powernv/pci-ioda.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index b5ff489213cd..8b64f89e68c9 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2079,12 +2079,18 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe)
long rc;
/*
+ * crashkernel= specifies the kdump kernel's maximum memory at
+ * some offset and there is no guaranteed the result is a power
+ * of 2, which will cause errors later.
+ */
+ const u64 max_memory = __rounddown_pow_of_two(memory_hotplug_max());
+
+ /*
* In memory constrained environments, e.g. kdump kernel, the
* DMA window can be larger than available memory, which will
* cause errors later.
*/
- const u64 window_size = min((u64)pe->table_group.tce32_size,
- memory_hotplug_max());
+ const u64 window_size = min((u64)pe->table_group.tce32_size, max_memory);
rc = pnv_pci_ioda2_create_table(&pe->table_group, 0,
IOMMU_PAGE_SHIFT_4K,