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authorNishanth Aravamudan <nacc@us.ibm.com>2011-05-09 12:58:03 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-05-19 14:30:43 +1000
commiteb0dd411bd90dd5ad3f1936930d3e83d9ef95561 (patch)
treeafb5a630b5ea5e9fb0bc869106759fb0b120630c
parent40f1ce7fb7e8b5d4d0821c0f3dc866cb1d47d99c (diff)
downloadlinux-eb0dd411bd90dd5ad3f1936930d3e83d9ef95561.tar.bz2
pseries/iommu: Restore iommu table pointer when restoring iommu ops
When we swtich to direct dma ops, we set the dma data union to have the dma offset. When we switch back to iommu table ops because of a later dma_set_mask, we need to restore the iommu table pointer. Without this change, crashes have been observed on kexec where (for reasons still being investigated) we fall back to a 32-bit dma mask on a particular device and then panic because the table pointer is not valid. The easiset way to find this value is to call pci_dma_dev_setup_pSeriesLP which will search up the pci tree until it finds the node with the table. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Milton Miller <miltonm@bga.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/platforms/pseries/iommu.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 019009b10e62..48eec3b87026 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1029,10 +1029,10 @@ static int dma_set_mask_pSeriesLP(struct device *dev, u64 dma_mask)
if (!dev->dma_mask || !dma_supported(dev, dma_mask))
return -EIO;
+ pdev = to_pci_dev(dev);
+
/* only attempt to use a new window if 64-bit DMA is requested */
if (!disable_ddw && dma_mask == DMA_BIT_MASK(64)) {
- pdev = to_pci_dev(dev);
-
dn = pci_device_to_OF_node(pdev);
dev_dbg(dev, "node is %s\n", dn->full_name);
@@ -1063,6 +1063,7 @@ static int dma_set_mask_pSeriesLP(struct device *dev, u64 dma_mask)
if (!ddw_enabled) {
dev_info(dev, "Using 32-bit DMA via iommu\n");
set_dma_ops(dev, &dma_iommu_ops);
+ pci_dma_dev_setup_pSeriesLP(pdev);
}
*dev->dma_mask = dma_mask;