Checking for device mask to cover the whole IOMMU table is too strict.
IOMMU allocators should handle mask constraint properly for each
allocation.
The patch enables to use old AirPort Extreme cards on PowerMacs with
more than 1GB of memory; without the patch the driver init fails with:
b43-pci-bridge 0001:01:01.0: Warning: IOMMU window too big for device mask
b43-pci-bridge 0001:01:01.0: mask: 0x3fffffff, table end: 0x80000000
b43-phy0 ERROR: The machine/kernel does not support the required 30-bit DMA
mask
Signed-off-by: Aaro Koskinen <aaro.koski...@iki.fi>
---
arch/powerpc/kernel/dma-iommu.c | 9 ++++-----
1 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index 2d7bb8c..e489752 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -83,11 +83,10 @@ static int dma_iommu_dma_supported(struct device *dev, u64
mask)
return 0;
}
- if ((tbl->it_offset + tbl->it_size) > (mask >> IOMMU_PAGE_SHIFT)) {
- dev_info(dev, "Warning: IOMMU window too big for device
mask\n");
- dev_info(dev, "mask: 0x%08llx, table end: 0x%08lx\n",
- mask, (tbl->it_offset + tbl->it_size) <<
- IOMMU_PAGE_SHIFT);
+ if (tbl->it_offset > (mask >> IOMMU_PAGE_SHIFT)) {
+ dev_info(dev, "Warning: IOMMU offset too big for device
mask\n");
+ dev_info(dev, "mask: 0x%08llx, table offset: 0x%08lx\n",
+ mask, tbl->it_offset << IOMMU_PAGE_SHIFT);
return 0;
} else
return 1;
--
1.7.2.5
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