From 4c374af5fdee4bc6b4f5ea96c1a0f0ad7d3566be Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Sat, 18 Aug 2012 07:34:15 +0000 Subject: powerpc/dma-iommu: Fix IOMMU window check 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 Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/dma-iommu.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c index 2d7bb8ced136..e4897523de41 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; -- cgit v1.2.3