diff options
| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2019-07-18 15:11:37 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-08-19 13:20:23 +1000 |
| commit | 4f7e0babbc7c46fc0db4f5c14fe96bf6f4d69502 (patch) | |
| tree | 549d02dccf2d289f3cc689b4880a6cbadc94b03c | |
| parent | 56090a3902c80c296e822d11acdb6a101b322c52 (diff) | |
| download | linux-4f7e0babbc7c46fc0db4f5c14fe96bf6f4d69502.tar.bz2 | |
powerpc/iommu: Allow bypass-only for DMA
POWER8 and newer support a bypass mode which maps all host memory to
PCI buses so an IOMMU table is not always required. However if we fail to
create such a table, the DMA setup fails and the kernel does not boot.
This skips the 32bit DMA setup check if the bypass is selected.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190718051139.74787-3-aik@ozlabs.ru
| -rw-r--r-- | arch/powerpc/kernel/dma-iommu.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c index a0879674a9c8..c963d704fa31 100644 --- a/arch/powerpc/kernel/dma-iommu.c +++ b/arch/powerpc/kernel/dma-iommu.c @@ -122,18 +122,17 @@ int dma_iommu_dma_supported(struct device *dev, u64 mask) { struct iommu_table *tbl = get_iommu_table_base(dev); - if (!tbl) { - dev_info(dev, "Warning: IOMMU dma not supported: mask 0x%08llx" - ", table unavailable\n", mask); - return 0; - } - if (dev_is_pci(dev) && dma_iommu_bypass_supported(dev, mask)) { dev->archdata.iommu_bypass = true; dev_dbg(dev, "iommu: 64-bit OK, using fixed ops\n"); return 1; } + if (!tbl) { + dev_err(dev, "Warning: IOMMU dma not supported: mask 0x%08llx, table unavailable\n", mask); + return 0; + } + if (tbl->it_offset > (mask >> tbl->it_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", |