On Thu, May 30, 2019 at 05:03:53PM +1000, Alexey Kardashevskiy wrote: > 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 can be selected. > > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
>
> This minor thing helped me debugging next 2 patches so it can help
> somebody else too.
> ---
> arch/powerpc/kernel/dma-iommu.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
> index 09231ef06d01..809c1dc01edf 100644
> --- a/arch/powerpc/kernel/dma-iommu.c
> +++ b/arch/powerpc/kernel/dma-iommu.c
> @@ -118,18 +118,17 @@ 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",
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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