Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1609943

Re: [RFC PATCH 1/3] of/pci: dma-ranges to account highest possible host bridge dma_mask

Show all headers | View raw

On Sat, Mar 25, 2017 at 12:31 AM, Oza Pawandeep <oza.oza@broadcom.com> wrote:
> it is possible that PCI device supports 64-bit DMA addressing,
> and thus it's driver sets device's dma_mask to DMA_BIT_MASK(64),
> however PCI host bridge may have limitations on the inbound
> transaction addressing. As an example, consider NVME SSD device
> connected to iproc-PCIe controller.
>
> Currently, the IOMMU DMA ops only considers PCI device dma_mask
> when allocating an IOVA. This is particularly problematic on
> ARM/ARM64 SOCs where the IOMMU (i.e. SMMU) translates IOVA to
> PA for in-bound transactions only after PCI Host has forwarded
> these transactions on SOC IO bus. This means on such ARM/ARM64
> SOCs the IOVA of in-bound transactions has to honor the addressing
> restrictions of the PCI Host.
>
> current pcie frmework and of framework integration assumes dma-ranges
> in a way where memory-mapped devices define their dma-ranges.
> dma-ranges: (child-bus-address, parent-bus-address, length).
>
> but iproc based SOCs and even Rcar based SOCs has PCI world dma-ranges.
> dma-ranges = <0x43000000 0x00 0x00 0x00 0x00 0x80 0x00>;

If you implement a common function, then I expect to see other users
converted to use it. There's also PCI hosts in arch/powerpc that parse
dma-ranges.

Rob

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RFC PATCH 1/3] of/pci: dma-ranges to account highest possible host bridge dma_mask Oza Pawandeep <oza.oza@broadcom.com> - 2017-03-25 06:40 +0100
  [RFC PATCH 3/3] of: fix node traversing in of_dma_get_range Oza Pawandeep <oza.oza@broadcom.com> - 2017-03-25 06:40 +0100
    Re: [RFC PATCH 3/3] of: fix node traversing in of_dma_get_range Rob Herring <robh@kernel.org> - 2017-03-27 16:40 +0200
      Re: [RFC PATCH 3/3] of: fix node traversing in of_dma_get_range Robin Murphy <robin.murphy@arm.com> - 2017-03-27 16:50 +0200
        Re: [RFC PATCH 3/3] of: fix node traversing in of_dma_get_range Oza Oza <oza.oza@broadcom.com> - 2017-03-28 07:00 +0200
  Re: [RFC PATCH 1/3] of/pci: dma-ranges to account highest possible  host bridge dma_mask Rob Herring <robh@kernel.org> - 2017-03-27 17:20 +0200
    Re: [RFC PATCH 1/3] of/pci: dma-ranges to account highest possible  host bridge dma_mask Oza Oza <oza.oza@broadcom.com> - 2017-03-28 07:30 +0200
      Re: [RFC PATCH 1/3] of/pci: dma-ranges to account highest possible  host bridge dma_mask Rob Herring <robh@kernel.org> - 2017-03-28 16:20 +0200
        Re: [RFC PATCH 1/3] of/pci: dma-ranges to account highest possible  host bridge dma_mask Oza Oza <oza.oza@broadcom.com> - 2017-03-30 12:20 +0200
      Re: [RFC PATCH 1/3] of/pci: dma-ranges to account highest possible  host bridge dma_mask Robin Murphy <robin.murphy@arm.com> - 2017-03-28 16:40 +0200
        Re: [RFC PATCH 1/3] of/pci: dma-ranges to account highest possible  host bridge dma_mask Oza Oza <oza.oza@broadcom.com> - 2017-03-29 06:50 +0200
          Re: [RFC PATCH 1/3] of/pci: dma-ranges to account highest possible  host bridge dma_mask Oza Oza <oza.oza@broadcom.com> - 2017-03-30 05:30 +0200

csiph-web