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Re: [PATCH v6 2/3] iommu/pci: reserve IOVA for PCI masters

From Bjorn Helgaas <helgaas@kernel.org>
Newsgroups linux.kernel
Subject Re: [PATCH v6 2/3] iommu/pci: reserve IOVA for PCI masters
Date 2017-05-17 19:20 +0200
Message-ID <tIaM9-5Vz-19@gated-at.bofh.it> (permalink)
References <tHDdv-1qC-3@gated-at.bofh.it> <tHDdw-1qC-17@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On Tue, May 16, 2017 at 10:52:06AM +0530, Oza Pawandeep wrote:
> this patch reserves the IOVA for PCI masters.
> ARM64 based SOCs may have scattered memory banks.
> such as iproc based SOC has
> 
> <0x00000000 0x80000000 0x0 0x80000000>, /* 2G @ 2G */
> <0x00000008 0x80000000 0x3 0x80000000>, /* 14G @ 34G */
> <0x00000090 0x00000000 0x4 0x00000000>, /* 16G @ 576G */
> <0x000000a0 0x00000000 0x4 0x00000000>; /* 16G @ 640G */
> 
> but incoming PCI transcation addressing capability is limited

s/transcation/transaction/

> by host bridge, for example if max incoming window capability
> is 512 GB, then 0x00000090 and 0x000000a0 will fall beyond it.
> 
> to address this problem, iommu has to avoid allocating IOVA which

s/iommu/IOMMU/

> are reserved. which inturn does not allocate IOVA if it falls into hole.

s/inturn/in turn/

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Thread

[PATCH v6 0/3] OF/PCI address PCI inbound memory limitations Oza Pawandeep <oza.oza@broadcom.com> - 2017-05-16 07:30 +0200
  [PATCH v6 2/3] iommu/pci: reserve IOVA for PCI masters Oza Pawandeep <oza.oza@broadcom.com> - 2017-05-16 07:30 +0200
    Re: [PATCH v6 2/3] iommu/pci: reserve IOVA for PCI masters Bjorn Helgaas <helgaas@kernel.org> - 2017-05-17 19:20 +0200
      Re: [PATCH v6 2/3] iommu/pci: reserve IOVA for PCI masters Oza Oza <oza.oza@broadcom.com> - 2017-05-19 03:30 +0200

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