Re: [PATCH v6 2/3] iommu/pci: reserve IOVA for PCI masters
From: Oza Oza
Date: Thu May 18 2017 - 21:21:34 EST
On Wed, May 17, 2017 at 10:41 PM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> 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/
Hi Bjorn,
Thank you for the comments.
Will take care of all your comments.
Regards,
Oza.