[GIT PULL v3] updates to qbman (soc drivers) to support arm/arm64

[Arnd Bergmann]

On Tue, Jun 27, 2017 at 11:10 AM, Russell King - ARM Linux
<linux at armlinux.org.uk> wrote:
> On Tue, Jun 27, 2017 at 11:05:38AM +0200, Arnd Bergmann wrote:
>> On Tue, Jun 27, 2017 at 10:17 AM, Russell King - ARM Linux
>> <linux at armlinux.org.uk> wrote:
>>
>> I wonder if doing memcpy_toio on the write-combining mapping
>> will do what Roy wants and and up sending a single bus transaction
>> for one descriptor most of the time, while fitting in with the ioremap_wc()
>> interface and its __iomem pointers.
>
> Either the CE region needs __iomem pointers and proper accessors, or
> it needs to be using memremap(offset, size, MEMREMAP_WC) and not use
> the iomem accessors.

Right, memremap() would work here as well. If there are no other constraints,
using ioremap_wc and __iomem pointers would have the advantage of giving
us a little more type safety, but it depends on what operations we actually
need to do on the data.

        Arnd