Re: [PATCH] drivers/char/mem.c: Add /dev/ioports, supporting 16-bit and 32-bit ports

From: H. Peter Anvin
Date: Tue Dec 22 2015 - 17:03:10 EST


On December 22, 2015 1:56:20 PM PST, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>On Tuesday 22 December 2015, Santosh Shukla wrote:
>> }
>>
>> So I care for /dev/ioport types interface who could do more than byte
>> data copy to/from user-space. I tested this patch with little
>> modification and could able to run pmd driver for arm/arm64 case.
>>
>> Like to know how to address pci_io region mapping problem for
>> arm/arm64, in-case /dev/ioports approach is not acceptable or else I
>> can spent time on restructuring the patch?
>>
>
>For the use case you describe, can't you use the vfio framework to
>access the PCI BARs?
>
>After all, you are talking about regular PCI devices, not access to
>random unknown I/O port numbers.
>
> Arnd

On that subject, shouldn't we have common infrastructure to deal with memory mapped I/O ports in the kernel? Or do we have that now? I obviously don't pay too much attention...
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