Re: [dpdk-dev] [PATCH v7 2/2] bus/pci: support MMIO in PCI ioport accessors

["谢华伟(此时此刻）" <huawei.xhw@alibaba-inc.com>]

On 2021/3/2 21:14, David Marchand wrote:
>>> This change is a fix/optimisation.
>>> This is a separate topic from adding MMIO support with x86 ioport.
>>> I would split as a separate patch.
>> Hi David:
>>
>> Maybe there is confuse? There is no change. The out/in is added. I don't
>> remove _p on purpose.
> Looking at v8 and repeating previous mails:
>
> +#if defined(RTE_ARCH_X86)
> ...
> +static inline void iowrite8(uint8_t val, void *addr)
> +{
> +    (uint64_t)(uintptr_t)addr >= PIO_MAX ?
> +        *(volatile uint8_t *)addr = val :
> +        outb(val, (unsigned long)addr); <======
> +}
>
> [...]
>
>
> -#if defined(RTE_ARCH_X86)
> -            outb_p(*s, reg); <======
> -#else
> -            *(volatile uint8_t *)reg = *s;
> -#endif
> +            iowrite8(*s, (void *)reg);
>
>
> This almost went unnoticed (thanks Ferruh for spotting).
>
> Do we_need_  this change on outX_p -> outX?

I understand where the confuse comes from. In the previous 
implementation, it is _p version, however i think _p is not needed.

In the initial DPDK virtio PMD, there is no _p, if my memory is correct. 
Don't know who added it, if any reason.

Anyway, i will send v9 with _p.

> I am not comfortable at touching such low level internal routines that
> have been in dpdk since v1.5.0.
>
> If there is a good reason, it has nothing to do with adding MMIO
> support and must be split in a separate patch.
> If there is no reason, please restore outX_p, since the safest is not to touch.