Re: [dpdk-dev] [PATCH v6 2/2] bus/pci: support MMIO in PCI ioport accessors

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 2/9/2021 2:51 PM, Ferruh Yigit wrote:
> On 1/29/2021 3:18 AM, 谢华伟(此时此刻） wrote:
>> From: "huawei.xhw" <huawei.xhw@alibaba-inc.com>
>>
>> With IO BAR, we get PIO(programmed IO) address.
>> With MMIO BAR, we get mapped virtual address.
>> We distinguish PIO(Programmed IO) and MMIO(memory mapped IO) by their address 
>> like how kernel does.
>> ioread/write8/16/32 is provided to access PIO/MMIO.
>> By the way, for virtio on arch other than x86, BAR flag indicates PIO but is 
>> mapped.
>>
>> Signed-off-by: huawei xie <huawei.xhw@alibaba-inc.com>
>> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> 
> <...>
> 
>> +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);
> 
> Is the 'outb_p' to 'outb' conversion intentional? And if so why?
> 
> Same of the all 'outb_p', 'outw_p', 'outl_p'.
> 

Reminder of above question.

Let's try to close this patch before release pressure hit again.
And as far as I understand already a new version is required for build errors on 
non x86 architectures.

> <...>
> 
>>               size = 1;
>> -#if defined(RTE_ARCH_X86)
>> -            outb_p(*s, reg);
>> -#else
>> -            *(volatile uint8_t *)reg = *s;
>> -#endif
>> +            iowrite8(*s, (void *)reg);
>>           }
>>       }
>>   }
>>
>