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

[Ferruh Yigit]

On 1/29/2021 3:18 AM, 谢华伟(此时此刻） wrote:
> From: "huawei.xhw" <huawei.xhw at 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 at alibaba-inc.com>
> Reviewed-by: Maxime Coquelin <maxime.coquelin at 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'.

<...>

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