Subject: [PATCH v3 2/5] ARM: vexpress: Get rid of MMIO_P2V

From: [email-masked] (Arnd Bergmann)
Date: Tue, 29 Nov 2011 21:15:10 +0000

On Tuesday 29 November 2011, Pawel Moll wrote:
> @@ -1,6 +1,3 @@
> -#define __MMIO_P2V(x)  (((x) & 0xfffff) | (((x) & 0x0f000000) >> 4) | 0xf8000000)
> -#define MMIO_P2V(x)    ((void __iomem *)__MMIO_P2V(x))
> -
...
> +
> +/* 2MB large area for motherboard's peripherals static mapping */
> +#define V2M_PERIPH 0xf8000000
> +#define V2M_PERIPH_P2V(offset) ((void __iomem *)(V2M_PERIPH | (offset)))
> +
> +/* Tile's peripherals static mappings should start here */
> +#define V2T_PERIPH 0xf8200000
> +#define V2T_PERIPH_P2V(offset) ((void __iomem *)(V2T_PERIPH | (offset)))

I think it would be even better if you could express the same with
pointer arithmetic instead of the macro, like:

#define V2M_PERIPH ((void __iomem *)0xf8000000)
#define V2T_PERIPH ((void __iomem *)0xf8200000)

and then instead of 

+       gic_init(0, 29, V2T_PERIPH_P2V(A9_MPCORE_GIC_DIST),
+                V2T_PERIPH_P2V(A9_MPCORE_GIC_CPU));

do 

+       gic_init(0, 29, V2T_PERIPH + A9_MPCORE_GIC_DIST,
+                V2T_PERIPH + A9_MPCORE_GIC_CPU);

and so on. This ends up being more readable IMHO because it
means you don't have to know what the macro does.

	Arnd