Re: [Qemu-devel] [PATCH v3 3/4] arm: Add PCIe host bridge in virt machine

[Peter Maydell]

On 29 January 2015 at 15:06, Alexander Graf <address@hidden> wrote:
> Now that we have a working "generic" PCIe host bridge driver, we can plug
> it into ARM's virt machine to always have PCIe available to normal ARM VMs.
> -    /* 0x10000000 .. 0x40000000 reserved for PCI */
> +    /* PCIe region layout: [ MMIO | PIO | ECAM ] */
> +    [VIRT_PCIE] =       { 0x10000000, 0x30000000 },

> +    /*
> +     * Align all the regions to their respective positions. Eventually
> +     * we want to have:
> +     *
> +     *  < MMIO space >
> +     *  < IO Port space >
> +     *  < ECAM space >
> +     *
> +     * all naturally aligned after each other. The MMIO region always starts
> +     * at 0 and shrinks depending on the size of the other 2 regions.
> +     */

This is still very opaque to me. Can't we just have a comment that
tells the reader how big the MMIO, IO and ECAM windows are without
requiring them to cross reference it with the previous array and
do a bunch of mental arithmetic?

For preference, this comment should live in the a15memmap[] array
where we document all the rest of the memory map.

thanks
-- PMM