Re: [PATCH 5/5] cmd646: move device-specific BMDMA registers to separate memory region

[Philippe Mathieu-Daudé]

On 12/6/23 21:28, Bernhard Beschow wrote:
> Am 9. Juni 2023 18:51:19 UTC schrieb Mark Cave-Ayland 
> <mark.cave-ayland@ilande.co.uk>:
> > The aim here is to eliminate any device-specific registers from the main BMDMA
> > bar memory region so it can potentially be moved into the shared PCI IDE device.
> >
> > For each BMDMA bus create a new cmd646-bmdma-specific memory region representing
> > the device-specific BMDMA registers and then map them using aliases onto the
> > existing BMDMAState memory region.
> >
> > Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> > ---
> > hw/ide/cmd646.c         | 111 +++++++++++++++++++++++++++++++---------
> > include/hw/ide/cmd646.h |   4 ++
> > 2 files changed, 90 insertions(+), 25 deletions(-)


> > struct CMD646IDEState {
> >      PCIIDEState parent_obj;
> > +
> > +    MemoryRegion bmdma_mem[2];
> > +    MemoryRegion bmdma_mem_alias[2][2];
>
> The added complexity of a two-dimensional alias array seems like a tough call 
> for me. I'm not totally against it but I'm reluctant.

Alternative:

        struct {
            MemoryRegion mem;
            MemoryRegion mem_alias[2];
        } bmdma[2];

> > };
> >
> > #endif