Re: [PATCH 04/14] sysbus: Add sysbus_mmio_map_in

[Peter Maydell]

On Thu, 23 Jun 2022 at 11:56, Peter Delevoryas <pdel@fb.com> wrote:
>
> Signed-off-by: Peter Delevoryas <pdel@fb.com>
> ---
>  hw/core/sysbus.c    | 6 ++++++
>  include/hw/sysbus.h | 2 ++
>  2 files changed, 8 insertions(+)
>
> diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c
> index cb4d6bae9d..7b63ec3fed 100644
> --- a/hw/core/sysbus.c
> +++ b/hw/core/sysbus.c
> @@ -160,6 +160,12 @@ void sysbus_mmio_map(SysBusDevice *dev, int n, hwaddr 
> addr)
>      sysbus_mmio_map_common(dev, n, addr, false, 0, get_system_memory());
>  }
>
> +void sysbus_mmio_map_in(SysBusDevice *dev, int n, hwaddr addr,
> +                        MemoryRegion *system_memory)
> +{
> +    sysbus_mmio_map_common(dev, n, addr, false, 0, system_memory);
> +}
> +
>  void sysbus_mmio_map_overlap(SysBusDevice *dev, int n, hwaddr addr,
>                               int priority)
>  {
> diff --git a/include/hw/sysbus.h b/include/hw/sysbus.h
> index a7c23d5fb1..f4578029e4 100644
> --- a/include/hw/sysbus.h
> +++ b/include/hw/sysbus.h
> @@ -80,6 +80,8 @@ void sysbus_connect_irq(SysBusDevice *dev, int n, qemu_irq 
> irq);
>  bool sysbus_is_irq_connected(SysBusDevice *dev, int n);
>  qemu_irq sysbus_get_connected_irq(SysBusDevice *dev, int n);
>  void sysbus_mmio_map(SysBusDevice *dev, int n, hwaddr addr);
> +void sysbus_mmio_map_in(SysBusDevice *dev, int n, hwaddr addr,
> +                        MemoryRegion *system_memory);
>  void sysbus_mmio_map_overlap(SysBusDevice *dev, int n, hwaddr addr,
>                               int priority);

What's this going to be used for?

The current standard way to map a sysbus MMIO region into something
other than the global system memory region is to do:
   memory_region_add_subregion(&container, addr,
                               sysbus_mmio_get_region(sbd, 0));

I'd rather not have two ways to do the same thing; we have
far too many of those already.

thanks
-- PMM