Re: [PATCH 02/20] nubus-device: expose separate super slot memory region

[Philippe Mathieu-Daudé]

On 9/12/21 7:20 PM, Mark Cave-Ayland wrote:
> On 12/09/2021 16:50, Philippe Mathieu-Daudé wrote:
> 
>> On 9/12/21 9:48 AM, Mark Cave-Ayland wrote:
>>> According to "Designing Cards and Drivers for the Macintosh Family"
>>> each physical
>>> nubus slot can access 2 separate address ranges: a super slot memory
>>> region which
>>> is 256MB and a standard slot memory region which is 16MB.
>>>
>>> Currently a Nubus device uses the physical slot number to determine
>>> whether it is
>>> using a standard slot memory region or a super slot memory region
>>> rather than
>>> exposing both memory regions for use as required.
>>>
>>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>>> ---
>>>   hw/nubus/nubus-device.c  | 36 ++++++++++++++++++------------------
>>>   include/hw/nubus/nubus.h |  1 +
>>>   2 files changed, 19 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/hw/nubus/nubus-device.c b/hw/nubus/nubus-device.c
>>> index be01269563..36203848e5 100644
>>> --- a/hw/nubus/nubus-device.c
>>> +++ b/hw/nubus/nubus-device.c
>>> @@ -168,26 +168,26 @@ static void nubus_device_realize(DeviceState
>>> *dev, Error **errp)
>>>       }
>>>         nd->slot = nubus->current_slot++;
>>> -    name = g_strdup_printf("nubus-slot-%d", nd->slot);
>>> -
>>> -    if (nd->slot < NUBUS_FIRST_SLOT) {
>>> -        /* Super */
>>> -        slot_offset = (nd->slot - 6) * NUBUS_SUPER_SLOT_SIZE;
>>> -
>>> -        memory_region_init(&nd->slot_mem, OBJECT(dev), name,
>>> -                           NUBUS_SUPER_SLOT_SIZE);
>>> -        memory_region_add_subregion(&nubus->super_slot_io, slot_offset,
>>> -                                    &nd->slot_mem);
>>> -    } else {
>>> -        /* Normal */
>>> -        slot_offset = nd->slot * NUBUS_SLOT_SIZE;
>>> -
>>> -        memory_region_init(&nd->slot_mem, OBJECT(dev), name,
>>> NUBUS_SLOT_SIZE);
>>> -        memory_region_add_subregion(&nubus->slot_io, slot_offset,
>>> -                                    &nd->slot_mem);
>>> -    }
>>>   +    /* Super */
>>> +    slot_offset = (nd->slot - 6) * NUBUS_SUPER_SLOT_SIZE;
>>> +
>>> +    name = g_strdup_printf("nubus-super-slot-%x", nd->slot);
>>> +    memory_region_init(&nd->super_slot_mem, OBJECT(dev), name,
>>> +                        NUBUS_SUPER_SLOT_SIZE);
>>> +    memory_region_add_subregion(&nubus->super_slot_io, slot_offset,
>>> +                                &nd->super_slot_mem);
>>> +    g_free(name);
>>> +
>>> +    /* Normal */
>>> +    slot_offset = nd->slot * NUBUS_SLOT_SIZE;
>>> +
>>> +    name = g_strdup_printf("nubus-slot-%x", nd->slot);
>>
>> I'd rather use "nubus-standard-slot-%x" or "nubus-normal-slot-%x"
>> to differentiate from super-bus. (This also applies to variable
>> names and trace events in this series).
> 
> I can see how this may seem ambiguous, however in "Designing Cards and
> Drivers for the Macintosh Family" the documentation always refers to
> "slot" as a standard slot so there shouldn't be any confusion for
> developers here.

OK, fine then.

>> Anyway,
>> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>