diff mbox series

[v4,02/20] nubus-device: expose separate super slot memory region

Message ID 20210917075057.20924-3-mark.cave-ayland@ilande.co.uk (mailing list archive)
State New, archived
Headers show
Series nubus: bus, device, bridge, IRQ and address space improvements | expand

Commit Message

Mark Cave-Ayland Sept. 17, 2021, 7:50 a.m. UTC 
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>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/nubus/nubus-device.c  | 36 ++++++++++++++++++------------------
 include/hw/nubus/nubus.h |  1 +
 2 files changed, 19 insertions(+), 18 deletions(-)

Comments

Laurent Vivier Sept. 20, 2021, 7:54 p.m. UTC | #1 
Le 17/09/2021 à 09:50, Mark Cave-Ayland a écrit :
> 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>
> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  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;
> +

Is it possible to remove this patch?

The "(nd->slot - 6)" looks weird and it is removed in patch 20.

If not:

Reviewed-by: Laurent Vivier <laurent@vivier.eu>

Thanks,
Laurent
Mark Cave-Ayland Sept. 22, 2021, 10:24 a.m. UTC | #2 
On 20/09/2021 20:54, Laurent Vivier wrote:

> Le 17/09/2021 à 09:50, Mark Cave-Ayland a écrit :
>> 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>
>> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>>   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;
>> +
> 
> Is it possible to remove this patch?
> 
> The "(nd->slot - 6)" looks weird and it is removed in patch 20.

This is another place where I decided to keep the existing logic as-is and then make 
the change to remove the -6 offset later on in patch 12 ("nubus: move nubus to its 
own 32-bit address space").

Certainly the existing offset is wrong, but given that there are currently no devices 
that use the super slot then I will bring the change to remove the offset forward to 
this patch in v5.

> If not:
> 
> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
> 
> Thanks,
> Laurent


ATB,

Mark.
diff mbox series

Patch

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);
+    memory_region_init(&nd->slot_mem, OBJECT(dev), name, NUBUS_SLOT_SIZE);
+    memory_region_add_subregion(&nubus->slot_io, slot_offset,
+                                &nd->slot_mem);
     g_free(name);
+
     nubus_register_format_block(nd);
 }
 
diff --git a/include/hw/nubus/nubus.h b/include/hw/nubus/nubus.h
index 424309dd73..89b0976aaa 100644
--- a/include/hw/nubus/nubus.h
+++ b/include/hw/nubus/nubus.h
@@ -43,6 +43,7 @@  struct NubusDevice {
     DeviceState qdev;
 
     int slot;
+    MemoryRegion super_slot_mem;
     MemoryRegion slot_mem;
 
     /* Format Block */