Re: [PATCH v2 1/2] hw/ide: split bmdma read and write functions from piix.c

[Liav Albani <liavalb@gmail.com>]

On 2/19/22 02:12, BALATON Zoltan wrote:
> On Fri, 18 Feb 2022, Liav Albani wrote:
>> This is a preparation before implementing another PCI IDE controller
>> that relies on these functions, so these can be shared between both
>> implementations.
>>
>> Signed-off-by: Liav Albani <liavalb@gmail.com>
>> ---
>> hw/ide/bmdma.c         | 84 ++++++++++++++++++++++++++++++++++++++++++
>> hw/ide/meson.build     |  2 +-
>> hw/ide/piix.c          | 51 ++-----------------------
>> include/hw/ide/bmdma.h | 34 +++++++++++++++++
>> 4 files changed, 122 insertions(+), 49 deletions(-)
>> create mode 100644 hw/ide/bmdma.c
>> create mode 100644 include/hw/ide/bmdma.h
>>
>> diff --git a/hw/ide/bmdma.c b/hw/ide/bmdma.c
>> new file mode 100644
>> index 0000000000..d12ed730dd
>> --- /dev/null
>> +++ b/hw/ide/bmdma.c
>> @@ -0,0 +1,84 @@
>> +/*
>> + * QEMU IDE Emulation: Intel PCI Bus master IDE support for PIIX3/4 
>> and ICH6/7.
>> + *
>> + * Copyright (c) 2003 Fabrice Bellard
>> + * Copyright (c) 2006 Openedhand Ltd.
>> + *
>> + * Permission is hereby granted, free of charge, to any person 
>> obtaining a copy
>> + * of this software and associated documentation files (the 
>> "Software"), to deal
>> + * in the Software without restriction, including without limitation 
>> the rights
>> + * to use, copy, modify, merge, publish, distribute, sublicense, 
>> and/or sell
>> + * copies of the Software, and to permit persons to whom the 
>> Software is
>> + * furnished to do so, subject to the following conditions:
>> + *
>> + * The above copyright notice and this permission notice shall be 
>> included in
>> + * all copies or substantial portions of the Software.
>> + *
>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
>> EXPRESS OR
>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
>> MERCHANTABILITY,
>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT 
>> SHALL
>> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES 
>> OR OTHER
>> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
>> ARISING FROM,
>> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
>> DEALINGS IN
>> + * THE SOFTWARE.
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "hw/pci/pci.h"
>> +#include "migration/vmstate.h"
>> +#include "qapi/error.h"
>> +#include "qemu/module.h"
>> +#include "sysemu/block-backend.h"
>> +#include "sysemu/blockdev.h"
>> +#include "sysemu/dma.h"
>> +
>> +#include "hw/ide/bmdma.h"
>> +#include "hw/ide/pci.h"
>> +#include "trace.h"
>
> Are you sure you need all these includes? I haven't checked but I 
> think there may be some unneeded ones here. On the other hand I'm not 
> sure putting these in a new file is worth it. There are already some 
> bmdma_* functions in hw/ide/pci.c which are declared in 
> include/hw/ide/pci.h so you could just move these there too then no 
> new file, new header nor changes to meson.build is needed in this patch..
>
Good question, probably not. I'll try to build without them, adding only 
what seems necessary to complete the build. Also, I think adding those 
functions to hw/ide/pci.c is a very good idea as it will make the patch 
smaller and it also makes total sense to me - Bus Master capabilities 
only appear on PCI IDE controllers and not on the ISA IDE controller 
(AFAIK).

It will happen in v3 :)

>> +
>> +uint64_t intel_ide_bmdma_read(void *opaque, hwaddr addr, unsigned size)
>
> As I said before these aren't intel specific as the same functions 
> also appear in other ide controllers such as via.c so maybe a better 
> name would be bmdma_default_read and bmdma_default_write or somehting 
> similar so these can be also reused by other non-intel devices too.
>
Right, I see now that via.c uses the exact same functions... I'll change 
it in v3. The names bmdma_default_read and bmdma_default_write seem like 
a good choice to me.
> Regards,
> BALATON Zoltan
Thanks for the review!