Re: [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable

From: Alexey Kardashevskiy
Date: Wed Jul 01 2020 - 20:21:40 EST




On 01/07/2020 23:28, Leonardo Bras wrote:
> On Wed, 2020-07-01 at 18:16 +1000, Alexey Kardashevskiy wrote:
>>
>> On 24/06/2020 16:24, Leonardo Bras wrote:
>>> Create defines to help handling ibm,ddw-applicable values, avoiding
>>> confusion about the index of given operations.
>>>
>>> Signed-off-by: Leonardo Bras <leobras.c@xxxxxxxxx>
>>> ---
>>> arch/powerpc/platforms/pseries/iommu.c | 40 +++++++++++++++-----------
>>> 1 file changed, 23 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
>>> index 6d47b4a3ce39..68d2aa9c71a8 100644
>>> --- a/arch/powerpc/platforms/pseries/iommu.c
>>> +++ b/arch/powerpc/platforms/pseries/iommu.c
>>> @@ -39,6 +39,11 @@
>>>
>>> #include "pseries.h"
>>>
>>> +#define DDW_QUERY_PE_DMA_WIN 0
>>> +#define DDW_CREATE_PE_DMA_WIN 1
>>> +#define DDW_REMOVE_PE_DMA_WIN 2
>>> +#define DDW_APPLICABLE_SIZE 3
>>
>> #define DDW_APPLICABLE_SIZE (DDW_REMOVE_PE_DMA_WIN + 1)
>>
>> thanks,
>
> Thanks for the feedback!
> About this (and patch #2), would it be better to use enum ?
> enum {
> DDW_QUERY_PE_DMA_WIN,
> DDW_CREATE_PE_DMA_WIN,
> DDW_REMOVE_PE_DMA_WIN,
>
> DDW_APPLICABLE_SIZE
> }
> IMO, it looks better than all the defines before.
>
> What do you think?

No, not really, these come from a binary interface so the reader of this
cares about absolute numbers and rather wants to see them explicitly.


--
Alexey