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Subject: Re: [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for
 operations in ibm,ddw-applicable
From:   Leonardo Bras <leobras.c@gmail.com>
To:     Alexey Kardashevskiy <aik@ozlabs.ru>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Thiago Jung Bauermann <bauerman@linux.ibm.com>,
        Ram Pai <linuxram@us.ibm.com>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Date:   Wed, 01 Jul 2020 21:36:12 -0300
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On Thu, 2020-07-02 at 10:21 +1000, Alexey Kardashevskiy wrote:
> > 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.

Makes sense to me.
I am still getting experience on where to use enum vs define. Thanks
for the tip!

Using something like 
enum {
	DDW_QUERY_PE_DMA_WIN = 0,
	DDW_CREATE_PE_DMA_WIN = 1,
	DDW_REMOVE_PE_DMA_WIN = 2,

	DDW_APPLICABLE_SIZE
};

would be fine too?
Or should one stick to #define in this case?

Thank you,