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Message-ID: <1af8c4ed38981332bcd8ffcf003d70c4a6f766ef.camel@gmail.com>
Subject: Re: [PATCH 1/1] powerpc/iommu: Enable remaining IOMMU Pagesizes
 present in LoPAR
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>,
        Christophe Leroy <christophe.leroy@c-s.fr>,
        Joel Stanley <joel@jms.id.au>, brking@linux.vnet.ibm.com
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Date:   Wed, 07 Apr 2021 16:58:27 -0300
In-Reply-To: <2088f84c-08fb-fecc-f5d4-5735357dc296@ozlabs.ru>
References: <20210322190943.715368-1-leobras.c@gmail.com>
         <2088f84c-08fb-fecc-f5d4-5735357dc296@ozlabs.ru>
Organization: IBM
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Hello Alexey,

On Tue, 2021-03-23 at 18:41 +1100, Alexey Kardashevskiy wrote:
[...]
> > +#define IOMMU_PAGE_SHIFT_16G	34
> > +#define IOMMU_PAGE_SHIFT_256M	28
> > +#define IOMMU_PAGE_SHIFT_128M	27
> > +#define IOMMU_PAGE_SHIFT_64M	26
> > +#define IOMMU_PAGE_SHIFT_32M	25
> > +#define IOMMU_PAGE_SHIFT_16M	24
> > +#define IOMMU_PAGE_SHIFT_64K	16
> 
> 
> These are not very descriptive, these are just normal shifts, could be 
> as simple as __builtin_ctz(SZ_4K) (gcc will optimize this) and so on.
> 
> OTOH the PAPR page sizes need macros as they are the ones which are 
> weird and screaming for macros.
> 
> I'd steal/rework spapr_page_mask_to_query_mask() from QEMU. Thanks,
> 

Thanks for this feedback!
I just sent a v2 applying your suggestions.

Best regards,
Leonardo Bras