Re: [PATCH v2 7/8] powerpc/pgtable: remove _PAGE_BIT_SWAP_TYPE for book3s

From: David Hildenbrand <david@redhat.com>
To: Christophe Leroy <christophe.leroy@csgroup.eu>,
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Subject: Re: [PATCH v2 7/8] powerpc/pgtable: remove _PAGE_BIT_SWAP_TYPE for book3s
Date: Wed, 30 Mar 2022 08:58:32 +0200	[thread overview]
Message-ID: <3272510e-ff5c-8694-c45c-7be9eaed4b42@redhat.com> (raw)
In-Reply-To: <22d3c42d-402f-8aeb-e989-c05d023b2ed3@csgroup.eu>

On 30.03.22 08:07, Christophe Leroy wrote:
> 
> 
> Le 29/03/2022 à 18:43, David Hildenbrand a écrit :
>> The swap type is simply stored in bits 0x1f of the swap pte. Let's
>> simplify by just getting rid of _PAGE_BIT_SWAP_TYPE. It's not like that
>> we can simply change it: _PAGE_SWP_SOFT_DIRTY would suddenly fall into
>> _RPAGE_RSV1, which isn't possible and would make the
>> BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_SOFT_DIRTY) angry.
>>
>> While at it, make it clearer which bit we're actually using for
>> _PAGE_SWP_SOFT_DIRTY by just using the proper define and introduce and
>> use SWP_TYPE_MASK.
>>
>> Signed-off-by: David Hildenbrand <david@redhat.com>
>> ---
>>   arch/powerpc/include/asm/book3s/64/pgtable.h | 12 +++++-------
> 
> Why only BOOK3S ? Why not BOOK3E as well ?

Hi Cristophe,

I'm focusing on the most relevant enterprise architectures for now. I
don't have the capacity to convert each and every architecture at this
point (especially, I don't to waste my time in case this doesn't get
merged, and book3e didn't look straight forward to me).

Once this series hits upstream, I can look into other architectures --
and I'll be happy if other people jump in that have more familiarity
with the architecture-specific swp pte layouts.

Thanks

-- 
Thanks,

David / dhildenb