From: Christoph Hellwig <hch@infradead.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@infradead.org>,
linux-kernel@vger.kernel.org, npiggin@gmail.com,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v1 05/10] powerpc/mm: Do early ioremaps from top to bottom on PPC64 too.
Date: Tue, 13 Aug 2019 23:14:20 -0700 [thread overview]
Message-ID: <20190814061420.GA17453@infradead.org> (raw)
In-Reply-To: <1d44ec1d-339d-e22c-2133-175e0aa745f6@c-s.fr>
On Wed, Aug 14, 2019 at 08:10:59AM +0200, Christophe Leroy wrote:
> > Note that while a few other architectures have a magic hack like powerpc
> > to make ioremap work before vmalloc, the normal practice would be
> > to explicitly use early_ioremap. I guess your change is fine for now,
> > but it might make sense convert powerpc to the explicit early_ioremap
> > scheme as well.
> >
>
> I've been looking into early_ioremap(), but IIUC early_ioremap() is for
> ephemeral mappings only, it expects all early mappings to be gone at the end
> of init.
Yes.
> PPC installs definitive early mappings (for instance for PCI). How does that
> have to be handled ?
Good question, and no good answer. I've just been looking at a generic
ioremap for simple architectures, and been finding all kinds of crap
and inconsistencies, and this is one of the things I noticed.
next prev parent reply other threads:[~2019-08-14 6:14 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-13 20:11 [PATCH v1 01/10] powerpc/mm: drop ppc_md.iounmap() Christophe Leroy
2019-08-13 20:11 ` [PATCH v1 02/10] powerpc/mm: rework io-workaround invocation Christophe Leroy
2019-08-14 5:38 ` Christoph Hellwig
2019-08-13 20:11 ` [PATCH v1 03/10] powerpc/mm: move common 32/64 bits ioremap functions into ioremap.c Christophe Leroy
2019-08-13 20:11 ` [PATCH v1 04/10] powerpc/mm: move ioremap_prot() " Christophe Leroy
2019-08-13 20:11 ` [PATCH v1 05/10] powerpc/mm: Do early ioremaps from top to bottom on PPC64 too Christophe Leroy
2019-08-14 5:55 ` Christoph Hellwig
2019-08-14 6:10 ` Christophe Leroy
2019-08-14 6:14 ` Christoph Hellwig [this message]
2019-08-19 13:42 ` Nicholas Piggin
2019-08-20 0:20 ` Michael Ellerman
2019-08-20 5:10 ` Christophe Leroy
2019-08-13 20:11 ` [PATCH v1 06/10] powerpc/mm: make ioremap_bot common to all Christophe Leroy
2019-08-13 20:11 ` [PATCH v1 07/10] powerpc/mm: move iounmap() into ioremap.c and drop __iounmap() Christophe Leroy
2019-08-19 12:55 ` Michael Ellerman
2019-08-13 20:11 ` [PATCH v1 08/10] powerpc/mm: move __ioremap_at() and __iounmap_at() into ioremap.c Christophe Leroy
2019-08-14 5:23 ` Christoph Hellwig
2019-08-20 0:18 ` Michael Ellerman
2019-08-13 20:11 ` [PATCH v1 09/10] powerpc/mm: make __ioremap_caller() common to PPC32 and PPC64 Christophe Leroy
2019-08-13 20:11 ` [PATCH v1 10/10] powerpc/mm: refactor ioremap_range() and use ioremap_page_range() Christophe Leroy
2019-08-14 5:49 ` Christoph Hellwig
2019-08-14 6:23 ` Christophe Leroy
2019-08-14 6:30 ` Christoph Hellwig
2019-08-14 5:19 ` [PATCH v1 01/10] powerpc/mm: drop ppc_md.iounmap() Christoph Hellwig
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