From: Christoph Hellwig <hch@infradead.org>
To: Vladimir Kondratiev <Vladimir.Kondratiev@mobileye.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Alexandre Ghiti <alex@ghiti.fr>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-riscv@lists.infradead.org"
<linux-riscv@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [PATCH v1] riscv: make ZONE_DMA32 optional
Date: Sun, 6 Oct 2024 23:22:11 -0700 [thread overview]
Message-ID: <ZwN-E279o4bUQG26@infradead.org> (raw)
In-Reply-To: <VI1PR09MB23335FF3B1274ED13F24AF06947D2@VI1PR09MB2333.eurprd09.prod.outlook.com>
On Mon, Oct 07, 2024 at 06:17:14AM +0000, Vladimir Kondratiev wrote:
> >Well, this doesn't get any more true by just irgnoring the previous
> >discussion and just reposting :(
>
> Sorry, this wasn't the intention. Perhaps I messed with the message-id, I see my "patch v1" in one mail thread together with the previous discussion, but not in the other thread.
>
> Anyway, I think making ZONE_DMA32 selection depend on NONPORTABLE answers the concern
> that was raised
It doesn't at all.
For one not having ZONE_DMA32 is going to break a lot of things.
Drivers do expect 32-bit addressable memory. And because SOC designers
know this there usually is a way to provide it, e.g. by doing window
translations between cpu physical and bus physical address. Please go
back to your data sheet or talk to the designers.
And if there really is not way to provide this, the right way is just
to stop the runtime allocation that triggered you to do this if
ZONE_DMA32 is empty, not to add a non-portable option.
next prev parent reply other threads:[~2024-10-07 6:22 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-27 11:36 [PATCH] " Vladimir Kondratiev
2024-08-27 23:10 ` Drew Fustini
2024-09-20 8:58 ` Palmer Dabbelt
2024-09-20 13:18 ` Drew Fustini
2024-09-23 9:46 ` Ben Dooks
2024-09-20 14:04 ` Christoph Hellwig
2024-09-22 10:06 ` Vladimir Kondratiev
2024-09-24 6:39 ` Christoph Hellwig
2024-09-30 9:55 ` Alexandre Ghiti
2024-10-06 10:44 ` Vladimir Kondratiev
2024-10-06 10:55 ` [PATCH v1] " Vladimir Kondratiev
2024-10-06 22:58 ` Drew Fustini
2024-10-07 5:41 ` Christoph Hellwig
2024-10-07 6:17 ` Vladimir Kondratiev
2024-10-07 6:22 ` Christoph Hellwig [this message]
2024-10-07 11:39 ` Nick Kossifidis
2024-10-07 13:03 ` Vladimir Kondratiev
2024-10-07 12:17 ` [PATCH] " Ben Dooks
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZwN-E279o4bUQG26@infradead.org \
--to=hch@infradead.org \
--cc=Vladimir.Kondratiev@mobileye.com \
--cc=akpm@linux-foundation.org \
--cc=alex@ghiti.fr \
--cc=aou@eecs.berkeley.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-riscv@lists.infradead.org \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox