From: Christoph Hellwig <hch@infradead.org>
To: Oliver O'Halloran <oohall@gmail.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>,
Greg KH <gregkh@linuxfoundation.org>,
Christoph Hellwig <hch@infradead.org>,
"Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>,
linuxppc-dev@ozlabs.org
Subject: Re: [PATCH v2 8/8] habanalabs: enable 64-bit DMA mask in POWER9
Date: Tue, 11 Jun 2019 23:53:14 -0700 [thread overview]
Message-ID: <20190612065314.GA28838@infradead.org> (raw)
In-Reply-To: <CAOSf1CE82uVVni638jkJJpQ7XLXX+HdD7xuB7Wv-f8mn=SBMeg@mail.gmail.com>
On Wed, Jun 12, 2019 at 04:35:22PM +1000, Oliver O'Halloran wrote:
> Setting a 48 bit DMA mask doesn't work today because we only allocate
> IOMMU tables to cover the 0..2GB range of PCI bus addresses.
I don't think that is true upstream, and if it is we need to fix bug
in the powerpc code. powerpc should be falling back treating a 48-bit
dma mask like a 32-bit one at least, that is use dynamic iommu mappings
instead of using the direct mapping. And from my reding of
arch/powerpc/kernel/dma-iommu.c that is exactly what it does.
next prev parent reply other threads:[~2019-06-12 6:55 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190611092144.11194-1-oded.gabbay@gmail.com>
[not found] ` <20190611095857.GB24058@kroah.com>
[not found] ` <20190611151753.GA11404@infradead.org>
[not found] ` <20190611152655.GA3972@kroah.com>
[not found] ` <CAFCwf13A73AxKzaa7Dk3tU-1NDgTFs4+xCO2os7SuSyUHZ9Z3Q@mail.gmail.com>
2019-06-11 17:22 ` [PATCH v2 8/8] habanalabs: enable 64-bit DMA mask in POWER9 Oded Gabbay
2019-06-11 22:53 ` Benjamin Herrenschmidt
2019-06-12 5:45 ` Oliver O'Halloran
2019-06-12 8:17 ` Benjamin Herrenschmidt
2019-06-12 6:25 ` Oded Gabbay
2019-06-12 8:18 ` Benjamin Herrenschmidt
2019-06-12 6:35 ` Oliver O'Halloran
2019-06-12 6:53 ` Christoph Hellwig [this message]
2019-06-12 11:48 ` Oliver O'Halloran
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=20190612065314.GA28838@infradead.org \
--to=hch@infradead.org \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@ozlabs.org \
--cc=oded.gabbay@gmail.com \
--cc=oohall@gmail.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;
as well as URLs for NNTP newsgroup(s).