From: Joerg Roedel <jroedel@suse.de>
To: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>, Andy Lutomirski <luto@kernel.org>,
Cornelia Huck <cornelia.huck@de.ibm.com>,
Sebastian Ott <sebott@linux.vnet.ibm.com>,
Paolo Bonzini <pbonzini@redhat.com>,
benh@kernel.crashing.org, KVM <kvm@vger.kernel.org>,
dwmw2@infradead.org, Martin Schwidefsky <schwidefsky@de.ibm.com>,
linux-s390 <linux-s390@vger.kernel.org>
Subject: Re: [PATCH 1/4] Provide simple noop dma ops
Date: Fri, 30 Oct 2015 23:45:58 +0900 [thread overview]
Message-ID: <20151030144558.GA2704@suse.de> (raw)
In-Reply-To: <563368DC.3080606@de.ibm.com>
On Fri, Oct 30, 2015 at 01:55:56PM +0100, Christian Borntraeger wrote:
> It not trivial without understanding the dma mask details. Do I read
> the x86 implementation right, that it limits the dma to 32 bit? Then
> we cannot collapse both implementations. Or maybe we can hide this in
> dma_capable. Dont know
No, DMA is not limited to 32bit on x86. Each device has its own
dma_mask, and the requested address+size is checked against it. The
DMA_BIT_MASK(32) check is only to there to print a warning when a 32bit
capable device trys to access memory above 4GB.
Joerg
next prev parent reply other threads:[~2015-10-30 14:45 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-27 22:48 [PATCH/RFC 0/4] dma ops and virtio Christian Borntraeger
2015-10-27 22:48 ` [PATCH 1/4] Provide simple noop dma ops Christian Borntraeger
2015-10-28 0:41 ` Joerg Roedel
2015-10-30 12:55 ` Christian Borntraeger
2015-10-30 14:45 ` Joerg Roedel [this message]
2015-10-27 22:48 ` [PATCH 2/4] alpha: use common " Christian Borntraeger
2015-10-27 22:48 ` [PATCH 3/4] s390/dma: Allow per device " Christian Borntraeger
2015-10-27 22:48 ` [PATCH 4/4] s390/virtio: use noop " Christian Borntraeger
2015-10-28 0:43 ` Joerg Roedel
2015-10-28 8:44 ` Cornelia Huck
2015-10-30 12:56 ` Christian Borntraeger
2015-10-30 12:17 ` Cornelia Huck
2015-10-30 12:26 ` Christian Borntraeger
2015-10-30 12:32 ` Cornelia Huck
2015-10-28 0:45 ` [PATCH/RFC 0/4] dma ops and virtio Joerg Roedel
2015-10-28 22:22 ` Andy Lutomirski
2015-10-29 0:04 ` Christian Borntraeger
2015-10-29 22:50 ` Andy Lutomirski
2015-10-30 8:25 ` Cornelia Huck
2015-10-30 20:33 ` Andy Lutomirski
2015-11-02 11:16 ` Cornelia Huck
2015-11-02 20:23 ` Andy Lutomirski
2015-11-03 8:14 ` Christian Borntraeger
2015-11-03 17:54 ` Andy Lutomirski
2015-11-03 17:59 ` Cornelia Huck
2015-11-03 18:45 ` Andy Lutomirski
2015-11-04 14:29 ` Cornelia Huck
2015-11-04 17:52 ` Cornelia Huck
2015-11-04 18:14 ` Andy Lutomirski
2015-11-05 8:11 ` Cornelia Huck
2015-11-12 7:56 ` Cornelia Huck
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=20151030144558.GA2704@suse.de \
--to=jroedel@suse.de \
--cc=benh@kernel.crashing.org \
--cc=borntraeger@de.ibm.com \
--cc=cornelia.huck@de.ibm.com \
--cc=dwmw2@infradead.org \
--cc=hch@lst.de \
--cc=kvm@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=luto@kernel.org \
--cc=pbonzini@redhat.com \
--cc=schwidefsky@de.ibm.com \
--cc=sebott@linux.vnet.ibm.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.