From: Sherry Sun <sherry.sun@nxp.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Sudeep Dutt <sudeep.dutt@intel.com>,
Ashutosh Dixit <ashutosh.dixit@intel.com>,
gregkh <gregkh@linuxfoundation.org>,
"wang.yi59@zte.com.cn" <wang.yi59@zte.com.cn>,
Rikard Falkeborn <rikard.falkeborn@gmail.com>,
Lee Jones <lee.jones@linaro.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
dl-linux-imx <linux-imx@nxp.com>,
linux-pci <linux-pci@vger.kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Kishon Vijay Abraham I <kishon@ti.com>,
"linux-ntb@googlegroups.com" <linux-ntb@googlegroups.com>
Subject: RE: [PATCH 0/5] Add noncoherent platform support for vop driver
Date: Sun, 27 Sep 2020 05:07:52 +0000 [thread overview]
Message-ID: <VI1PR04MB496047225BD131296FA8EE0F92340@VI1PR04MB4960.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <CAK8P3a3fog3jE_cPUTELDkFKoO2FbCJufQiDZhfL2FsZ5s5q3Q@mail.gmail.com>
Hi Arnd,
> Subject: Re: [PATCH 0/5] Add noncoherent platform support for vop driver
>
> On Fri, Sep 25, 2020 at 9:27 AM Sherry Sun <sherry.sun@nxp.com> wrote:
> >
> > Change the way of allocating vring to support noncoherent platform for
> > vop driver, and add some related dma changes to make sure noncoherent
> > platform works well.
>
> Could you describe why you are doing this? Are you using Intel MIC devices
> on Arm hosts, or trying to reuse the code for other add-on cards?
>
We want to reuse the vop driver between two i.MX boards which are arm64 architecture. And in fact we have successfully verified it.
But the biggest problem we currently encounter is about the noncoherent memory.
Since the hardware device of our platform is not dma coherent,
when use the original way(__get_free_pages and dma_map_single, but without dma_sync_single_for_cpu/device) will meet errors.
Device pages/vring which are interact between ep and rc should use consistent memory without caching effects,
so allocate them by dma_alloc_coherent is a better way.
> Note that we have a couple of frameworks in the kernel that try to do some
> of the same things here, notably the NTB drivers and the PCI endpoint
> support, both of which are designed to be somewhat more generic than the
> MIC driver.
>
> Have you considered using that instead?
>
> Arnd
>
Sorry I don't much about NTB, but for PCI endpoint driver, we will use it for pci data interaction below the vop layer.
Best regards
Sherry
> > Sherry Sun (5):
> > misc: vop: change the way of allocating vring for noncoherent platform
> > misc: vop: change the way of allocating used ring
> > misc: vop: simply return the saved dma address instead of virt_to_phys
> > misc: vop: set VIRTIO_F_ACCESS_PLATFORM for nocoherent platform
> > misc: vop: mapping kernel memory to user space as noncached
> >
> > drivers/misc/mic/bus/vop_bus.h | 2 +
> > drivers/misc/mic/host/mic_boot.c | 8 ++
> > drivers/misc/mic/vop/vop_main.c | 51 +++++++++----
> > drivers/misc/mic/vop/vop_vringh.c | 117
> > ++++++++++++++++++++----------
> > 4 files changed, 125 insertions(+), 53 deletions(-)
> >
> > --
> > 2.17.1
> >
prev parent reply other threads:[~2020-09-27 5:07 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200925072630.8157-1-sherry.sun@nxp.com>
2020-09-25 11:25 ` [PATCH 0/5] Add noncoherent platform support for vop driver Arnd Bergmann
2020-09-27 5:07 ` Sherry Sun [this message]
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=VI1PR04MB496047225BD131296FA8EE0F92340@VI1PR04MB4960.eurprd04.prod.outlook.com \
--to=sherry.sun@nxp.com \
--cc=arnd@arndb.de \
--cc=ashutosh.dixit@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=kishon@ti.com \
--cc=lee.jones@linaro.org \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-ntb@googlegroups.com \
--cc=linux-pci@vger.kernel.org \
--cc=lorenzo.pieralisi@arm.com \
--cc=rikard.falkeborn@gmail.com \
--cc=sudeep.dutt@intel.com \
--cc=wang.yi59@zte.com.cn \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).