From: Andy Duan <fugang.duan@nxp.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: "bjorn.andersson@linaro.org" <bjorn.andersson@linaro.org>,
"ohad@wizery.com" <ohad@wizery.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
Robin Murphy <robin.murphy@arm.com>,
"linux-remoteproc@vger.kernel.org"
<linux-remoteproc@vger.kernel.org>,
"anup@brainfault.org" <anup@brainfault.org>,
"loic.pallardy@st.com" <loic.pallardy@st.com>,
dl-linux-imx <linux-imx@nxp.com>,
Richard Zhu <hongxing.zhu@nxp.com>,
Jason Liu <jason.hui.liu@nxp.com>, Peng Fan <peng.fan@nxp.com>
Subject: RE: [rpmsg PATCH v2 1/1] rpmsg: virtio_rpmsg_bus: fix unexpected huge vmap mappings
Date: Wed, 16 Jan 2019 03:38:38 +0000 [thread overview]
Message-ID: <VI1PR0402MB36000DE975EBFBD40D1352C4FF820@VI1PR0402MB3600.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <20190114095315.GA24495@infradead.org>
From: Christoph Hellwig <hch@infradead.org> Sent: Monday, January 14, 2019 5:53 PM
> On Fri, Jan 11, 2019 at 01:28:46AM +0000, Andy Duan wrote:
> > As NXP i.MX8 platform requirement that M4 only access the fixed memory
> > region, so do You have any suggestion to fix the issue and satisfy the
> > requirement ? Or do you have plan To fix the root cause ?
>
> I think the answer is to use RESERVEDMEM_OF_DECLARE without the DMA
> coherent boilerplate code.
If use RESERVEDMEM_OF_DECLARE with DMA contiguous code (CMA), it can
match the requirement, but as you know, the CMA size alignment is 32M bytes,
we only need 8M bytes contiguous mem for rpmsg.
>
> For the initial prototype just do it inside the driver, although I'd like to
> eventually factor this out into common code, especially if my proposal for
> more general availability of DMA_ATTR_NON_CONSISTENT goes ahead.
prev parent reply other threads:[~2019-01-16 3:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-26 8:25 Andy Duan
2018-12-26 12:27 ` Ard Biesheuvel
2018-12-26 12:27 ` Ard Biesheuvel
2018-12-26 14:50 ` Christoph Hellwig
2018-12-27 2:36 ` Andy Duan
2018-12-27 12:19 ` Christoph Hellwig
2018-12-28 1:48 ` Andy Duan
2019-01-10 1:45 ` Andy Duan
2019-01-10 13:06 ` Loic PALLARDY
2019-01-11 1:56 ` Andy Duan
2019-01-10 14:07 ` Christoph Hellwig
2019-01-11 1:28 ` Andy Duan
2019-01-14 9:53 ` Christoph Hellwig
2019-01-16 3:38 ` Andy Duan [this message]
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