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From:   Daniel Baluta <daniel.baluta@gmail.com>
Date:   Thu, 2 Mar 2023 13:44:35 +0200
Message-ID: <CAEnQRZAN4YRZ3VQYXuEU57WdQs4tJQtXZKpWzSM-hS1c-_20vg@mail.gmail.com>
Subject: Re: [PATCH v5] remoteproc: imx_dsp_rproc: add custom memory copy
 implementation for i.MX DSP Cores
To:     Mathieu Poirier <mathieu.poirier@linaro.org>
Cc:     "Iuliana Prodan (OSS)" <iuliana.prodan@oss.nxp.com>,
        Bjorn Andersson <andersson@kernel.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        "S.J. Wang" <shengjiu.wang@nxp.com>,
        Fabio Estevam <festevam@gmail.com>,
        Daniel Baluta <daniel.baluta@nxp.com>,
        Iuliana Prodan <iuliana.prodan@nxp.com>,
        linux-imx <linux-imx@nxp.com>, linux-remoteproc@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Peng Fan <peng.fan@nxp.com>
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On Wed, Mar 1, 2023 at 9:11=E2=80=AFPM Mathieu Poirier
<mathieu.poirier@linaro.org> wrote:
>
> On Wed, Mar 01, 2023 at 11:49:16AM -0700, Mathieu Poirier wrote:
> > Hi Iuliana,
> >
> > On Tue, Feb 21, 2023 at 07:03:56PM +0200, Iuliana Prodan (OSS) wrote:
> > > From: Iuliana Prodan <iuliana.prodan@nxp.com>
> > >
> > > The IRAM is part of the HiFi DSP.
> > > According to hardware specification only 32-bits write are allowed
> > > otherwise we get a Kernel panic.
> > >
> > > Therefore add a custom memory copy and memset functions to deal with
> > > the above restriction.
> > >
> > > Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
> > > ---
> > > Changes since v4
> > > - use GENMASK;
> > > - s/ioread32/readl;
> > > - s/iowrite32/writel;
> > > - use for loop with writel instead of __iowrite32_copy;
> > > - update multi-line comment format.
> > >
> >
> > This looks good now.  I will queue this on March 13th when 6.3-rc2 is o=
ut.
> >
>
> And out of curiosity, are the remote processors handled by imx_rproc.c al=
so have
> the same 32-bit write constraints?  If so, it would be nice to have a pat=
ch that
> fixes that as well.  In such a case, imx_dsp_rproc_memcpy() and
> imx_dsp_rproc_memset() should be renamed to something more generic and re=
-used
> in imx_rproc.c.

Paging Peng Fan.

imx_rproc handles M4/M7 cores.
imx_dsp_rproc handles HIFI4 DSP cores.

From what I experienced 32 bit read/writes are only mandatory for
certain memory areas
that fall inside the HIFI4 address spaces but this doesn't happen for
M4/M7 memory maps.

thanks,
Daniel.