[EXT] Re: [PATCH v2 4/5] firmware: imx: add driver for NXP EdgeLock Enclave

[Pankaj Gupta]

> -----Original Message-----
> From: Sascha Hauer <s.hauer at pengutronix.de>
> Sent: Friday, May 24, 2024 5:56 PM
> To: Pankaj Gupta <pankaj.gupta at nxp.com>
> Cc: Jonathan Corbet <corbet at lwn.net>; Rob Herring <robh+dt at kernel.org>;
> Krzysztof Kozlowski <krzysztof.kozlowski+dt at linaro.org>; Conor Dooley
> <conor+dt at kernel.org>; Shawn Guo <shawnguo at kernel.org>; Pengutronix
> Kernel Team <kernel at pengutronix.de>; Fabio Estevam
> <festevam at gmail.com>; Rob Herring <robh at kernel.org>; Krzysztof
> Kozlowski <krzk+dt at kernel.org>; linux-doc at vger.kernel.org; linux-
> kernel at vger.kernel.org; devicetree at vger.kernel.org; imx at lists.linux.dev;
> linux-arm-kernel at lists.infradead.org
> Subject: Re: [EXT] Re: [PATCH v2 4/5] firmware: imx: add driver for NXP
> EdgeLock Enclave
>
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>
> On Fri, May 24, 2024 at 12:08:14PM +0000, Pankaj Gupta wrote:
> >
> >
> > > -----Original Message-----
> > > From: Sascha Hauer <s.hauer at pengutronix.de>
> > > Sent: Friday, May 24, 2024 4:04 PM
> > > To: Pankaj Gupta <pankaj.gupta at nxp.com>
> > > Cc: Jonathan Corbet <corbet at lwn.net>; Rob Herring
> > > <robh+dt at kernel.org>; Krzysztof Kozlowski
> > > <krzysztof.kozlowski+dt at linaro.org>; Conor Dooley
> > > <conor+dt at kernel.org>; Shawn Guo <shawnguo at kernel.org>;
> Pengutronix
> > > Kernel Team <kernel at pengutronix.de>; Fabio Estevam
> > > <festevam at gmail.com>; Rob Herring <robh at kernel.org>; Krzysztof
> > > Kozlowski <krzk+dt at kernel.org>; linux-doc at vger.kernel.org; linux-
> > > kernel at vger.kernel.org; devicetree at vger.kernel.org;
> > > imx at lists.linux.dev; linux-arm-kernel at lists.infradead.org
> > > Subject: [EXT] Re: [PATCH v2 4/5] firmware: imx: add driver for NXP
> > > EdgeLock Enclave
> > >
> > > Caution: This is an external email. Please take care when clicking
> > > links or opening attachments. When in doubt, report the message
> > > using the 'Report this email' button
> > >
> > >
> > > On Thu, May 23, 2024 at 04:19:35PM +0530, Pankaj Gupta wrote:
> > > > NXP hardware IP(s) for secure-enclaves like Edgelock Enclave(ELE),
> > > > are embedded in the SoC to support the features like HSM, SHE &
> > > > V2X, using message based communication interface.
> > > >
> > > > The secure enclave FW communicates on a dedicated messaging
> > > > unit(MU) based interface(s) with application core, where kernel is
> running.
> > > > It exists on specific i.MX processors. e.g. i.MX8ULP, i.MX93.
> > > >
> > > > This patch adds the driver for communication interface to
> > > > secure-enclave, for exchanging messages with NXP secure enclave HW
> > > > IP(s) like EdgeLock Enclave (ELE) from Kernel-space, used by
> > > > kernel management layers like
> > > > - DM-Crypt.
> > > >
> > > > Signed-off-by: Pankaj Gupta <pankaj.gupta at nxp.com>
> > > > ---
> > > >  drivers/firmware/imx/Kconfig        |  12 +
> > > >  drivers/firmware/imx/Makefile       |   2 +
> > > >  drivers/firmware/imx/ele_base_msg.c | 286 +++++++++++++++++++
> > > > drivers/firmware/imx/ele_base_msg.h |  92 +++++++
> > > >  drivers/firmware/imx/ele_common.c   | 239 ++++++++++++++++
> > > >  drivers/firmware/imx/ele_common.h   |  43 +++
> > > >  drivers/firmware/imx/se_ctrl.c      | 531
> > > ++++++++++++++++++++++++++++++++++++
> > > >  drivers/firmware/imx/se_ctrl.h      |  99 +++++++
> > > >  include/linux/firmware/imx/se_api.h |  14 +
> > > >  9 files changed, 1318 insertions(+)
> > > >
> > >
> > > > +static int se_probe_if_cleanup(struct platform_device *pdev) {
> > > > +     struct device *dev = &pdev->dev;
> > > > +     struct se_if_priv *priv;
> > > > +     int ret = 0;
> > > > +
> > > > +     priv = dev_get_drvdata(dev);
> > > > +     if (!priv) {
> > > > +             ret = 0;
> > > > +             dev_dbg(dev, "SE-MU Priv data is NULL;");
> > > > +             return ret;
> > > > +     }
> > > > +
> > > > +     if (priv->tx_chan)
> > > > +             mbox_free_channel(priv->tx_chan);
> > > > +     if (priv->rx_chan)
> > > > +             mbox_free_channel(priv->rx_chan);
> > > > +
> > > > +     /* free the buffer in se remove, previously allocated
> > > > +      * in se probe to store encrypted IMEM
> > > > +      */
> > > > +     if (priv->imem.buf) {
> > > > +             dmam_free_coherent(dev,
> > > > +                                ELE_IMEM_SIZE,
> > > > +                                priv->imem.buf,
> > > > +                                priv->imem.phyaddr);
> > > > +             priv->imem.buf = NULL;
> > > > +     }
> > > > +
> > > > +     if (priv->flags & RESERVED_DMA_POOL) {
> > > > +             of_reserved_mem_device_release(dev);
> > >
> > > You can call this unconditionally, no need to keep track if you
> > > called
> > > of_reserved_mem_device_init() successfully.
> >
> > But it will not be called for each SoC.
> > The memory is not reserved for i.MX95 platforms.
> > This is required.
>
> Again: You can call this unconditionally. Look at the code,
> of_reserved_mem_device_release() won't do anything if you haven't called
> of_reserved_mem_device_init() before.


Agree. Accepted and will removed in v3.

>



> Sascha
>
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