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From: Jens Wiklander <jens.wiklander@linaro.org>
Date: Tue, 7 May 2024 11:21:58 +0200
Message-ID: <CAHUa44GLGT7F0=LL6fjw1inf0N-OPpVL+D44F84yndUmk-xLhA@mail.gmail.com>
Subject: Re: [PATCH v5 2/3] mmc: block: register RPMB partition with the RPMB subsystem
To: Avri Altman <Avri.Altman@wdc.com>
Cc: Manuel Traut <manut@mecka.net>, 
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, 
	"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>, 
	"op-tee@lists.trustedfirmware.org" <op-tee@lists.trustedfirmware.org>, 
	Shyam Saini <shyamsaini@linux.microsoft.com>, Ulf Hansson <ulf.hansson@linaro.org>, 
	Linus Walleij <linus.walleij@linaro.org>, Jerome Forissier <jerome.forissier@linaro.org>, 
	Sumit Garg <sumit.garg@linaro.org>, Ilias Apalodimas <ilias.apalodimas@linaro.org>, 
	Bart Van Assche <bvanassche@acm.org>, Randy Dunlap <rdunlap@infradead.org>, 
	Ard Biesheuvel <ardb@kernel.org>, Arnd Bergmann <arnd@arndb.de>, 
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Tomas Winkler <tomas.winkler@intel.com>, 
	Alexander Usyskin <alexander.usyskin@intel.com>
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On Mon, Apr 29, 2024 at 9:36=E2=80=AFPM Avri Altman <Avri.Altman@wdc.com> w=
rote:
>
> > > > >
> > > > > Is it possible that idata->buf is not DMA capable? Any other idea=
s?
> > > >
> > > > Thanks for testing. I don't know, the idata->buf is allocated using
> > > > alloc_pages_exact(nr_pages * PAGE_SIZE, GFP_KERNEL | __GFP_ZERO); i=
n
> > > > optee_pool_op_alloc_helper().
> > >
> > > Is this really true for idata->buf or isnt the complete RPMB frame
> > > memory allocated like this and therefore idata->buf not page aligned?
> >
> > You're right.
> Maybe add an assert of PAGE_ALIGNED(idata->buf)?

That might be a bit much. It turned out that there was a 2-byte
alignment causing the trouble. I don't know exactly what's needed, but
the amount used by kmalloc() by default is good.

Cheers,
Jens

>
> Thanks,
> Avri
>
> >
> > >
> > > For RPMB via tee-supplicant the idata->buf is allocated within
> > > memdup_user and therefore page aligned.
> >
> > Yes, that's a difference. Have you tested with page-aligned buffers to =
see if it
> > helps?