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From:   Sumit Garg <sumit.garg@linaro.org>
Date:   Wed, 25 Oct 2023 19:01:31 +0530
Message-ID: <CAFA6WYPKXFftMzqJ4GnXT-zqu21_Jzn8aKti_wU-pQ4KpEVNrA@mail.gmail.com>
Subject: Re: [PATCH 0/3] Introduce DMA APIs to allocate and free TEE shared memory
To:     jeshwank <JESHWANTHKUMAR.NK@amd.com>
Cc:     thomas.lendacky@amd.com, john.allen@amd.com,
        herbert@gondor.apana.org.au, davem@davemloft.net,
        jens.wiklander@linaro.org, jarkko.nikula@linux.intel.com,
        mario.limonciello@amd.com, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org, op-tee@lists.trustedfirmware.org,
        Mythri.Pandeshwarakrishna@amd.com, Devaraj.Rangasamy@amd.com,
        Rijo-john.Thomas@amd.com, nimesh.easow@amd.com
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Hi Jeshwank,

On Wed, 25 Oct 2023 at 12:27, jeshwank <JESHWANTHKUMAR.NK@amd.com> wrote:
>
> From: Jeshwanth Kumar N K <JESHWANTHKUMAR.NK@amd.com>
>
> At present, the shared memory for TEE ring buffer, command buffer and
> data buffer is allocated using get_free_pages(). The driver shares the
> physical address of these buffers with PSP so that it can be mapped by
> the Trusted OS.
>
> In this patch series we have replaced get_free_pages() with
> dma_alloc_coherent() to allocate shared memory to cleanup the existing
> allocation method.

Thanks for putting this together but I can't find the reasoning behind
this change neither in this commit message and nor in the patch
descriptions. Care to explain why?

-Sumit

>
> Rijo Thomas (3):
>   crypto: ccp - Add function to allocate and free memory using DMA APIs
>   crypto: ccp - Use psp_tee_alloc_buffer() and psp_tee_free_buffer()
>   tee: amdtee: Use psp_tee_alloc_buffer() and psp_tee_free_buffer()
>
>  drivers/crypto/ccp/psp-dev.c        |   3 +
>  drivers/crypto/ccp/tee-dev.c        | 119 ++++++++++++++++++----------
>  drivers/crypto/ccp/tee-dev.h        |  11 +--
>  drivers/tee/amdtee/amdtee_private.h |  18 ++---
>  drivers/tee/amdtee/call.c           |  74 ++++++++---------
>  drivers/tee/amdtee/core.c           |  72 ++++++++++-------
>  drivers/tee/amdtee/shm_pool.c       |  21 ++---
>  include/linux/psp-tee.h             |  47 +++++++++++
>  8 files changed, 221 insertions(+), 144 deletions(-)
>
> --
> 2.25.1
>