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From:   Bartosz Golaszewski <brgl@bgdev.pl>
Date:   Thu, 12 Oct 2023 10:57:52 +0200
Message-ID: <CAMRc=MeyDkV2YY08oo5ELnbFs65=VtZJgZwonSfv3c1H1mwEsA@mail.gmail.com>
Subject: Re: [PATCH v3 15/15] arm64: defconfig: enable SHM Bridge support for
 the TZ memory allocator
To:     Andrew Halaney <ahalaney@redhat.com>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Elliot Berman <quic_eberman@quicinc.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Guru Das Srinagesh <quic_gurus@quicinc.com>,
        Maximilian Luz <luzmaximilian@gmail.com>,
        Alex Elder <elder@linaro.org>,
        Srini Kandagatla <srinivas.kandagatla@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, kernel@quicinc.com,
        Bartosz Golaszewski <bartosz.golaszewski@linaro.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@arndb.de>
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On Wed, Oct 11, 2023 at 11:20=E2=80=AFPM Andrew Halaney <ahalaney@redhat.co=
m> wrote:
>
> On Mon, Oct 09, 2023 at 05:34:27PM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> >
> > Enable SHM Bridge support in the Qualcomm TrustZone allocator by defaul=
t
> > as even on architectures that don't support it, we automatically fall
> > back to the default behavior.
>
> Can you give some motivation for the Kconfig? It seems like what you've
> wrote should just fallback to the non SHM bridge allocated memory, so I
> don't see what having the option to exclude that at build time gives us.
>

If the hypervisor gets quirky in a new place other than the PAS image
calls, we will be able to just disable SHM Bridge, otherwise the
kernel will use it if it's supported even if it causes problems?

Bart

> >
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> > ---
> >  arch/arm64/configs/defconfig | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfi=
g
> > index 07011114eef8..ebe97fec6e33 100644
> > --- a/arch/arm64/configs/defconfig
> > +++ b/arch/arm64/configs/defconfig
> > @@ -255,6 +255,7 @@ CONFIG_INTEL_STRATIX10_RSU=3Dm
> >  CONFIG_EFI_CAPSULE_LOADER=3Dy
> >  CONFIG_IMX_SCU=3Dy
> >  CONFIG_IMX_SCU_PD=3Dy
> > +CONFIG_QCOM_TZMEM_MODE_SHMBRIDGE=3Dy
> >  CONFIG_GNSS=3Dm
> >  CONFIG_GNSS_MTK_SERIAL=3Dm
> >  CONFIG_MTD=3Dy
> > --
> > 2.39.2
> >
>