Date:   Fri, 10 Mar 2023 11:56:54 +0000
Message-ID: <86v8j8yg3d.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Peter Geis <pgwipeout@gmail.com>
Cc:     Lucas Tanure <lucas.tanure@collabora.com>,
        Vinod Koul <vkoul@kernel.org>,
        Kishon Vijay Abraham I <kishon@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Heiko Stuebner <heiko@sntech.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Krzysztof Wilczynski <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>, Qu Wenruo <wqu@suse.com>,
        Piotr Oniszczuk <piotr.oniszczuk@gmail.com>,
        Kever Yang <kever.yang@rock-chips.com>,
        linux-phy@lists.infradead.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org, kernel@collabora.com,
        Robin Murphy <robin.murphy@arm.com>
Subject: Re: [PATCH 1/7] irqchip/gic-v3: Add a DMA Non-Coherent flag
In-Reply-To: <CAMdYzYpL7V6udw=T7ZChTFi0xOj1tb-5CVHb84u1pL4kj3eDZA@mail.gmail.com>
References: <20230310080518.78054-1-lucas.tanure@collabora.com>
        <20230310080518.78054-2-lucas.tanure@collabora.com>
        <CAMdYzYpL7V6udw=T7ZChTFi0xOj1tb-5CVHb84u1pL4kj3eDZA@mail.gmail.com>
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On Fri, 10 Mar 2023 11:41:46 +0000,
Peter Geis <pgwipeout@gmail.com> wrote:
> 
> On Fri, Mar 10, 2023 at 3:05 AM Lucas Tanure <lucas.tanure@collabora.com> wrote:
> >
> > The GIC600 integration in RK356x, used in rk3588, doesn't support
> > any of the shareability or cacheability attributes, and requires
> > both values to be set to 0b00 for all the ITS and Redistributor
> > tables.
> >
> > This is loosely based on prior work from XiaoDong Huang and
> > Peter Geis fixing this issue specifically for Rockchip 356x.
> 
> Good Morning,
> 
> Since the gic is using dma, would it be reasonable to have all memory
> allocations be requested with the GFP_DMA flag? Otherwise this doesn't
> fully solve the problem for rk356x, where only the lower 4GB range is
> DMA capable, but this tends to get allocated in the upper 4GB on 8GB
> boards.

That's an erratum. Please treat as such.

	M.

-- 
Without deviation from the norm, progress is not possible.