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Date:   Tue, 12 Sep 2023 13:43:44 +0100
Message-ID: <87il8f4l4v.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Douglas Anderson <dianders@chromium.org>
Cc:     Mark Rutland <mark.rutland@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Sumit Garg <sumit.garg@linaro.org>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        linux-arm-kernel@lists.infradead.org,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Lecopzer Chen <lecopzer.chen@mediatek.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Tomohiro Misono <misono.tomohiro@fujitsu.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Masayoshi Mizuma <msys.mizuma@gmail.com>,
        Stephane Eranian <eranian@google.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        kgdb-bugreport@lists.sourceforge.net,
        Stephen Boyd <swboyd@chromium.org>,
        linux-perf-users@vger.kernel.org,
        Thomas Gleixner <tglx@linutronix.de>, ito-yuichi@fujitsu.com,
        Chen-Yu Tsai <wenst@chromium.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v13 1/7] irqchip/gic-v3: Enable support for SGIs to act as NMIs
In-Reply-To: <20230906090246.v13.1.I1223c11c88937bd0cbd9b086d4ef216985797302@changeid>
References: <20230906160505.2431857-1-dianders@chromium.org>
        <20230906090246.v13.1.I1223c11c88937bd0cbd9b086d4ef216985797302@changeid>
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On Wed, 06 Sep 2023 17:02:56 +0100,
Douglas Anderson <dianders@chromium.org> wrote:
> 
> As of commit 6abbd6988971 ("irqchip/gic, gic-v3: Make SGIs use
> handle_percpu_devid_irq()") SGIs are treated the same as PPIs/EPPIs
> and use handle_percpu_devid_irq() by default. Unfortunately,
> handle_percpu_devid_irq() isn't NMI safe, and so to run in an NMI
> context those should use handle_percpu_devid_fasteoi_nmi().
> 
> In order to accomplish this, we just have to make room for SGIs in the
> array of refcounts that keeps track of which interrupts are set as
> NMI. We also rename the array and create a new indexing scheme that
> accounts for SGIs.
> 
> Also, enable NMI support prior to gic_smp_init() as allocation of SGIs
> as IRQs/NMIs happen as part of this routine.
> 
> Co-developed-by: Sumit Garg <sumit.garg@linaro.org>
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
> Acked-by: Mark Rutland <mark.rutland@arm.com>
> Tested-by: Chen-Yu Tsai <wenst@chromium.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Acked-by: Marc Zyngier <maz@kernel.org>

	M.

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