Re: [PATCH v2 2/2] irqchip/sifive-plic: Add support for Renesas RZ/Five SoC

From: Pavel Machek <pavel@ucw.cz>
To: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Cc: Marc Zyngier <maz@kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Sagar Kadam <sagar.kadam@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	linux-riscv <linux-riscv@lists.infradead.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Biju Das <biju.das.jz@bp.renesas.com>
Subject: Re: [PATCH v2 2/2] irqchip/sifive-plic: Add support for Renesas RZ/Five SoC
Date: Wed, 29 Jun 2022 15:41:47 +0200	[thread overview]
Message-ID: <20220629134147.GA16868@duo.ucw.cz> (raw)
In-Reply-To: <CA+V-a8u8X+bne_a3LY13zGTKr-hOWhm=R9gGX1JyE8PzWRNXpQ@mail.gmail.com>

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Hi!

> > >> +#define PLIC_QUIRK_EDGE_INTERRUPT      BIT(0)
> > >>
> > >>  struct plic_priv {
> > >>         struct cpumask lmask;
> > >>         struct irq_domain *irqdomain;
> > >>         void __iomem *regs;
> > >> +       u32 plic_quirks;
> > >>  };
> > >>
> > >> What about something like above?
> > >
> > > LGTM.
> > >
> > > Marc suggested to make this unsigned long, but TBH, that won't make
> > > much of a difference.  PLICs are present on RV32 SoCs, too, so you
> > > cannot rely on having more than 32 bits anyway.
> >
> > But it will make a difference on a 64bit platform, as we want to
> > use test_bit() and co to check for features.
> >
> Ok will change that to unsigned long and use the test_bit/set_bit instead.

Is there good enough reason for that? test_bit/... are when you need
atomicity, and that's not the case here. Plain old & ... should be
enough.

Best regards,
								Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.

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