linux-kernel - [PATCH/RFC 0/2] of/irq: Fix root interrupt controller handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <cover.1759485668.git.geert+renesas@glider.be>
Date: Fri,  3 Oct 2025 12:07:47 +0200
From: Geert Uytterhoeven <geert+renesas@...der.be>
To: Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Paul Walmsley <pjw@...nel.org>,
	Palmer Dabbelt <palmer@...belt.com>,
	Albert Ou <aou@...s.berkeley.edu>,
	Alexandre Ghiti <alex@...ti.fr>,
	Samuel Holland <samuel@...lland.org>,
	Marc Zyngier <maz@...nel.org>,
	Saravana Kannan <saravanak@...gle.com>,
	Magnus Damm <magnus.damm@...il.com>
Cc: linux-renesas-soc@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-riscv@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH/RFC 0/2] of/irq: Fix root interrupt controller handling

	Hi all,

On ARM, the main interrupt controller is typically the GIC, and one can
safely put "interrupt-parent = <&gic>;" in the root node.  The GIC node
has an interrupts property, but it points to itself, causing
of_irq_init() to treat it as the root interrupt controller.

On RISC-V, the main interrupt controller is typically the PLIC.
However, one can not put "interrupt-parent = <&plic>;" in the root node,
as that would cause a kernel panic ("No interrupt controller found").
The main difference with ARM is that the PLIC is not the root interrupt
controller: its interrupt parent is the RISC-V CPU or Hart-Level
Interrupt Controller (HLIC).  The latter is the root interrupt
controller, and despite having no interrupts property, it is currently
not considered the root interrupt controller when an interrupt-parent
property is present in the root node.

This series fixes the issue in of_irq_init(), and moves the
"interrupt-parent = <&plic>;" for the RZ/Five (R9A07G043F) SoC from the
soc node to the top node, like was done recently for the very similar
RZ/G2UL (R9A07G043U) SoC[1].

Thanks for your comments!

[1] https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel.git/commit/?h=renesas-dts-for-v6.19&id=0070434f4a910179a23cd7ab812c33811f00b253)

Geert Uytterhoeven (2):
  of/irq: Ignore interrupt parent for nodes without interrupts
  riscv: dts: renesas: r9a07g043f: Move interrupt-parent to top node

 arch/riscv/boot/dts/renesas/r9a07g043f.dtsi | 3 ++-
 drivers/of/irq.c                            | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

-- 
2.43.0

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds