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From: Marek Vasut <marek.vasut+renesas@mailbox.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Marek Vasut <marek.vasut+renesas@mailbox.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
	Magnus Damm <magnus.damm@gmail.com>,
	Marc Zyngier <maz@kernel.org>, Rob Herring <robh@kernel.org>,
	devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org
Subject: [PATCH] arm64: dts: renesas: r8a78000: Fix GIC-720AE View 1 Redistributor description
Date: Thu, 14 May 2026 00:30:08 +0200	[thread overview]
Message-ID: <20260513223125.43337-1-marek.vasut+renesas@mailbox.org> (raw)

The Renesas R-Car X5H (R8A78000) SoC contains Arm CoreLink GIC-720AE
Generic Interrupt Controller with Multi View capability. Firmware has
access to configuration View 0, Linux kernel has access to View 1.

The Arm CoreLink GIC-720AE Generic Interrupt Controller Technical
Reference Manual, currently latest r2p1 [1], chapter "Programmers model
for GIC-720AE", subchapter "Redistributor registers for control and
physical LPIs summary", part "GICR_TYPER, Redistributor Type Register"
clarifies register "GICR_TYPER" bit 4 "Last" behavior in Multi View
setup as follows:

"
Last
Last Redistributor:

0 ... This Redistributor is not the last Redistributor on the chip.
1 ... This Redistributor is the last Redistributor on the chip.
      When GICD_CFGID.VIEW == 1, for views 1, 2, or 3 this bit
      always returns 1.
"

On this SoC, GICD_CFGID.VIEW is 1 and the Linux kernel has access to
View 1, therefore Linux kernel GICv3 driver will interpret register
"GICR_TYPER" bit 4 "Last" = 1 in the first Redistributor in continuous
Redistributor page as that first Redistributor being the one and only
Redistributor and will stop processing the continuous Redistributor
page further. This will prevent the other Redistributors from being
recognized by the system and used for other PEs.

Because the hardware indicates that the continuous Redistributor page
is not continuous for View 1, 2, or 3, describe every Redistributor
separately in the DT. This makes all Redistributors for all cores
accessible in Linux.

[1] https://developer.arm.com/documentation/102666/0201/Programmers-model-for-GIC-720AE/Redistributor-registers-for-control-and-physical-LPIs-summary/GICR-TYPER--Redistributor-Type-Register?lang=en

Fixes: 63500d12cf76 ("arm64: dts: renesas: Add R8A78000 SoC support")
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 arch/arm64/boot/dts/renesas/r8a78000.dtsi | 36 +++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/renesas/r8a78000.dtsi b/arch/arm64/boot/dts/renesas/r8a78000.dtsi
index 3ec1b53d27828..73be51787265c 100644
--- a/arch/arm64/boot/dts/renesas/r8a78000.dtsi
+++ b/arch/arm64/boot/dts/renesas/r8a78000.dtsi
@@ -689,8 +689,40 @@ gic: interrupt-controller@39000000 {
 			#interrupt-cells = <3>;
 			#address-cells = <0>;
 			interrupt-controller;
-			reg = <0 0x39000000 0 0x10000>,
-			      <0 0x39080000 0 0x800000>;
+			#redistributor-regions = <32>;
+			reg = <0x0 0x39000000 0x0 0x10000>,
+			      <0x0 0x39080000 0x0 0x40000>,
+			      <0x0 0x390c0000 0x0 0x40000>,
+			      <0x0 0x39100000 0x0 0x40000>,
+			      <0x0 0x39140000 0x0 0x40000>,
+			      <0x0 0x39180000 0x0 0x40000>,
+			      <0x0 0x391c0000 0x0 0x40000>,
+			      <0x0 0x39200000 0x0 0x40000>,
+			      <0x0 0x39240000 0x0 0x40000>,
+			      <0x0 0x39280000 0x0 0x40000>,
+			      <0x0 0x392c0000 0x0 0x40000>,
+			      <0x0 0x39300000 0x0 0x40000>,
+			      <0x0 0x39340000 0x0 0x40000>,
+			      <0x0 0x39380000 0x0 0x40000>,
+			      <0x0 0x393c0000 0x0 0x40000>,
+			      <0x0 0x39400000 0x0 0x40000>,
+			      <0x0 0x39440000 0x0 0x40000>,
+			      <0x0 0x39480000 0x0 0x40000>,
+			      <0x0 0x394c0000 0x0 0x40000>,
+			      <0x0 0x39500000 0x0 0x40000>,
+			      <0x0 0x39540000 0x0 0x40000>,
+			      <0x0 0x39580000 0x0 0x40000>,
+			      <0x0 0x395c0000 0x0 0x40000>,
+			      <0x0 0x39600000 0x0 0x40000>,
+			      <0x0 0x39640000 0x0 0x40000>,
+			      <0x0 0x39680000 0x0 0x40000>,
+			      <0x0 0x396c0000 0x0 0x40000>,
+			      <0x0 0x39700000 0x0 0x40000>,
+			      <0x0 0x39740000 0x0 0x40000>,
+			      <0x0 0x39780000 0x0 0x40000>,
+			      <0x0 0x397c0000 0x0 0x40000>,
+			      <0x0 0x39800000 0x0 0x40000>,
+			      <0x0 0x39840000 0x0 0x40000>;
 			interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
 		};
 
-- 
2.53.0


             reply	other threads:[~2026-05-13 22:31 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-13 22:30 Marek Vasut [this message]
2026-05-14  7:04 ` [PATCH] arm64: dts: renesas: r8a78000: Fix GIC-720AE View 1 Redistributor description Marc Zyngier
2026-05-14 12:45   ` Marek Vasut

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