arm64: dts: renesas: r8a78000: Fix GIC-720AE View 1 Redistributor description

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 "5. Programmers
model for GIC-720AE", subchapter "5.4 Redistributor registers
for control and physical LPIs summary", part "5.4.3 GICR_TYPER,
Redistributor Type Register", "Table 5-50: GICR_TYPER bit descriptions"
on page 200, 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://documentation-service.arm.com/static/69ef3c1cd35efd294e335c43
    Arm® CoreLink™ GIC-720AE Generic Interrupt Controller
    Revision: r2p1 / Issue 12 / 102666_0201_12_en

Fixes: 63500d12cf76 ("arm64: dts: renesas: Add R8A78000 SoC support")
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260514125328.20954-1-marek.vasut+renesas@mailbox.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

0 files changed, 0 insertions, 0 deletions