RK356x GIC ITS support

RK356x has the same GIC ITS integration issue as RK3588, which already got solved upstream. Additionally RK356x only has access to the first 32 bit of address space. Rockchip assigned the following Errata numbers:

• #3568001 - GIC600 can not support shareable attribute
• #3568002 - GIC600 can not support DDR address of higher than 4GB

Upstream solution for RK3588:

• https://lore.kernel.org/all/20230418142109.49762-2-sebastian.reichel@collabora.com/

Downstream code (useful to understand which parts need to be patched for the 32bit issue):

• https://github.com/radxa/kernel/blob/stable-5.10-rock5/drivers/irqchip/irq-gic-v3-its.c

Sub-Tasks:

• Add workaround for #3568001
• Add workaround for #3568002 (see GFP_DMA32 in downstream code)
• Enable/Add GIC ITS node in rk356x.dtsi

Lorenzo Pieralisi is working on a generic DT/ACPI based solution for the "GIC600 can not support shareable attribute" issue (#3568001, the one also affecting RK3588):

https://lore.kernel.org/all/20230906094139.16032-1-lpieralisi@kernel.org/

added T42059 label

mentioned in commit 2acc59dd

mentioned in commit c90399fb

mentioned in commit 0c9f4ac8

mentioned in commit f6944d4a

mentioned in commit ff388fe5

mentioned in commit c3a5e3e8

mentioned in commit 7dc5537c

mentioned in commit 12f9386e

mentioned in commit 3d041393

mentioned in commit 88fd2b70

mentioned in commit 2d2d4f60

mentioned in commit 5641e82c

mentioned in commit 1b10a519

mentioned in commit b0fce54b

mentioned in commit 1c7b17cf

Dmitry prepared a series for this. The driver changes got Acked-by Marc Zyngier already, so this could potentially land in 6.15:

https://lore.kernel.org/linux-rockchip/20250216221634.364158-1-dmitry.osipenko@collabora.com/

marked the checklist item Add workaround for #3568001 as completed

marked the checklist item Add workaround for #3568002 (see GFP_DMA32 in downstream code) as completed