[PATCH v2 2/3] riscv: dts: spacemit: k3: Drop guest properties from M-level IMSIC

[E Shattow <e@freeshell.de>]

From: Junhui Liu <junhui.liu@pigmoral.tech>

The mimsic node describes the machine-level IMSIC, whose MMIO region is
0x10000 (64 KiB) for all 8 harts. However, the node also specifies
riscv,guest-index-bits = <6>, and per the AIA specification the
per-hart stride is 2^(guest-index-bits + 12) bytes when guest interrupt
files exist, i.e. 2^(6 + 12) = 256 KiB per hart and 2 MiB for all 8
harts. The described region cannot hold even a single hart's files, so
the node contradicts itself. OpenSBI enforces exactly this constraint in
imsic_data_check() and rejects the node with -EINVAL, preventing the
M-level IMSIC from initializing:

  fdt_driver_init_by_offset: interrupt-controller@f1000000 (riscv,imsics) init failed: -3
  init_coldboot: irqchip init failed (error -3)

Moreover, guest interrupt files exist to act as the supervisor-level
interrupt files of virtual harts; there is no machine-level counterpart.
riscv,num-guest-ids is equally meaningless for the machine-level IMSIC.

Drop both "riscv,guest-index-bits" and "riscv,num-guest-ids" properties
from the mimsic node so the node matches the actual hardware layout.

Fixes: 56f37e391a62 ("riscv: dts: spacemit: add initial support for K3 SoC")
Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
Reviewed-by: Yixun Lan <dlan@kernel.org>
Link: https://patch.msgid.link/20260729-k3-mimsic-fix-v1-1-368c0aec04b9@pigmoral.tech
Signed-off-by: Yixun Lan <dlan@kernel.org>

[ upstream commit: 01e2f07c44fc46180bdb10e70506f8acf44a53dd ]

(cherry picked from commit d44cd4bcf93bb5c99a4762ed5f11656b93f9e5cc)
---
 dts/upstream/src/riscv/spacemit/k3.dtsi | 2 --
 1 file changed, 2 deletions(-)

diff --git a/dts/upstream/src/riscv/spacemit/k3.dtsi b/dts/upstream/src/riscv/spacemit/k3.dtsi
index c3f2dce0969c..2d022e1364f1 100644
--- a/dts/upstream/src/riscv/spacemit/k3.dtsi
+++ b/dts/upstream/src/riscv/spacemit/k3.dtsi
@@ -1287,9 +1287,7 @@
 					      <&cpu4_intc 11>, <&cpu5_intc 11>,
 					      <&cpu6_intc 11>, <&cpu7_intc 11>;
 			msi-controller;
-			riscv,guest-index-bits = <6>;
 			riscv,hart-index-bits = <4>;
-			riscv,num-guest-ids = <511>;
 			riscv,num-ids = <511>;
 			status = "reserved";
 		};
-- 
2.53.0