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From: "Troy Mitchell" <troy.mitchell@linux.spacemit.com>
To: "Junhui Liu" <junhui.liu@pigmoral.tech>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Yixun Lan" <dlan@kernel.org>, "Paul Walmsley" <pjw@kernel.org>,
	"Palmer Dabbelt" <palmer@dabbelt.com>,
	"Albert Ou" <aou@eecs.berkeley.edu>,
	"Alexandre Ghiti" <alex@ghiti.fr>,
	"Guodong Xu" <guodong@riscstar.com>
Cc: <devicetree@vger.kernel.org>, <linux-riscv@lists.infradead.org>,
	<spacemit@lists.linux.dev>, <linux-kernel@vger.kernel.org>,
	"Troy Mitchell" <troy.mitchell@linux.spacemit.com>
Subject: Re: [PATCH] riscv: dts: spacemit: k3: Drop guest properties from M-level IMSIC
Date: Mon, 07 Sep 2026 21:31:51 +0800	[thread overview]
Message-ID: <DL94E69AG90Y.5UYVE3ZUKVM6@linux.spacemit.com> (raw)
In-Reply-To: <20260729-k3-mimsic-fix-v1-1-368c0aec04b9@pigmoral.tech>


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On Wed Jul 29, 2026 at 12:40 AM +08, Junhui Liu wrote:
> 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: Troy Mitchell <troy.mitchell@linux.spacemit.com>


-- 
Troy Mitchell


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  parent reply	other threads:[~2026-09-07 13:33 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-28 16:40 [PATCH] riscv: dts: spacemit: k3: Drop guest properties from M-level IMSIC Junhui Liu
2026-09-07  7:44 ` Yixun Lan
2026-09-07 13:31 ` Troy Mitchell [this message]
2026-09-08 21:26 ` Yixun Lan

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