From nobody Thu Oct 2 14:25:55 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 91C7D273D81; Tue, 16 Sep 2025 09:19:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758014342; cv=none; b=ZYQQRZfPS2z4wH7Dcjzgh7EUOSpu8/JFbRSHhsMVgXzMUVWQeDcLRKwby1jTj+cGJk0Jg4fOqmmoriTxNpajBS3K5vviYizEdF8sCZ83pFpqJWiROmj9nyETe5McMvfW1EtNRHgGx/PjY+xeH52rBL4kZwMyqwPousOf0Zbtxfk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758014342; c=relaxed/simple; bh=qB2g+ZKw2xWUvs4kudjzzew1W4c1a8eYuOTpRkQDpds=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=aJBZUBiGPdhYhF+9JjAKxl7Hi6JP6FwIHtya7aO/1nklBEqUXUA+WjaVDMEV2s1mZABHMLOeLP8yo4/rqKPk7cxF8k4T2tIF5+AXrd3wtFyV4C9bqhjZJBg2BOylxHp0KgVmRuXDw+CE8aDw03HdlB9OF5TWCCSRTUnTlMdOOno= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Hk+ZZzly; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Hk+ZZzly" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68820C4CEEB; Tue, 16 Sep 2025 09:19:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758014342; bh=qB2g+ZKw2xWUvs4kudjzzew1W4c1a8eYuOTpRkQDpds=; h=From:To:Cc:Subject:Date:From; b=Hk+ZZzlyxx3MGy8TLfOdkdC2u/ZQjIH5cGi7IH5AnKnDRtVqNnUeM84pRQPzJBujj VcOB3EKTNUAl74KNtprTUCeEkaBLLv5mxbgOOSJLh9QFzDCtHPrWZ7RvmV+XYrL9II LyZ0u1aliYpEr0TyAFAl7YiLaJ4SFHsNnhohg6l9RDHWx4tuZDgUZdXRRm2WBi+VA8 johVPGHutqMY4WsNWQL7V+KqBBWMbPx2vs8gP5B4i+yAUeDCq/d1LW+1vfFWKOaAzm onjhGqRExD0Pe3Tab/o+c1OtCUI40hnEAMif/xNUPFnBhODNnK1jtXmcXJveLdY3qi k8BOG99C9SZAw== From: Lorenzo Pieralisi To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Sascha Bischoff , Rob Herring , Marc Zyngier Subject: [PATCH] of/irq: Add msi-parent check to of_msi_xlate() Date: Tue, 16 Sep 2025 11:18:58 +0200 Message-ID: <20250916091858.257868-1-lpieralisi@kernel.org> X-Mailer: git-send-email 2.48.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In some legacy platforms the MSI controller for a PCI host bridge is identified by an msi-parent property whose phandle points at an MSI controller node with no #msi-cells property, that implicitly means #msi-cells =3D=3D 0. For such platforms, mapping a device ID and retrieving the MSI controller node becomes simply a matter of checking whether in the device hierarchy there is an msi-parent property pointing at an MSI controller node with such characteristics. Add a helper function to of_msi_xlate() to check the msi-parent property in addition to msi-map and retrieve the MSI controller node (with a 1:1 ID deviceID-IN<->deviceID-OUT mapping) to provide support for deviceID mapping and MSI controller node retrieval for such platforms. Signed-off-by: Lorenzo Pieralisi Cc: Sascha Bischoff Cc: Rob Herring Cc: Marc Zyngier --- drivers/of/irq.c | 38 +++++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) diff --git a/drivers/of/irq.c b/drivers/of/irq.c index e7c12abd10ab..d0e2dfd0ee28 100644 --- a/drivers/of/irq.c +++ b/drivers/of/irq.c @@ -670,6 +670,35 @@ void __init of_irq_init(const struct of_device_id *mat= ches) } } =20 +static int of_check_msi_parent(struct device_node *dev_node, struct device= _node **msi_node) +{ + struct of_phandle_args msi_spec; + int ret; + + /* + * An msi-parent phandle with a missing or =3D=3D 0 #msi-cells + * property identifies a 1:1 ID translation mapping. + * + * Set the msi controller node if the firmware matches this + * condition. + */ + ret =3D of_parse_phandle_with_optional_args(dev_node, "msi-parent", "#msi= -cells", + 0, &msi_spec); + if (!ret) { + if ((*msi_node && *msi_node !=3D msi_spec.np) || msi_spec.args_count != =3D 0) + ret =3D -EINVAL; + + if (!ret) { + /* Return with a node reference held */ + *msi_node =3D msi_spec.np; + return 0; + } + of_node_put(msi_spec.np); + } + + return ret; +} + /** * of_msi_xlate - map a MSI ID and find relevant MSI controller node * @dev: device for which the mapping is to be done. @@ -677,7 +706,7 @@ void __init of_irq_init(const struct of_device_id *matc= hes) * @id_in: Device ID. * * Walk up the device hierarchy looking for devices with a "msi-map" - * property. If found, apply the mapping to @id_in. + * or "msi-parent" property. If found, apply the mapping to @id_in. * If @msi_np points to a non-NULL device node pointer, only entries targe= ting * that node will be matched; if it points to a NULL value, it will receiv= e the * device node of the first matching target phandle, with a reference held. @@ -691,12 +720,15 @@ u32 of_msi_xlate(struct device *dev, struct device_no= de **msi_np, u32 id_in) =20 /* * Walk up the device parent links looking for one with a - * "msi-map" property. + * "msi-map" or an "msi-parent" property. */ - for (parent_dev =3D dev; parent_dev; parent_dev =3D parent_dev->parent) + for (parent_dev =3D dev; parent_dev; parent_dev =3D parent_dev->parent) { if (!of_map_id(parent_dev->of_node, id_in, "msi-map", "msi-map-mask", msi_np, &id_out)) break; + if (!of_check_msi_parent(parent_dev->of_node, msi_np)) + break; + } return id_out; } =20 --=20 2.48.0