From mboxrd@z Thu Jan 1 00:00:00 1970 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 3DA4A21171B; Thu, 18 Sep 2025 13:55:56 +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=1758203757; cv=none; b=KdbF+DCsXF40SqnCGxhW3nbIM0OXSIeI2D9pVxSgGSwVq5MXK1Qjjj5jTVjNIEdu7U8iUDq7AcT6dpMzT4n01o9tmbo+UvpX9vTIEcEQBQL38k5e4qSq0efByTjhMguH0+qLVbzQ+iMDn6qlfUGq8r0E23L3WB9vVevIhYROhnk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758203757; c=relaxed/simple; bh=G7/78i6RoQRQodPeKCJlvCChMtkjXdabJYnM8oOuRa8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jPqQWYzNUsksm6ASQm+UYfsZ9HAqjS2xSgrTFhmfqnEv9V7QHKf4nXeUmsoX0kqhNw5CBWGsNBz3Z0w7btKXKTLwCc+acZBCxaV3BPIncvMcFQ7fWVm7vFAgu27BogzvaSpGboo5m9r+tzsEjt4/GJ0yhc4wMCZMkvZyJS2EqBY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WTCWsD6L; 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="WTCWsD6L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8938DC4CEE7; Thu, 18 Sep 2025 13:55:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758203756; bh=G7/78i6RoQRQodPeKCJlvCChMtkjXdabJYnM8oOuRa8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WTCWsD6L7/v5r0aazrPV4ecf3YGy+0V6OCMU84LAqsRbFvd4h07tCGJfl4JcB7Iex q0EOF4zuSUAEnYPpTCabSIrITdqQATMaexeXvPifNm6R/b/oh3GW4AZ4b6XHjAwSsd jIQ44AM12/V1Et0YlNXrJnWEQR7Q8/hmk0nZzetqn0kSk2lk0UFq5GGyRsth1je6gZ QOCbB5Z17UW0ZPfMdsktxJe0fkQS9MzQV4kbpBEx0N2mRhkIX92Irr3txGNA/zoKpN FF9t2GH/t0d7U7Sy0qh3WibSWz4BwNB5Of8FvdVkTh/dHRSHF7V3AxUAOTc0aQpH2U zx6OijYZr3/ZA== Date: Thu, 18 Sep 2025 08:55:55 -0500 From: Rob Herring To: Lorenzo Pieralisi Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Sascha Bischoff , Marc Zyngier Subject: Re: [PATCH] of/irq: Add msi-parent check to of_msi_xlate() Message-ID: <20250918135555.GA1540012-robh@kernel.org> References: <20250916091858.257868-1-lpieralisi@kernel.org> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250916091858.257868-1-lpieralisi@kernel.org> On Tue, Sep 16, 2025 at 11:18:58AM +0200, Lorenzo Pieralisi wrote: > 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 == 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. Your line wrapping is a bit short. I had a look at who is parsing "msi-parent" themselves as that's typically a recipe for doing it incorrectly ('interrupt-map' anyone). Can we make iproc_pcie_msi_enable() use this? It's quite ugly reaching into the GICv3 node... And perhaps irq-gic-its-msi-parent.c could use this? And looks like pcie-layerscape-gen4 is leaking a node reference... > > 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 *matches) > } > } > > +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 == 0 #msi-cells > + * property identifies a 1:1 ID translation mapping. > + * > + * Set the msi controller node if the firmware matches this > + * condition. > + */ > + ret = of_parse_phandle_with_optional_args(dev_node, "msi-parent", "#msi-cells", > + 0, &msi_spec); > + if (!ret) { > + if ((*msi_node && *msi_node != msi_spec.np) || msi_spec.args_count != 0) > + ret = -EINVAL; > + > + if (!ret) { > + /* Return with a node reference held */ > + *msi_node = 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 *matches) > * @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 targeting > * that node will be matched; if it points to a NULL value, it will receive 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_node **msi_np, u32 id_in) > > /* > * Walk up the device parent links looking for one with a > - * "msi-map" property. > + * "msi-map" or an "msi-parent" property. > */ > - for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) > + for (parent_dev = dev; parent_dev; parent_dev = 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; > } > > -- > 2.48.0 >