From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 75545CCD190 for ; Wed, 15 Oct 2025 07:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jj4swPbH5fkwOQTkXgIAs/tjDn9iczH/GQH5A6fEQUs=; b=wIUyoQ2JJx3kQXQsP5DrSL3Bym PODkpOncOxy8wUxv/9xOgbkh37LuSSUGG/IQ1c+CcNrrsGduK0oPQidfbNd+NUh9CmoUNAx/38CBR 2AhItDWrDp+o2rz1ez4Tq78AfljLIFAKTZWiPhJtZZs8lPZJ4hsT7KXDx478GXzvfqVdgdEs/iMjd f0KxCEq+1cp18m67hdd7Ck3miRKIgJMXnyN+3mL2qhI1MGbBMPTjsVdEuzRHIfErQC8s11NzxLzGC 2c1nr9lHgExlEjTQ6WILEgf2rQAE30xoOWrY34sj4+d89dbUkhScq2h4Q3QJgN/A0sB79qJE7IMEw EFd4jF+w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v8wD3-00000000na3-0C6p; Wed, 15 Oct 2025 07:46:09 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v8wD1-00000000nZU-3BEv for linux-arm-kernel@lists.infradead.org; Wed, 15 Oct 2025 07:46:07 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id F241C624F7; Wed, 15 Oct 2025 07:46:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CA96C4CEF8; Wed, 15 Oct 2025 07:46:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760514366; bh=FXxCGMHSbseazrQCYcPIDrNhWuFK4U8Cv/qXKnF+kwY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rZb4uENYfMPKz6ON8rBY5Mda5+j+JTjC63EEdgH4BjNQI0935J1WgvTHUtezuqSWl b2clk0q7u48bcqZ7XWfIoJ2tTVpbzuZThWfeOJ9IExTlsNuQVhBHjiYUPjGFxK3zXg cMbbXtM8aZFQCoMmEtTZfAZVTvSU9gp3oX/6TO7+pejkW0wvLdhhOmrWw6HZWqxn54 IlTwJMcxk6GOg5zS60bEneYLmBHUtQgw8DWxDR+GIFeDwSa8H9cUP6Ba3KzXZnbLLy 3yudmXwirei0ZQX9UnEpP6U7c6BAL0pBijnk4oRYlbuwCttvJf8fdbJ8N+N5GXtXAf rV0vmhJQwZPAw== Date: Wed, 15 Oct 2025 09:46:00 +0200 From: Lorenzo Pieralisi To: Marc Zyngier Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-pci@vger.kernel.org, Sascha Bischoff , Thomas Gleixner , Rob Herring , Frank Li , Scott Branden , Bjorn Helgaas , Ray Jui , Manivannan Sadhasivam , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= Subject: Re: [PATCH v2 4/4] irqchip/gic-its: Rework platform MSI deviceID detection Message-ID: References: <20251014095845.1310624-1-lpieralisi@kernel.org> <20251014095845.1310624-5-lpieralisi@kernel.org> <87ecr5xv9w.wl-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87ecr5xv9w.wl-maz@kernel.org> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Oct 14, 2025 at 06:12:11PM +0100, Marc Zyngier wrote: > On Tue, 14 Oct 2025 10:58:45 +0100, > Lorenzo Pieralisi wrote: > > > > Current code retrieving platform devices MSI devID in the GIC ITS MSI > > parent helpers suffers from some minor issues: > > > > - It leaks a struct device_node reference > > - It triggers an excessive WARN_ON on wrong of_phandle_args count detection > > Well, if your DT is that rotten, maybe you actually deserve some > console spamming, don't you think? Yes from that standpoint it would make sense to leave the WARN_ON there, I can add it back. > > - It is duplicated between GICv3 and GICv5 for no good reason > > - It does not use the OF phandle iterator code that simplifies > > the msi-parent property parsing > > > > Implement a helper function that addresses the full set of issues in one go > > by consolidating GIC v3 and v5 code and converting the msi-parent parsing > > loop to the more modern OF phandle iterator API, fixing the > > struct device_node reference leak in the process. > > > > Signed-off-by: Lorenzo Pieralisi > > Cc: Sascha Bischoff > > Cc: Thomas Gleixner > > Cc: Rob Herring > > Cc: Frank Li > > Cc: Marc Zyngier > > --- > > drivers/irqchip/irq-gic-its-msi-parent.c | 98 ++++++++---------------- > > 1 file changed, 33 insertions(+), 65 deletions(-) > > > > diff --git a/drivers/irqchip/irq-gic-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c > > index eb1473f1448a..a65f762b7dd4 100644 > > --- a/drivers/irqchip/irq-gic-its-msi-parent.c > > +++ b/drivers/irqchip/irq-gic-its-msi-parent.c > > @@ -142,83 +142,51 @@ static int its_v5_pci_msi_prepare(struct irq_domain *domain, struct device *dev, > > #define its_v5_pci_msi_prepare NULL > > #endif /* !CONFIG_PCI_MSI */ > > > > -static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev, > > - u32 *dev_id) > > +static int __of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev, u32 *dev_id, > > + phys_addr_t *pa, bool is_v5) > > { > > - int ret, index = 0; > > + struct of_phandle_iterator it; > > + uint32_t args; > > Use u32, this is not userspace-visible (the OF code will cope). And > move it to where it matters instead of having such a wide scope. Ok. > > + int ret; > > > > /* Suck the DeviceID out of the msi-parent property */ > > - do { > > - struct of_phandle_args args; > > + of_for_each_phandle(&it, ret, dev->of_node, "msi-parent", "#msi-cells", -1) { > > + /* GICv5 ITS domain matches the MSI controller node parent */ > > + struct device_node *np __free(device_node) = is_v5 ? of_get_parent(it.node) > > + : of_node_get(it.node); > > > > - ret = of_parse_phandle_with_args(dev->of_node, > > - "msi-parent", "#msi-cells", > > - index, &args); > > - if (args.np == irq_domain_get_of_node(domain)) { > > - if (WARN_ON(args.args_count != 1)) > > - return -EINVAL; > > - *dev_id = args.args[0]; > > - break; > > + if (np == irq_domain_get_of_node(domain)) { > > + if (of_phandle_iterator_args(&it, &args, 1) != 1) { > > + dev_warn(dev, "Bogus msi-parent property\n"); > > + ret = -EINVAL; > > + } > > + > > + if (!ret && is_v5) > > + ret = its_translate_frame_address(it.node, pa); > > Why do you need this is_v5 hack, since the only case were you pass a > pointer to get the translate register address is for v5? Yep, I thought about this what you are suggesting makes sense - is_v5 is useless (and terrible). > > + > > + if (!ret) > > + *dev_id = args; > > + > > + of_node_put(it.node); > > + return ret; > > } > > - index++; > > - } while (!ret); > > - > > - if (ret) { > > - struct device_node *np = NULL; > > - > > - ret = of_map_id(dev->of_node, dev->id, "msi-map", "msi-map-mask", &np, dev_id); > > - if (np) > > - of_node_put(np); > > } > > > > - return ret; > > + struct device_node *msi_ctrl __free(device_node) = NULL; > > + > > + return of_map_id(dev->of_node, dev->id, "msi-map", "msi-map-mask", &msi_ctrl, dev_id); > > +} > > + > > +static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev, > > + u32 *dev_id) > > +{ > > + return __of_pmsi_get_dev_id(domain, dev, dev_id, NULL, false); > > } > > At this stage, we really don't need these on-liners, as they only > obfuscate the logic. Just use the main helper directly. Something like > the hack below. That makes sense. Thanks ! Lorenzo > > M. > > diff --git a/drivers/irqchip/irq-gic-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c > index a65f762b7dd4d..7c82fd152655e 100644 > --- a/drivers/irqchip/irq-gic-its-msi-parent.c > +++ b/drivers/irqchip/irq-gic-its-msi-parent.c > @@ -142,26 +142,27 @@ static int its_v5_pci_msi_prepare(struct irq_domain *domain, struct device *dev, > #define its_v5_pci_msi_prepare NULL > #endif /* !CONFIG_PCI_MSI */ > > -static int __of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev, u32 *dev_id, > - phys_addr_t *pa, bool is_v5) > +static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u32 *dev_id, > + phys_addr_t *pa) > { > struct of_phandle_iterator it; > - uint32_t args; > int ret; > > /* Suck the DeviceID out of the msi-parent property */ > of_for_each_phandle(&it, ret, dev->of_node, "msi-parent", "#msi-cells", -1) { > /* GICv5 ITS domain matches the MSI controller node parent */ > - struct device_node *np __free(device_node) = is_v5 ? of_get_parent(it.node) > + struct device_node *np __free(device_node) = pa ? of_get_parent(it.node) > : of_node_get(it.node); > > if (np == irq_domain_get_of_node(domain)) { > + u32 args; > + > if (of_phandle_iterator_args(&it, &args, 1) != 1) { > dev_warn(dev, "Bogus msi-parent property\n"); > ret = -EINVAL; > } > > - if (!ret && is_v5) > + if (!ret && pa) > ret = its_translate_frame_address(it.node, pa); > > if (!ret) > @@ -177,18 +178,6 @@ static int __of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev, u > return of_map_id(dev->of_node, dev->id, "msi-map", "msi-map-mask", &msi_ctrl, dev_id); > } > > -static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev, > - u32 *dev_id) > -{ > - return __of_pmsi_get_dev_id(domain, dev, dev_id, NULL, false); > -} > - > -static int of_v5_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, > - u32 *dev_id, phys_addr_t *pa) > -{ > - return __of_pmsi_get_dev_id(domain, dev, dev_id, pa, true); > -} > - > int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id) > { > return -1; > @@ -202,7 +191,7 @@ static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev, > int ret; > > if (dev->of_node) > - ret = of_pmsi_get_dev_id(domain->parent, dev, &dev_id); > + ret = of_pmsi_get_msi_info(domain->parent, dev, &dev_id, NULL); > else > ret = iort_pmsi_get_dev_id(dev, &dev_id); > if (ret) > @@ -230,7 +219,7 @@ static int its_v5_pmsi_prepare(struct irq_domain *domain, struct device *dev, > if (!dev->of_node) > return -ENODEV; > > - ret = of_v5_pmsi_get_msi_info(domain->parent, dev, &dev_id, &pa); > + ret = of_pmsi_get_msi_info(domain->parent, dev, &dev_id, &pa); > if (ret) > return ret; > > > -- > Jazz isn't dead. It just smells funny.