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 7767BA47; Thu, 27 Feb 2025 00:23:29 +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=1740615809; cv=none; b=mjePfhGod1u+1VwHyoY7EOhoOqilF5BPavn9HTSLmqXj5ciilb2fNug+3sswYrA3YebEEiSMXScZu0mIe23TdYVoliFRPhHI5OEEhdfhg6JQ1ObjqxLuhmp991WER3vsDNRxWIcNAPD00ubt32f8Da2FSpDNw5stmJ1by0cCQ+I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740615809; c=relaxed/simple; bh=Snbn7RL/BEWOlEKJMOnfQXtsEkFO1ZODqdbhYhfuwis=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=JAn/S7ep1sZrxVCKhwszsFQIt4s7m+j+2FUwojgzGWfvhSO2dPMYRKs01pfk4drWKRRFD29yBbSg7JFlTFeTJw23YZgwe8cWqqPcxRf9IhgsgwWz0pOeBv1T57ewveX8G1t21adl3C/7lsW/XGmHGeHyVKDnO9eKYN6tdHSj100= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tL83cyzx; 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="tL83cyzx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2E91C4CED6; Thu, 27 Feb 2025 00:23:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740615808; bh=Snbn7RL/BEWOlEKJMOnfQXtsEkFO1ZODqdbhYhfuwis=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=tL83cyzxc1jmWFi+Npy+ataI7BSMe3WmInn/gZ433hDXbfcUXE43I1HFOv1mKSDWe R/TFB1Y9hNmlzeSjIGXMoN8W7IC6rVYbyd1y7+fccn56zqBsfk2eok2QCDSkA+wKOs Vgin+CiJAEZyxgCZE4vw4l7TrWuolCUeRW3QXgWQSn++AUAFdEvoL4P9n3swqBWzxs jWySl0T4WQ9LQIg4poVHPxMxnIi68JL9rxSVx0uRSJOKynxbfviWne7o5czp4jxMQs vfdNO2dsIFSz4HFDF1jUDeopba30bsGitUiyXKL864E4UsNQ0EDs9pppksASriq5hb s1VOyJ48mrG8A== Date: Wed, 26 Feb 2025 18:23:26 -0600 From: Bjorn Helgaas To: Frank Li Cc: Rob Herring , Saravana Kannan , Jingoo Han , Manivannan Sadhasivam , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Bjorn Helgaas , Richard Zhu , Lucas Stach , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev, Niklas Cassel Subject: Re: [PATCH v9 3/7] PCI: Add parent_bus_offset to resource_entry Message-ID: <20250227002326.GA566507@bhelgaas> 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: <20250128-pci_fixup_addr-v9-3-3c4bb506f665@nxp.com> On Tue, Jan 28, 2025 at 05:07:36PM -0500, Frank Li wrote: > Introduce `parent_bus_offset` in `resource_entry` and a new API, > `pci_add_resource_parent_bus_offset()`, to provide necessary information > for PCI controllers with address translation units. > > Typical PCI data flow involves: > CPU (CPU address) -> Bus Fabric (Intermediate address) -> > PCI Controller (PCI bus address) -> PCI Bus. > > While most bus fabrics preserve address consistency, some modify addresses > to intermediate values. The `parent_bus_offset` enables PCI controllers to > translate these intermediate addresses correctly to PCI bus addresses. > > Pave the road to remove hardcoded cpu_addr_fixup() and similar patterns in > PCI controller drivers. > ... > +++ b/drivers/pci/of.c > @@ -402,7 +402,17 @@ static int devm_of_pci_get_host_bridge_resources(struct device *dev, > res->flags &= ~IORESOURCE_MEM_64; > } > > - pci_add_resource_offset(resources, res, res->start - range.pci_addr); > + /* > + * IORESOURCE_IO res->start is io space start address. > + * IORESOURCE_MEM res->start is cpu start address, which is the > + * same as range.cpu_addr. > + * > + * Use (range.cpu_addr - range.parent_bus_addr) to align both > + * IO and MEM's parent_bus_offset always offset to cpu address. > + */ > + > + pci_add_resource_parent_bus_offset(resources, res, res->start - range.pci_addr, > + range.cpu_addr - range.parent_bus_addr); I don't know exactly where it needs to go, but I think we can call .cpu_addr_fixup() once at startup on the base of the region. This will tell us the offset that applies to the entire region, i.e., parent_bus_offset. Then we can remove all the .cpu_addr_fixup() calls in cdns_pcie_host_init_address_translation(), cdns_pcie_set_outbound_region(), and dw_pcie_prog_outbound_atu(). Until we can get rid of all the .cpu_addr_fixup() implementations, We'll still have that single call at startup (I guess once for cadence and another for designware), but it should simplify the current callers quite a bit. > } > > /* Check for dma-ranges property */ > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 47b31ad724fa5..0d7e67b47be47 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1510,6 +1510,8 @@ static inline void pci_release_config_region(struct pci_dev *pdev, > void pci_add_resource(struct list_head *resources, struct resource *res); > void pci_add_resource_offset(struct list_head *resources, struct resource *res, > resource_size_t offset); > +void pci_add_resource_parent_bus_offset(struct list_head *resources, struct resource *res, > + resource_size_t offset, resource_size_t parent_bus_offset); > void pci_free_resource_list(struct list_head *resources); > void pci_bus_add_resource(struct pci_bus *bus, struct resource *res); > struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n); > diff --git a/include/linux/resource_ext.h b/include/linux/resource_ext.h > index ff0339df56afc..b6ec6cc318203 100644 > --- a/include/linux/resource_ext.h > +++ b/include/linux/resource_ext.h > @@ -24,6 +24,7 @@ struct resource_entry { > struct list_head node; > struct resource *res; /* In master (CPU) address space */ > resource_size_t offset; /* Translation offset for bridge */ > + resource_size_t parent_bus_offset; /* Parent bus address offset for bridge */ > struct resource __res; /* Default storage for res */ > }; > > > -- > 2.34.1 >