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 1685E252CA6; Thu, 16 Jan 2025 23:29:17 +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=1737070158; cv=none; b=pjRLqZeKtZpq4toSxZxslcbafIq3zs/Y8NCXSqV18suClP16qvRmeMK5qGcszGzWMUOPWW1K1bZJ4KLyDTtJfU9VGr/IYYlfqZaOk07TN8FhuCT6iEAzCs+U0v/AbzPOBKAkmxm6xNxvG3KtvYXFPnig2C25eUhAt7qIZbGky3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737070158; c=relaxed/simple; bh=dMwwqya1n7mouM0thH4tLEBVCAjWJzbR4JIYV6x+c8k=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=M7XGuc0I2z+f2JAEO6NM6UYQbA9vhqVFwZ+SALf+JTLUgOb1Bok2VPmJQAR3/EgMGtMYp105Rj51Krytj1LRLUDJIrEuF0QdRVK6cOg65K1jC7eSkE5lxOJZq1vZ/aAdekBliR6Gv+Im+BeiHPfqMP7eNAYRF22Y6Xda8vPA5g4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cp95TFTo; 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="cp95TFTo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66D40C4CED6; Thu, 16 Jan 2025 23:29:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737070157; bh=dMwwqya1n7mouM0thH4tLEBVCAjWJzbR4JIYV6x+c8k=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=cp95TFTojT43ishZ8WQ4Mwsx3PoDWTZzdjzqZ2MTjofA4fLE8O8H2NZi0DrJToqfR EN9p7UiHkjHhzTnEX/Nnfw+Cdxgdj/equtDNoIPcUVHou6MH8M6OCgjFKCjv+HGZwp IC37Tez0mu7Tp2y+CJAlmCj4QkXPrCmdP4CEtIKKc0En35zUsz+1iuISun5r2YKuNS xmEpPjEcmg9u+Y25j6aMDWqbPqIC5nVLoe7a2/zMsu6AmzR2eZeTWLJ18iDQAeUt8s Qop6AaZZcCjRAJADxFbga5cNKEgIFrVBd0C5IEt1BxzWQFNGeeW+QfYjM6iTVNvmM0 QoTEoKHRcE27A== Date: Thu, 16 Jan 2025 17:29:16 -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 Subject: Re: [PATCH v8 2/7] PCI: dwc: Use devicetree 'ranges' property to get rid of cpu_addr_fixup() callback Message-ID: <20250116232916.GA617353@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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250116231358.GA616783@bhelgaas> On Thu, Jan 16, 2025 at 05:14:00PM -0600, Bjorn Helgaas wrote: > On Tue, Nov 19, 2024 at 02:44:20PM -0500, Frank Li wrote: > > parent_bus_addr in struct of_range can indicate address information just > > ahead of PCIe controller. Most system's bus fabric use 1:1 map between > > input and output address. but some hardware like i.MX8QXP doesn't use 1:1 > > map. See below diagram: > > > > ┌─────────┐ ┌────────────┐ > > ┌─────┐ │ │ IA: 0x8ff8_0000 │ │ > > │ CPU ├───►│ ┌────►├─────────────────┐ │ PCI │ > > └─────┘ │ │ │ IA: 0x8ff0_0000 │ │ │ > > CPU Addr │ │ ┌─►├─────────────┐ │ │ Controller │ > > 0x7ff8_0000─┼───┘ │ │ │ │ │ │ > > │ │ │ │ │ │ │ PCI Addr > > 0x7ff0_0000─┼──────┘ │ │ └──► IOSpace ─┼────────────► > > │ │ │ │ │ 0 > > 0x7000_0000─┼────────►├─────────┐ │ │ │ > > └─────────┘ │ └──────► CfgSpace ─┼────────────► > > BUS Fabric │ │ │ 0 > > │ │ │ > > └──────────► MemSpace ─┼────────────► > > IA: 0x8000_0000 │ │ 0x8000_0000 > > └────────────┘ > > > > bus@5f000000 { > > compatible = "simple-bus"; > > #address-cells = <1>; > > #size-cells = <1>; > > ranges = <0x80000000 0x0 0x70000000 0x10000000>; > > > > pcie@5f010000 { > > compatible = "fsl,imx8q-pcie"; > > reg = <0x5f010000 0x10000>, <0x8ff00000 0x80000>; > > reg-names = "dbi", "config"; > > #address-cells = <3>; > > #size-cells = <2>; > > device_type = "pci"; > > bus-range = <0x00 0xff>; > > ranges = <0x81000000 0 0x00000000 0x8ff80000 0 0x00010000>, > > <0x82000000 0 0x80000000 0x80000000 0 0x0ff00000>; > > ... > > }; > > }; > > > > Term internal address (IA) here means the address just before PCIe > > controller. After ATU use this IA instead CPU address, cpu_addr_fixup() can > > be removed. > > > @@ -730,9 +779,15 @@ static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp) > > > > atu.index = i; > > atu.type = PCIE_ATU_TYPE_MEM; > > - atu.cpu_addr = entry->res->start; > > + parent_bus_addr = entry->res->start; > > atu.pci_addr = entry->res->start - entry->offset; > > > > + ret = dw_pcie_get_parent_addr(pci, entry->res->start, &parent_bus_addr); > > + if (ret) > > + return ret; > > + > > + atu.cpu_addr = parent_bus_addr; > > Here you set atu.cpu_addr to the intermediate bus address instead > of the CPU physical address before calling > dw_pcie_prog_outbound_atu(). > > But what about other callers of dw_pcie_prog_outbound_atu()? Don't > all of them need to use the intermediate bus address? Somehow I expected the patch to skip calling ->cpu_addr_fixup() if the driver had set 'use_parent_dt_ranges'. In fact, I think that's a requirement. Since dw_pcie_prog_outbound_atu() is the only dwc caller, maybe the parent_bus_addr change should go *there* instead of in the callers? Bjorn