From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Pieralisi Subject: Re: [PATCH] arm64: acpi: Support PCI devices numa_node property in ACPI mode Date: Wed, 12 Apr 2017 18:04:33 +0100 Message-ID: <20170412170433.GA7412@red-moon> References: <0dada57f-4215-4ced-482d-88203857e06d@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from foss.arm.com ([217.140.101.70]:47270 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751101AbdDLRD5 (ORCPT ); Wed, 12 Apr 2017 13:03:57 -0400 Content-Disposition: inline In-Reply-To: <0dada57f-4215-4ced-482d-88203857e06d@codeaurora.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Sinan Kaya Cc: linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org On Sat, Apr 08, 2017 at 01:17:32PM -0400, Sinan Kaya wrote: > On 12/31/1969 7:00 PM, linux-arm-kernel [mailto:linux-arm-kernel-bounces@lists.infradead.org] On Behalf Of Sergey Temerkhanov wrote: > > int pcibus_to_node(struct pci_bus *bus) { > > - return dev_to_node(&bus->dev); > > + struct pci_config_window *cfg = bus->sysdata; > > + struct acpi_device *adev = NULL; > > + struct device *dev; > > + > > + if (!acpi_disabled) > > + adev = to_acpi_device(cfg->parent); > > + > > I see a problem here that NUMA node information is read from the > parent device. PCI bus can have multiple levels of switches and > bridges. The NUMA information is only present on the host bridge. > > This code only works if the endpoint is directly connected to the root > port. That's not what this code does. This code retrieves the struct device backing the ACPI device representing the PNP0A08 host bridge and its dev->numa_node value (that was set in pci_acpi_scan_root()). I am not a big fan of this. I wonder if we could not make it DT/ACPI agnostic by simply setting the numa_node in the pci_bus->dev field, and propagate it downstream a PCI hierarcy (as we do with sysdata) in pci_alloc_child_bus(). This way pcibus_to_node() would become straightforward (ie as it is now - provided the above is doable): dev_to_node(&bus->dev); This is suspiciously similar to the domain number song and dance except that the NUMA node now is in the struct pci_bus->dev->numa_node instead of struct pci_bus->domain_nr. Lorenzo