From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.101.70]:60670 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726636AbeHBSq1 (ORCPT ); Thu, 2 Aug 2018 14:46:27 -0400 Date: Thu, 2 Aug 2018 17:54:30 +0100 From: Lorenzo Pieralisi To: Christoph Hellwig Cc: Bjorn Helgaas , Palmer Dabbelt , "Wesley W . Terpstra" , Arnd Bergmann , linux-pci@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH 1/3] PCI: add a callback to struct pci_host_bridge for adding a new device Message-ID: <20180802165430.GA13725@red-moon> References: <20180801151403.20660-1-hch@lst.de> <20180801151403.20660-2-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180801151403.20660-2-hch@lst.de> Sender: linux-pci-owner@vger.kernel.org List-ID: On Wed, Aug 01, 2018 at 05:14:01PM +0200, Christoph Hellwig wrote: > There is currently no way for a PCIe bridge to impose constraints on > devices added to it. For example, the Xilinx PCIe host bridge only > supports 32-bit physical addresses (due to a limitation on the AXI > port's address width). Thus, even devices that claim to support 64-bit > DMA addresses must be restricted to 32-bit addresses when attached to > this host controller. > > This patch adds a "add_dev" method to struct pci_host_bridge that > allows the host driver to act upon acting adding devices. > > Based on an earlier patch from Wesley W. Terpstra . > > Signed-off-by: Christoph Hellwig > --- > drivers/pci/probe.c | 4 ++++ > include/linux/pci.h | 1 + > 2 files changed, 5 insertions(+) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index ac876e32de4b..8736d78ffc66 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -2290,6 +2290,7 @@ static void pci_set_msi_domain(struct pci_dev *dev) > > void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) > { > + struct pci_host_bridge *host = pci_find_host_bridge(bus); > int ret; > > pci_configure_device(dev); > @@ -2331,6 +2332,9 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) > /* Set up MSI IRQ domain */ > pci_set_msi_domain(dev); > > + if (host->add_dev) > + host->add_dev(dev); Hi Christoph, while at it, IMHO it would be good to match the current pcibios_add_device() prototype (ie returning an int error value) so that this change can pave the way to removing yet another pcibios call. Actually we could make pcibios_add_device() removal as part of this series but you would have to patch all related host bridge drivers initializations so I am happy for this patch to go standalone (I can patch the rest of the code) - I leave it to Bjorn's decision. Thanks, Lorenzo > + > /* Notifier could use PCI capabilities */ > dev->match_driver = false; > ret = device_add(&dev->dev); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index abd5d5e17aee..5eedae8e8f2b 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -485,6 +485,7 @@ struct pci_host_bridge { > resource_size_t start, > resource_size_t size, > resource_size_t align); > + void (*add_dev)(struct pci_dev *dev); > unsigned long private[0] ____cacheline_aligned; > }; > > -- > 2.18.0 >