Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756227AbaGHBAD (ORCPT ); Mon, 7 Jul 2014 21:00:03 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:41607 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753121AbaGHA76 (ORCPT ); Mon, 7 Jul 2014 20:59:58 -0400 Date: Mon, 7 Jul 2014 18:59:54 -0600 From: Bjorn Helgaas To: Liviu Dudau Cc: linux-pci , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Arnd Bergmann , linaro-kernel , Tanmay Inamdar , Grant Likely , Sinan Kaya , Jingoo Han , Kukjin Kim , Suravee Suthikulanit , LKML , Device Tree ML , LAKML Subject: Re: [PATCH v8 6/9] pci: Introduce a domain number for pci_host_bridge. Message-ID: <20140708005954.GC22939@google.com> References: <1404240214-9804-1-git-send-email-Liviu.Dudau@arm.com> <1404240214-9804-7-git-send-email-Liviu.Dudau@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1404240214-9804-7-git-send-email-Liviu.Dudau@arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 01, 2014 at 07:43:31PM +0100, Liviu Dudau wrote: > Make it easier to discover the domain number of a bus by storing > the number in pci_host_bridge for the root bus. Several architectures > have their own way of storing this information, so it makes sense > to try to unify the code. While at this, add a new function that > creates a root bus in a given domain and make pci_create_root_bus() > a wrapper around this function. "While at this" is always a good clue that maybe something should be split into a separate patch :) This is a very good example, since it adds a new interface that deserves its own changelog. > Signed-off-by: Liviu Dudau > Tested-by: Tanmay Inamdar > --- > drivers/pci/probe.c | 41 +++++++++++++++++++++++++++++++++-------- > include/linux/pci.h | 4 ++++ > 2 files changed, 37 insertions(+), 8 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 2c92662..abf5e82 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1748,8 +1748,9 @@ void __weak pcibios_remove_bus(struct pci_bus *bus) > { > } > > -struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > - struct pci_ops *ops, void *sysdata, struct list_head *resources) > +struct pci_bus *pci_create_root_bus_in_domain(struct device *parent, > + int domain, int bus, struct pci_ops *ops, void *sysdata, > + struct list_head *resources) I don't think we should do it this way; this makes it possible to have a host bridge where "bridge->domain_nr != pci_domain_nr(bridge->bus)". I wonder if it would help to make a weak pci_domain_nr() function that returns "bridge->domain_nr". Then each arch could individually drop its pci_domain_nr() definition as it was converted, e.g., something like this: - Convert every arch pci_domain_nr() from a #define to a non-inline function - Add bridge.domain_nr, initialized from pci_domain_nr() - Add a weak generic pci_domain_nr() that returns bridge.domain_nr - Add a way to create a host bridge in a specified domain, so we can initialize bridge.domain_nr without using pci_domain_nr() - Convert each arch to use the new creation mechanism and drop its pci_domain_nr() implementation > { > int error; > struct pci_host_bridge *bridge; > @@ -1762,27 +1763,31 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > > bridge = pci_alloc_host_bridge(); > if (!bridge) > - return NULL; > + return ERR_PTR(-ENOMEM); > > bridge->dev.parent = parent; > bridge->dev.release = pci_release_host_bridge_dev; > + bridge->domain_nr = domain; > > b = pci_alloc_bus(); > - if (!b) > + if (!b) { > + error = -ENOMEM; > goto err_out; > + } > > b->sysdata = sysdata; > b->ops = ops; > b->number = b->busn_res.start = bus; > - b2 = pci_find_bus(pci_domain_nr(b), bus); > + b2 = pci_find_bus(bridge->domain_nr, bus); > if (b2) { > /* If we already got to this bus through a different bridge, ignore it */ > dev_dbg(&b2->dev, "bus already known\n"); > + error = -EEXIST; > goto err_bus_out; > } > > bridge->bus = b; > - dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); > + dev_set_name(&bridge->dev, "pci%04x:%02x", bridge->domain_nr, bus); > error = pcibios_root_bridge_prepare(bridge); > if (error) > goto err_out; > @@ -1801,7 +1806,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > > b->dev.class = &pcibus_class; > b->dev.parent = b->bridge; > - dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus); > + dev_set_name(&b->dev, "%04x:%02x", bridge->domain_nr, bus); > error = device_register(&b->dev); > if (error) > goto class_dev_reg_err; > @@ -1851,7 +1856,27 @@ err_bus_out: > kfree(b); > err_out: > kfree(bridge); > - return NULL; > + return ERR_PTR(error); > +} > + > +struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > + struct pci_ops *ops, void *sysdata, struct list_head *resources) > +{ > + int domain_nr; > + struct pci_bus *b = pci_alloc_bus(); > + if (!b) > + return NULL; > + > + b->sysdata = sysdata; > + domain_nr = pci_domain_nr(b); > + kfree(b); > + > + b = pci_create_root_bus_in_domain(parent, domain_nr, bus, > + ops, sysdata, resources); > + if (IS_ERR(b)) > + return NULL; > + > + return b; > } > > int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 466bcd1..7e7b939 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -401,6 +401,7 @@ struct pci_host_bridge_window { > struct pci_host_bridge { > struct device dev; > struct pci_bus *bus; /* root bus */ > + int domain_nr; > struct list_head windows; /* pci_host_bridge_windows */ > void (*release_fn)(struct pci_host_bridge *); > void *release_data; > @@ -769,6 +770,9 @@ struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, void *sysdata); > struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > struct pci_ops *ops, void *sysdata, > struct list_head *resources); > +struct pci_bus *pci_create_root_bus_in_domain(struct device *parent, > + int domain, int bus, struct pci_ops *ops, > + void *sysdata, struct list_head *resources); > int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax); > int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax); > void pci_bus_release_busn_res(struct pci_bus *b); > -- > 2.0.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/