From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e35.co.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 263F7B7011 for ; Tue, 26 Jun 2012 10:31:15 +1000 (EST) Received: from /spool/local by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 25 Jun 2012 18:31:11 -0600 Received: from d03relay03.boulder.ibm.com (d03relay03.boulder.ibm.com [9.17.195.228]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 80ECDC40006 for ; Tue, 26 Jun 2012 00:30:24 +0000 (WET) Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay03.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q5Q0UPeh170950 for ; Mon, 25 Jun 2012 18:30:25 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q5Q0UOGO021329 for ; Mon, 25 Jun 2012 18:30:24 -0600 Date: Tue, 26 Jun 2012 08:30:21 +0800 From: Gavin Shan To: Yinghai Lu Subject: Re: [PATCH V3 1/2] PCI: retrieve host bridge by PCI bus Message-ID: <20120626003020.GA6307@shangw> References: <1340593821-19011-1-git-send-email-shangw@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: Cc: bhelgaas@google.com, linux-pci@vger.kernel.org, Gavin Shan , linuxppc-dev@ozlabs.org Reply-To: Gavin Shan List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , >> With current implementation, there is one function to retrieve >> the corresponding host bridge (struct pci_host_bridge) according >> to the given PCI device (struct pci_dev) and that function has >> been declared as "static". Further, we don't have the public >> function to retrieve host bridge from PCI bus yet. The function >> is useful somewhere. >> >> The additional information like minimal resource alignment for I/O >> and MMIO bars of p2p bridges will be put into the PCI host bridge. >> The patch introduces the public function pci_bus_host_bridge() to >> retrieve the corresponding PCI host bridge according to the specified >> PCI bus, then accessing the information regarding the minimal resource >> alignment for I/O and MMIO bars of p2p bridges. >> >> Signed-off-by: Gavin Shan >> Reviewed-by: Ram Pai >> Reviewed-by: Richard Yang >> Acked-by: Benjamin Herrenschmidt >> --- >>  drivers/pci/host-bridge.c |   13 +++++++++++++ >>  include/linux/pci.h       |    2 +- >>  2 files changed, 14 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c >> index a68dc61..b95f0ce 100644 >> --- a/drivers/pci/host-bridge.c >> +++ b/drivers/pci/host-bridge.c >> @@ -27,6 +27,19 @@ static struct pci_host_bridge *find_pci_host_bridge(struct pci_dev *dev) >>        return to_pci_host_bridge(bus->bridge); >>  } >> >> +struct pci_host_bridge *pci_bus_host_bridge(struct pci_bus *bus) >> +{ >> +       struct pci_bus *b = bus; >> + >> +       /* Find the PCI root bus */ >> +       while (b->parent) >> +               b = b->parent; >> + >> +       return to_pci_host_bridge(b->bridge); >> +} >> + >> +EXPORT_SYMBOL(pci_bus_host_bridge); Yinghai, thanks for your time on this :-) > >why do you need to export it? > The reason is that we have introduced extra fields to "struct pci_host_bridge" in [PATCH 2/2] and platform want to access those extra fields. int io_align_shift; /* P2P I/O bar minimal alignment shift */ int mem_align_shift; /* P2P MMIO bar minimal alignment shift */ int pmem_align_shift; /* P2P prefetchable MMIO bar minimal alignment shift */ >> + >>  void pci_set_host_bridge_release(struct pci_host_bridge *bridge, >>                                 void (*release_fn)(struct pci_host_bridge *), >>                                 void *release_data) >> diff --git a/include/linux/pci.h b/include/linux/pci.h >> index fefb4e1..6d5bb1c 100644 >> --- a/include/linux/pci.h >> +++ b/include/linux/pci.h >> @@ -656,7 +656,7 @@ void pcibios_update_irq(struct pci_dev *, int irq); >>  void pci_fixup_cardbus(struct pci_bus *); >> >>  /* Generic PCI functions used internally */ >> - >> +struct pci_host_bridge *pci_bus_host_bridge(struct pci_bus *bus); >>  void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region, >>                             struct resource *res); >>  void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res, > >have one patch will change parameter all to bus instead of bridge. > >http://git.kernel.org/?p=linux/kernel/git/yinghai/linux-yinghai.git;a=commitdiff;h=3dc90c8f31e5e6153e1ac9a903189d3013690e80 > >in that case, we can just make find_pci_host_bridge() global. > Yeah, I think your patch meets the requirement: access "struct pci_host_bridge", and when will you merge your patch into mainline? By the way, could you please take your a litle bit time to review [PATCH 2/2]? >Thanks > >Yinghai > Thanks, Gavin