From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Subject: Re: [PATCH v6 03/30] PCI: Export busn_resource to drivers/pci Date: Wed, 11 Mar 2015 17:28:35 -0500 Message-ID: <20150311222835.GA1082@google.com> References: <1425868467-9667-1-git-send-email-wangyijing@huawei.com> <1425868467-9667-4-git-send-email-wangyijing@huawei.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=mS/D9My6itRFc4W9dSkiOYUFpZg5NuYMjp1cDw9QD+U=; b=ptaLP3DT5tAwyOnJ5GCpOtQXHD5b5KcUlqNFbALoC0rau3uZsVRbqEwVx9a1n/6UCm 9fiOGURLHudsdrRjHSMRVwdnYxXwa/D0JfjE3zPA/rvDVKl+e1CbDt1RZouf/r7Qqua/ bESmzwf9HqIRHmW7oiX48f9sVqEHaUmu7CLhup+zCnWE8S0Bzk75qTYUPhF5SI7KarEt 1BzJqTib/yf1Lt2pyXECAr8eee8Cj1kJGt3xMcehZToc1NdguS/XxnrqQK7+D6rYj7QZ cgHefC0n82DCMYpkmdOfRcAtW+qbJ6rmK4QUiUJP5XtdFPgsmGOjXjKJ0P+qgqUw5BAW GzLg== Content-Disposition: inline In-Reply-To: <1425868467-9667-4-git-send-email-wangyijing@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Yijing Wang Cc: Jiang Liu , linux-pci@vger.kernel.org, Yinghai Lu , linux-kernel@vger.kernel.org, Marc Zyngier , linux-arm-kernel@lists.infradead.org, Russell King , x86@kernel.org, Thomas Gleixner , Benjamin Herrenschmidt , Rusty Russell , Tony Luck , linux-ia64@vger.kernel.org, "David S. Miller" , Guan Xuetao , linux-alpha@vger.kernel.org, linux-m68k@lists.linux-m68k.org, Liviu Dudau , Arnd Bergmann , Geert Uytterhoeven On Mon, Mar 09, 2015 at 10:34:00AM +0800, Yijing Wang wrote: > Export out busn_resource. Xen pcifront module need it. > > Signed-off-by: Yijing Wang > --- > drivers/pci/pci.h | 2 ++ > drivers/pci/probe.c | 3 ++- > 2 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 4091f82..eeacab9 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -10,6 +10,8 @@ bool pcie_cap_has_lnkctl(const struct pci_dev *dev); > > /* Functions internal to the PCI core code */ > > +extern struct resource busn_resource; > + > int pci_create_sysfs_dev_files(struct pci_dev *pdev); > void pci_remove_sysfs_dev_files(struct pci_dev *pdev); > #if !defined(CONFIG_DMI) && !defined(CONFIG_ACPI) > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 8ef0375..b97ea81 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -17,12 +17,13 @@ > #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ > #define CARDBUS_RESERVE_BUSNR 3 > > -static struct resource busn_resource = { > +struct resource busn_resource = { > .name = "PCI busn", > .start = 0, > .end = 255, > .flags = IORESOURCE_BUS, > }; > +EXPORT_SYMBOL(busn_resource); I don't think this is a good idea. We support multiple PCI domains, and each domain has its own 0-255 bus number range. This busn_resource is only for domain 0 and probably should be handled in arch code instead of the PCI core. Right now, I think it's possible to call pci_scan_bus_parented() or pci_scan_bus() several times for buses in different domains, and they would all share the same busn_resource, which would cause corruption. So it's already broken, but I don't want to make it harder to fix by exporting this stuff. > > /* Ugh. Need to stop exporting this to modules. */ > LIST_HEAD(pci_root_buses); > -- > 1.7.1 > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Date: Wed, 11 Mar 2015 22:28:35 +0000 Subject: Re: [PATCH v6 03/30] PCI: Export busn_resource to drivers/pci Message-Id: <20150311222835.GA1082@google.com> List-Id: References: <1425868467-9667-1-git-send-email-wangyijing@huawei.com> <1425868467-9667-4-git-send-email-wangyijing@huawei.com> In-Reply-To: <1425868467-9667-4-git-send-email-wangyijing@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Yijing Wang Cc: Jiang Liu , linux-pci@vger.kernel.org, Yinghai Lu , linux-kernel@vger.kernel.org, Marc Zyngier , linux-arm-kernel@lists.infradead.org, Russell King , x86@kernel.org, Thomas Gleixner , Benjamin Herrenschmidt , Rusty Russell , Tony Luck , linux-ia64@vger.kernel.org, "David S. Miller" , Guan Xuetao , linux-alpha@vger.kernel.org, linux-m68k@vger.kernel.org, Liviu Dudau , Arnd Bergmann , Geert Uytterhoeven On Mon, Mar 09, 2015 at 10:34:00AM +0800, Yijing Wang wrote: > Export out busn_resource. Xen pcifront module need it. > > Signed-off-by: Yijing Wang > --- > drivers/pci/pci.h | 2 ++ > drivers/pci/probe.c | 3 ++- > 2 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 4091f82..eeacab9 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -10,6 +10,8 @@ bool pcie_cap_has_lnkctl(const struct pci_dev *dev); > > /* Functions internal to the PCI core code */ > > +extern struct resource busn_resource; > + > int pci_create_sysfs_dev_files(struct pci_dev *pdev); > void pci_remove_sysfs_dev_files(struct pci_dev *pdev); > #if !defined(CONFIG_DMI) && !defined(CONFIG_ACPI) > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 8ef0375..b97ea81 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -17,12 +17,13 @@ > #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ > #define CARDBUS_RESERVE_BUSNR 3 > > -static struct resource busn_resource = { > +struct resource busn_resource = { > .name = "PCI busn", > .start = 0, > .end = 255, > .flags = IORESOURCE_BUS, > }; > +EXPORT_SYMBOL(busn_resource); I don't think this is a good idea. We support multiple PCI domains, and each domain has its own 0-255 bus number range. This busn_resource is only for domain 0 and probably should be handled in arch code instead of the PCI core. Right now, I think it's possible to call pci_scan_bus_parented() or pci_scan_bus() several times for buses in different domains, and they would all share the same busn_resource, which would cause corruption. So it's already broken, but I don't want to make it harder to fix by exporting this stuff. > > /* Ugh. Need to stop exporting this to modules. */ > LIST_HEAD(pci_root_buses); > -- > 1.7.1 > From mboxrd@z Thu Jan 1 00:00:00 1970 From: bhelgaas@google.com (Bjorn Helgaas) Date: Wed, 11 Mar 2015 17:28:35 -0500 Subject: [PATCH v6 03/30] PCI: Export busn_resource to drivers/pci In-Reply-To: <1425868467-9667-4-git-send-email-wangyijing@huawei.com> References: <1425868467-9667-1-git-send-email-wangyijing@huawei.com> <1425868467-9667-4-git-send-email-wangyijing@huawei.com> Message-ID: <20150311222835.GA1082@google.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Mar 09, 2015 at 10:34:00AM +0800, Yijing Wang wrote: > Export out busn_resource. Xen pcifront module need it. > > Signed-off-by: Yijing Wang > --- > drivers/pci/pci.h | 2 ++ > drivers/pci/probe.c | 3 ++- > 2 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 4091f82..eeacab9 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -10,6 +10,8 @@ bool pcie_cap_has_lnkctl(const struct pci_dev *dev); > > /* Functions internal to the PCI core code */ > > +extern struct resource busn_resource; > + > int pci_create_sysfs_dev_files(struct pci_dev *pdev); > void pci_remove_sysfs_dev_files(struct pci_dev *pdev); > #if !defined(CONFIG_DMI) && !defined(CONFIG_ACPI) > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 8ef0375..b97ea81 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -17,12 +17,13 @@ > #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ > #define CARDBUS_RESERVE_BUSNR 3 > > -static struct resource busn_resource = { > +struct resource busn_resource = { > .name = "PCI busn", > .start = 0, > .end = 255, > .flags = IORESOURCE_BUS, > }; > +EXPORT_SYMBOL(busn_resource); I don't think this is a good idea. We support multiple PCI domains, and each domain has its own 0-255 bus number range. This busn_resource is only for domain 0 and probably should be handled in arch code instead of the PCI core. Right now, I think it's possible to call pci_scan_bus_parented() or pci_scan_bus() several times for buses in different domains, and they would all share the same busn_resource, which would cause corruption. So it's already broken, but I don't want to make it harder to fix by exporting this stuff. > > /* Ugh. Need to stop exporting this to modules. */ > LIST_HEAD(pci_root_buses); > -- > 1.7.1 > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753050AbbCKW2n (ORCPT ); Wed, 11 Mar 2015 18:28:43 -0400 Received: from mail-ob0-f170.google.com ([209.85.214.170]:39692 "EHLO mail-ob0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751668AbbCKW2k (ORCPT ); Wed, 11 Mar 2015 18:28:40 -0400 Date: Wed, 11 Mar 2015 17:28:35 -0500 From: Bjorn Helgaas To: Yijing Wang Cc: Jiang Liu , linux-pci@vger.kernel.org, Yinghai Lu , linux-kernel@vger.kernel.org, Marc Zyngier , linux-arm-kernel@lists.infradead.org, Russell King , x86@kernel.org, Thomas Gleixner , Benjamin Herrenschmidt , Rusty Russell , Tony Luck , linux-ia64@vger.kernel.org, "David S. Miller" , Guan Xuetao , linux-alpha@vger.kernel.org, linux-m68k@vger.kernel.org, Liviu Dudau , Arnd Bergmann , Geert Uytterhoeven Subject: Re: [PATCH v6 03/30] PCI: Export busn_resource to drivers/pci Message-ID: <20150311222835.GA1082@google.com> References: <1425868467-9667-1-git-send-email-wangyijing@huawei.com> <1425868467-9667-4-git-send-email-wangyijing@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1425868467-9667-4-git-send-email-wangyijing@huawei.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 Mon, Mar 09, 2015 at 10:34:00AM +0800, Yijing Wang wrote: > Export out busn_resource. Xen pcifront module need it. > > Signed-off-by: Yijing Wang > --- > drivers/pci/pci.h | 2 ++ > drivers/pci/probe.c | 3 ++- > 2 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 4091f82..eeacab9 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -10,6 +10,8 @@ bool pcie_cap_has_lnkctl(const struct pci_dev *dev); > > /* Functions internal to the PCI core code */ > > +extern struct resource busn_resource; > + > int pci_create_sysfs_dev_files(struct pci_dev *pdev); > void pci_remove_sysfs_dev_files(struct pci_dev *pdev); > #if !defined(CONFIG_DMI) && !defined(CONFIG_ACPI) > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 8ef0375..b97ea81 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -17,12 +17,13 @@ > #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ > #define CARDBUS_RESERVE_BUSNR 3 > > -static struct resource busn_resource = { > +struct resource busn_resource = { > .name = "PCI busn", > .start = 0, > .end = 255, > .flags = IORESOURCE_BUS, > }; > +EXPORT_SYMBOL(busn_resource); I don't think this is a good idea. We support multiple PCI domains, and each domain has its own 0-255 bus number range. This busn_resource is only for domain 0 and probably should be handled in arch code instead of the PCI core. Right now, I think it's possible to call pci_scan_bus_parented() or pci_scan_bus() several times for buses in different domains, and they would all share the same busn_resource, which would cause corruption. So it's already broken, but I don't want to make it harder to fix by exporting this stuff. > > /* Ugh. Need to stop exporting this to modules. */ > LIST_HEAD(pci_root_buses); > -- > 1.7.1 >