Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755674Ab2BFUpS (ORCPT ); Mon, 6 Feb 2012 15:45:18 -0500 Received: from mail-yx0-f174.google.com ([209.85.213.174]:61563 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755314Ab2BFUpQ convert rfc822-to-8bit (ORCPT ); Mon, 6 Feb 2012 15:45:16 -0500 MIME-Version: 1.0 In-Reply-To: References: <1328425088-6562-1-git-send-email-yinghai@kernel.org> <1328425088-6562-5-git-send-email-yinghai@kernel.org> Date: Mon, 6 Feb 2012 12:45:15 -0800 X-Google-Sender-Auth: axV7VndAtjbcCfqqPvhldjcCC_8 Message-ID: Subject: Re: [PATCH 04/24] PCI: Add busn_res operation functions From: Yinghai Lu To: Bjorn Helgaas Cc: Jesse Barnes , Benjamin Herrenschmidt , Tony Luck , Dominik Brodowski , Andrew Morton , Linus Torvalds , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2608 Lines: 72 On Mon, Feb 6, 2012 at 10:59 AM, Bjorn Helgaas wrote: > On Sat, Feb 4, 2012 at 10:57 PM, Yinghai Lu wrote: >> will use them insert/update busn res in pci_bus >> >> Signed-off-by: Yinghai Lu >> --- >> ?drivers/pci/probe.c | ? 42 ++++++++++++++++++++++++++++++++++++++++++ >> ?include/linux/pci.h | ? ?3 +++ >> ?2 files changed, 45 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c >> index a114173..8d4de5e 100644 >> --- a/drivers/pci/probe.c >> +++ b/drivers/pci/probe.c >> @@ -1622,6 +1622,48 @@ err_out: >> ? ? ? ?return NULL; >> ?} >> >> +void pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) >> +{ >> + ? ? ? struct resource *res = &b->busn_res; >> + ? ? ? struct resource *parent_res = &iobusn_resource; >> + ? ? ? int ret; >> + >> + ? ? ? res->start = busn(pci_domain_nr(b), bus); >> + ? ? ? res->end = busn(pci_domain_nr(b), bus_max); >> + ? ? ? res->flags = IORESOURCE_BUS; >> + >> + ? ? ? if (!pci_is_root_bus(b)) >> + ? ? ? ? ? ? ? parent_res = &b->parent->busn_res; >> + >> + ? ? ? ret = insert_resource(parent_res, res); >> + >> + ? ? ? dev_printk(KERN_DEBUG, &b->dev, >> + ? ? ? ? ? ? ? ? ? ? ? "busn_res: %pR %s inserted under %pR\n", >> + ? ? ? ? ? ? ? ? ? ? ? res, ret ? "can not be" : "is", parent_res); >> +} >> + >> +void pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max) >> +{ >> + ? ? ? struct resource *res = &b->busn_res; >> + ? ? ? struct resource old_res = *res; >> + >> + ? ? ? res->end = busn_update_bus_nr(res->end, bus_max); > > I think this design is a mistake. ?Here's what you're doing: > > ?- initialize struct resource (keys are "start" and "end") > ?- insert into tree (placed in tree by kernel/resource.c based on > "start" and "end") > ?- update "end" > > You "know" in this case that the update is safe because the caller has > validated "bus_max." ?But that still breaks the kernel/resource.c > encapsulation. ?If we change the kernel/resource.c implementation, > this code might break. the point is: I only want to reuse allocate_resource() to get right position. and the code does not depends to kernel/resource.c much. > > I think it would be better to remove the bus resource from the tree, > change its "end," then re-insert it. how about parent buses that have extended top? Yinghai -- 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/