From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yijing Wang Subject: Re: [PATCH v8 19/30] powerpc/pci: Use pci_scan_host_bridge() for simplicity Date: Thu, 26 Mar 2015 14:20:07 +0800 Message-ID: <5513A517.8080205__31198.1172803373$1427350893$gmane$org@huawei.com> References: <1427168064-8657-1-git-send-email-wangyijing@huawei.com> <1427168064-8657-20-git-send-email-wangyijing@huawei.com> <1427241523.2685.18.camel@axtens.net> <551266DE.3030609@huawei.com> <1427321631.2575.3.camel@axtens.net> <55135E16.6060909@huawei.com> <1427347180.2575.91.camel@axtens.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1427347180.2575.91.camel@axtens.net> Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: Daniel Axtens Cc: Liviu Dudau , Rusty Russell , linux-ia64@vger.kernel.org, Arnd Bergmann , Marc Zyngier , linux-pci@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, "David S. Miller" , linuxppc-dev@lists.ozlabs.org, linux-m68k@lists.linux-m68k.org, Tony Luck , Geert Uytterhoeven , linux-alpha@vger.kernel.org, Bjorn Helgaas , Russell King , Thomas Gleixner , Guan Xuetao , Yinghai Lu , Jiang Liu , linux-arm-kernel@lists.infradead.org On 2015/3/26 13:19, Daniel Axtens wrote: > Hi Yijing, > > Pulled. > > I'm now getting build errors: > > /scratch/dja/linux-patches/arch/powerpc/kernel/pci-common.c: In function 'pcibios_scan_phb': > /scratch/dja/linux-patches/arch/powerpc/kernel/pci-common.c:1638:14: error: 'bus' undeclared (first use in this function) > /scratch/dja/linux-patches/arch/powerpc/kernel/pci-common.c:1638:14: note: each undeclared identifier is reported only once for each function it appears in > > That relates to your changes to pcibios_scan_phb: > - struct pci_bus *bus; > + struct pci_host_bridge *host; > clashing with line 1638: > hose->bus = bus; > which occurs later in the same unction. > > If I fix that, I'll get more errors with lines in that function that > still reference hose instead of host. > > As well as line 1638, there's still big chunks of the function that > reference hose, for example: > > /* Get some IO space for the new PHB */ > pcibios_setup_phb_io_space(hose); > > /* Wire up PHB bus resources */ > pcibios_setup_phb_resources(hose, &resources); > > hose->busn.start = hose->first_busno; > hose->busn.end = hose->last_busno; > hose->busn.flags = IORESOURCE_BUS; > pci_add_resource(&resources, &hose->busn); > > pci_host_ops.pci_ops = hose->ops; > > > Basically, the changes in PowerPC need to be quite a bit more through > just to get the changes to build. > > I'm keen to work on simplifying PCI code in PowerPC, but at this point, > it will need a lot more work before it's ready to go in. Hi Daniel, I'm really so sorry about that, I will update it today. Thanks! Yijing. > > Regards, > Daniel > > > On Thu, 2015-03-26 at 09:17 +0800, Yijing Wang wrote: >> On 2015/3/26 6:13, Daniel Axtens wrote: >>> Hi Yijing, >>> >>> I wasn't quite sure I understood your comments, so I was trying to apply >>> your patch series and test it, but patch 3 doesn't apply cleanly to >>> 4.0-rc5 or master. Can you respin the series? >> >> Hi Daniel, >> Could you pull the series from Bjorn's git tree ? The URL is >> https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git pci/enumeration-yw8 >> >> Thanks! >> Yijing. >> >>> >>> Thanks, >>> Daniel >>> >>> >>>> Hi Daniel, thanks for your review and comments. We want to make a generic pci_host_bridge, >>>> which would hold the common host information, for example, pci domain is common info for >>>> pci host bridge, this series saved domain in pci_host_bridge, then we no need to >>>> extract out domain by pci_bus->sysdata by platform specific pci_domain_nr(). >>>> Also we store the sysdata in pci_host_bridge, and pci_bus_to_host() is the platform >>>> interface, I think use the common interface would be better. >>>> >>>>>> + >>>>>> + /* Get probe mode and perform scan */ >>>>>> + if (hose->dn && ppc_md.pci_probe_mode) >>>>>> + mode = ppc_md.pci_probe_mode(bus); >>>>>> + >>>>>> + pr_debug(" probe mode: %d\n", mode); >>>>>> + if (mode == PCI_PROBE_DEVTREE) >>>>>> + of_scan_bus(hose->dn, bus); >>>>>> + >>>>>> + if (mode == PCI_PROBE_NORMAL) { >>>>>> + pci_bus_update_busn_res_end(bus, 255); >>>>>> + hose->last_busno = pci_scan_child_bus(bus); >>>>>> + pci_bus_update_busn_res_end(bus, hose->last_busno); >>>>>> + } >>>>>> + >>>>>> + return pci_bus_child_max_busnr(bus); >>>>>> +} >>>>>> + >>>>> I'm having trouble convincing myself that this patch covers every >>>>> variation within our PCI implementations. In particular, there's a >>>>> stanza in of_scan_pci_bridge in kernel/pci_of_scan.c that's almost >>>>> identical to this function. Does that implementation need to be cleaned >>>>> up and replaced with this function too? >>>>> >>>> >>>> This is a pci_host_bridge_ops hook function, which would be called in >>>> PCI core, and after applied this series, we only need to call pci_scan_host_bridge() >>>> to scan pci devices, and this function is also extracted from the pcibios_scan_phb(), >>>> it's not the redundant code. >>>> >>>>> >>>>>> @@ -1641,9 +1655,9 @@ void pcibios_scan_phb(struct pci_controller *hose) >>>>>> ppc_md.pcibios_fixup_phb(hose); >>>>>> >>>>>> /* Configure PCI Express settings */ >>>>>> - if (bus && !pci_has_flag(PCI_PROBE_ONLY)) { >>>>>> + if (host->bus && !pci_has_flag(PCI_PROBE_ONLY)) { >>>>>> struct pci_bus *child; >>>>>> - list_for_each_entry(child, &bus->children, node) >>>>>> + list_for_each_entry(child, &host->bus->children, node) >>>>>> pcie_bus_configure_settings(child); >>>>>> } >>>>>> } >>>>> Two things: Firstly, the function uses hose throughout, not host. >>>>> Secondly, you're not deleting the bus variable: what's the purpose of >>>>> this change? >>>> >>>> host is the common pci_host_bridge which is created by PCI core for pci host bridge driver, >>>> the hose is the platform data used in powerpc. The purpose of the patch/series is to simplify >>>> pci enumeration interface, and try to reduce the weak functions which were used to setup pci bus/devices >>>> during PCI enumeration. >>>> >>>>> >>>>> Regards, >>>>> Daniel >>>>> >>>> >>>> >>> >> >> > -- Thanks! Yijing