From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Subject: Re: [PATCH V2 5/5] Microblaze: Modifying microblaze PCI subsytem to support generic Xilinx AXI PCIe Host Bridge IP driver Date: Thu, 4 Feb 2016 08:51:48 -0600 Message-ID: <20160204145148.GA26361@localhost> References: <1452620173-4905-1-git-send-email-bharatku@xilinx.com> <1452620173-4905-6-git-send-email-bharatku@xilinx.com> <20160203163207.GC32546@localhost> <20160203163805.GA6112@localhost> <8520D5D51A55D047800579B0941471982587F199@XAP-PVEXMBX01.xlnx.xilinx.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <8520D5D51A55D047800579B0941471982587F199@XAP-PVEXMBX01.xlnx.xilinx.com> Sender: linux-pci-owner@vger.kernel.org To: Bharat Kumar Gogada Cc: "bhelgaas@google.com" , Michal Simek , "lorenzo.pieralisi@arm.com" , "paul.burton@imgtec.com" , "yinghai@kernel.org" , "wangyijing@huawei.com" , "robh@kernel.org" , "russell.joyce@york.ac.uk" , Soren Brinkmann , "jiang.liu@linux.intel.com" , "arnd@arndb.de" , "pawel.moll@arm.com" , "mark.rutland@arm.com" , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org On Thu, Feb 04, 2016 at 05:49:20AM +0000, Bharat Kumar Gogada wrote: > > Subject: Re: [PATCH V2 5/5] Microblaze: Modifying microblaze PCI subsytem > > to support generic Xilinx AXI PCIe Host Bridge IP driver > > > > [+cc Ben for real this time] > > > > On Wed, Feb 03, 2016 at 10:32:07AM -0600, Bjorn Helgaas wrote: > > > [+cc Ben, pcibios_get_phb_of_node() question] > > > > > > On Tue, Jan 12, 2016 at 11:06:13PM +0530, Bharat Kumar Gogada wrote: > > > > This patch does required modifications to microblaze PCI subsystem, > > > > to work with generic driver (drivers/pci/host/pcie-xilinx.c) on > > > > Microblaze and Zynq. > > > > > > > > Signed-off-by: Bharat Kumar Gogada > > > > Signed-off-by: Ravi Kiran Gummaluri ... > > > > > > > resource_size_t pcibios_align_resource(void *data, const struct resource > > *res, > > > > resource_size_t size, resource_size_t align) { > > > > - struct pci_dev *dev = data; > > > > resource_size_t start = res->start; > > > > > > > > - if (res->flags & IORESOURCE_IO) { > > > > - if (skip_isa_ioresource_align(dev)) > > > > - return start; > > > > - if (start & 0x300) > > > > - start = (start + 0x3ff) & ~0x3ff; > > > > - } > > > > - > > > > return start; > > > > > > "return res->start;" is sufficient; no need for a temporary variable. > > > > Agreed will address in next patch. > > > > } > > > > EXPORT_SYMBOL(pcibios_align_resource); > > > > > > > > +int pcibios_add_device(struct pci_dev *dev) { > > > > + dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); > > > > + > > > > + return 0; > > > > +} > > > > +EXPORT_SYMBOL(pcibios_add_device); > > > > + > > > > /* > > > > * Reparent resource children of pr that conflict with res > > > > * under res, and make res replace those children. > > > > @@ -1335,9 +1308,21 @@ static void > > > > pcibios_setup_phb_resources(struct pci_controller *hose, > > > > > > > > struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus) { > > > > - struct pci_controller *hose = bus->sysdata; > > > > + struct device_node *np; > > > > + > > > > + for_each_node_by_type(np, "pci") { > > > > + const void *prop; > > > > + unsigned int bus_min; > > > > + > > > > + prop = of_get_property(np, "bus-range", NULL); > > > > + if (!prop) > > > > + continue; > > > > + bus_min = be32_to_cpup(prop); > > > > + if (bus->number == bus_min) > > > > + return np; > > > > + } > > > > > > > > - return of_node_get(hose->dn); > > > > + return NULL; > > > > > > Hmmm. The old microblaze code ("return of_node_get(hose->dn);") is > > > basically the same as the mips and powerpc versions. The new code is > > > basically the same as the x86 version. > > > > > > I like the generic weak version in drivers/pci/of.c because it doesn't > > > use any arch-specific data, and it looks like if we just set the > > > struct device.of_node members correctly, everything should Just Work. > > > > > > But Ben added both the generic and the x86 versions the same day, so > > > there must be some complication: > > > > > > 98d9f30c820d ("pci/of: Match PCI devices to OF nodes dynamically") > > > 3d5fe5a65af9 ("x86/devicetree: Use generic PCI <-> OF matching") > > > > > > So I guess my question is, why do we need a microblaze-specific > > > version at all? > > > > I did not notice the weak version in /pci/of.c, I have tested with > weak version also and it is working. We might not need this > microblaze specific version, but will wait for ben's reply. If the generic version works, and you don't need the microblaze- specific version, just remove it and we'll get this wrapped up. No need to wait for Ben. Bjorn