From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liviu Dudau Subject: Re: [PATCH v10 08/10] OF: PCI: Add support for parsing PCI host bridge resources from DT Date: Wed, 10 Sep 2014 15:22:41 +0100 Message-ID: <20140910142241.GD27864@e106497-lin.cambridge.arm.com> References: <1410184472-17630-1-git-send-email-Liviu.Dudau@arm.com> <1410184472-17630-9-git-send-email-Liviu.Dudau@arm.com> <20140909133546.GB2636@e102568-lin.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20140909133546.GB2636@e102568-lin.cambridge.arm.com> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Lorenzo Pieralisi Cc: Bjorn Helgaas , Arnd Bergmann , Rob Herring , Jason Gunthorpe , Benjamin Herrenschmidt , Catalin Marinas , Will Deacon , Russell King , linux-pci , Linus Walleij , Tanmay Inamdar , Grant Likely , Sinan Kaya , Jingoo Han , Kukjin Kim , Suravee Suthikulanit , linux-arch , LKML , Device Tree ML , LAKML , "grant.likely@linaro.org" List-Id: devicetree@vger.kernel.org On Tue, Sep 09, 2014 at 02:35:46PM +0100, Lorenzo Pieralisi wrote: > On Mon, Sep 08, 2014 at 02:54:30PM +0100, Liviu Dudau wrote: > > Provide a function to parse the PCI DT ranges that can be used to > > create a pci_host_bridge structure together with its associated > > bus. > >=20 > > Cc: Bjorn Helgaas > > Cc: Arnd Bergmann > > Cc: Grant Likely > > Cc: Rob Herring > > Cc: Catalin Marinas > > Signed-off-by: Liviu Dudau > > --- > > drivers/of/of_pci.c | 102 +++++++++++++++++++++++++++++++++++++= ++++++++++++ > > include/linux/of_pci.h | 11 ++++++ > > 2 files changed, 113 insertions(+) > >=20 > > diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c > > index a107edb..36701da 100644 > > --- a/drivers/of/of_pci.c > > +++ b/drivers/of/of_pci.c > > @@ -1,7 +1,9 @@ > > #include > > #include > > #include > > +#include > > #include > > +#include > > =20 > > static inline int __of_pci_pci_compare(struct device_node *node, > > unsigned int data) > > @@ -123,6 +125,106 @@ int of_pci_get_domain_nr(struct device_node *= node, bool allocate_if_missing) > > } > > EXPORT_SYMBOL_GPL(of_pci_get_domain_nr); > > =20 > > +/** > > + * of_pci_get_host_bridge_resources - Parse PCI host bridge resour= ces from DT > > + * @dev: device node of the host bridge having the range property > > + * @busno: bus number associated with the bridge root bus > > + * @bus_max: maximum number of busses for this bridge > > + * @resources: list where the range of resources will be added aft= er DT parsing > > + * @io_base: pointer to a variable that will contain on return the= physical > > + * address for the start of the I/O range. > > + * > > + * It is the callers job to free the @resources list. > > + * > > + * This function will parse the "ranges" property of a PCI host br= idge device > > + * node and setup the resource mapping based on its content. It is= expected > > + * that the property conforms with the Power ePAPR document. >=20 > You should also define what it returns and when. Thanks, will do. >=20 > > + * > > + */ > > +int of_pci_get_host_bridge_resources(struct device_node *dev, > > + unsigned char busno, unsigned char bus_max, > > + struct list_head *resources, resource_size_t *io_base) > > +{ > > + struct resource *res; > > + struct resource *bus_range; > > + struct of_pci_range range; > > + struct of_pci_range_parser parser; > > + char range_type[4]; > > + int err; > > + > > + bus_range =3D kzalloc(sizeof(*bus_range), GFP_KERNEL); > > + if (!bus_range) > > + return -ENOMEM; > > + > > + pr_info("PCI host bridge %s ranges:\n", dev->full_name); > > + > > + err =3D of_pci_parse_bus_range(dev, bus_range); > > + if (err) { > > + bus_range->start =3D busno; > > + bus_range->end =3D bus_max; > > + bus_range->flags =3D IORESOURCE_BUS; > > + pr_info(" No bus range found for %s, using %pR\n", > > + dev->full_name, &bus_range); > > + } else { > > + if (bus_range->end > bus_range->start + bus_max) > > + bus_range->end =3D bus_range->start + bus_max; > > + } > > + pci_add_resource(resources, bus_range); >=20 > This means that eg in the PCI generic host controller I cannot "filte= r" > the bus resource, unless I remove it, "filter" it, and add it again. I'm not sure what you mean. Why do you have to remove the bus resource = and add it again? What you get back from of_pci_get_host_bridge_resources()= is a list of resources as they have been parsed from DT. You now have the = option of doing any filtering that you might have done pre-v10 in the pcibios_fixup_bridge_ranges() but that is only on the list that was ret= urned from of_pci_get_host_bridge_resources(). At this moment no root bus or host bridge structure has been created so no resource was added to thos= e. With the filtered list you can use it to call pci_scan_root_bus() and *= then* it gets added to the pci_host_bridge structure. >=20 > I certainly can't filter a resource that has been already added witho= ut > removing it first. >=20 > Thoughts ? Hope I have explained what happens. Please let me know if you have any = other comments. Best regards, Liviu >=20 > > + > > + /* Check for ranges property */ > > + err =3D of_pci_range_parser_init(&parser, dev); > > + if (err) > > + goto parse_failed; > > + > > + pr_debug("Parsing ranges property...\n"); > > + for_each_of_pci_range(&parser, &range) { > > + /* Read next ranges element */ > > + if ((range.flags & IORESOURCE_TYPE_BITS) =3D=3D IORESOURCE_IO) > > + snprintf(range_type, 4, " IO"); > > + else if ((range.flags & IORESOURCE_TYPE_BITS) =3D=3D IORESOURCE_= MEM) > > + snprintf(range_type, 4, "MEM"); > > + else > > + snprintf(range_type, 4, "err"); > > + pr_info(" %s %#010llx..%#010llx -> %#010llx\n", range_type, > > + range.cpu_addr, range.cpu_addr + range.size - 1, > > + range.pci_addr); > > + > > + /* > > + * If we failed translation or got a zero-sized region > > + * then skip this range > > + */ > > + if (range.cpu_addr =3D=3D OF_BAD_ADDR || range.size =3D=3D 0) > > + continue; > > + > > + res =3D kzalloc(sizeof(struct resource), GFP_KERNEL); > > + if (!res) { > > + err =3D -ENOMEM; > > + goto parse_failed; > > + } > > + > > + err =3D of_pci_range_to_resource(&range, dev, res); > > + if (err) { > > + kfree(res); >=20 > You might want to add a label to free res to make things more uniform= =2E >=20 > > + goto parse_failed; > > + } > > + > > + if (resource_type(res) =3D=3D IORESOURCE_IO) { > > + if (*io_base) >=20 > You do not zero io_base in the first place so you should ask the API > user to do that. Is 0 a valid value BTW ? If it is you've got to reso= rt > to something else to detect multiple IO resources. >=20 > Lorenzo --=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- =C2=AF\_(=E3=83=84)_/=C2=AF