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 16:32:33 +0100 Message-ID: <20140910153233.GG27864@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> <20140910142241.GD27864@e106497-lin.cambridge.arm.com> <20140910151026.GB11640@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: <20140910151026.GB11640@e102568-lin.cambridge.arm.com> Content-Disposition: inline Sender: linux-pci-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 Wed, Sep 10, 2014 at 04:10:26PM +0100, Lorenzo Pieralisi wrote: > On Wed, Sep 10, 2014 at 03:22:41PM +0100, Liviu Dudau wrote: > > 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 *nod= e, > > > > unsigned int data) > > > > @@ -123,6 +125,106 @@ int of_pci_get_domain_nr(struct device_no= de *node, bool allocate_if_missing) > > > > } > > > > EXPORT_SYMBOL_GPL(of_pci_get_domain_nr); > > > > =20 > > > > +/** > > > > + * of_pci_get_host_bridge_resources - Parse PCI host bridge re= sources from DT > > > > + * @dev: device node of the host bridge having the range prope= rty > > > > + * @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= after 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 hos= t bridge device > > > > + * node and setup the resource mapping based on its content. I= t is expected > > > > + * that the property conforms with the Power ePAPR document. > > >=20 > > > You should also define what it returns and when. > >=20 > > Thanks, will do. > >=20 > > >=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 "f= ilter" > > > the bus resource, unless I remove it, "filter" it, and add it aga= in. > >=20 > > I'm not sure what you mean. Why do you have to remove the bus resou= rce and > > add it again? What you get back from of_pci_get_host_bridge_resourc= es() 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= returned > > 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 = those. > > With the filtered list you can use it to call pci_scan_root_bus() a= nd *then* > > it gets added to the pci_host_bridge structure. >=20 > You are right sorry. As discussed, I just have to remove the resource= s > assignment in the respective host controller drivers (because you do > that in the API) and grab the resource pointers to "filter" them. >=20 > > > I certainly can't filter a resource that has been already added w= ithout > > > removing it first. > > >=20 > > > Thoughts ? > >=20 > > Hope I have explained what happens. Please let me know if you have = any other > > comments. >=20 > There were other comments below ;) My PgDn key is broken ;) >=20 > Thanks, > Lorenzo >=20 > >=20 > > Best regards, > > Liviu > >=20 > > >=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_I= O) > > > > + snprintf(range_type, 4, " IO"); > > > > + else if ((range.flags & IORESOURCE_TYPE_BITS) =3D=3D IORESOU= RCE_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 uni= form. Sorry, not following you. How would a label help here? > > >=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 = resort > > > to something else to detect multiple IO resources. No, zero is not a valid value. It is the cpu_addr value from the IO ran= ge, I'm hopying that no one is crazy enough to map PCI address space at CPU add= ress zero. Thanks for spotting the lack of initialisation though, I need to fix it= =2E Best regards, Liviu > > >=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