From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liviu Dudau Subject: Re: [PATCH v8 6/9] pci: Introduce a domain number for pci_host_bridge. Date: Tue, 8 Jul 2014 11:46:56 +0100 Message-ID: <20140708104655.GC6501@e106497-lin.cambridge.arm.com> References: <1404240214-9804-1-git-send-email-Liviu.Dudau@arm.com> <1404240214-9804-7-git-send-email-Liviu.Dudau@arm.com> <20140708005954.GC22939@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20140708005954.GC22939@google.com> Content-Disposition: inline Sender: linux-pci-owner@vger.kernel.org To: Bjorn Helgaas Cc: linux-pci , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Arnd Bergmann , linaro-kernel , Tanmay Inamdar , Grant Likely , Sinan Kaya , Jingoo Han , Kukjin Kim , Suravee Suthikulanit , LKML , Device Tree ML , LAKML List-Id: devicetree@vger.kernel.org On Tue, Jul 08, 2014 at 01:59:54AM +0100, Bjorn Helgaas wrote: > On Tue, Jul 01, 2014 at 07:43:31PM +0100, Liviu Dudau wrote: > > Make it easier to discover the domain number of a bus by storing > > the number in pci_host_bridge for the root bus. Several architectur= es > > have their own way of storing this information, so it makes sense > > to try to unify the code. While at this, add a new function that > > creates a root bus in a given domain and make pci_create_root_bus() > > a wrapper around this function. >=20 > "While at this" is always a good clue that maybe something should be > split into a separate patch :) This is a very good example, since it > adds a new interface that deserves its own changelog. Yes, I'm coming to the same conclusion. :) >=20 > > Signed-off-by: Liviu Dudau > > Tested-by: Tanmay Inamdar > > --- > > drivers/pci/probe.c | 41 +++++++++++++++++++++++++++++++++-------- > > include/linux/pci.h | 4 ++++ > > 2 files changed, 37 insertions(+), 8 deletions(-) > >=20 > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > > index 2c92662..abf5e82 100644 > > --- a/drivers/pci/probe.c > > +++ b/drivers/pci/probe.c > > @@ -1748,8 +1748,9 @@ void __weak pcibios_remove_bus(struct pci_bus= *bus) > > { > > } > > =20 > > -struct pci_bus *pci_create_root_bus(struct device *parent, int bus= , > > - struct pci_ops *ops, void *sysdata, struct list_head *resources) > > +struct pci_bus *pci_create_root_bus_in_domain(struct device *paren= t, > > + int domain, int bus, struct pci_ops *ops, void *sysdata, > > + struct list_head *resources) >=20 > I don't think we should do it this way; this makes it possible to hav= e a > host bridge where "bridge->domain_nr !=3D pci_domain_nr(bridge->bus)"= =2E >=20 > I wonder if it would help to make a weak pci_domain_nr() function tha= t > returns "bridge->domain_nr". Then each arch could individually drop = its > pci_domain_nr() definition as it was converted, e.g., something like = this: >=20 > - Convert every arch pci_domain_nr() from a #define to a non-inline > function > - Add bridge.domain_nr, initialized from pci_domain_nr() > - Add a weak generic pci_domain_nr() that returns bridge.domain_nr > - Add a way to create a host bridge in a specified domain, so we ca= n > initialize bridge.domain_nr without using pci_domain_nr() > - Convert each arch to use the new creation mechanism and drop its > pci_domain_nr() implementation I will try to propose a patch implementing this. Best regards, Liviu >=20 > > { > > int error; > > struct pci_host_bridge *bridge; > > @@ -1762,27 +1763,31 @@ struct pci_bus *pci_create_root_bus(struct = device *parent, int bus, > > =20 > > bridge =3D pci_alloc_host_bridge(); > > if (!bridge) > > - return NULL; > > + return ERR_PTR(-ENOMEM); > > =20 > > bridge->dev.parent =3D parent; > > bridge->dev.release =3D pci_release_host_bridge_dev; > > + bridge->domain_nr =3D domain; > > =20 > > b =3D pci_alloc_bus(); > > - if (!b) > > + if (!b) { > > + error =3D -ENOMEM; > > goto err_out; > > + } > > =20 > > b->sysdata =3D sysdata; > > b->ops =3D ops; > > b->number =3D b->busn_res.start =3D bus; > > - b2 =3D pci_find_bus(pci_domain_nr(b), bus); > > + b2 =3D pci_find_bus(bridge->domain_nr, bus); > > if (b2) { > > /* If we already got to this bus through a different bridge, ign= ore it */ > > dev_dbg(&b2->dev, "bus already known\n"); > > + error =3D -EEXIST; > > goto err_bus_out; > > } > > =20 > > bridge->bus =3D b; > > - dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus)= ; > > + dev_set_name(&bridge->dev, "pci%04x:%02x", bridge->domain_nr, bus= ); > > error =3D pcibios_root_bridge_prepare(bridge); > > if (error) > > goto err_out; > > @@ -1801,7 +1806,7 @@ struct pci_bus *pci_create_root_bus(struct de= vice *parent, int bus, > > =20 > > b->dev.class =3D &pcibus_class; > > b->dev.parent =3D b->bridge; > > - dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus); > > + dev_set_name(&b->dev, "%04x:%02x", bridge->domain_nr, bus); > > error =3D device_register(&b->dev); > > if (error) > > goto class_dev_reg_err; > > @@ -1851,7 +1856,27 @@ err_bus_out: > > kfree(b); > > err_out: > > kfree(bridge); > > - return NULL; > > + return ERR_PTR(error); > > +} > > + > > +struct pci_bus *pci_create_root_bus(struct device *parent, int bus= , > > + struct pci_ops *ops, void *sysdata, struct list_head *resources) > > +{ > > + int domain_nr; > > + struct pci_bus *b =3D pci_alloc_bus(); > > + if (!b) > > + return NULL; > > + > > + b->sysdata =3D sysdata; > > + domain_nr =3D pci_domain_nr(b); > > + kfree(b); > > + > > + b =3D pci_create_root_bus_in_domain(parent, domain_nr, bus, > > + ops, sysdata, resources); > > + if (IS_ERR(b)) > > + return NULL; > > + > > + return b; > > } > > =20 > > int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_ma= x) > > diff --git a/include/linux/pci.h b/include/linux/pci.h > > index 466bcd1..7e7b939 100644 > > --- a/include/linux/pci.h > > +++ b/include/linux/pci.h > > @@ -401,6 +401,7 @@ struct pci_host_bridge_window { > > struct pci_host_bridge { > > struct device dev; > > struct pci_bus *bus; /* root bus */ > > + int domain_nr; > > struct list_head windows; /* pci_host_bridge_windows */ > > void (*release_fn)(struct pci_host_bridge *); > > void *release_data; > > @@ -769,6 +770,9 @@ struct pci_bus *pci_scan_bus(int bus, struct pc= i_ops *ops, void *sysdata); > > struct pci_bus *pci_create_root_bus(struct device *parent, int bus= , > > struct pci_ops *ops, void *sysdata, > > struct list_head *resources); > > +struct pci_bus *pci_create_root_bus_in_domain(struct device *paren= t, > > + int domain, int bus, struct pci_ops *ops, > > + void *sysdata, struct list_head *resources); > > int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax= ); > > int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax); > > void pci_bus_release_busn_res(struct pci_bus *b); > > --=20 > > 2.0.0 > >=20 >=20 --=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