Bjorn, Guenter, On Thu, Jul 09, 2015 at 11:59:16AM +0100, Lorenzo Pieralisi wrote: > When a PCI bus is scanned, upon PCI bridge detection the kernel > has to read the bridge registers to set-up its resources so that > the PCI resource hierarchy can be validated properly. > > Most if not all architectures read PCI bridge registers in the > pcibios_fixup_bus hook, that is called by the PCI generic layer > whenever a PCI bus is scanned. > > Since pci_read_bridge_bases is an arch agnostic operation (and it > is carried out on all architectures) it can be moved to the generic > PCI layer in order to consolidate code and remove the respective > calls from the architectures back-ends. > > The PCI_PROBE_ONLY flag is not checked before calling > pci_read_bridge_buses in the generic layer since reading the bridge > bases is not related to resources assignment; this implies that it > can be carried out safely on PCI_PROBE_ONLY systems too and should > not affect architectures (alpha, mips) that check the PCI_PROBE_ONLY > flag before reading the bridge bases. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com> > Cc: Ralf Baechle <r...@linux-mips.org> > Cc: James E.J. Bottomley <j...@parisc-linux.org> > Cc: Michael Ellerman <m...@ellerman.id.au> > Cc: Bjorn Helgaas <bhelg...@google.com> > Cc: Richard Henderson <r...@twiddle.net> > Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> > Cc: David Howells <dhowe...@redhat.com> > Cc: Russell King <li...@arm.linux.org.uk> > Cc: Tony Luck <tony.l...@intel.com> > Cc: David S. Miller <da...@davemloft.net> > Cc: Ingo Molnar <mi...@redhat.com> > Cc: Guenter Roeck <li...@roeck-us.net> > Cc: Michal Simek <mon...@monstr.eu> > Cc: Chris Zankel <ch...@zankel.net> > --- > v2->v3: > > - Dropped RFC status > - Removed bridge resources claiming from pci_read_bridge_bases()
What do you want me to do with this patch ? I removed the resource claiming - ie the only controversial bit, I can only test on arm64, I would like to make some progress on this otherwise I will have to add the bridge bases read to arm64 pcibios_fixup_bus() and be done with this. Thanks, Lorenzo > v2: https://lkml.org/lkml/2015/6/9/187 > > v1->v2: > > - Moved pci_read_bridge_bases call to pci_scan_bridge to read bases before > scanning devices > - Added bridge resources claiming > > v1: https://lkml.org/lkml/2015/5/21/359 > > arch/alpha/kernel/pci.c | 7 +------ > arch/frv/mb93090-mb00/pci-vdk.c | 2 -- > arch/ia64/pci/pci.c | 1 - > arch/microblaze/pci/pci-common.c | 9 +-------- > arch/mips/pci/pci.c | 6 ------ > arch/mn10300/unit-asb2305/pci.c | 1 - > arch/powerpc/kernel/pci-common.c | 8 +------- > arch/x86/pci/common.c | 1 - > arch/xtensa/kernel/pci.c | 4 ---- > drivers/parisc/dino.c | 3 --- > drivers/parisc/lba_pci.c | 1 - > drivers/pci/probe.c | 9 +++++++++ > 12 files changed, 12 insertions(+), 40 deletions(-) > > diff --git a/arch/alpha/kernel/pci.c b/arch/alpha/kernel/pci.c > index 82f738e..cded02c 100644 > --- a/arch/alpha/kernel/pci.c > +++ b/arch/alpha/kernel/pci.c > @@ -242,12 +242,7 @@ pci_restore_srm_config(void) > > void pcibios_fixup_bus(struct pci_bus *bus) > { > - struct pci_dev *dev = bus->self; > - > - if (pci_has_flag(PCI_PROBE_ONLY) && dev && > - (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) { > - pci_read_bridge_bases(bus); > - } > + struct pci_dev *dev; > > list_for_each_entry(dev, &bus->devices, bus_list) { > pdev_save_srm_config(dev); > diff --git a/arch/frv/mb93090-mb00/pci-vdk.c b/arch/frv/mb93090-mb00/pci-vdk.c > index f211839..f9c86c4 100644 > --- a/arch/frv/mb93090-mb00/pci-vdk.c > +++ b/arch/frv/mb93090-mb00/pci-vdk.c > @@ -294,8 +294,6 @@ void pcibios_fixup_bus(struct pci_bus *bus) > printk("### PCIBIOS_FIXUP_BUS(%d)\n",bus->number); > #endif > > - pci_read_bridge_bases(bus); > - > if (bus->number == 0) { > struct pci_dev *dev; > list_for_each_entry(dev, &bus->devices, bus_list) { > diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c > index 7cc3be9..563228b 100644 > --- a/arch/ia64/pci/pci.c > +++ b/arch/ia64/pci/pci.c > @@ -534,7 +534,6 @@ void pcibios_fixup_bus(struct pci_bus *b) > struct pci_dev *dev; > > if (b->self) { > - pci_read_bridge_bases(b); > pcibios_fixup_bridge_resources(b->self); > } > list_for_each_entry(dev, &b->devices, bus_list) > diff --git a/arch/microblaze/pci/pci-common.c > b/arch/microblaze/pci/pci-common.c > index ae838ed..6b8b752 100644 > --- a/arch/microblaze/pci/pci-common.c > +++ b/arch/microblaze/pci/pci-common.c > @@ -863,14 +863,7 @@ void pcibios_setup_bus_devices(struct pci_bus *bus) > > void pcibios_fixup_bus(struct pci_bus *bus) > { > - /* When called from the generic PCI probe, read PCI<->PCI bridge > - * bases. This is -not- called when generating the PCI tree from > - * the OF device-tree. > - */ > - if (bus->self != NULL) > - pci_read_bridge_bases(bus); > - > - /* Now fixup the bus bus */ > + /* Fixup the bus */ > pcibios_setup_bus_self(bus); > > /* Now fixup devices on that bus */ > diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c > index b8a0bf5..c6996cf 100644 > --- a/arch/mips/pci/pci.c > +++ b/arch/mips/pci/pci.c > @@ -311,12 +311,6 @@ int pcibios_enable_device(struct pci_dev *dev, int mask) > > void pcibios_fixup_bus(struct pci_bus *bus) > { > - struct pci_dev *dev = bus->self; > - > - if (pci_has_flag(PCI_PROBE_ONLY) && dev && > - (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) { > - pci_read_bridge_bases(bus); > - } > } > > EXPORT_SYMBOL(PCIBIOS_MIN_IO); > diff --git a/arch/mn10300/unit-asb2305/pci.c b/arch/mn10300/unit-asb2305/pci.c > index 3dfe2d3..deaa893 100644 > --- a/arch/mn10300/unit-asb2305/pci.c > +++ b/arch/mn10300/unit-asb2305/pci.c > @@ -324,7 +324,6 @@ void pcibios_fixup_bus(struct pci_bus *bus) > struct pci_dev *dev; > > if (bus->self) { > - pci_read_bridge_bases(bus); > pcibios_fixup_bridge_resources(bus->self); > } > > diff --git a/arch/powerpc/kernel/pci-common.c > b/arch/powerpc/kernel/pci-common.c > index b9de34d..02c1d5d 100644 > --- a/arch/powerpc/kernel/pci-common.c > +++ b/arch/powerpc/kernel/pci-common.c > @@ -1044,13 +1044,7 @@ void pcibios_set_master(struct pci_dev *dev) > > void pcibios_fixup_bus(struct pci_bus *bus) > { > - /* When called from the generic PCI probe, read PCI<->PCI bridge > - * bases. This is -not- called when generating the PCI tree from > - * the OF device-tree. > - */ > - pci_read_bridge_bases(bus); > - > - /* Now fixup the bus bus */ > + /* Fixup the bus */ > pcibios_setup_bus_self(bus); > > /* Now fixup devices on that bus */ > diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c > index 8fd6f44..3bff244 100644 > --- a/arch/x86/pci/common.c > +++ b/arch/x86/pci/common.c > @@ -166,7 +166,6 @@ void pcibios_fixup_bus(struct pci_bus *b) > { > struct pci_dev *dev; > > - pci_read_bridge_bases(b); > list_for_each_entry(dev, &b->devices, bus_list) > pcibios_fixup_device_resources(dev); > } > diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c > index b848cc3..d27b4dc 100644 > --- a/arch/xtensa/kernel/pci.c > +++ b/arch/xtensa/kernel/pci.c > @@ -210,10 +210,6 @@ subsys_initcall(pcibios_init); > > void pcibios_fixup_bus(struct pci_bus *bus) > { > - if (bus->parent) { > - /* This is a subordinate bridge */ > - pci_read_bridge_bases(bus); > - } > } > > void pcibios_set_master(struct pci_dev *dev) > diff --git a/drivers/parisc/dino.c b/drivers/parisc/dino.c > index a0580af..baec33c 100644 > --- a/drivers/parisc/dino.c > +++ b/drivers/parisc/dino.c > @@ -560,9 +560,6 @@ dino_fixup_bus(struct pci_bus *bus) > } else if (bus->parent) { > int i; > > - pci_read_bridge_bases(bus); > - > - > for(i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { > if((bus->self->resource[i].flags & > (IORESOURCE_IO | IORESOURCE_MEM)) == 0) > diff --git a/drivers/parisc/lba_pci.c b/drivers/parisc/lba_pci.c > index dceb9dd..901e1a3 100644 > --- a/drivers/parisc/lba_pci.c > +++ b/drivers/parisc/lba_pci.c > @@ -693,7 +693,6 @@ lba_fixup_bus(struct pci_bus *bus) > if (bus->parent) { > int i; > /* PCI-PCI Bridge */ > - pci_read_bridge_bases(bus); > for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) > pci_claim_bridge_resource(bus->self, i); > } else { > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index c80626f..de1c424 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -842,6 +842,11 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev > *dev, int max, int pass) > child->bridge_ctl = bctl; > } > > + /* > + * Read and initialize bridge resources. > + */ > + pci_read_bridge_bases(child); > + > cmax = pci_scan_child_bus(child); > if (cmax > subordinate) > dev_warn(&dev->dev, "bridge has subordinate %02x but > max busn %02x\n", > @@ -902,6 +907,10 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev > *dev, int max, int pass) > > if (!is_cardbus) { > child->bridge_ctl = bctl; > + /* > + * Read and initialize bridge resources. > + */ > + pci_read_bridge_bases(child); > max = pci_scan_child_bus(child); > } else { > /* > -- > 2.2.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
