Messages in this thread | | | From | Bjorn Helgaas <> | Date | Mon, 30 Jan 2012 07:50:17 -0800 | Subject | Re: [PATCH 08/13] PCI: Add pci_bus_extend/shrink_top() |
| |
On Fri, Jan 27, 2012 at 6:49 PM, Yinghai Lu <yinghai@kernel.org> wrote: > extend or shrink bus and parent buses top (subordinate) > > extended range is verified safe range, and stop at recorded parent_res. > > Signed-off-by: Yinghai Lu <yinghai@kernel.org> > --- > drivers/pci/probe.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 50 insertions(+), 0 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 55404c3..3e62f45 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -624,6 +624,56 @@ static void pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max) > } > } > > +static void __devinit pci_bus_extend_top(struct pci_bus *parent, > + resource_size_t size, struct resource *parent_res) > +{ > + struct resource *res; > + > + if (!size) > + return; > + > + while (parent) { > + res = &parent->busn_res; > + if (res == parent_res) > + break; > + res->end += size; > + parent->subordinate += size;
This makes me nervous for the same reason as pci_bus_update_busn_res_end() -- we're changing res->end for resources already in a tree. How do we know the tree remains consistent?
> + pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS, > + parent->subordinate); > + dev_printk(KERN_DEBUG, &parent->dev, > + "busn_res: extended %02llx to %06llx-%06llx\n", > + (unsigned long long)size, > + (unsigned long long)res->start, > + (unsigned long long)res->end); > + parent = parent->parent; > + } > +} > + > +static void __devinit pci_bus_shrink_top(struct pci_bus *parent, > + resource_size_t size, struct resource *parent_res) > +{ > + struct resource *res; > + > + if (!size) > + return; > + > + while (parent) { > + res = &parent->busn_res; > + if (res == parent_res) > + break; > + res->end -= size; > + parent->subordinate -= size; > + pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS, > + parent->subordinate); > + dev_printk(KERN_DEBUG, &parent->dev, > + "busn_res: shrunk %02llx to %06llx-%06llx\n", > + (unsigned long long)size, > + (unsigned long long)res->start, > + (unsigned long long)res->end); > + parent = parent->parent; > + } > +} > + > /* > * If it's a bridge, configure it and scan the bus behind it. > * For CardBus bridges, we don't scan behind as the devices will > -- > 1.7.7 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |