Messages in this thread |  | | From | Bjorn Helgaas <> | Date | Mon, 30 Jan 2012 07:28:56 -0800 | Subject | Re: [PATCH 02/13] PCI: Add busn_res operation functions |
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On Fri, Jan 27, 2012 at 6:49 PM, Yinghai Lu <yinghai@kernel.org> wrote: > will use them insert/update busn res in pci_bus > > Signed-off-by: Yinghai Lu <yinghai@kernel.org> > --- > drivers/pci/probe.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/pci.h | 3 +++ > 2 files changed, 47 insertions(+), 0 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index a114173..71261da 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1622,6 +1622,50 @@ err_out: > return NULL; > } > > +void pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) > +{ > + struct resource *res = &b->busn_res; > + struct resource *parent_res = &iobusn_resource; > + int ret; > + > + res->start = (pci_domain_nr(b) << 8) | bus; > + res->end = (pci_domain_nr(b) << 8) | bus_max; > + res->flags = IORESOURCE_BUS; > + > + if (!pci_is_root_bus(b)) > + parent_res = &b->parent->busn_res; > + > + ret = insert_resource(parent_res, res); > + > + dev_printk(KERN_DEBUG, &b->dev, > + "busn_res: %06llx-%06llx %s inserted under %06llx-%06llx\n", > + (unsigned long long)res->start, > + (unsigned long long)res->end, > + ret ? "can not be" : "is", > + (unsigned long long)parent_res->start, > + (unsigned long long)parent_res->end);
Please update the %pR implementation so you can use it instead of having to fiddle around with start/end separately and casts.
> +} > + > +void pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max) > +{ > + struct resource *res = &b->busn_res; > + unsigned long long old_end = res->end; > + > + res->end &= ~0xff; > + res->end |= bus_max;
This updates a resource in place, without removing it from the resource tree and re-inserting it. Doesn't this make it possible to corrupt the resource tree? For example, let's say you have this tree:
00-3f : host bridge A 00-1f : P2P bridge B 40-7f : host bridge C
Now you use pci_bus_update_busn_res_end() to update the resource for P2P bridge B, setting its end to 5f. I think the resource tree is now corrupted.
> + dev_printk(KERN_DEBUG, &b->dev, > + "busn_res: %06llx-%06llx end updated to %06llx-%06llx\n", > + (unsigned long long)res->start, > + old_end, > + (unsigned long long)res->start, > + (unsigned long long)res->end); > +} > + > +void pci_bus_release_busn_res(struct pci_bus *b) > +{ > + release_resource(&b->busn_res); > +} > + > struct pci_bus * __devinit pci_scan_root_bus(struct device *parent, int bus, > struct pci_ops *ops, void *sysdata, struct list_head *resources) > { > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 94ad468..3da935c 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -665,6 +665,9 @@ struct pci_bus *pci_scan_bus(int bus, struct pci_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); > +void pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax); > +void pci_bus_update_busn_res_end(struct pci_bus *b, int busmax); > +void pci_bus_release_busn_res(struct pci_bus *b); > struct pci_bus * __devinit pci_scan_root_bus(struct device *parent, int bus, > struct pci_ops *ops, void *sysdata, > struct list_head *resources); > -- > 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/
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