On Wed, Jan 19, 2011 at 5:00 PM, Ram Pai <linuxram@xxxxxxxxxx> wrote: > PCI: pre-allocate additional resources to devices only after successful > allocation of essential resources. > > Linux tries to pre-allocate minimal resources to hotplug bridges. This > works fine as long as there are enough resources to satisfy all other > genuine resource requirements. However if enough resources are not > available to satisfy any of these nice-to-have pre-allocations, the > resource-allocator reports errors and returns failure. > > This patch distinguishes between must-have resource from nice-to-have > resource. Any failure to allocate nice-to-have resources are ignored. > > This behavior can be particularly useful to trigger automatic > reallocation when the OS discovers genuine allocation-conflicts > or genuine unallocated-requests caused by buggy allocation behavior > of the native BIOS/uEFI. > > https://bugzilla.kernel.org/show_bug.cgi?id=15960 captures the movitation > behind the patch. > > changelog v2: o fixed a bug where pci_assign_resource() was called on a > resource of zero resource size. > > changelog v3: addressed Bjorn's comment > o "Please don't indent and right-justify the changelog". > o removed add_size from struct resource. The additional > size is now tracked using a linked list. > > changelog v4: o moved freeing up of elements of head list from > assign_requested_resources_sorted() to > __assign_resources_sorted(). This fixes a corruption bug. > o removed a wrong reference to 'add_size' in > pbus_size_mem(). Erroneously got introduced while > generating the patch. > o some code optimizations in adjust_resources_sorted() > and assign_requested_resources_sorted() > > Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx> > > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 66cb8f4..efbdff2 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -33,11 +33,23 @@ struct resource_list_x { > struct pci_dev *dev; > resource_size_t start; > resource_size_t end; > + resource_size_t add_size; > unsigned long flags; > }; > > -static void add_to_failed_list(struct resource_list_x *head, > - struct pci_dev *dev, struct resource *res) > +#define free_list(type, head) do { \ > + struct type *list, *tmp; \ > + for (list = (head)->next; list;) { \ > + tmp = list; \ > + list = list->next; \ > + kfree(tmp); \ > + } \ > + (head)->next = NULL; \ > +} while (0) inline function should be better? Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
