On Sat, Nov 30, 2013 at 3:40 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > Some x86 systems expose above 4G 64bit mmio in _CRS as non-pref mmio range. > [ 49.415281] PCI host bridge to bus 0000:00 > [ 49.419921] pci_bus 0000:00: root bus resource [bus 00-1e] > [ 49.426107] pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7] > [ 49.433041] pci_bus 0000:00: root bus resource [io 0x1000-0x5fff] > [ 49.440010] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff] > [ 49.447768] pci_bus 0000:00: root bus resource [mem 0xfed8c000-0xfedfffff] > [ 49.455532] pci_bus 0000:00: root bus resource [mem 0x90000000-0x9fffbfff] > [ 49.463259] pci_bus 0000:00: root bus resource [mem 0x380000000000-0x381fffffffff] > > During assign unassigned 64bit mmio resource, it will go through > every non-pref mmio for root bus in pci_bus_alloc_resource(). > As the loop is with pci_bus_for_each_resource(), and could have chance > to use under 4G mmio range instead of above 4G mmio range if the requested > range is not big enough, even it could handle above 4G 64bit pref mmio. > > For root bus, we can order list from high to low in pci_add_resource_offset(), > during creating root bus, it will still keep the same order in final bus > resource list. > pci_acpi_scan_root > ==> add_resources > ==> pci_add_resource_offset: # Add to temp resources > ==> pci_create_root_bus > ==> pci_bus_add_resource # add to final bus resources. > > After that, we can make sure 64bit pref mmio for pci bridges will be allocated > higest of mmio non-pref, and in this case it is above 4G instead of under 4G. It really irritates me when I ask a question [1] and you just repost the patch without even trying to answer it. [1] http://lkml.kernel.org/r/CAErSpo4r6eJhgmfpth7haKDiKzDB+ZnEq0p_qdfTPo+kqySGgg@xxxxxxxxxxxxxx > Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> > --- > drivers/pci/bus.c | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > index 82eb234..30993ab 100644 > --- a/drivers/pci/bus.c > +++ b/drivers/pci/bus.c > @@ -21,7 +21,8 @@ > void pci_add_resource_offset(struct list_head *resources, struct resource *res, > resource_size_t offset) > { > - struct pci_host_bridge_window *window; > + struct pci_host_bridge_window *window, *tmp; > + struct list_head *n; > > window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL); > if (!window) { > @@ -31,7 +32,17 @@ void pci_add_resource_offset(struct list_head *resources, struct resource *res, > > window->res = res; > window->offset = offset; > - list_add_tail(&window->list, resources); > + > + /* sorted it according to res end */ > + n = resources; > + list_for_each_entry(tmp, resources, list) > + if (window->res->end > tmp->res->end) { > + n = &tmp->list; > + break; > + } > + > + /* Insert it just before n */ > + list_add_tail(&window->list, n); > } > EXPORT_SYMBOL(pci_add_resource_offset); > > -- > 1.8.1.4 > -- 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
