On Thu, 29 Oct 2009 02:52:00 -0700
Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>
> only for index < 3
>
> v2: Jesse doesn't like it is in find_free_bus_resource...
> try to move out of pci_bus_size_bridges loop.
> need to apply after:
> [PATCH] pci: pciehp update the slot bridge res to get big
> range for pcie devices - v4 v3: add pci_setup_bridge calling after
> pci_bridge_release_not_used_res. only clear release those res for x86.
> v4: Bjorn want to release use dev instead of bus.
> v5: Kenji pointed out it will have problem with several level bridge.
> so let only handle leaf bridge.
> v6: address Kenji's request (new pci_bus_release...). and change
> applying order move back release to pci_assign_unassigned_resource
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Starting to look better...
>
> ---
> drivers/pci/setup-bus.c | 65
> +++++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/pci.h | 1 2 files changed, 65 insertions(+), 1
> deletion(-)
>
> Index: linux-2.6/drivers/pci/setup-bus.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/setup-bus.c
> +++ linux-2.6/drivers/pci/setup-bus.c
> @@ -573,13 +573,68 @@ void __ref pci_bus_assign_resources(cons
> }
> EXPORT_SYMBOL(pci_bus_assign_resources);
>
> +static void pci_bridge_release_not_used_res(struct pci_bus *bus)
Can we call these functions something else? Maybe
pci_bridge_release_unused() with a kdoc comment describing exactly what
it does and why?
> +{
> + int idx;
> + bool changed = false;
> + struct pci_dev *dev;
> + struct resource *r;
> + unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
> + IORESOURCE_PREFETCH;
> +
> + /* for pci bridges res only */
> + dev = bus->self;
> + for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_BRIDGE_RESOURCES
> + 3;
> + idx++) {
> + r = &dev->resource[idx];
> + if (!(r->flags & type_mask))
> + continue;
> + if (!r->parent)
> + continue;
> + /* if there is no child under that, we should
> release it */
> + if (r->child)
> + continue;
> + if (!release_resource(r)) {
> + dev_info(&dev->dev, "resource %d %pRt
> released\n",
> + idx, r);
> + r->flags = 0;
> + changed = true;
> + }
> + }
> +
> + if (changed)
> + pci_setup_bridge(bus);
> +}
> +
> +void __ref pci_bus_release_bridges_not_used_res(struct pci_bus *bus)
Likewise, maybe pci_bus_release_unused_bridge_res or something, with
comments again.
> +{
> + struct pci_bus *b;
> +
> + /* If the bus is cardbus, do nothing */
> + if (bus->self && (bus->self->class >> 8) ==
> PCI_CLASS_BRIDGE_CARDBUS)
> + return;
> +
> + /* We only release the resources under the leaf bridge */
> + if (list_empty(&bus->children)) {
> + if (!pci_is_root_bus(bus))
> + pci_bridge_release_not_used_res(bus);
> + return;
> + }
> +
> + /* Scan child buses if the bus is not leaf */
> + list_for_each_entry(b, &bus->children, node)
> + pci_bus_release_bridges_not_used_res(b);
> +}
> +EXPORT_SYMBOL(pci_bus_release_bridges_not_used_res);
> +
> static void pci_bus_dump_res(struct pci_bus *bus)
> {
> int i;
>
> for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
> struct resource *res = bus->resource[i];
> - if (!res || !res->end)
> +
> + if (!res || !res->end || !res->flags)
> continue;
>
> dev_printk(KERN_DEBUG, &bus->dev, "resource %d
> %pRt\n", i, res); @@ -608,6 +663,14 @@
> pci_assign_unassigned_resources(void) {
> struct pci_bus *bus;
>
> + /*
> + * Try to release leaf bridge's resources that there is not
> child
> + * under it
> + */
> + list_for_each_entry(bus, &pci_root_buses, node) {
> + pci_bus_release_bridges_not_used_res(bus);
> + }
> +
Also I wonder if we need to make this a command line option that isn't
run by default?
Really, as Eric says, we need a real dynamic allocation system with the
ability to move devices around at some point. Any volunteers? :)
--
Jesse Barnes, Intel Open Source Technology Center
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