On Fri, 27 Nov 2009 23:35:14 -0800
Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>
> so later we could use it to release small resource before pci assign
> unassign res
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> ---
> drivers/pci/setup-bus.c | 114
> +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 113
> 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
> @@ -609,6 +609,118 @@ void __ref pci_bus_assign_resources(cons
> }
> EXPORT_SYMBOL(pci_bus_assign_resources);
>
> +static void release_children_resource(struct resource *r)
release_child_resources?
> +{
> + struct resource *p;
> + resource_size_t size;
> +
> + p = r->child;
> + while (p) {
> + release_children_resource(p);
> + release_resource(p);
> + printk(KERN_DEBUG "PCI: release child resource
> %pRt\n", p);
> + /* need to restore size, and keep flags */
> + size = resource_size(p);
> + p->start = 0;
> + p->end = size - 1;
> + p = r->child;
> + }
> +}
Also seems like it should go into resource.c instead?
> +
> +static void pci_bridge_release_unused_res(struct pci_bus *bus,
> + unsigned long type)
> +{
> + 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) != type)
> + continue;
> + if (!r->parent)
> + continue;
> + /*
> + * if there are children under that, we should
> release them
> + * all
> + */
> + release_children_resource(r);
> + if (!release_resource(r)) {
> + dev_printk(KERN_DEBUG, &dev->dev,
> + "resource %d %pRt released\n", idx,
> r);
> + /* keep the old size */
> + r->end = resource_size(r) - 1;
> + r->start = 0;
> + r->flags = 0;
> + changed = true;
> + }
> + }
> +
> + if (changed) {
> + if (type & IORESOURCE_PREFETCH) {
> + /* avoiding touch the one without PREF */
> + type = IORESOURCE_PREFETCH;
> + }
> + __pci_setup_bridge(bus, type);
> + }
> +}
> +
> +/*
> + * try to release pci bridge resources that is from leaf bridge,
> + * so we can allocate big new one later
> + * check:
> + * 0: only release the bridge and only the bridge is leaf
> + * 1: release all down side bridge for third shoot
> + */
> +static void __ref pci_bus_release_unused_bridge_res(struct pci_bus
> *bus,
> + unsigned long
> type,
> + int check_leaf)
> +{
> + struct pci_dev *dev;
> + bool is_leaf_bridge = true;
> +
> + list_for_each_entry(dev, &bus->devices, bus_list) {
> + struct pci_bus *b = dev->subordinate;
> + if (!b)
> + continue;
> +
> + switch (dev->class >> 8) {
> + case PCI_CLASS_BRIDGE_CARDBUS:
> + is_leaf_bridge = false;
> + break;
> +
> + case PCI_CLASS_BRIDGE_PCI:
> + default:
> + is_leaf_bridge = false;
> + if (!check_leaf)
> + pci_bus_release_unused_bridge_res(b,
> type,
> + check_leaf);
> + break;
> + }
> + }
> +
> + /* The root bus? */
> + if (!bus->self)
> + return;
> +
> + switch (bus->self->class >> 8) {
> + case PCI_CLASS_BRIDGE_CARDBUS:
> + break;
> +
> + case PCI_CLASS_BRIDGE_PCI:
> + default:
> + if ((check_leaf && is_leaf_bridge) || !check_leaf)
> + pci_bridge_release_unused_res(bus, type);
> + break;
> + }
> +}
> +
> static void pci_bus_dump_res(struct pci_bus *bus)
> {
The idea here seems good, of allowing reallocation of bridge windows
when the space is insufficient. Would be good if Linus could check out
this series though.
--
Jesse Barnes, Intel Open Source Technology Center
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