[PATCH 1/9] pci: add pci_bridge_release_unused_res and pci_bus_release_unused_bridge_res

Yinghai Lu
2010-01-21T06:14:59Z

so later we could use it to release small resource before pci assign unassign res

-v2: change name to release_child_resources according to Jesse
-v3: according to Linus, move release_child_resources to resource.c
also need to put the lock around them all to avoid recursive deep.
(my test case only have one level that need to be released)
-v4: seperate release_child_resources to another patch
according to Bjorn, change hard code 3 to PCI_BRIDGE_RESOURCE_END
-v5: remove unused in the name, and also use enum for release type according
to Jesse
-v6: use pci_is_root_bus instead acording to Alex.
-v7: remove the switch case in pci_bus_release_resources accord to Alex

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
drivers/pci/setup-bus.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 85 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 52fbd42..5b42255 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -604,6 +604,91 @@ void __ref pci_bus_assign_resources(const struct pci_bus *bus)
}
EXPORT_SYMBOL(pci_bus_assign_resources);

+static void pci_bridge_release_resources(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;
+
+ dev = bus->self;
+ for (idx = PCI_BRIDGE_RESOURCES; idx <= PCI_BRIDGE_RESOURCE_END;
+ 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_child_resources(r);
+ if (!release_resource(r)) {
+ dev_printk(KERN_DEBUG, &dev->dev,
+ "resource %d %pR 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);
+ }
+}
+
+enum release_type {
+ leaf_only,
+ whole_subtree,
+};
+/*
+ * try to release pci bridge resources that is from leaf bridge,
+ * so we can allocate big new one later
+ */
+static void __ref pci_bus_release_bridge_resources(struct pci_bus *bus,
+ unsigned long type,
+ enum release_type rel_type)
+{
+ 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;
+
+ is_leaf_bridge = false;
+
+ if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+ continue;
+
+ if (rel_type == whole_subtree)
+ pci_bus_release_bridge_resources(b, type,
+ whole_subtree);
+ }
+
+ /* The root bus? */
+ if (pci_is_root_bus(bus))
+ return;
+
+ if ((bus->self->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+ return;
+
+ if (((rel_type == leaf_only) && is_leaf_bridge) ||
+ (rel_type == whole_subtree))
+ pci_bridge_release_resources(bus, type);
+}
+
static void pci_bus_dump_res(struct pci_bus *bus)
{
int i;
--
1.6.4.2