[PATCH -v11 23/30] PCI: Strict checking of valid range for bridge

From: Yinghai Lu
Date: Mon Mar 19 2012 - 01:45:50 EST


Children bridges busn range should be allocated from parent bus range.

So we could avoid overlapping between sibling bridges on same bus.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/probe.c | 27 +++++++++++++++++++++++++++
1 files changed, 27 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index bf577e8..5710411 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -730,6 +730,28 @@ static int __devinit pci_bridge_probe_busn_res(struct pci_bus *bus,
return ret;
}

+static int __devinit pci_bridge_check_busn_broken(struct pci_bus *bus,
+ struct pci_dev *dev,
+ int secondary, int subordinate)
+{
+ int ret;
+ struct resource busn_res;
+
+ memset(&busn_res, 0, sizeof(struct resource));
+ dev_printk(KERN_DEBUG, &dev->dev,
+ "check if busn %02x-%02x is in busn_res: %pR\n",
+ secondary, subordinate, &bus->busn_res);
+ ret = allocate_resource(&bus->busn_res, &busn_res,
+ (subordinate - secondary + 1),
+ secondary, subordinate,
+ 1, NULL, NULL);
+ if (ret)
+ return 1;
+
+ release_resource(&busn_res);
+
+ return 0;
+}
/*
* If it's a bridge, configure it and scan the bus behind it.
* For CardBus bridges, we don't scan behind as the devices will
@@ -768,6 +790,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
(primary != bus->number || secondary <= bus->number))
broken = 1;

+ /* more strict checking */
+ if (!pass && !broken && !dev->subordinate)
+ broken = pci_bridge_check_busn_broken(bus, dev,
+ secondary, subordinate);
+
if (broken)
dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n");

--
1.7.7

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