Patchwork [3/5] PCI/cpcihp: simplify code by hotplug safe pci_get_domain_bus_and_slot()

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Submitter Jiang Liu
Date Aug. 28, 2012, 3:43 p.m.
Message ID <1346168638-32724-4-git-send-email-jiang.liu@huawei.com>
Download mbox | patch
Permalink /patch/180513/
State Accepted
Headers show

Comments

Jiang Liu - Aug. 28, 2012, 3:43 p.m.
Following code has a race window between pci_find_bus() and pci_get_slot()
if PCI hotplug operation happens between them which removes the pci_bus.
So use PCI hotplug safe interface pci_get_domain_bus_and_slot() instead,
which also reduces code complexity.

struct pci_bus *pci_bus = pci_find_bus(domain, busno);
struct pci_dev *pci_dev = pci_get_slot(pci_bus, devfn);

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
---
 drivers/pci/hotplug/cpcihp_generic.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

Patch

diff --git a/drivers/pci/hotplug/cpcihp_generic.c b/drivers/pci/hotplug/cpcihp_generic.c
index 81af764..a6a71c4 100644
--- a/drivers/pci/hotplug/cpcihp_generic.c
+++ b/drivers/pci/hotplug/cpcihp_generic.c
@@ -154,12 +154,8 @@  static int __init cpcihp_generic_init(void)
 	if(!r)
 		return -EBUSY;
 
-	bus = pci_find_bus(0, bridge_busnr);
-	if (!bus) {
-		err("Invalid bus number %d", bridge_busnr);
-		return -EINVAL;
-	}
-	dev = pci_get_slot(bus, PCI_DEVFN(bridge_slot, 0));
+	dev = pci_get_domain_bus_and_slot(0, bridge_busnr,
+					  PCI_DEVFN(bridge_slot, 0));
 	if(!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
 		err("Invalid bridge device %s", bridge);
 		pci_dev_put(dev);