[PATCH v3 1/3] xen/pciback: simplify pcistub device handling

From: Juergen Gross
Date: Thu Sep 22 2016 - 04:46:18 EST


The Xen pciback driver maintains a list of all its seized devices.
There are two functions searching the list for a specific device with
basically the same semantics just returning different structures in
case of a match.

Split out the search function.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
drivers/xen/xen-pciback/pci_stub.c | 50 +++++++++++++++++++-------------------
1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 258b7c3..79a9e4d 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -149,29 +149,36 @@ static inline void pcistub_device_put(struct pcistub_device *psdev)
kref_put(&psdev->kref, pcistub_device_release);
}

+static struct pcistub_device *pcistub_device_find_locked(int domain, int bus,
+ int slot, int func)
+{
+ struct pcistub_device *psdev;
+
+ list_for_each_entry(psdev, &pcistub_devices, dev_list) {
+ if (psdev->dev != NULL
+ && domain == pci_domain_nr(psdev->dev->bus)
+ && bus == psdev->dev->bus->number
+ && slot == PCI_SLOT(psdev->dev->devfn)
+ && func == PCI_FUNC(psdev->dev->devfn)) {
+ return psdev;
+ }
+ }
+
+ return NULL;
+}
+
static struct pcistub_device *pcistub_device_find(int domain, int bus,
int slot, int func)
{
- struct pcistub_device *psdev = NULL;
+ struct pcistub_device *psdev;
unsigned long flags;

spin_lock_irqsave(&pcistub_devices_lock, flags);

- list_for_each_entry(psdev, &pcistub_devices, dev_list) {
- if (psdev->dev != NULL
- && domain == pci_domain_nr(psdev->dev->bus)
- && bus == psdev->dev->bus->number
- && slot == PCI_SLOT(psdev->dev->devfn)
- && func == PCI_FUNC(psdev->dev->devfn)) {
- pcistub_device_get(psdev);
- goto out;
- }
- }
+ psdev = pcistub_device_find_locked(domain, bus, slot, func);
+ if (psdev)
+ pcistub_device_get(psdev);

- /* didn't find it */
- psdev = NULL;
-
-out:
spin_unlock_irqrestore(&pcistub_devices_lock, flags);
return psdev;
}
@@ -207,16 +214,9 @@ struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,

spin_lock_irqsave(&pcistub_devices_lock, flags);

- list_for_each_entry(psdev, &pcistub_devices, dev_list) {
- if (psdev->dev != NULL
- && domain == pci_domain_nr(psdev->dev->bus)
- && bus == psdev->dev->bus->number
- && slot == PCI_SLOT(psdev->dev->devfn)
- && func == PCI_FUNC(psdev->dev->devfn)) {
- found_dev = pcistub_device_get_pci_dev(pdev, psdev);
- break;
- }
- }
+ psdev = pcistub_device_find_locked(domain, bus, slot, func);
+ if (psdev)
+ found_dev = pcistub_device_get_pci_dev(pdev, psdev);

spin_unlock_irqrestore(&pcistub_devices_lock, flags);
return found_dev;
--
2.6.6