3 files changed, 63 insertions, 3 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index d911e0c1f359..4393c12e9135 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -216,6 +216,13 @@ const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
         return NULL;
 }
 
+static const struct pci_device_id pci_device_id_any = {
+        .vendor = PCI_ANY_ID,
+        .device = PCI_ANY_ID,
+        .subvendor = PCI_ANY_ID,
+        .subdevice = PCI_ANY_ID,
+};
+
 /**
  * pci_match_device - Tell if a PCI device structure has a matching PCI device id structure
  * @drv: the PCI driver to match against
@@ -229,18 +236,30 @@ static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
                                                     struct pci_dev *dev)
 {
         struct pci_dynid *dynid;
+        const struct pci_device_id *found_id = NULL;
+
+        /* When driver_override is set, only bind to the matching driver */
+        if (dev->driver_override && strcmp(dev->driver_override, drv->name))
+                return NULL;
 
         /* Look at the dynamic ids first, before the static ones */
         spin_lock(&drv->dynids.lock);
         list_for_each_entry(dynid, &drv->dynids.list, node) {
                 if (pci_match_one_device(&dynid->id, dev)) {
-                        spin_unlock(&drv->dynids.lock);
-                        return &dynid->id;
+                        found_id = &dynid->id;
+                        break;
                 }
         }
         spin_unlock(&drv->dynids.lock);
 
-        return pci_match_id(drv->id_table, dev);
+        if (!found_id)
+                found_id = pci_match_id(drv->id_table, dev);
+
+        /* driver_override will always match, send a dummy id */
+        if (!found_id && dev->driver_override)
+                found_id = &pci_device_id_any;
+
+        return found_id;
 }
 
 struct drv_dev_and_id {
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 4e0acefb7565..faa4ab554d68 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -499,6 +499,45 @@ static struct device_attribute sriov_numvfs_attr =
                        sriov_numvfs_show, sriov_numvfs_store);
 #endif /* CONFIG_PCI_IOV */
 
+static ssize_t driver_override_store(struct device *dev,
+                                     struct device_attribute *attr,
+                                     const char *buf, size_t count)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        char *driver_override, *old = pdev->driver_override, *cp;
+
+        if (count > PATH_MAX)
+                return -EINVAL;
+
+        driver_override = kstrndup(buf, count, GFP_KERNEL);
+        if (!driver_override)
+                return -ENOMEM;
+
+        cp = strchr(driver_override, '\n');
+        if (cp)
+                *cp = '\0';
+
+        if (strlen(driver_override)) {
+                pdev->driver_override = driver_override;
+        } else {
+                kfree(driver_override);
+                pdev->driver_override = NULL;
+        }
+
+        kfree(old);
+
+        return count;
+}
+
+static ssize_t driver_override_show(struct device *dev,
+                                    struct device_attribute *attr, char *buf)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        return sprintf(buf, "%s\n", pdev->driver_override);
+}
+static DEVICE_ATTR_RW(driver_override);
+
 static struct attribute *pci_dev_attrs[] = {
         &dev_attr_resource.attr,
         &dev_attr_vendor.attr,
@@ -521,6 +560,7 @@ static struct attribute *pci_dev_attrs[] = {
 #if defined(CONFIG_PM_RUNTIME) && defined(CONFIG_ACPI)
         &dev_attr_d3cold_allowed.attr,
 #endif
+        &dev_attr_driver_override.attr,
         NULL,
 };
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ef09f5f2fe6c..54268de45f59 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1215,6 +1215,7 @@ static void pci_release_dev(struct device *dev)
         pci_release_of_node(pci_dev);
         pcibios_release_device(pci_dev);
         pci_bus_put(pci_dev->bus);
+        kfree(pci_dev->driver_override);
         kfree(pci_dev);
 }