PCI: separate out pci_add_dynid()

Separate out pci_add_dynid() from store_new_id() and export it so that
in-kernel code can add PCI IDs dynamically.  As the function will be
available regardless of HOTPLUG, put it and pull pci_free_dynids()
outside of CONFIG_HOTPLUG.

This will be used by pci-stub to initialize initial IDs via module
param.

While at it, remove bogus get_driver() failure check.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

2 files changed, 79 insertions, 45 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index f99bc7f089f1..c66dc4341fa0 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -19,37 +19,98 @@
 #include <linux/cpu.h>
 #include "pci.h"
 
-/*
- * Dynamic device IDs are disabled for !CONFIG_HOTPLUG
- */
-
 struct pci_dynid {
         struct list_head node;
         struct pci_device_id id;
 };
 
-#ifdef CONFIG_HOTPLUG
+/**
+ * pci_add_dynid - add a new PCI device ID to this driver and re-probe devices
+ * @drv: target pci driver
+ * @vendor: PCI vendor ID
+ * @device: PCI device ID
+ * @subvendor: PCI subvendor ID
+ * @subdevice: PCI subdevice ID
+ * @class: PCI class
+ * @class_mask: PCI class mask
+ * @driver_data: private driver data
+ *
+ * Adds a new dynamic pci device ID to this driver and causes the
+ * driver to probe for all devices again.  @drv must have been
+ * registered prior to calling this function.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int pci_add_dynid(struct pci_driver *drv,
+                  unsigned int vendor, unsigned int device,
+                  unsigned int subvendor, unsigned int subdevice,
+                  unsigned int class, unsigned int class_mask,
+                  unsigned long driver_data)
+{
+        struct pci_dynid *dynid;
+        int retval;
+
+        dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
+        if (!dynid)
+                return -ENOMEM;
+
+        dynid->id.vendor = vendor;
+        dynid->id.device = device;
+        dynid->id.subvendor = subvendor;
+        dynid->id.subdevice = subdevice;
+        dynid->id.class = class;
+        dynid->id.class_mask = class_mask;
+        dynid->id.driver_data = driver_data;
 
+        spin_lock(&drv->dynids.lock);
+        list_add_tail(&dynid->node, &drv->dynids.list);
+        spin_unlock(&drv->dynids.lock);
+
+        get_driver(&drv->driver);
+        retval = driver_attach(&drv->driver);
+        put_driver(&drv->driver);
+
+        return retval;
+}
+
+static void pci_free_dynids(struct pci_driver *drv)
+{
+        struct pci_dynid *dynid, *n;
+
+        spin_lock(&drv->dynids.lock);
+        list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
+                list_del(&dynid->node);
+                kfree(dynid);
+        }
+        spin_unlock(&drv->dynids.lock);
+}
+
+/*
+ * Dynamic device ID manipulation via sysfs is disabled for !CONFIG_HOTPLUG
+ */
+#ifdef CONFIG_HOTPLUG
 /**
- * store_new_id - add a new PCI device ID to this driver and re-probe devices
+ * store_new_id - sysfs frontend to pci_add_dynid()
  * @driver: target device driver
  * @buf: buffer for scanning device ID data
  * @count: input size
  *
- * Adds a new dynamic pci device ID to this driver,
- * and causes the driver to probe for all devices again.
+ * Allow PCI IDs to be added to an existing driver via sysfs.
  */
 static ssize_t
 store_new_id(struct device_driver *driver, const char *buf, size_t count)
 {
-        struct pci_dynid *dynid;
         struct pci_driver *pdrv = to_pci_driver(driver);
         const struct pci_device_id *ids = pdrv->id_table;
         __u32 vendor, device, subvendor=PCI_ANY_ID,
                 subdevice=PCI_ANY_ID, class=0, class_mask=0;
         unsigned long driver_data=0;
         int fields=0;
-        int retval=0;
+        int retval;
 
         fields = sscanf(buf, "%x %x %x %x %x %x %lx",
                         &vendor, &device, &subvendor, &subdevice,
@@ -72,27 +133,8 @@ store_new_id(struct device_driver *driver, const char *buf, size_t count)
                         return retval;
         }
 
-        dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
-        if (!dynid)
-                return -ENOMEM;
-
-        dynid->id.vendor = vendor;
-        dynid->id.device = device;
-        dynid->id.subvendor = subvendor;
-        dynid->id.subdevice = subdevice;
-        dynid->id.class = class;
-        dynid->id.class_mask = class_mask;
-        dynid->id.driver_data = driver_data;
-
-        spin_lock(&pdrv->dynids.lock);
-        list_add_tail(&dynid->node, &pdrv->dynids.list);
-        spin_unlock(&pdrv->dynids.lock);
-
-        if (get_driver(&pdrv->driver)) {
-                retval = driver_attach(&pdrv->driver);
-                put_driver(&pdrv->driver);
-        }
-
+        retval = pci_add_dynid(pdrv, vendor, device, subvendor, subdevice,
+                               class, class_mask, driver_data);
         if (retval)
                 return retval;
         return count;
@@ -145,19 +187,6 @@ store_remove_id(struct device_driver *driver, const char *buf, size_t count)
 }
 static DRIVER_ATTR(remove_id, S_IWUSR, NULL, store_remove_id);
 
-static void
-pci_free_dynids(struct pci_driver *drv)
-{
-        struct pci_dynid *dynid, *n;
-
-        spin_lock(&drv->dynids.lock);
-        list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
-                list_del(&dynid->node);
-                kfree(dynid);
-        }
-        spin_unlock(&drv->dynids.lock);
-}
-
 static int
 pci_create_newid_file(struct pci_driver *drv)
 {
@@ -186,7 +215,6 @@ static void pci_remove_removeid_file(struct pci_driver *drv)
         driver_remove_file(&drv->driver, &driver_attr_remove_id);
 }
 #else /* !CONFIG_HOTPLUG */
-static inline void pci_free_dynids(struct pci_driver *drv) {}
 static inline int pci_create_newid_file(struct pci_driver *drv)
 {
         return 0;
@@ -1106,6 +1134,7 @@ static int __init pci_driver_init(void)
 
 postcore_initcall(pci_driver_init);
 
+EXPORT_SYMBOL_GPL(pci_add_dynid);
 EXPORT_SYMBOL(pci_match_id);
 EXPORT_SYMBOL(__pci_register_driver);
 EXPORT_SYMBOL(pci_unregister_driver);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index da90217a7b0e..d75668317705 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -796,6 +796,11 @@ int __must_check __pci_register_driver(struct pci_driver *, struct module *,
 void pci_unregister_driver(struct pci_driver *dev);
 void pci_remove_behind_bridge(struct pci_dev *dev);
 struct pci_driver *pci_dev_driver(const struct pci_dev *dev);
+int pci_add_dynid(struct pci_driver *drv,
+                  unsigned int vendor, unsigned int device,
+                  unsigned int subvendor, unsigned int subdevice,
+                  unsigned int class, unsigned int class_mask,
+                  unsigned long driver_data);
 const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
                                          struct pci_dev *dev);
 int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,