phylib: introduce mdiobus_alloc_size()

Introduce function mdiobus_alloc_size() as an alternative to mdiobus_alloc().
Most callers of mdiobus_alloc() also allocate a private data structure, and
then manually point bus->priv to this object.  mdiobus_alloc_size()
combines the two operations into one, which simplifies memory management.

The original mdiobus_alloc() now just calls mdiobus_alloc_size(0).

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 25 insertions, 6 deletions

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 6c58da2b882c..88cc5db9affd 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -37,22 +37,36 @@
 #include <asm/uaccess.h>
 
 /**
- * mdiobus_alloc - allocate a mii_bus structure
+ * mdiobus_alloc_size - allocate a mii_bus structure
  *
  * Description: called by a bus driver to allocate an mii_bus
  * structure to fill in.
+ *
+ * 'size' is an an extra amount of memory to allocate for private storage.
+ * If non-zero, then bus->priv is points to that memory.
  */
-struct mii_bus *mdiobus_alloc(void)
+struct mii_bus *mdiobus_alloc_size(size_t size)
 {
         struct mii_bus *bus;
+        size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
+        size_t alloc_size;
+
+        /* If we alloc extra space, it should be aligned */
+        if (size)
+                alloc_size = aligned_size + size;
+        else
+                alloc_size = sizeof(*bus);
 
-        bus = kzalloc(sizeof(*bus), GFP_KERNEL);
-        if (bus != NULL)
+        bus = kzalloc(alloc_size, GFP_KERNEL);
+        if (bus) {
                 bus->state = MDIOBUS_ALLOCATED;
+                if (size)
+                        bus->priv = (void *)bus + aligned_size;
+        }
 
         return bus;
 }
-EXPORT_SYMBOL(mdiobus_alloc);
+EXPORT_SYMBOL(mdiobus_alloc_size);
 
 /**
  * mdiobus_release - mii_bus device release callback
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 79f337c47388..c599f7eca1e7 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -129,7 +129,12 @@ struct mii_bus {
 };
 #define to_mii_bus(d) container_of(d, struct mii_bus, dev)
 
-struct mii_bus *mdiobus_alloc(void);
+struct mii_bus *mdiobus_alloc_size(size_t);
+static inline struct mii_bus *mdiobus_alloc(void)
+{
+        return mdiobus_alloc_size(0);
+}
+
 int mdiobus_register(struct mii_bus *bus);
 void mdiobus_unregister(struct mii_bus *bus);
 void mdiobus_free(struct mii_bus *bus);