ARM: OMAP2+: AM43XX: Enable autoidle for clks in am43xx_init_late

[karo-tx-linux.git] / mm / zpool.c

diff --git a/mm/zpool.c b/mm/zpool.c
index 68d2dd8ed2d8c6b43b6ed8e3f2f9cb29a287049f..8f670d3e87060f6277f5651a79cfaa8d27a30713 100644 (file)
--- a/mm/zpool.c
+++ b/mm/zpool.c
@@ -99,6 +99,39 @@ static void zpool_put_driver(struct zpool_driver *driver)
        module_put(driver->owner);
 }
 
+/**
+ * zpool_has_pool() - Check if the pool driver is available
+ * @type       The type of the zpool to check (e.g. zbud, zsmalloc)
+ *
+ * This checks if the @type pool driver is available.  This will try to load
+ * the requested module, if needed, but there is no guarantee the module will
+ * still be loaded and available immediately after calling.  If this returns
+ * true, the caller should assume the pool is available, but must be prepared
+ * to handle the @zpool_create_pool() returning failure.  However if this
+ * returns false, the caller should assume the requested pool type is not
+ * available; either the requested pool type module does not exist, or could
+ * not be loaded, and calling @zpool_create_pool() with the pool type will
+ * fail.
+ *
+ * Returns: true if @type pool is available, false if not
+ */
+bool zpool_has_pool(char *type)
+{
+       struct zpool_driver *driver = zpool_get_driver(type);
+
+       if (!driver) {
+               request_module("zpool-%s", type);
+               driver = zpool_get_driver(type);
+       }
+
+       if (!driver)
+               return false;
+
+       zpool_put_driver(driver);
+       return true;
+}
+EXPORT_SYMBOL(zpool_has_pool);
+
 /**
  * zpool_create_pool() - Create a new zpool
  * @type       The type of the zpool to create (e.g. zbud, zsmalloc)