genalloc: add name arg to gen_pool_get() and devm_gen_pool_create()

This change modifies gen_pool_get() and devm_gen_pool_create() client
interfaces adding one more argument "name" of a gen_pool object.

Due to implementation gen_pool_get() is capable to retrieve only one
gen_pool associated with a device even if multiple gen_pools are created,
fortunately right at the moment it is sufficient for the clients, hence
provide NULL as a valid argument on both producer devm_gen_pool_create()
and consumer gen_pool_get() sides.

Because only one created gen_pool per device is addressable, explicitly
add a restriction to devm_gen_pool_create() to create only one gen_pool
per device, this implies two possible error codes returned by the
function, account it on client side (only misc/sram).  This completes
client side changes related to genalloc updates.

[akpm@linux-foundation.org: gen_pool_get() cleanup]
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 28 insertions, 21 deletions

diff --git a/lib/genalloc.c b/lib/genalloc.c
index daf0afb6d979..b13cfd1a366e 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -571,23 +571,46 @@ static void devm_gen_pool_release(struct device *dev, void *res)
 }
 
 /**
+ * gen_pool_get - Obtain the gen_pool (if any) for a device
+ * @dev: device to retrieve the gen_pool from
+ * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
+ *
+ * Returns the gen_pool for the device if one is present, or NULL.
+ */
+struct gen_pool *gen_pool_get(struct device *dev, const char *name)
+{
+	struct gen_pool **p;
+
+	p = devres_find(dev, devm_gen_pool_release, NULL, NULL);
+	if (!p)
+		return NULL;
+	return *p;
+}
+EXPORT_SYMBOL_GPL(gen_pool_get);
+
+/**
  * devm_gen_pool_create - managed gen_pool_create
  * @dev: device that provides the gen_pool
  * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
- * @nid: node id of the node the pool structure should be allocated on, or -1
+ * @nid: node selector for allocated gen_pool, %NUMA_NO_NODE for all nodes
+ * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
  *
  * Create a new special memory pool that can be used to manage special purpose
  * memory not managed by the regular kmalloc/kfree interface. The pool will be
  * automatically destroyed by the device management code.
  */
 struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order,
-		int nid)
+				      int nid, const char *name)
 {
 	struct gen_pool **ptr, *pool;
 
+	/* Check that genpool to be created is uniquely addressed on device */
+	if (gen_pool_get(dev, name))
+		return ERR_PTR(-EINVAL);
+
 	ptr = devres_alloc(devm_gen_pool_release, sizeof(*ptr), GFP_KERNEL);
 	if (!ptr)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	pool = gen_pool_create(min_alloc_order, nid);
 	if (pool) {
@@ -595,29 +618,13 @@ struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order,
 		devres_add(dev, ptr);
 	} else {
 		devres_free(ptr);
+		return ERR_PTR(-ENOMEM);
 	}
 
 	return pool;
 }
 EXPORT_SYMBOL(devm_gen_pool_create);
 
-/**
- * gen_pool_get - Obtain the gen_pool (if any) for a device
- * @dev: device to retrieve the gen_pool from
- *
- * Returns the gen_pool for the device if one is present, or NULL.
- */
-struct gen_pool *gen_pool_get(struct device *dev)
-{
-	struct gen_pool **p = devres_find(dev, devm_gen_pool_release, NULL,
-					NULL);
-
-	if (!p)
-		return NULL;
-	return *p;
-}
-EXPORT_SYMBOL_GPL(gen_pool_get);
-
 #ifdef CONFIG_OF
 /**
  * of_gen_pool_get - find a pool by phandle property
@@ -642,7 +649,7 @@ struct gen_pool *of_gen_pool_get(struct device_node *np,
 	of_node_put(np_pool);
 	if (!pdev)
 		return NULL;
-	return gen_pool_get(&pdev->dev);
+	return gen_pool_get(&pdev->dev, NULL);
 }
 EXPORT_SYMBOL_GPL(of_gen_pool_get);
 #endif /* CONFIG_OF */