genalloc: add devres support, allow to find a managed pool by device

This patch adds three exported functions to lib/genalloc.c:
devm_gen_pool_create, dev_get_gen_pool, and of_get_named_gen_pool.

devm_gen_pool_create is a managed version of gen_pool_create that keeps
track of the pool via devres and allows the management code to
automatically destroy it after device removal.

dev_get_gen_pool retrieves the gen_pool for a given device, if it was
created with devm_gen_pool_create, using devres_find.

of_get_named_gen_pool retrieves the gen_pool for a given device node and
property name, where the property must contain a phandle pointing to a
platform device node.  The corresponding platform device is then fed into
dev_get_gen_pool and the resulting gen_pool is returned.

[akpm@linux-foundation.org: make the of_get_named_gen_pool() stub static, fixing a zillion link errors]
[akpm@linux-foundation.org: squish "struct device declared inside parameter list" warning]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Michal Simek <monstr@monstr.eu>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Matt Porter <mporter@ti.com>
Cc: Dong Aisheng <dong.aisheng@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index dd7c569aacad..661d374aeb2d 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -29,6 +29,10 @@
 
 #ifndef __GENALLOC_H__
 #define __GENALLOC_H__
+
+struct device;
+struct device_node;
+
 /**
  * Allocation callback function type definition
  * @map: Pointer to bitmap
@@ -105,4 +109,18 @@ extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
 extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
                 unsigned long start, unsigned int nr, void *data);
 
+extern struct gen_pool *devm_gen_pool_create(struct device *dev,
+                int min_alloc_order, int nid);
+extern struct gen_pool *dev_get_gen_pool(struct device *dev);
+
+#ifdef CONFIG_OF
+extern struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+        const char *propname, int index);
+#else
+static inline struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+        const char *propname, int index)
+{
+        return NULL;
+}
+#endif
 #endif /* __GENALLOC_H__ */