genalloc:support allocating specific region

Add new algo for genalloc, it reserve a specific region of
memory

Signed-off-by: Zhao Qiang <qiang.zhao@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 3c676ce..29d4385 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -84,6 +84,13 @@
 	int align;		/* alignment by bytes for starting address */
 };
 
+/*
+ *  gen_pool data descriptor for gen_pool_fixed_alloc.
+ */
+struct genpool_data_fixed {
+	unsigned long offset;		/* The offset of the specific region */
+};
+
 extern struct gen_pool *gen_pool_create(int, int);
 extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long);
 extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t,
@@ -124,6 +131,10 @@
 		unsigned long start, unsigned int nr, void *data,
 		struct gen_pool *pool);
 
+extern unsigned long gen_pool_fixed_alloc(unsigned long *map,
+		unsigned long size, unsigned long start, unsigned int nr,
+		void *data, struct gen_pool *pool);
+
 extern unsigned long gen_pool_first_fit_align(unsigned long *map,
 		unsigned long size, unsigned long start, unsigned int nr,
 		void *data, struct gen_pool *pool);