lib/genalloc.c: add genpool range check function

After allocating an address from a particular genpool, there is no good way to verify if that address actually belongs to a genpool. Introduce addr_in_gen_pool which will return if an address plus size falls completely within the genpool range. Signed-off-by: Laura Abbott <[email protected]> Acked-by: Will Deacon <[email protected]> Reviewed-by: Olof Johansson <[email protected]> Reviewed-by: Catalin Marinas <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: David Riley <[email protected]> Cc: Ritesh Harjain <[email protected]> Cc: Russell King <[email protected]> Cc: Thierry Reding <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
mrcsosa · Oct 10, 2014 · 9efb3a4 · 9efb3a4
1 parent 505e3be
commit 9efb3a4
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diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
@@ -121,6 +121,9 @@ 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);
 
+bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
+			size_t size);
+
 #ifdef CONFIG_OF
 extern struct gen_pool *of_get_named_gen_pool(struct device_node *np,
 	const char *propname, int index);

diff --git a/lib/genalloc.c b/lib/genalloc.c
@@ -402,6 +402,35 @@ void gen_pool_for_each_chunk(struct gen_pool *pool,
 }
 EXPORT_SYMBOL(gen_pool_for_each_chunk);
 
+/**
+ * addr_in_gen_pool - checks if an address falls within the range of a pool
+ * @pool:	the generic memory pool
+ * @start:	start address
+ * @size:	size of the region
+ *
+ * Check if the range of addresses falls within the specified pool. Returns
+ * true if the entire range is contained in the pool and false otherwise.
+ */
+bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
+			size_t size)
+{
+	bool found = false;
+	unsigned long end = start + size;
+	struct gen_pool_chunk *chunk;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk) {
+		if (start >= chunk->start_addr && start <= chunk->end_addr) {
+			if (end <= chunk->end_addr) {
+				found = true;
+				break;
+			}
+		}
+	}
+	rcu_read_unlock();
+	return found;
+}
+
 /**
  * gen_pool_avail - get available free space of the pool
  * @pool: pool to get available free space