1 files changed, 137 insertions, 0 deletions
diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
new file mode 100644
index 000000000..1ccaab44a
--- /dev/null
+++ b/include/linux/genalloc.h
@@ -0,0 +1,137 @@
+/*
+ * Basic general purpose allocator for managing special purpose
+ * memory, for example, memory that is not managed by the regular
+ * kmalloc/kfree interface.  Uses for this includes on-device special
+ * memory, uncached memory etc.
+ *
+ * It is safe to use the allocator in NMI handlers and other special
+ * unblockable contexts that could otherwise deadlock on locks.  This
+ * is implemented by using atomic operations and retries on any
+ * conflicts.  The disadvantage is that there may be livelocks in
+ * extreme cases.  For better scalability, one allocator can be used
+ * for each CPU.
+ *
+ * The lockless operation only works if there is enough memory
+ * available.  If new memory is added to the pool a lock has to be
+ * still taken.  So any user relying on locklessness has to ensure
+ * that sufficient memory is preallocated.
+ *
+ * The basic atomic operation of this allocator is cmpxchg on long.
+ * On architectures that don't have NMI-safe cmpxchg implementation,
+ * the allocator can NOT be used in NMI handler.  So code uses the
+ * allocator in NMI handler should depend on
+ * CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+
+#ifndef __GENALLOC_H__
+#define __GENALLOC_H__
+
+#include <linux/spinlock_types.h>
+
+struct device;
+struct device_node;
+
+/**
+ * Allocation callback function type definition
+ * @map: Pointer to bitmap
+ * @size: The bitmap size in bits
+ * @start: The bitnumber to start searching at
+ * @nr: The number of zeroed bits we're looking for
+ * @data: optional additional data used by @genpool_algo_t
+ */
+typedef unsigned long (*genpool_algo_t)(unsigned long *map,
+			unsigned long size,
+			unsigned long start,
+			unsigned int nr,
+			void *data);
+
+/*
+ *  General purpose special memory pool descriptor.
+ */
+struct gen_pool {
+	spinlock_t lock;
+	struct list_head chunks;	/* list of chunks in this pool */
+	int min_alloc_order;		/* minimum allocation order */
+
+	genpool_algo_t algo;		/* allocation function */
+	void *data;
+};
+
+/*
+ *  General purpose special memory pool chunk descriptor.
+ */
+struct gen_pool_chunk {
+	struct list_head next_chunk;	/* next chunk in pool */
+	atomic_t avail;
+	phys_addr_t phys_addr;		/* physical starting address of memory chunk */
+	unsigned long start_addr;	/* start address of memory chunk */
+	unsigned long end_addr;		/* end address of memory chunk (inclusive) */
+	unsigned long bits[0];		/* bitmap for allocating memory chunk */
+};
+
+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,
+			     size_t, int);
+/**
+ * gen_pool_add - add a new chunk of special memory to the pool
+ * @pool: pool to add new memory chunk to
+ * @addr: starting address of memory chunk to add to pool
+ * @size: size in bytes of the memory chunk to add to pool
+ * @nid: node id of the node the chunk structure and bitmap should be
+ *       allocated on, or -1
+ *
+ * Add a new chunk of special memory to the specified pool.
+ *
+ * Returns 0 on success or a -ve errno on failure.
+ */
+static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr,
+			       size_t size, int nid)
+{
+	return gen_pool_add_virt(pool, addr, -1, size, nid);
+}
+extern void gen_pool_destroy(struct gen_pool *);
+extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
+extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size,
+		dma_addr_t *dma);
+extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
+extern void gen_pool_for_each_chunk(struct gen_pool *,
+	void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);
+extern size_t gen_pool_avail(struct gen_pool *);
+extern size_t gen_pool_size(struct gen_pool *);
+
+extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo,
+		void *data);
+
+extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
+		unsigned long start, unsigned int nr, void *data);
+
+extern unsigned long gen_pool_first_fit_order_align(unsigned long *map,
+		unsigned long size, unsigned long start, unsigned int nr,
+		void *data);
+
+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);
+
+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);
+#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__ */