+ nbits = (size + (1UL << order) - 1) >> order;
+
+ read_lock(&pool->lock);
+ list_for_each(_chunk, &pool->chunks) {
+ chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
+
+ end_bit = (chunk->end_addr - chunk->start_addr) >> order;
+ end_bit -= nbits + 1;
+
+ spin_lock_irqsave(&chunk->lock, flags);
+ bit = -1;
+ while (bit + 1 < end_bit) {
+ bit = find_next_zero_bit(chunk->bits, end_bit, bit + 1);
+ if (bit >= end_bit)
+ break;
+
+ start_bit = bit;
+ if (nbits > 1) {
+ bit = find_next_bit(chunk->bits, bit + nbits,
+ bit + 1);
+ if (bit - start_bit < nbits)
+ continue;
+ }
+
+ addr = chunk->start_addr +
+ ((unsigned long)start_bit << order);
+ while (nbits--)
+ __set_bit(start_bit++, chunk->bits);
+ spin_unlock_irqrestore(&chunk->lock, flags);
+ read_unlock(&pool->lock);
+ return addr;
+ }
+ spin_unlock_irqrestore(&chunk->lock, flags);
+ }
+ read_unlock(&pool->lock);
+ return 0;
+}
+EXPORT_SYMBOL(gen_pool_alloc);
+
+/**
+ * gen_pool_free - free allocated special memory back to the pool
+ * @pool: pool to free to
+ * @addr: starting address of memory to free back to pool
+ * @size: size in bytes of memory to free
+ *
+ * Free previously allocated special memory back to the specified pool.
+ */
+void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size)
+{
+ struct list_head *_chunk;
+ struct gen_pool_chunk *chunk;
+ unsigned long flags;
+ int order = pool->min_alloc_order;
+ int bit, nbits;
+
+ nbits = (size + (1UL << order) - 1) >> order;
+
+ read_lock(&pool->lock);
+ list_for_each(_chunk, &pool->chunks) {
+ chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
+
+ if (addr >= chunk->start_addr && addr < chunk->end_addr) {
+ BUG_ON(addr + size > chunk->end_addr);
+ spin_lock_irqsave(&chunk->lock, flags);
+ bit = (addr - chunk->start_addr) >> order;
+ while (nbits--)
+ __clear_bit(bit++, chunk->bits);
+ spin_unlock_irqrestore(&chunk->lock, flags);