[PATCH 1/7] mm: introduce simple_malloc()/simple_free()

[Lai Jiangshan <laijs@cn.fujitsu.com>]

some subsystem needs vmalloc() when required memory is large.
but current kernel has not APIs for this requirement.
this patch introduces simple_malloc() and simple_free().

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ffee2f7..e9c11f7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -13,6 +13,7 @@
 #include <linux/prio_tree.h>
 #include <linux/debug_locks.h>
 #include <linux/mm_types.h>
+#include <linux/vmalloc.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -278,6 +279,36 @@ static inline int is_vmalloc_addr(const void *x)
 #endif
 }
 
+static inline void *__simple_malloc(unsigned long size, int pages_hint)
+{
+	if (size <= PAGE_SIZE * pages_hint)
+		return kmalloc(size, GFP_KERNEL);
+	else
+		return vmalloc(size);
+}
+
+/**
+ * simple_malloc - allocate memory by kmalloc() or vmalloc()
+ *
+ * if @size <= PAGE_SIZE, memory is allocated by kmalloc(),
+ * otherwise by vmalloc()
+ */
+static inline void *simple_malloc(unsigned long size)
+{
+	return __simple_malloc(size, 1);
+}
+
+/**
+ * simple_free - free the memory by kfree(), or vfree() if it is vmalloc addr
+ */
+static inline void simple_free(void *ptr)
+{
+	if (is_vmalloc_addr(ptr))
+		vfree(ptr);
+	else
+		kfree(ptr);
+}
+
 static inline struct page *compound_head(struct page *page)
 {
 	if (unlikely(PageTail(page)))