slab: add kmalloc() to kernel API documentation

At the moment, kmalloc() isn't even listed in the kernel API
documentation (DocBook/kernel-api.html after running "make htmldocs").

Another issue is that the documentation for kmalloc_node()
refers to kcalloc()'s documentation to describe its 'flags' parameter,
while kcalloc() refered to kmalloc()'s documentation, which doesn't exist!

This patch is a proposed fix for this. It also removes the documentation
for kmalloc() in include/linux/slob_def.h which isn't included to
generate the documentation anyway. This way, kmalloc() is described
in only one place.
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

include/linux/slab.h

@@ -373,9 +373,8 @@ int cache_show(struct kmem_cache *s, struct seq_file *m);
 void print_slabinfo_header(struct seq_file *m);
 
 /**
- * kmalloc_array - allocate memory for an array.
- * @n: number of elements.
- * @size: element size.
+ * kmalloc - allocate memory
+ * @size: how many bytes of memory are required.
  * @flags: the type of memory to allocate.
  *
  * The @flags argument may be one of:
@@ -422,6 +421,17 @@ void print_slabinfo_header(struct seq_file *m);
  * There are other flags available as well, but these are not intended
  * for general use, and so are not documented here. For a full list of
  * potential flags, always refer to linux/gfp.h.
+ *
+ * kmalloc is the normal method of allocating memory
+ * in the kernel.
+ */
+static __always_inline void *kmalloc(size_t size, gfp_t flags);
+
+/**
+ * kmalloc_array - allocate memory for an array.
+ * @n: number of elements.
+ * @size: element size.
+ * @flags: the type of memory to allocate (see kmalloc).
  */
 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
 {
@@ -445,7 +455,7 @@ static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
 /**
  * kmalloc_node - allocate memory from a specific node
  * @size: how many bytes of memory are required.
- * @flags: the type of memory to allocate (see kcalloc).
+ * @flags: the type of memory to allocate (see kmalloc).
  * @node: node to allocate from.
  *
  * kmalloc() for non-local nodes, used to allocate from a specific node

include/linux/slob_def.h

@@ -18,14 +18,6 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 	return __kmalloc_node(size, flags, node);
 }
 
-/**
- * kmalloc - allocate memory
- * @size: how many bytes of memory are required.
- * @flags: the type of memory to allocate (see kcalloc).
- *
- * kmalloc is the normal method of allocating memory
- * in the kernel.
- */
 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 {
 	return __kmalloc_node(size, flags, NUMA_NO_NODE);