Documentation: add kernel-api section on Math functions

Add a kernel-api section on Math Functions.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/core-api/kernel-api.rst

@@ -103,6 +103,30 @@ idr/ida Functions
 .. kernel-doc:: lib/idr.c
    :export:
 
+Math Functions in Linux
+=======================
+
+Base 2 log and power Functions
+------------------------------
+
+.. kernel-doc:: include/linux/log2.h
+   :internal:
+
+Division Functions
+------------------
+
+.. kernel-doc:: include/asm-generic/div64.h
+   :functions: do_div
+
+.. kernel-doc:: include/linux/math64.h
+   :internal:
+
+.. kernel-doc:: lib/div64.c
+   :functions: div_s64_rem div64_u64_rem div64_u64 div64_s64
+
+.. kernel-doc:: lib/gcd.c
+   :export:
+
 Memory Management in Linux
 ==========================