lib: Move mathematic helpers to separate folder

For better maintenance and expansion move the mathematic helpers to the
separate folder.

No functional change intended.

Note, the int_sqrt() is not used as a part of lib, so, moved to regular
obj.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Thierry Reding <[e-mail]>
Cc: Lee Jones <[e-mail]>
Cc: Daniel Thompson <[e-mail]>
Cc: Ray Jui <[e-mail]>
[[e-mail]: fix broken doc references for div64.c and gcd.c]
Link: http://lkml.kernel.org/r/734f49b[e-mail]
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/core-api/kernel-api.rst

···
 .. kernel-doc:: include/linux/math64.h
    :internal:
 
-.. kernel-doc:: lib/div64.c
+.. kernel-doc:: lib/math/div64.c
    :functions: div_s64_rem div64_u64_rem div64_u64 div64_s64
 
-.. kernel-doc:: lib/gcd.c
+.. kernel-doc:: lib/math/gcd.c
    :export:
 
 UUID/GUID

lib/Kconfig

···
 	  This option enables the use of hardware bit-reversal instructions on
 	  architectures which support such operations.
 
-config RATIONAL
-	bool
-
 config GENERIC_STRNCPY_FROM_USER
 	bool
 
···
 
 config GENERIC_FIND_FIRST_BIT
 	bool
+
+source "lib/math/Kconfig"
 
 config NO_GENERIC_PCI_IOPORT_MAP
 	bool
···
 config CLZ_TAB
 	bool
 
-config CORDIC
-	tristate "CORDIC algorithm"
-	help
-	  This option provides an implementation of the CORDIC algorithm;
-	  calculations are in fixed point. Module will be called cordic.
-
 config DDR
 	bool "JEDEC DDR data"
 	help
···
 
 config PARMAN
 	tristate "parman" if COMPILE_TEST
-
-config PRIME_NUMBERS
-	tristate
 
 config STRING_SELFTEST
 	tristate "Test string functions"

lib/Makefile

···
 
 lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 rbtree.o radix-tree.o timerqueue.o xarray.o \
-	 idr.o int_sqrt.o extable.o \
+	 idr.o extable.o \
 	 sha1.o chacha.o irq_regs.o argv_split.o \
 	 flex_proportions.o ratelimit.o show_mem.o \
 	 is_single_threaded.o plist.o decompress.o kobject_uevent.o \
···
 lib-y	+= kobject.o klist.o
 obj-y	+= lockref.o
 
-obj-y += bcd.o div64.o sort.o parser.o debug_locks.o random32.o \
+obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \
 	 bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \
-	 gcd.o lcm.o list_sort.o uuid.o iov_iter.o clz_ctz.o \
+	 list_sort.o uuid.o iov_iter.o clz_ctz.o \
 	 bsearch.o find_bit.o llist.o memweight.o kfifo.o \
-	 percpu-refcount.o rhashtable.o reciprocal_div.o \
+	 percpu-refcount.o rhashtable.o \
 	 once.o refcount.o usercopy.o errseq.o bucket_locks.o \
 	 generic-radix-tree.o
 obj-$(CONFIG_STRING_SELFTEST) += test_string.o
···
 obj-$(CONFIG_DEBUG_INFO_REDUCED) += debug_info.o
 CFLAGS_debug_info.o += $(call cc-option, -femit-struct-debug-detailed=any)
 
+obj-y += math/
+
 obj-$(CONFIG_GENERIC_IOMAP) += iomap.o
 obj-$(CONFIG_GENERIC_PCI_IOMAP) += pci_iomap.o
 obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o
···
 
 obj-$(CONFIG_BITREVERSE) += bitrev.o
 obj-$(CONFIG_PACKING)	+= packing.o
-obj-$(CONFIG_RATIONAL)	+= rational.o
 obj-$(CONFIG_CRC_CCITT)	+= crc-ccitt.o
 obj-$(CONFIG_CRC16)	+= crc16.o
 obj-$(CONFIG_CRC_T10DIF)+= crc-t10dif.o
···
 
 obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
 
-obj-$(CONFIG_CORDIC) += cordic.o
-
 obj-$(CONFIG_DQL) += dynamic_queue_limits.o
 
 obj-$(CONFIG_GLOB) += glob.o
···
 obj-$(CONFIG_ASN1) += asn1_decoder.o
 
 obj-$(CONFIG_FONT_SUPPORT) += fonts/
-
-obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o
 
 hostprogs-y	:= gen_crc32table
 hostprogs-y	+= gen_crc64table

lib/div64.c lib/math/div64.c

···
  * Generic C version of 64bit/32bit division and modulo, with
  * 64bit result and 32bit remainder.
  *
- * The fast case for (n>>32 == 0) is handled inline by do_div(). 
+ * The fast case for (n>>32 == 0) is handled inline by do_div().
  *
  * Code generated for this function might be very inefficient
  * for some CPUs. __div64_32() can be overridden by linking arch-specific

lib/math/Kconfig

···
+config CORDIC
+	tristate "CORDIC algorithm"
+	help
+	  This option provides an implementation of the CORDIC algorithm;
+	  calculations are in fixed point. Module will be called cordic.
+
+config PRIME_NUMBERS
+	tristate
+
+config RATIONAL
+	bool

lib/math/Makefile

···
+obj-y += div64.o gcd.o lcm.o int_sqrt.o reciprocal_div.o
+
+obj-$(CONFIG_CORDIC)		+= cordic.o
+obj-$(CONFIG_PRIME_NUMBERS)	+= prime_numbers.o
+obj-$(CONFIG_RATIONAL)		+= rational.o