[PATCH v1 1/2] lib: Move mathematic helpers to separate folder

[PATCH v1 1/2] lib: Move mathematic helpers to separate folder

[Andy Shevchenko]

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.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 lib/Kconfig                     | 14 ++------------
 lib/Makefile                    | 15 ++++++---------
 lib/math/Kconfig                | 11 +++++++++++
 lib/math/Makefile               |  5 +++++
 lib/{ => math}/cordic.c         |  0
 lib/{ => math}/div64.c          |  0
 lib/{ => math}/gcd.c            |  0
 lib/{ => math}/int_sqrt.c       |  0
 lib/{ => math}/lcm.c            |  0
 lib/{ => math}/prime_numbers.c  |  0
 lib/{ => math}/rational.c       |  0
 lib/{ => math}/reciprocal_div.c |  0
 12 files changed, 24 insertions(+), 21 deletions(-)
 create mode 100644 lib/math/Kconfig
 create mode 100644 lib/math/Makefile
 rename lib/{ => math}/cordic.c (100%)
 rename lib/{ => math}/div64.c (100%)
 rename lib/{ => math}/gcd.c (100%)
 rename lib/{ => math}/int_sqrt.c (100%)
 rename lib/{ => math}/lcm.c (100%)
 rename lib/{ => math}/prime_numbers.c (100%)
 rename lib/{ => math}/rational.c (100%)
 rename lib/{ => math}/reciprocal_div.c (100%)

diff --git a/lib/Kconfig b/lib/Kconfig
index a9e56539bd11..fb453afff32e 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -29,9 +29,6 @@ config HAVE_ARCH_BITREVERSE
 	  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
 
@@ -44,6 +41,8 @@ config GENERIC_NET_UTILS
 config GENERIC_FIND_FIRST_BIT
 	bool
 
+source "lib/math/Kconfig"
+
 config NO_GENERIC_PCI_IOPORT_MAP
 	bool
 
@@ -514,12 +513,6 @@ config LRU_CACHE
 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
@@ -607,9 +600,6 @@ config SBITMAP
 config PARMAN
 	tristate "parman" if COMPILE_TEST
 
-config PRIME_NUMBERS
-	tristate
-
 config STRING_SELFTEST
 	tristate "Test string functions"
 
diff --git a/lib/Makefile b/lib/Makefile
index 3b08673e8881..4eeb814eee2e 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -19,7 +19,7 @@ KCOV_INSTRUMENT_dynamic_debug.o := n
 
 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 \
@@ -33,11 +33,11 @@ lib-$(CONFIG_SMP) += cpumask.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-$(CONFIG_STRING_SELFTEST) += test_string.o
@@ -90,6 +90,8 @@ endif
 obj-$(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-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o
@@ -108,7 +110,6 @@ obj-$(CONFIG_DEBUG_LIST) += list_debug.o
 obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o
 
 obj-$(CONFIG_BITREVERSE) += bitrev.o
-obj-$(CONFIG_RATIONAL)	+= rational.o
 obj-$(CONFIG_CRC_CCITT)	+= crc-ccitt.o
 obj-$(CONFIG_CRC16)	+= crc16.o
 obj-$(CONFIG_CRC_T10DIF)+= crc-t10dif.o
@@ -182,8 +183,6 @@ obj-$(CONFIG_ATOMIC64_SELFTEST) += atomic64_test.o
 
 obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
 
-obj-$(CONFIG_CORDIC) += cordic.o
-
 obj-$(CONFIG_DQL) += dynamic_queue_limits.o
 
 obj-$(CONFIG_GLOB) += glob.o
@@ -225,8 +224,6 @@ obj-$(CONFIG_ASN1) += asn1_decoder.o
 
 obj-$(CONFIG_FONT_SUPPORT) += fonts/
 
-obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o
-
 hostprogs-y	:= gen_crc32table
 hostprogs-y	+= gen_crc64table
 clean-files	:= crc32table.h
diff --git a/lib/math/Kconfig b/lib/math/Kconfig
new file mode 100644
index 000000000000..73bdf37178d1
--- /dev/null
+++ b/lib/math/Kconfig
@@ -0,0 +1,11 @@
+config CORDIC
+	tristate "CORDIC algorithm"
+	help
+	  This option provides an implementation of the CORDIC algorithm;
+	  calculations are in fixed point. Module will be called cordic.
+
+config PRIME_NUMBERS
+	tristate
+
+config RATIONAL
+	bool
diff --git a/lib/math/Makefile b/lib/math/Makefile
new file mode 100644
index 000000000000..b75878420da6
--- /dev/null
+++ b/lib/math/Makefile
@@ -0,0 +1,5 @@
+obj-y += div64.o gcd.o lcm.o int_sqrt.o reciprocal_div.o
+
+obj-$(CONFIG_CORDIC)		+= cordic.o
+obj-$(CONFIG_PRIME_NUMBERS)	+= prime_numbers.o
+obj-$(CONFIG_RATIONAL)		+= rational.o
diff --git a/lib/cordic.c b/lib/math/cordic.c
similarity index 100%
rename from lib/cordic.c
rename to lib/math/cordic.c
diff --git a/lib/div64.c b/lib/math/div64.c
similarity index 100%
rename from lib/div64.c
rename to lib/math/div64.c
diff --git a/lib/gcd.c b/lib/math/gcd.c
similarity index 100%
rename from lib/gcd.c
rename to lib/math/gcd.c
diff --git a/lib/int_sqrt.c b/lib/math/int_sqrt.c
similarity index 100%
rename from lib/int_sqrt.c
rename to lib/math/int_sqrt.c
diff --git a/lib/lcm.c b/lib/math/lcm.c
similarity index 100%
rename from lib/lcm.c
rename to lib/math/lcm.c
diff --git a/lib/prime_numbers.c b/lib/math/prime_numbers.c
similarity index 100%
rename from lib/prime_numbers.c
rename to lib/math/prime_numbers.c
diff --git a/lib/rational.c b/lib/math/rational.c
similarity index 100%
rename from lib/rational.c
rename to lib/math/rational.c
diff --git a/lib/reciprocal_div.c b/lib/math/reciprocal_div.c
similarity index 100%
rename from lib/reciprocal_div.c
rename to lib/math/reciprocal_div.c
-- 
2.20.1

[PATCH v1 2/2] lib/math: Move int_pow() from pwm_bl.c for wider use

[Andy Shevchenko]

The integer exponentiation is used in few places and might be used
in the future by other call sites. Move it to wider use.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/video/backlight/pwm_bl.c | 15 ---------------
 include/linux/kernel.h           |  1 +
 lib/math/Makefile                |  2 +-
 lib/math/int_pow.c               | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 34 insertions(+), 16 deletions(-)
 create mode 100644 lib/math/int_pow.c

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 53b8ceea9bde..fb45f866b923 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -155,21 +155,6 @@ static const struct backlight_ops pwm_backlight_ops = {
 #ifdef CONFIG_OF
 #define PWM_LUMINANCE_SCALE	10000 /* luminance scale */
 
-/* An integer based power function */
-static u64 int_pow(u64 base, int exp)
-{
-	u64 result = 1;
-
-	while (exp) {
-		if (exp & 1)
-			result *= base;
-		exp >>= 1;
-		base *= base;
-	}
-
-	return result;
-}
-
 /*
  * CIE lightness to PWM conversion.
  *
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index bb8958690b69..d327fe835f2c 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -500,6 +500,7 @@ extern int __kernel_text_address(unsigned long addr);
 extern int kernel_text_address(unsigned long addr);
 extern int func_ptr_is_kernel_text(void *ptr);
 
+u64 int_pow(u64 base, unsigned int exp);
 unsigned long int_sqrt(unsigned long);
 
 #if BITS_PER_LONG < 64
diff --git a/lib/math/Makefile b/lib/math/Makefile
index b75878420da6..583bbfebfc09 100644
--- a/lib/math/Makefile
+++ b/lib/math/Makefile
@@ -1,4 +1,4 @@
-obj-y += div64.o gcd.o lcm.o int_sqrt.o reciprocal_div.o
+obj-y += div64.o gcd.o lcm.o int_pow.o int_sqrt.o reciprocal_div.o
 
 obj-$(CONFIG_CORDIC)		+= cordic.o
 obj-$(CONFIG_PRIME_NUMBERS)	+= prime_numbers.o
diff --git a/lib/math/int_pow.c b/lib/math/int_pow.c
new file mode 100644
index 000000000000..622fc1ab3c74
--- /dev/null
+++ b/lib/math/int_pow.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * An integer based power function
+ *
+ * Derived from drivers/video/backlight/pwm_bl.c
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+/**
+ * int_pow - computes the exponentiation of the given base and exponent
+ * @base: base which will be raised to the given power
+ * @exp: power to be raised to
+ *
+ * Computes: pow(base, exp), i.e. @base raised to the @exp power
+ */
+u64 int_pow(u64 base, unsigned int exp)
+{
+	u64 result = 1;
+
+	while (exp) {
+		if (exp & 1)
+			result *= base;
+		exp >>= 1;
+		base *= base;
+	}
+
+	return result;
+}
+EXPORT_SYMBOL_GPL(int_pow);
-- 
2.20.1