lib/math: move int_pow() from pwm_bl.c for wider use (9f615894) · Commits · 戴 / test

drivers/video/backlight/pwm_bl.c

+0 −15

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		@@ -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.
		*

+1 −0

Original line number	Diff line number	Diff line
		@@ -484,6 +484,7 @@ 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

+1 −1

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		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

0 → 100644

+32 −0

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		// 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);