[SCSI] lib: add generic helper to print sizes rounded to the correct SI range

#ifndef _LINUX_STRING_HELPERS_H_

#define _LINUX_STRING_HELPERS_H_

#include <linux/types.h>

/* Descriptions of the types of units to

 * print in */

enum string_size_units {

	STRING_UNITS_10,	/* use powers of 10^3 (standard SI) */

	STRING_UNITS_2,		/* use binary powers of 2^10 */

};

int string_get_size(u64 size, enum string_size_units units,

		    char *buf, int len);

#endif

lib-y	+= kobject.o kref.o klist.o

obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \

	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o

	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \

	 string_helpers.o

ifeq ($(CONFIG_DEBUG_KOBJECT),y)

CFLAGS_kobject.o += -DDEBUG

/*

 * Helpers for formatting and printing strings

 *

 * Copyright 31 August 2008 James Bottomley

 */

#include <linux/kernel.h>

#include <linux/math64.h>

#include <linux/module.h>

#include <linux/string_helpers.h>

/**

 * string_get_size - get the size in the specified units

 * @size:	The size to be converted

 * @units:	units to use (powers of 1000 or 1024)

 * @buf:	buffer to format to

 * @len:	length of buffer

 *

 * This function returns a string formatted to 3 significant figures

 * giving the size in the required units.  Returns 0 on success or

 * error on failure.  @buf is always zero terminated.

 *

 */

int string_get_size(u64 size, const enum string_size_units units,

		    char *buf, int len)

{

	const char *units_10[] = { "B", "KB", "MB", "GB", "TB", "PB",

				   "EB", "ZB", "YB", NULL};

	const char *units_2[] = {"B", "KiB", "MiB", "GiB", "TiB", "PiB",

				 "EiB", "ZiB", "YiB", NULL };

	const char **units_str[] = {

		[STRING_UNITS_10] =  units_10,

		[STRING_UNITS_2] = units_2,

	};

	const int divisor[] = {

		[STRING_UNITS_10] = 1000,

		[STRING_UNITS_2] = 1024,

	};

	int i, j;

	u64 remainder = 0, sf_cap;

	char tmp[8];

	tmp[0] = '\0';

	for (i = 0; size > divisor[units] && units_str[units][i]; i++)

		remainder = do_div(size, divisor[units]);

	sf_cap = size;

	for (j = 0; sf_cap*10 < 1000; j++)

		sf_cap *= 10;

	if (j) {

		remainder *= 1000;

		do_div(remainder, divisor[units]);

		snprintf(tmp, sizeof(tmp), ".%03lld",

			 (unsigned long long)remainder);

		tmp[j+1] = '\0';

	}

	snprintf(buf, len, "%lld%s%s", (unsigned long long)size,

		 tmp, units_str[units][i]);

	return 0;

}

EXPORT_SYMBOL(string_get_size);