cregit-Linux how code gets into the kernel

Release 4.12 lib/bitmap.c

Directory: lib
/*
 * lib/bitmap.c
 * Helper functions for bitmap.h.
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */
#include <linux/export.h>
#include <linux/thread_info.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/uaccess.h>

#include <asm/page.h>

/*
 * bitmaps provide an array of bits, implemented using an an
 * array of unsigned longs.  The number of valid bits in a
 * given bitmap does _not_ need to be an exact multiple of
 * BITS_PER_LONG.
 *
 * The possible unused bits in the last, partially used word
 * of a bitmap are 'don't care'.  The implementation makes
 * no particular effort to keep them zero.  It ensures that
 * their value will not affect the results of any operation.
 * The bitmap operations that return Boolean (bitmap_empty,
 * for example) or scalar (bitmap_weight, for example) results
 * carefully filter out these unused bits from impacting their
 * results.
 *
 * These operations actually hold to a slightly stronger rule:
 * if you don't input any bitmaps to these ops that have some
 * unused bits set, then they won't output any set unused bits
 * in output bitmaps.
 *
 * The byte ordering of bitmaps is more natural on little
 * endian architectures.  See the big-endian headers
 * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
 * for the best explanations of this ordering.
 */




int __bitmap_equal(const unsigned long *bitmap1,
		const unsigned long *bitmap2, unsigned int bits)
{
	unsigned int k, lim = bits/BITS_PER_LONG;
	for (k = 0; k < lim; ++k)
		if (bitmap1[k] != bitmap2[k])
			return 0;

	if (bits % BITS_PER_LONG)
		if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
			return 0;

	return 1;
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton8897.78%375.00%


Rasmus Villemoes22.22%125.00%


Total90100.00%4100.00%




EXPORT_SYMBOL(__bitmap_equal);




void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
{
	unsigned int k, lim = bits/BITS_PER_LONG;
	for (k = 0; k < lim; ++k)
		dst[k] = ~src[k];

	if (bits % BITS_PER_LONG)
		dst[k] = ~src[k];
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton6997.18%480.00%


Rasmus Villemoes22.82%120.00%


Total71100.00%5100.00%




EXPORT_SYMBOL(__bitmap_complement);

/**
 * __bitmap_shift_right - logical right shift of the bits in a bitmap
 *   @dst : destination bitmap
 *   @src : source bitmap
 *   @shift : shift by this many bits
 *   @nbits : bitmap size, in bits
 *
 * Shifting right (dividing) means moving bits in the MS -> LS bit
 * direction.  Zeros are fed into the vacated MS positions and the
 * LS bits shifted off the bottom are lost.
 */



void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
			unsigned shift, unsigned nbits)
{
	unsigned k, lim = BITS_TO_LONGS(nbits);
	unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
	unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
	for (k = 0; off + k < lim; ++k) {
		unsigned long upper, lower;

		/*
                 * If shift is not word aligned, take lower rem bits of
                 * word above and make them the top rem bits of result.
                 */
		if (!rem || off + k + 1 >= lim)
			upper = 0;
		else {
			upper = src[off + k + 1];
			if (off + k + 1 == lim - 1)
				upper &= mask;
			upper <<= (BITS_PER_LONG - rem);
		}
		lower = src[off + k];
		if (off + k == lim - 1)
			lower &= mask;
		lower >>= rem;
		dst[k] = lower | upper;
	}
	if (off)
		memset(&dst[lim - off], 0, off*sizeof(unsigned long));
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton16585.05%450.00%


Rasmus Villemoes2211.34%337.50%


Jan Kara73.61%112.50%


Total194100.00%8100.00%




EXPORT_SYMBOL(__bitmap_shift_right);


/**
 * __bitmap_shift_left - logical left shift of the bits in a bitmap
 *   @dst : destination bitmap
 *   @src : source bitmap
 *   @shift : shift by this many bits
 *   @nbits : bitmap size, in bits
 *
 * Shifting left (multiplying) means moving bits in the LS -> MS
 * direction.  Zeros are fed into the vacated LS bit positions
 * and those MS bits shifted off the top are lost.
 */




void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
			unsigned int shift, unsigned int nbits)
{
	int k;
	unsigned int lim = BITS_TO_LONGS(nbits);
	unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
	for (k = lim - off - 1; k >= 0; --k) {
		unsigned long upper, lower;

		/*
                 * If shift is not word aligned, take upper rem bits of
                 * word below and make them the bottom rem bits of result.
                 */
		if (rem && k > 0)
			lower = src[k - 1] >> (BITS_PER_LONG - rem);
		else
			lower = 0;
		upper = src[k] << rem;
		dst[k + off] = lower | upper;
	}
	if (off)
		memset(dst, 0, off*sizeof(unsigned long));
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton11882.52%457.14%


Rasmus Villemoes1711.89%228.57%


Jan Kara85.59%114.29%


Total143100.00%7100.00%




EXPORT_SYMBOL(__bitmap_shift_left);




int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
				const unsigned long *bitmap2, unsigned int bits)
{
	unsigned int k;
	unsigned int lim = bits/BITS_PER_LONG;
	unsigned long result = 0;

	for (k = 0; k < lim; k++)
		result |= (dst[k] = bitmap1[k] & bitmap2[k]);
	if (bits % BITS_PER_LONG)
		result |= (dst[k] = bitmap1[k] & bitmap2[k] &
			   BITMAP_LAST_WORD_MASK(bits));
	return result != 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton5852.25%240.00%


Rasmus Villemoes3733.33%240.00%


Linus Torvalds1614.41%120.00%


Total111100.00%5100.00%




EXPORT_SYMBOL(__bitmap_and);




void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
				const unsigned long *bitmap2, unsigned int bits)
{
	unsigned int k;
	unsigned int nr = BITS_TO_LONGS(bits);

	for (k = 0; k < nr; k++)
		dst[k] = bitmap1[k] | bitmap2[k];
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton6495.52%266.67%


Rasmus Villemoes34.48%133.33%


Total67100.00%3100.00%




EXPORT_SYMBOL(__bitmap_or);




void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
				const unsigned long *bitmap2, unsigned int bits)
{
	unsigned int k;
	unsigned int nr = BITS_TO_LONGS(bits);

	for (k = 0; k < nr; k++)
		dst[k] = bitmap1[k] ^ bitmap2[k];
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton6495.52%266.67%


Rasmus Villemoes34.48%133.33%


Total67100.00%3100.00%




EXPORT_SYMBOL(__bitmap_xor);




int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
				const unsigned long *bitmap2, unsigned int bits)
{
	unsigned int k;
	unsigned int lim = bits/BITS_PER_LONG;
	unsigned long result = 0;

	for (k = 0; k < lim; k++)
		result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
	if (bits % BITS_PER_LONG)
		result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
			   BITMAP_LAST_WORD_MASK(bits));
	return result != 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton5952.21%240.00%


Rasmus Villemoes3833.63%240.00%


Linus Torvalds1614.16%120.00%


Total113100.00%5100.00%




EXPORT_SYMBOL(__bitmap_andnot);




int __bitmap_intersects(const unsigned long *bitmap1,
			const unsigned long *bitmap2, unsigned int bits)
{
	unsigned int k, lim = bits/BITS_PER_LONG;
	for (k = 0; k < lim; ++k)
		if (bitmap1[k] & bitmap2[k])
			return 1;

	if (bits % BITS_PER_LONG)
		if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
			return 1;
	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton8897.78%266.67%


Rasmus Villemoes22.22%133.33%


Total90100.00%3100.00%




EXPORT_SYMBOL(__bitmap_intersects);




int __bitmap_subset(const unsigned long *bitmap1,
		    const unsigned long *bitmap2, unsigned int bits)
{
	unsigned int k, lim = bits/BITS_PER_LONG;
	for (k = 0; k < lim; ++k)
		if (bitmap1[k] & ~bitmap2[k])
			return 0;

	if (bits % BITS_PER_LONG)
		if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
			return 0;
	return 1;
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton9097.83%266.67%


Rasmus Villemoes22.17%133.33%


Total92100.00%3100.00%




EXPORT_SYMBOL(__bitmap_subset);




int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
{
	unsigned int k, lim = bits/BITS_PER_LONG;
	int w = 0;

	for (k = 0; k < lim; k++)
		w += hweight_long(bitmap[k]);

	if (bits % BITS_PER_LONG)
		w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));

	return w;
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton6888.31%250.00%


Rasmus Villemoes79.09%125.00%


Akinobu Mita22.60%125.00%


Total77100.00%4100.00%




EXPORT_SYMBOL(__bitmap_weight);




void bitmap_set(unsigned long *map, unsigned int start, int len)
{
	unsigned long *p = map + BIT_WORD(start);
	const unsigned int size = start + len;
	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
	unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);

	while (len - bits_to_set >= 0) {
		*p |= mask_to_set;
		len -= bits_to_set;
		bits_to_set = BITS_PER_LONG;
		mask_to_set = ~0UL;
		p++;
	}
	if (len) {
		mask_to_set &= BITMAP_LAST_WORD_MASK(size);
		*p |= mask_to_set;
	}
}

Contributors
PersonTokensPropCommitsCommitProp
Akinobu Mita10093.46%150.00%


Rasmus Villemoes76.54%150.00%


Total107100.00%2100.00%




EXPORT_SYMBOL(bitmap_set);




void bitmap_clear(unsigned long *map, unsigned int start, int len)
{
	unsigned long *p = map + BIT_WORD(start);
	const unsigned int size = start + len;
	int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
	unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);

	while (len - bits_to_clear >= 0) {
		*p &= ~mask_to_clear;
		len -= bits_to_clear;
		bits_to_clear = BITS_PER_LONG;
		mask_to_clear = ~0UL;
		p++;
	}
	if (len) {
		mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
		*p &= ~mask_to_clear;
	}
}

Contributors
PersonTokensPropCommitsCommitProp
Akinobu Mita10293.58%150.00%


Rasmus Villemoes76.42%150.00%


Total109100.00%2100.00%




EXPORT_SYMBOL(bitmap_clear);

/**
 * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
 * @map: The address to base the search on
 * @size: The bitmap size in bits
 * @start: The bitnumber to start searching at
 * @nr: The number of zeroed bits we're looking for
 * @align_mask: Alignment mask for zero area
 * @align_offset: Alignment offset for zero area.
 *
 * The @align_mask should be one less than a power of 2; the effect is that
 * the bit offset of all zero areas this function finds plus @align_offset
 * is multiple of that power of 2.
 */



unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
					     unsigned long size,
					     unsigned long start,
					     unsigned int nr,
					     unsigned long align_mask,
					     unsigned long align_offset)
{
	unsigned long index, end, i;
again:
	index = find_next_zero_bit(map, size, start);

	/* Align allocation */
	index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;

	end = index + nr;
	if (end > size)
		return end;
	i = find_next_bit(map, end, index);
	if (i < end) {
		start = i + 1;
		goto again;
	}
	return index;
}

Contributors
PersonTokensPropCommitsCommitProp
Akinobu Mita10391.96%150.00%


Michal Nazarewicz98.04%150.00%


Total112100.00%2100.00%




EXPORT_SYMBOL(bitmap_find_next_zero_area_off);

/*
 * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
 * second version by Paul Jackson, third by Joe Korty.
 */


#define CHUNKSZ				32

#define nbits_to_hold_value(val)	fls(val)

#define BASEDEC 10		
/* fancier cpuset lists input in decimal */

/**
 * __bitmap_parse - convert an ASCII hex string into a bitmap.
 * @buf: pointer to buffer containing string.
 * @buflen: buffer size in bytes.  If string is smaller than this
 *    then it must be terminated with a \0.
 * @is_user: location of buffer, 0 indicates kernel space
 * @maskp: pointer to bitmap array that will contain result.
 * @nmaskbits: size of bitmap, in bits.
 *
 * Commas group hex digits into chunks.  Each chunk defines exactly 32
 * bits of the resultant bitmask.  No chunk may specify a value larger
 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
 * then leading 0-bits are prepended.  %-EINVAL is returned for illegal
 * characters and for grouping errors such as "1,,5", ",44", "," and "".
 * Leading and trailing whitespace accepted, but not embedded whitespace.
 */



int __bitmap_parse(const char *buf, unsigned int buflen,
		int is_user, unsigned long *maskp,
		int nmaskbits)
{
	int c, old_c, totaldigits, ndigits, nchunks, nbits;
	u32 chunk;
	const char __user __force *ubuf = (const char __user __force *)buf;

	bitmap_zero(maskp, nmaskbits);

	nchunks = nbits = totaldigits = c = 0;
	do {
		chunk = 0;
		ndigits = totaldigits;

		/* Get the next chunk of the bitmap */
		while (buflen) {
			old_c = c;
			if (is_user) {
				if (__get_user(c, ubuf++))
					return -EFAULT;
			}
			else
				c = *buf++;
			buflen--;
			if (isspace(c))
				continue;

			/*
                         * If the last character was a space and the current
                         * character isn't '\0', we've got embedded whitespace.
                         * This is a no-no, so throw an error.
                         */
			if (totaldigits && c && isspace(old_c))
				return -EINVAL;

			/* A '\0' or a ',' signal the end of the chunk */
			if (c == '\0' || c == ',')
				break;

			if (!isxdigit(c))
				return -EINVAL;

			/*
                         * Make sure there are at least 4 free bits in 'chunk'.
                         * If not, this hexdigit will overflow 'chunk', so
                         * throw an error.
                         */
			if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
				return -EOVERFLOW;

			chunk = (chunk << 4) | hex_to_bin(c);
			totaldigits++;
		}
		if (ndigits == totaldigits)
			return -EINVAL;
		if (nchunks == 0 && chunk == 0)
			continue;

		__bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
		*maskp |= chunk;
		nchunks++;
		nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
		if (nbits > nmaskbits)
			return -EOVERFLOW;
	} while (buflen && c == ',');

	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Andrew Morton24784.88%450.00%


Reinette Chatre3110.65%112.50%


H Hartley Sweeten82.75%112.50%


Pan Xinhui41.37%112.50%


Andy Shevchenko10.34%112.50%


Total291100.00%8100.00%




EXPORT_SYMBOL(__bitmap_parse);

/**
 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
 *
 * @ubuf: pointer to user buffer containing string.
 * @ulen: buffer size in bytes.  If string is smaller than this
 *    then it must be terminated with a \0.
 * @maskp: pointer to bitmap array that will contain result.
 * @nmaskbits: size of bitmap, in bits.
 *
 * Wrapper for __bitmap_parse(), providing it with user buffer.
 *
 * We cannot have this as an inline function in bitmap.h because it needs
 * linux/uaccess.h to get the access_ok() declaration and this causes
 * cyclic dependencies.
 */



int bitmap_parse_user(const char __user *ubuf,
			unsigned int ulen, unsigned long *maskp,
			int nmaskbits)
{
	if (!access_ok(VERIFY_READ, ubuf, ulen))
		return -EFAULT;
	return __bitmap_parse((const char __force *)ubuf,
				ulen, 1, maskp, nmaskbits);

}

Contributors
PersonTokensPropCommitsCommitProp
Reinette Chatre5898.31%150.00%


H Hartley Sweeten11.69%150.00%


Total59100.00%2100.00%




EXPORT_SYMBOL(bitmap_parse_user);

/**
 * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
 * @list: indicates whether the bitmap must be list
 * @buf: page aligned buffer into which string is placed
 * @maskp: pointer to bitmap to convert
 * @nmaskbits: size of bitmap, in bits
 *
 * Output format is a comma-separated list of decimal numbers and
 * ranges if list is specified or hex digits grouped into comma-separated
 * sets of 8 digits/set. Returns the number of characters written to buf.
 *
 * It is assumed that @buf is a pointer into a PAGE_SIZE area and that
 * sufficient storage remains at @buf to accommodate the
 * bitmap_print_to_pagebuf() output.
 */



int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
			    int nmaskbits)
{
	ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
	int n = 0;

	if (len > 1)
		n = list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
			   scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
	return n;
}

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Sudeep Holla7592.59%266.67%


Tejun Heo67.41%133.33%


Total81100.00%3100.00%




EXPORT_SYMBOL(bitmap_print_to_pagebuf);

/**
 * __bitmap_parselist - convert list format ASCII string to bitmap
 * @buf: read nul-terminated user string from this buffer
 * @buflen: buffer size in bytes.  If string is smaller than this
 *    then it must be terminated with a \0.
 * @is_user: location of buffer, 0 indicates kernel space
 * @maskp: write resulting mask here
 * @nmaskbits: number of bits in mask to be written
 *
 * Input format is a comma-separated list of decimal numbers and
 * ranges.  Consecutively set bits are shown as two hyphen-separated
 * decimal numbers, the smallest and largest bit numbers set in
 * the range.
 * Optionally each range can be postfixed to denote that only parts of it
 * should be set. The range will divided to groups of specific size.
 * From each group will be used only defined amount of bits.
 * Syntax: range:used_size/group_size
 * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
 *
 * Returns: 0 on success, -errno on invalid input strings. Error values:
 *
 *   - ``-EINVAL``: second number in range smaller than first
 *   - ``-EINVAL``: invalid character in string
 *   - ``-ERANGE``: bit number specified too large for mask
 */



static int __bitmap_parselist(const char *buf, unsigned int buflen,
		int is_user, unsigned long *maskp,
		int nmaskbits)
{
	unsigned int a, b, old_a, old_b;
	unsigned int group_size, used_size;
	int c, old_c, totaldigits, ndigits;
	const char __user __force *ubuf = (const char __user __force *)buf;
	int at_start, in_range, in_partial_range;

	totaldigits = c = 0;
	old_a = old_b = 0;
	group_size = used_size = 0;
	bitmap_zero(maskp, nmaskbits);
	do {
		at_start = 1;
		in_range = 0;
		in_partial_range = 0;
		a = b = 0;
		ndigits = totaldigits;

		/* Get the next cpu# or a range of cpu#'s */
		while (buflen) {
			old_c = c;
			if (is_user) {
				if (__get_user(c, ubuf++))
					return -EFAULT;
			} else
				c = *buf++;
			buflen--;
			if (isspace(c))
				continue;

			/* A '\0' or a ',' signal the end of a cpu# or range */
			if (c == '\0' || c == ',')
				break;
			/*
                        * whitespaces between digits are not allowed,
                        * but it's ok if whitespaces are on head or tail.
                        * when old_c is whilespace,
                        * if totaldigits == ndigits, whitespace is on head.
                        * if whitespace is on tail, it should not run here.
                        * as c was ',' or '\0',
                        * the last code line has broken the current loop.
                        */
			if ((totaldigits != ndigits) && isspace(old_c))
				return -EINVAL;

			if (c == '/') {
				used_size = a;
				at_start = 1;
				in_range = 0;
				a = b = 0;
				continue;
			}

			if (c == ':') {
				old_a = a;
				old_b = b;
				at_start = 1;
				in_range = 0;
				in_partial_range = 1;
				a = b = 0;
				continue;
			}

			if (c == '-') {
				if (at_start || in_range)
					return -EINVAL;
				b = 0;
				in_range = 1;
				at_start = 1;
				continue;
			}

			if (!isdigit(c))
				return -EINVAL;

			b = b * 10 + (c - '0');
			if (!in_range)
				a = b;
			at_start = 0;
			totaldigits++;
		}
		if (ndigits == totaldigits)
			continue;
		if (in_partial_range) {
			group_size = a;
			a = old_a;
			b = old_b;
			old_a = old_b = 0;
		}
		/* if no digit is after '-', it's wrong*/
		if (at_start && in_range)
			return -EINVAL;
		if (!(a <= b) || !(used_size <= group_size))
			return -EINVAL;
		if (b >= nmaskbits)
			return -ERANGE;
		while (a <= b) {
			if (in_partial_range) {
				static int pos_in_group = 1;

				if (pos_in_group <= used_size)
					set_bit(a, maskp);

				if (a == b || ++pos_in_group > group_size)
					pos_in_group = 1;
			} else
				set_bit(a, maskp);
			a++;
		}
	} while (buflen && c == ',');
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Noam Camus16334.03%114.29%


Mike Travis14931.11%114.29%


Paul Jackson11022.96%114.29%


Pan Xinhui459.39%228.57%


H Hartley Sweeten81.67%114.29%


Chris Metcalf40.84%114.29%


Total479100.00%7100.00%






int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
{
	char *nl  = strchrnul(bp, '\n');
	int len = nl - bp;

	return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
}

Contributors
PersonTokensPropCommitsCommitProp
Mike Travis4080.00%133.33%


Paul Jackson714.00%133.33%


Rasmus Villemoes36.00%133.33%


Total50100.00%3100.00%




EXPORT_SYMBOL(bitmap_parselist);


/**
 * bitmap_parselist_user()
 *
 * @ubuf: pointer to user buffer containing string.
 * @ulen: buffer size in bytes.  If string is smaller than this
 *    then it must be terminated with a \0.
 * @maskp: pointer to bitmap array that will contain result.
 * @nmaskbits: size of bitmap, in bits.
 *
 * Wrapper for bitmap_parselist(), providing it with user buffer.
 *
 * We cannot have this as an inline function in bitmap.h because it needs
 * linux/uaccess.h to get the access_ok() declaration and this causes
 * cyclic dependencies.
 */



int bitmap_parselist_user(const char __user *ubuf,
			unsigned int ulen, unsigned long *maskp,
			int nmaskbits)
{
	if (!access_ok(VERIFY_READ, ubuf, ulen))
		return -EFAULT;
	return __bitmap_parselist((const char __force *)ubuf,
					ulen, 1, maskp, nmaskbits);
}

Contributors
PersonTokensPropCommitsCommitProp
Mike Travis5898.31%150.00%


H Hartley Sweeten11.69%150.00%


Total59100.00%2100.00%




EXPORT_SYMBOL(bitmap_parselist_user);


/**
 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
 *      @buf: pointer to a bitmap
 *      @pos: a bit position in @buf (0 <= @pos < @nbits)
 *      @nbits: number of valid bit positions in @buf
 *
 * Map the bit at position @pos in @buf (of length @nbits) to the
 * ordinal of which set bit it is.  If it is not set or if @pos
 * is not a valid bit position, map to -1.
 *
 * If for example, just bits 4 through 7 are set in @buf, then @pos
 * values 4 through 7 will get mapped to 0 through 3, respectively,
 * and other @pos values will get mapped to -1.  When @pos value 7
 * gets mapped to (returns) @ord value 3 in this example, that means
 * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
 *
 * The bit positions 0 through @bits are valid positions in @buf.
 */



static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
{
	if (pos >= nbits || !test_bit(pos, buf))
		return -1;

	return __bitmap_weight(buf, pos);
}


Contributors
PersonTokensPropCommitsCommitProp
Paul Jackson4086.96%266.67%


Rasmus Villemoes613.04%133.33%


Total46100.00%3100.00%



/**
 * bitmap_ord_to_pos - find position of n-th set bit in bitmap
 *      @buf: pointer to bitmap
 *      @ord: ordinal bit position (n-th set bit, n >= 0)
 *      @nbits: number of valid bit positions in @buf
 *
 * Map the ordinal offset of bit @ord in @buf to its position in @buf.
 * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
 * >= weight(buf), returns @nbits.
 *
 * If for example, just bits 4 through 7 are set in @buf, then @ord
 * values 0 through 3 will get mapped to 4 through 7, respectively,
 * and all other @ord values returns @nbits.  When @ord value 3
 * gets mapped to (returns) @pos value 7 in this example, that means
 * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
 *
 * The bit positions 0 through @nbits-1 are valid positions in @buf.
 */



unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
{
	unsigned int pos;

	for (pos = find_first_bit(buf, nbits);
	     pos < nbits && ord;
	     pos = find_next_bit(buf, nbits, pos + 1))
		ord--;

	return pos;
}


Contributors
PersonTokensPropCommitsCommitProp