v4.19.13 snapshot.
diff --git a/lib/bitmap.c b/lib/bitmap.c
new file mode 100644
index 0000000..2fd07f6
--- /dev/null
+++ b/lib/bitmap.c
@@ -0,0 +1,1195 @@
+/*
+ * 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/slab.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+
+#include <asm/page.h>
+
+/**
+ * DOC: bitmap introduction
+ *
+ * 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;
+}
+EXPORT_SYMBOL(__bitmap_equal);
+
+void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
+{
+ unsigned int k, lim = BITS_TO_LONGS(bits);
+ for (k = 0; k < lim; ++k)
+ dst[k] = ~src[k];
+}
+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));
+}
+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));
+}
+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;
+}
+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];
+}
+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];
+}
+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;
+}
+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;
+}
+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;
+}
+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;
+}
+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;
+ }
+}
+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;
+ }
+}
+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;
+}
+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;
+}
+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);
+
+}
+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;
+}
+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, off;
+ 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;
+ } else {
+ used_size = group_size = b - a + 1;
+ }
+ /* if no digit is after '-', it's wrong*/
+ if (at_start && in_range)
+ return -EINVAL;
+ if (!(a <= b) || group_size == 0 || !(used_size <= group_size))
+ return -EINVAL;
+ if (b >= nmaskbits)
+ return -ERANGE;
+ while (a <= b) {
+ off = min(b - a + 1, used_size);
+ bitmap_set(maskp, a, off);
+ a += group_size;
+ }
+ } while (buflen && c == ',');
+ return 0;
+}
+
+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);
+}
+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);
+}
+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);
+}
+
+/**
+ * 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;
+}
+
+/**
+ * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
+ * @dst: remapped result
+ * @src: subset to be remapped
+ * @old: defines domain of map
+ * @new: defines range of map
+ * @nbits: number of bits in each of these bitmaps
+ *
+ * Let @old and @new define a mapping of bit positions, such that
+ * whatever position is held by the n-th set bit in @old is mapped
+ * to the n-th set bit in @new. In the more general case, allowing
+ * for the possibility that the weight 'w' of @new is less than the
+ * weight of @old, map the position of the n-th set bit in @old to
+ * the position of the m-th set bit in @new, where m == n % w.
+ *
+ * If either of the @old and @new bitmaps are empty, or if @src and
+ * @dst point to the same location, then this routine copies @src
+ * to @dst.
+ *
+ * The positions of unset bits in @old are mapped to themselves
+ * (the identify map).
+ *
+ * Apply the above specified mapping to @src, placing the result in
+ * @dst, clearing any bits previously set in @dst.
+ *
+ * For example, lets say that @old has bits 4 through 7 set, and
+ * @new has bits 12 through 15 set. This defines the mapping of bit
+ * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
+ * bit positions unchanged. So if say @src comes into this routine
+ * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
+ * 13 and 15 set.
+ */
+void bitmap_remap(unsigned long *dst, const unsigned long *src,
+ const unsigned long *old, const unsigned long *new,
+ unsigned int nbits)
+{
+ unsigned int oldbit, w;
+
+ if (dst == src) /* following doesn't handle inplace remaps */
+ return;
+ bitmap_zero(dst, nbits);
+
+ w = bitmap_weight(new, nbits);
+ for_each_set_bit(oldbit, src, nbits) {
+ int n = bitmap_pos_to_ord(old, oldbit, nbits);
+
+ if (n < 0 || w == 0)
+ set_bit(oldbit, dst); /* identity map */
+ else
+ set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
+ }
+}
+EXPORT_SYMBOL(bitmap_remap);
+
+/**
+ * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
+ * @oldbit: bit position to be mapped
+ * @old: defines domain of map
+ * @new: defines range of map
+ * @bits: number of bits in each of these bitmaps
+ *
+ * Let @old and @new define a mapping of bit positions, such that
+ * whatever position is held by the n-th set bit in @old is mapped
+ * to the n-th set bit in @new. In the more general case, allowing
+ * for the possibility that the weight 'w' of @new is less than the
+ * weight of @old, map the position of the n-th set bit in @old to
+ * the position of the m-th set bit in @new, where m == n % w.
+ *
+ * The positions of unset bits in @old are mapped to themselves
+ * (the identify map).
+ *
+ * Apply the above specified mapping to bit position @oldbit, returning
+ * the new bit position.
+ *
+ * For example, lets say that @old has bits 4 through 7 set, and
+ * @new has bits 12 through 15 set. This defines the mapping of bit
+ * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
+ * bit positions unchanged. So if say @oldbit is 5, then this routine
+ * returns 13.
+ */
+int bitmap_bitremap(int oldbit, const unsigned long *old,
+ const unsigned long *new, int bits)
+{
+ int w = bitmap_weight(new, bits);
+ int n = bitmap_pos_to_ord(old, oldbit, bits);
+ if (n < 0 || w == 0)
+ return oldbit;
+ else
+ return bitmap_ord_to_pos(new, n % w, bits);
+}
+EXPORT_SYMBOL(bitmap_bitremap);
+
+/**
+ * bitmap_onto - translate one bitmap relative to another
+ * @dst: resulting translated bitmap
+ * @orig: original untranslated bitmap
+ * @relmap: bitmap relative to which translated
+ * @bits: number of bits in each of these bitmaps
+ *
+ * Set the n-th bit of @dst iff there exists some m such that the
+ * n-th bit of @relmap is set, the m-th bit of @orig is set, and
+ * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
+ * (If you understood the previous sentence the first time your
+ * read it, you're overqualified for your current job.)
+ *
+ * In other words, @orig is mapped onto (surjectively) @dst,
+ * using the map { <n, m> | the n-th bit of @relmap is the
+ * m-th set bit of @relmap }.
+ *
+ * Any set bits in @orig above bit number W, where W is the
+ * weight of (number of set bits in) @relmap are mapped nowhere.
+ * In particular, if for all bits m set in @orig, m >= W, then
+ * @dst will end up empty. In situations where the possibility
+ * of such an empty result is not desired, one way to avoid it is
+ * to use the bitmap_fold() operator, below, to first fold the
+ * @orig bitmap over itself so that all its set bits x are in the
+ * range 0 <= x < W. The bitmap_fold() operator does this by
+ * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
+ *
+ * Example [1] for bitmap_onto():
+ * Let's say @relmap has bits 30-39 set, and @orig has bits
+ * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
+ * @dst will have bits 31, 33, 35, 37 and 39 set.
+ *
+ * When bit 0 is set in @orig, it means turn on the bit in
+ * @dst corresponding to whatever is the first bit (if any)
+ * that is turned on in @relmap. Since bit 0 was off in the
+ * above example, we leave off that bit (bit 30) in @dst.
+ *
+ * When bit 1 is set in @orig (as in the above example), it
+ * means turn on the bit in @dst corresponding to whatever
+ * is the second bit that is turned on in @relmap. The second
+ * bit in @relmap that was turned on in the above example was
+ * bit 31, so we turned on bit 31 in @dst.
+ *
+ * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
+ * because they were the 4th, 6th, 8th and 10th set bits
+ * set in @relmap, and the 4th, 6th, 8th and 10th bits of
+ * @orig (i.e. bits 3, 5, 7 and 9) were also set.
+ *
+ * When bit 11 is set in @orig, it means turn on the bit in
+ * @dst corresponding to whatever is the twelfth bit that is
+ * turned on in @relmap. In the above example, there were
+ * only ten bits turned on in @relmap (30..39), so that bit
+ * 11 was set in @orig had no affect on @dst.
+ *
+ * Example [2] for bitmap_fold() + bitmap_onto():
+ * Let's say @relmap has these ten bits set::
+ *
+ * 40 41 42 43 45 48 53 61 74 95
+ *
+ * (for the curious, that's 40 plus the first ten terms of the
+ * Fibonacci sequence.)
+ *
+ * Further lets say we use the following code, invoking
+ * bitmap_fold() then bitmap_onto, as suggested above to
+ * avoid the possibility of an empty @dst result::
+ *
+ * unsigned long *tmp; // a temporary bitmap's bits
+ *
+ * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
+ * bitmap_onto(dst, tmp, relmap, bits);
+ *
+ * Then this table shows what various values of @dst would be, for
+ * various @orig's. I list the zero-based positions of each set bit.
+ * The tmp column shows the intermediate result, as computed by
+ * using bitmap_fold() to fold the @orig bitmap modulo ten
+ * (the weight of @relmap):
+ *
+ * =============== ============== =================
+ * @orig tmp @dst
+ * 0 0 40
+ * 1 1 41
+ * 9 9 95
+ * 10 0 40 [#f1]_
+ * 1 3 5 7 1 3 5 7 41 43 48 61
+ * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
+ * 0 9 18 27 0 9 8 7 40 61 74 95
+ * 0 10 20 30 0 40
+ * 0 11 22 33 0 1 2 3 40 41 42 43
+ * 0 12 24 36 0 2 4 6 40 42 45 53
+ * 78 102 211 1 2 8 41 42 74 [#f1]_
+ * =============== ============== =================
+ *
+ * .. [#f1]
+ *
+ * For these marked lines, if we hadn't first done bitmap_fold()
+ * into tmp, then the @dst result would have been empty.
+ *
+ * If either of @orig or @relmap is empty (no set bits), then @dst
+ * will be returned empty.
+ *
+ * If (as explained above) the only set bits in @orig are in positions
+ * m where m >= W, (where W is the weight of @relmap) then @dst will
+ * once again be returned empty.
+ *
+ * All bits in @dst not set by the above rule are cleared.
+ */
+void bitmap_onto(unsigned long *dst, const unsigned long *orig,
+ const unsigned long *relmap, unsigned int bits)
+{
+ unsigned int n, m; /* same meaning as in above comment */
+
+ if (dst == orig) /* following doesn't handle inplace mappings */
+ return;
+ bitmap_zero(dst, bits);
+
+ /*
+ * The following code is a more efficient, but less
+ * obvious, equivalent to the loop:
+ * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
+ * n = bitmap_ord_to_pos(orig, m, bits);
+ * if (test_bit(m, orig))
+ * set_bit(n, dst);
+ * }
+ */
+
+ m = 0;
+ for_each_set_bit(n, relmap, bits) {
+ /* m == bitmap_pos_to_ord(relmap, n, bits) */
+ if (test_bit(m, orig))
+ set_bit(n, dst);
+ m++;
+ }
+}
+EXPORT_SYMBOL(bitmap_onto);
+
+/**
+ * bitmap_fold - fold larger bitmap into smaller, modulo specified size
+ * @dst: resulting smaller bitmap
+ * @orig: original larger bitmap
+ * @sz: specified size
+ * @nbits: number of bits in each of these bitmaps
+ *
+ * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
+ * Clear all other bits in @dst. See further the comment and
+ * Example [2] for bitmap_onto() for why and how to use this.
+ */
+void bitmap_fold(unsigned long *dst, const unsigned long *orig,
+ unsigned int sz, unsigned int nbits)
+{
+ unsigned int oldbit;
+
+ if (dst == orig) /* following doesn't handle inplace mappings */
+ return;
+ bitmap_zero(dst, nbits);
+
+ for_each_set_bit(oldbit, orig, nbits)
+ set_bit(oldbit % sz, dst);
+}
+EXPORT_SYMBOL(bitmap_fold);
+
+/*
+ * Common code for bitmap_*_region() routines.
+ * bitmap: array of unsigned longs corresponding to the bitmap
+ * pos: the beginning of the region
+ * order: region size (log base 2 of number of bits)
+ * reg_op: operation(s) to perform on that region of bitmap
+ *
+ * Can set, verify and/or release a region of bits in a bitmap,
+ * depending on which combination of REG_OP_* flag bits is set.
+ *
+ * A region of a bitmap is a sequence of bits in the bitmap, of
+ * some size '1 << order' (a power of two), aligned to that same
+ * '1 << order' power of two.
+ *
+ * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
+ * Returns 0 in all other cases and reg_ops.
+ */
+
+enum {
+ REG_OP_ISFREE, /* true if region is all zero bits */
+ REG_OP_ALLOC, /* set all bits in region */
+ REG_OP_RELEASE, /* clear all bits in region */
+};
+
+static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
+{
+ int nbits_reg; /* number of bits in region */
+ int index; /* index first long of region in bitmap */
+ int offset; /* bit offset region in bitmap[index] */
+ int nlongs_reg; /* num longs spanned by region in bitmap */
+ int nbitsinlong; /* num bits of region in each spanned long */
+ unsigned long mask; /* bitmask for one long of region */
+ int i; /* scans bitmap by longs */
+ int ret = 0; /* return value */
+
+ /*
+ * Either nlongs_reg == 1 (for small orders that fit in one long)
+ * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
+ */
+ nbits_reg = 1 << order;
+ index = pos / BITS_PER_LONG;
+ offset = pos - (index * BITS_PER_LONG);
+ nlongs_reg = BITS_TO_LONGS(nbits_reg);
+ nbitsinlong = min(nbits_reg, BITS_PER_LONG);
+
+ /*
+ * Can't do "mask = (1UL << nbitsinlong) - 1", as that
+ * overflows if nbitsinlong == BITS_PER_LONG.
+ */
+ mask = (1UL << (nbitsinlong - 1));
+ mask += mask - 1;
+ mask <<= offset;
+
+ switch (reg_op) {
+ case REG_OP_ISFREE:
+ for (i = 0; i < nlongs_reg; i++) {
+ if (bitmap[index + i] & mask)
+ goto done;
+ }
+ ret = 1; /* all bits in region free (zero) */
+ break;
+
+ case REG_OP_ALLOC:
+ for (i = 0; i < nlongs_reg; i++)
+ bitmap[index + i] |= mask;
+ break;
+
+ case REG_OP_RELEASE:
+ for (i = 0; i < nlongs_reg; i++)
+ bitmap[index + i] &= ~mask;
+ break;
+ }
+done:
+ return ret;
+}
+
+/**
+ * bitmap_find_free_region - find a contiguous aligned mem region
+ * @bitmap: array of unsigned longs corresponding to the bitmap
+ * @bits: number of bits in the bitmap
+ * @order: region size (log base 2 of number of bits) to find
+ *
+ * Find a region of free (zero) bits in a @bitmap of @bits bits and
+ * allocate them (set them to one). Only consider regions of length
+ * a power (@order) of two, aligned to that power of two, which
+ * makes the search algorithm much faster.
+ *
+ * Return the bit offset in bitmap of the allocated region,
+ * or -errno on failure.
+ */
+int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
+{
+ unsigned int pos, end; /* scans bitmap by regions of size order */
+
+ for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
+ if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
+ continue;
+ __reg_op(bitmap, pos, order, REG_OP_ALLOC);
+ return pos;
+ }
+ return -ENOMEM;
+}
+EXPORT_SYMBOL(bitmap_find_free_region);
+
+/**
+ * bitmap_release_region - release allocated bitmap region
+ * @bitmap: array of unsigned longs corresponding to the bitmap
+ * @pos: beginning of bit region to release
+ * @order: region size (log base 2 of number of bits) to release
+ *
+ * This is the complement to __bitmap_find_free_region() and releases
+ * the found region (by clearing it in the bitmap).
+ *
+ * No return value.
+ */
+void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
+{
+ __reg_op(bitmap, pos, order, REG_OP_RELEASE);
+}
+EXPORT_SYMBOL(bitmap_release_region);
+
+/**
+ * bitmap_allocate_region - allocate bitmap region
+ * @bitmap: array of unsigned longs corresponding to the bitmap
+ * @pos: beginning of bit region to allocate
+ * @order: region size (log base 2 of number of bits) to allocate
+ *
+ * Allocate (set bits in) a specified region of a bitmap.
+ *
+ * Return 0 on success, or %-EBUSY if specified region wasn't
+ * free (not all bits were zero).
+ */
+int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
+{
+ if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
+ return -EBUSY;
+ return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
+}
+EXPORT_SYMBOL(bitmap_allocate_region);
+
+/**
+ * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
+ * @dst: destination buffer
+ * @src: bitmap to copy
+ * @nbits: number of bits in the bitmap
+ *
+ * Require nbits % BITS_PER_LONG == 0.
+ */
+#ifdef __BIG_ENDIAN
+void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
+{
+ unsigned int i;
+
+ for (i = 0; i < nbits/BITS_PER_LONG; i++) {
+ if (BITS_PER_LONG == 64)
+ dst[i] = cpu_to_le64(src[i]);
+ else
+ dst[i] = cpu_to_le32(src[i]);
+ }
+}
+EXPORT_SYMBOL(bitmap_copy_le);
+#endif
+
+unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
+{
+ return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
+ flags);
+}
+EXPORT_SYMBOL(bitmap_alloc);
+
+unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
+{
+ return bitmap_alloc(nbits, flags | __GFP_ZERO);
+}
+EXPORT_SYMBOL(bitmap_zalloc);
+
+void bitmap_free(const unsigned long *bitmap)
+{
+ kfree(bitmap);
+}
+EXPORT_SYMBOL(bitmap_free);
+
+#if BITS_PER_LONG == 64
+/**
+ * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
+ * @bitmap: array of unsigned longs, the destination bitmap
+ * @buf: array of u32 (in host byte order), the source bitmap
+ * @nbits: number of bits in @bitmap
+ */
+void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
+{
+ unsigned int i, halfwords;
+
+ halfwords = DIV_ROUND_UP(nbits, 32);
+ for (i = 0; i < halfwords; i++) {
+ bitmap[i/2] = (unsigned long) buf[i];
+ if (++i < halfwords)
+ bitmap[i/2] |= ((unsigned long) buf[i]) << 32;
+ }
+
+ /* Clear tail bits in last word beyond nbits. */
+ if (nbits % BITS_PER_LONG)
+ bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
+}
+EXPORT_SYMBOL(bitmap_from_arr32);
+
+/**
+ * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits
+ * @buf: array of u32 (in host byte order), the dest bitmap
+ * @bitmap: array of unsigned longs, the source bitmap
+ * @nbits: number of bits in @bitmap
+ */
+void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
+{
+ unsigned int i, halfwords;
+
+ halfwords = DIV_ROUND_UP(nbits, 32);
+ for (i = 0; i < halfwords; i++) {
+ buf[i] = (u32) (bitmap[i/2] & UINT_MAX);
+ if (++i < halfwords)
+ buf[i] = (u32) (bitmap[i/2] >> 32);
+ }
+
+ /* Clear tail bits in last element of array beyond nbits. */
+ if (nbits % BITS_PER_LONG)
+ buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
+}
+EXPORT_SYMBOL(bitmap_to_arr32);
+
+#endif