| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * lib/bitmap.c |
| * Helper functions for bitmap.h. |
| */ |
| #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/mm.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| #include <linux/uaccess.h> |
| |
| #include <asm/page.h> |
| |
| #include "kstrtox.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. |
| * |
| * 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); |
| |
| bool __bitmap_or_equal(const unsigned long *bitmap1, |
| const unsigned long *bitmap2, |
| const unsigned long *bitmap3, |
| unsigned int bits) |
| { |
| unsigned int k, lim = bits / BITS_PER_LONG; |
| unsigned long tmp; |
| |
| for (k = 0; k < lim; ++k) { |
| if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) |
| return false; |
| } |
| |
| if (!(bits % BITS_PER_LONG)) |
| return true; |
| |
| tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; |
| return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; |
| } |
| |
| 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); |
| |
| /** |
| * bitmap_cut() - remove bit region from bitmap and right shift remaining bits |
| * @dst: destination bitmap, might overlap with src |
| * @src: source bitmap |
| * @first: start bit of region to be removed |
| * @cut: number of bits to remove |
| * @nbits: bitmap size, in bits |
| * |
| * Set the n-th bit of @dst iff the n-th bit of @src is set and |
| * n is less than @first, or the m-th bit of @src is set for any |
| * m such that @first <= n < nbits, and m = n + @cut. |
| * |
| * In pictures, example for a big-endian 32-bit architecture: |
| * |
| * The @src bitmap is:: |
| * |
| * 31 63 |
| * | | |
| * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101 |
| * | | | | |
| * 16 14 0 32 |
| * |
| * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is:: |
| * |
| * 31 63 |
| * | | |
| * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010 |
| * | | | |
| * 14 (bit 17 0 32 |
| * from @src) |
| * |
| * Note that @dst and @src might overlap partially or entirely. |
| * |
| * This is implemented in the obvious way, with a shift and carry |
| * step for each moved bit. Optimisation is left as an exercise |
| * for the compiler. |
| */ |
| void bitmap_cut(unsigned long *dst, const unsigned long *src, |
| unsigned int first, unsigned int cut, unsigned int nbits) |
| { |
| unsigned int len = BITS_TO_LONGS(nbits); |
| unsigned long keep = 0, carry; |
| int i; |
| |
| memmove(dst, src, len * sizeof(*dst)); |
| |
| if (first % BITS_PER_LONG) { |
| keep = src[first / BITS_PER_LONG] & |
| (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG)); |
| } |
| |
| while (cut--) { |
| for (i = first / BITS_PER_LONG; i < len; i++) { |
| if (i < len - 1) |
| carry = dst[i + 1] & 1UL; |
| else |
| carry = 0; |
| |
| dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1)); |
| } |
| } |
| |
| dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG); |
| dst[first / BITS_PER_LONG] |= keep; |
| } |
| EXPORT_SYMBOL(bitmap_cut); |
| |
| 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); |
| |
| void __bitmap_replace(unsigned long *dst, |
| const unsigned long *old, const unsigned long *new, |
| const unsigned long *mask, unsigned int nbits) |
| { |
| unsigned int k; |
| unsigned int nr = BITS_TO_LONGS(nbits); |
| |
| for (k = 0; k < nr; k++) |
| dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]); |
| } |
| EXPORT_SYMBOL(__bitmap_replace); |
| |
| 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. |
| */ |
| |
| /** |
| * 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. |
| */ |
| int bitmap_parse_user(const char __user *ubuf, |
| unsigned int ulen, unsigned long *maskp, |
| int nmaskbits) |
| { |
| char *buf; |
| int ret; |
| |
| buf = memdup_user_nul(ubuf, ulen); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| |
| ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits); |
| |
| kfree(buf); |
| return ret; |
| } |
| 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, page-aligned |
| * area and that sufficient storage remains at @buf to accommodate the |
| * bitmap_print_to_pagebuf() output. Returns the number of characters |
| * actually printed to @buf, excluding terminating '\0'. |
| */ |
| int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, |
| int nmaskbits) |
| { |
| ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); |
| |
| return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : |
| scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); |
| } |
| EXPORT_SYMBOL(bitmap_print_to_pagebuf); |
| |
| /* |
| * Region 9-38:4/10 describes the following bitmap structure: |
| * 0 9 12 18 38 |
| * .........****......****......****...... |
| * ^ ^ ^ ^ |
| * start off group_len end |
| */ |
| struct region { |
| unsigned int start; |
| unsigned int off; |
| unsigned int group_len; |
| unsigned int end; |
| }; |
| |
| static int bitmap_set_region(const struct region *r, |
| unsigned long *bitmap, int nbits) |
| { |
| unsigned int start; |
| |
| if (r->end >= nbits) |
| return -ERANGE; |
| |
| for (start = r->start; start <= r->end; start += r->group_len) |
| bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); |
| |
| return 0; |
| } |
| |
| static int bitmap_check_region(const struct region *r) |
| { |
| if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static const char *bitmap_getnum(const char *str, unsigned int *num) |
| { |
| unsigned long long n; |
| unsigned int len; |
| |
| len = _parse_integer(str, 10, &n); |
| if (!len) |
| return ERR_PTR(-EINVAL); |
| if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) |
| return ERR_PTR(-EOVERFLOW); |
| |
| *num = n; |
| return str + len; |
| } |
| |
| static inline bool end_of_str(char c) |
| { |
| return c == '\0' || c == '\n'; |
| } |
| |
| static inline bool __end_of_region(char c) |
| { |
| return isspace(c) || c == ','; |
| } |
| |
| static inline bool end_of_region(char c) |
| { |
| return __end_of_region(c) || end_of_str(c); |
| } |
| |
| /* |
| * The format allows commas and whitespases at the beginning |
| * of the region. |
| */ |
| static const char *bitmap_find_region(const char *str) |
| { |
| while (__end_of_region(*str)) |
| str++; |
| |
| return end_of_str(*str) ? NULL : str; |
| } |
| |
| static const char *bitmap_find_region_reverse(const char *start, const char *end) |
| { |
| while (start <= end && __end_of_region(*end)) |
| end--; |
| |
| return end; |
| } |
| |
| static const char *bitmap_parse_region(const char *str, struct region *r) |
| { |
| str = bitmap_getnum(str, &r->start); |
| if (IS_ERR(str)) |
| return str; |
| |
| if (end_of_region(*str)) |
| goto no_end; |
| |
| if (*str != '-') |
| return ERR_PTR(-EINVAL); |
| |
| str = bitmap_getnum(str + 1, &r->end); |
| if (IS_ERR(str)) |
| return str; |
| |
| if (end_of_region(*str)) |
| goto no_pattern; |
| |
| if (*str != ':') |
| return ERR_PTR(-EINVAL); |
| |
| str = bitmap_getnum(str + 1, &r->off); |
| if (IS_ERR(str)) |
| return str; |
| |
| if (*str != '/') |
| return ERR_PTR(-EINVAL); |
| |
| return bitmap_getnum(str + 1, &r->group_len); |
| |
| no_end: |
| r->end = r->start; |
| no_pattern: |
| r->off = r->end + 1; |
| r->group_len = r->end + 1; |
| |
| return end_of_str(*str) ? NULL : str; |
| } |
| |
| /** |
| * bitmap_parselist - convert list format ASCII string to bitmap |
| * @buf: read user string from this buffer; must be terminated |
| * with a \0 or \n. |
| * @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``: wrong region format |
| * - ``-EINVAL``: invalid character in string |
| * - ``-ERANGE``: bit number specified too large for mask |
| * - ``-EOVERFLOW``: integer overflow in the input parameters |
| */ |
| int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) |
| { |
| struct region r; |
| long ret; |
| |
| bitmap_zero(maskp, nmaskbits); |
| |
| while (buf) { |
| buf = bitmap_find_region(buf); |
| if (buf == NULL) |
| return 0; |
| |
| buf = bitmap_parse_region(buf, &r); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| |
| ret = bitmap_check_region(&r); |
| if (ret) |
| return ret; |
| |
| ret = bitmap_set_region(&r, maskp, nmaskbits); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |
| 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. |
| */ |
| int bitmap_parselist_user(const char __user *ubuf, |
| unsigned int ulen, unsigned long *maskp, |
| int nmaskbits) |
| { |
| char *buf; |
| int ret; |
| |
| buf = memdup_user_nul(ubuf, ulen); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| |
| ret = bitmap_parselist(buf, maskp, nmaskbits); |
| |
| kfree(buf); |
| return ret; |
| } |
| EXPORT_SYMBOL(bitmap_parselist_user); |
| |
| static const char *bitmap_get_x32_reverse(const char *start, |
| const char *end, u32 *num) |
| { |
| u32 ret = 0; |
| int c, i; |
| |
| for (i = 0; i < 32; i += 4) { |
| c = hex_to_bin(*end--); |
| if (c < 0) |
| return ERR_PTR(-EINVAL); |
| |
| ret |= c << i; |
| |
| if (start > end || __end_of_region(*end)) |
| goto out; |
| } |
| |
| if (hex_to_bin(*end--) >= 0) |
| return ERR_PTR(-EOVERFLOW); |
| out: |
| *num = ret; |
| return end; |
| } |
| |
| /** |
| * bitmap_parse - convert an ASCII hex string into a bitmap. |
| * @start: pointer to buffer containing string. |
| * @buflen: buffer size in bytes. If string is smaller than this |
| * then it must be terminated with a \0 or \n. In that case, |
| * UINT_MAX may be provided instead of string length. |
| * @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. Grouping such as "1,,5", ",44", "," or "" is allowed. |
| * Leading, embedded and trailing whitespace accepted. |
| */ |
| int bitmap_parse(const char *start, unsigned int buflen, |
| unsigned long *maskp, int nmaskbits) |
| { |
| const char *end = strnchrnul(start, buflen, '\n') - 1; |
| int chunks = BITS_TO_U32(nmaskbits); |
| u32 *bitmap = (u32 *)maskp; |
| int unset_bit; |
| |
| while (1) { |
| end = bitmap_find_region_reverse(start, end); |
| if (start > end) |
| break; |
| |
| if (!chunks--) |
| return -EOVERFLOW; |
| |
| end = bitmap_get_x32_reverse(start, end, bitmap++); |
| if (IS_ERR(end)) |
| return PTR_ERR(end); |
| } |
| |
| unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; |
| if (unset_bit < nmaskbits) { |
| bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit); |
| return 0; |
| } |
| |
| if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit) |
| return -EOVERFLOW; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(bitmap_parse); |
| |
| |
| #ifdef CONFIG_NUMA |
| /** |
| * 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); |
| } |
| } |
| |
| /** |
| * 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); |
| } |
| |
| /** |
| * 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++; |
| } |
| } |
| |
| /** |
| * 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); |
| } |
| #endif /* CONFIG_NUMA */ |
| |
| /* |
| * 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 |