diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/bitmap.c | 680 |
1 files changed, 2 insertions, 678 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c index ddb31015e3..09522af227 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -6,21 +6,10 @@ #include <linux/bitmap.h> #include <linux/bitops.h> -#include <linux/bug.h> #include <linux/ctype.h> #include <linux/device.h> -#include <linux/errno.h> #include <linux/export.h> -#include <linux/kernel.h> -#include <linux/mm.h> #include <linux/slab.h> -#include <linux/string.h> -#include <linux/thread_info.h> -#include <linux/uaccess.h> - -#include <asm/page.h> - -#include "kstrtox.h" /** * DOC: bitmap introduction @@ -440,508 +429,6 @@ again: } 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); - -/** - * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string - * @list: indicates whether the bitmap must be list - * true: print in decimal list format - * false: print in hexadecimal bitmask format - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - */ -static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - const char *fmt = list ? "%*pbl\n" : "%*pb\n"; - ssize_t size; - void *data; - - data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp); - if (!data) - return -ENOMEM; - - size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1); - kfree(data); - - return size; -} - -/** - * bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - * - * The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper - * cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal - * bitmask and decimal list to userspace by sysfs ABI. - * Drivers might be using a normal attribute for this kind of ABIs. A - * normal attribute typically has show entry as below:: - * - * static ssize_t example_attribute_show(struct device *dev, - * struct device_attribute *attr, char *buf) - * { - * ... - * return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max); - * } - * - * show entry of attribute has no offset and count parameters and this - * means the file is limited to one page only. - * bitmap_print_to_pagebuf() API works terribly well for this kind of - * normal attribute with buf parameter and without offset, count:: - * - * bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, - * int nmaskbits) - * { - * } - * - * The problem is once we have a large bitmap, we have a chance to get a - * bitmask or list more than one page. Especially for list, it could be - * as complex as 0,3,5,7,9,... We have no simple way to know it exact size. - * It turns out bin_attribute is a way to break this limit. bin_attribute - * has show entry as below:: - * - * static ssize_t - * example_bin_attribute_show(struct file *filp, struct kobject *kobj, - * struct bin_attribute *attr, char *buf, - * loff_t offset, size_t count) - * { - * ... - * } - * - * With the new offset and count parameters, this makes sysfs ABI be able - * to support file size more than one page. For example, offset could be - * >= 4096. - * bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their - * cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf() - * make those drivers be able to support large bitmask and list after they - * move to use bin_attribute. In result, we have to pass the corresponding - * parameters such as off, count from bin_attribute show entry to this API. - * - * The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf() - * is similar with cpumap_print_to_pagebuf(), the difference is that - * bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption - * the destination buffer is exactly one page and won't be more than one page. - * cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other - * hand, mainly serves bin_attribute which doesn't work with exact one page, - * and it can break the size limit of converted decimal list and hexadecimal - * bitmask. - * - * WARNING! - * - * This function is not a replacement for sprintf() or bitmap_print_to_pagebuf(). - * It is intended to workaround sysfs limitations discussed above and should be - * used carefully in general case for the following reasons: - * - * - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf(). - * - Memory complexity is O(nbits), comparing to O(1) for snprintf(). - * - @off and @count are NOT offset and number of bits to print. - * - If printing part of bitmap as list, the resulting string is not a correct - * list representation of bitmap. Particularly, some bits within or out of - * related interval may be erroneously set or unset. The format of the string - * may be broken, so bitmap_parselist-like parser may fail parsing it. - * - If printing the whole bitmap as list by parts, user must ensure the order - * of calls of the function such that the offset is incremented linearly. - * - If printing the whole bitmap as list by parts, user must keep bitmap - * unchanged between the very first and very last call. Otherwise concatenated - * result may be incorrect, and format may be broken. - * - * Returns the number of characters actually printed to @buf - */ -int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count); -} -EXPORT_SYMBOL(bitmap_print_bitmask_to_buf); - -/** - * bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - * - * Everything is same with the above bitmap_print_bitmask_to_buf() except - * the print format. - */ -int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count); -} -EXPORT_SYMBOL(bitmap_print_list_to_buf); - -/* - * Region 9-38:4/10 describes the following bitmap structure: - * 0 9 12 18 38 N - * .........****......****......****.................. - * ^ ^ ^ ^ ^ - * start off group_len end nbits - */ -struct region { - unsigned int start; - unsigned int off; - unsigned int group_len; - unsigned int end; - unsigned int nbits; -}; - -static void bitmap_set_region(const struct region *r, unsigned long *bitmap) -{ - unsigned int start; - - for (start = r->start; start <= r->end; start += r->group_len) - bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); -} - -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; - - if (r->end >= r->nbits) - return -ERANGE; - - return 0; -} - -static const char *bitmap_getnum(const char *str, unsigned int *num, - unsigned int lastbit) -{ - unsigned long long n; - unsigned int len; - - if (str[0] == 'N') { - *num = lastbit; - return str + 1; - } - - 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 whitespaces 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) -{ - unsigned int lastbit = r->nbits - 1; - - if (!strncasecmp(str, "all", 3)) { - r->start = 0; - r->end = lastbit; - str += 3; - - goto check_pattern; - } - - str = bitmap_getnum(str, &r->start, lastbit); - 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, lastbit); - if (IS_ERR(str)) - return str; - -check_pattern: - if (end_of_region(*str)) - goto no_pattern; - - if (*str != ':') - return ERR_PTR(-EINVAL); - - str = bitmap_getnum(str + 1, &r->off, lastbit); - if (IS_ERR(str)) - return str; - - if (*str != '/') - return ERR_PTR(-EINVAL); - - return bitmap_getnum(str + 1, &r->group_len, lastbit); - -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 - * The value 'N' can be used as a dynamically substituted token for the - * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is - * dynamic, so if system changes cause the bitmap width to change, such - * as more cores in a CPU list, then any ranges using N will also change. - * - * 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; - - r.nbits = nmaskbits; - bitmap_zero(maskp, r.nbits); - - 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; - - bitmap_set_region(&r, maskp); - } - - return 0; -} -EXPORT_SYMBOL(bitmap_parselist); - - -/** - * bitmap_parselist_user() - convert user buffer's list format ASCII - * string to 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_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; - int chunk; - - for (chunk = 0; ; chunk++) { - end = bitmap_find_region_reverse(start, end); - if (start > end) - break; - - if (!chunks--) - return -EOVERFLOW; - -#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) - end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); -#else - end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); -#endif - 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); - /** * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap * @buf: pointer to a bitmap @@ -988,7 +475,7 @@ static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigne * to @dst. * * The positions of unset bits in @old are mapped to themselves - * (the identify map). + * (the identity map). * * Apply the above specified mapping to @src, placing the result in * @dst, clearing any bits previously set in @dst. @@ -1037,7 +524,7 @@ EXPORT_SYMBOL(bitmap_remap); * 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). + * (the identity map). * * Apply the above specified mapping to bit position @oldbit, returning * the new bit position. @@ -1220,169 +707,6 @@ void bitmap_fold(unsigned long *dst, const unsigned long *orig, } #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), |