From 7733aa893847f021c674d0d30b723d892109369d Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 17 Aug 2023 19:20:54 +0300 Subject: bitmap: Remove dead code, i.e. bitmap_copy_le() Besides the fact it's not used anywhere it should be implemented differently, i.e. via helpers from linux/byteorder/generic.h. Yet the helpers themselves need to be introduced first. Also note, the function lacks of the test cases, they must be provided. Hence, drop the current dead code for good. Signed-off-by: Andy Shevchenko Signed-off-by: Yury Norov --- include/linux/bitmap.h | 5 ----- 1 file changed, 5 deletions(-) (limited to 'include/linux/bitmap.h') diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 03644237e1ef..1516ff979315 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -220,11 +220,6 @@ int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); -#ifdef __BIG_ENDIAN -void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); -#else -#define bitmap_copy_le bitmap_copy -#endif int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits); -- cgit From aae06fc1b5a2e4b52f8504a1f12f9b8b98e80641 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sat, 7 Oct 2023 16:35:10 -0700 Subject: lib/bitmap: split-out string-related operations to a separate files lib/bitmap.c and corresponding include/linux/bitmap.h are intended to hold functions related to operations on bitmaps, like bitmap_shift or bitmap_set. Historically, some string-related operations like bitmap_parse are also reside in lib/bitmap.c. Now that the subsystem evolves, string-related bitmap operations became a significant part of the file. Because they are quite different from the other bitmap functions by nature, it's worth to split them to a separate source/header files. CC: Andrew Morton CC: Andy Shevchenko CC: Rasmus Villemoes Signed-off-by: Yury Norov --- MAINTAINERS | 2 + include/linux/bitmap-str.h | 16 ++ include/linux/bitmap.h | 18 +- lib/Makefile | 2 +- lib/bitmap-str.c | 510 ++++++++++++++++++++++++++++++++++++++++++++ lib/bitmap.c | 512 --------------------------------------------- 6 files changed, 530 insertions(+), 530 deletions(-) create mode 100644 include/linux/bitmap-str.h create mode 100644 lib/bitmap-str.c (limited to 'include/linux/bitmap.h') diff --git a/MAINTAINERS b/MAINTAINERS index 6c4cce45a09d..561def8239f9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3506,12 +3506,14 @@ R: Andy Shevchenko R: Rasmus Villemoes S: Maintained F: include/linux/bitfield.h +F: include/linux/bitmap-str.h F: include/linux/bitmap.h F: include/linux/bits.h F: include/linux/cpumask.h F: include/linux/find.h F: include/linux/nodemask.h F: include/vdso/bits.h +F: lib/bitmap-str.c F: lib/bitmap.c F: lib/cpumask.c F: lib/cpumask_kunit.c diff --git a/include/linux/bitmap-str.h b/include/linux/bitmap-str.h new file mode 100644 index 000000000000..17caeca94cab --- /dev/null +++ b/include/linux/bitmap-str.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_BITMAP_STR_H +#define __LINUX_BITMAP_STR_H + +int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, unsigned long *dst, int nbits); +int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits); +extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count); +extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count); +int bitmap_parse(const char *buf, unsigned int buflen, unsigned long *dst, int nbits); +int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits); +int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, + unsigned long *dst, int nbits); + +#endif /* __LINUX_BITMAP_STR_H */ diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 1516ff979315..1cca950a54ae 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -10,6 +10,7 @@ #include #include #include +#include struct device; @@ -200,14 +201,6 @@ bitmap_find_next_zero_area(unsigned long *map, align_mask, 0); } -int bitmap_parse(const char *buf, unsigned int buflen, - unsigned long *dst, int nbits); -int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, - unsigned long *dst, int nbits); -int bitmap_parselist(const char *buf, unsigned long *maskp, - int nmaskbits); -int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, - unsigned long *dst, int nbits); void bitmap_remap(unsigned long *dst, const unsigned long *src, const unsigned long *old, const unsigned long *new, unsigned int nbits); int bitmap_bitremap(int oldbit, @@ -220,15 +213,6 @@ int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); -int bitmap_print_to_pagebuf(bool list, char *buf, - const unsigned long *maskp, int nmaskbits); - -extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count); - -extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count); - #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) diff --git a/lib/Makefile b/lib/Makefile index 740109b6e2c8..9e8f9f6dd3b2 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -48,7 +48,7 @@ obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \ bsearch.o find_bit.o llist.o memweight.o kfifo.o \ percpu-refcount.o rhashtable.o base64.o \ once.o refcount.o rcuref.o usercopy.o errseq.o bucket_locks.o \ - generic-radix-tree.o + generic-radix-tree.o bitmap-str.o obj-$(CONFIG_STRING_SELFTEST) += test_string.o obj-y += string_helpers.o obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o diff --git a/lib/bitmap-str.c b/lib/bitmap-str.c new file mode 100644 index 000000000000..be745209507a --- /dev/null +++ b/lib/bitmap-str.c @@ -0,0 +1,510 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kstrtox.h" + +/** + * 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); diff --git a/lib/bitmap.c b/lib/bitmap.c index 935e0f96e785..abc5579768e9 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -6,21 +6,11 @@ #include #include -#include #include #include #include #include -#include -#include #include -#include -#include -#include - -#include - -#include "kstrtox.h" /** * DOC: bitmap introduction @@ -440,508 +430,6 @@ 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 -- cgit From 6cb42f91aa6dfd10fd847c469caebe63b35141ff Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:17 -0700 Subject: bitmap: move bitmap_*_region() functions to bitmap.h Now that bitmap_*_region() functions are implemented as thin wrappers around others, it's worth to move them to the header, as it opens room for compile-time optimizations. CC: Andy Shevchenko CC: Rasmus Villemoes CC: Greg Kroah-Hartman Signed-off-by: Yury Norov --- include/linux/bitmap.h | 64 +++++++++++++++++++++++++++++++++++++++++++++++--- lib/bitmap.c | 64 -------------------------------------------------- 2 files changed, 61 insertions(+), 67 deletions(-) (limited to 'include/linux/bitmap.h') diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 1cca950a54ae..99451431e4d6 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -6,6 +6,7 @@ #include #include +#include #include #include #include @@ -209,9 +210,6 @@ void bitmap_onto(unsigned long *dst, const unsigned long *orig, const unsigned long *relmap, unsigned int bits); void bitmap_fold(unsigned long *dst, const unsigned long *orig, unsigned int sz, unsigned int nbits); -int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); -void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); -int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) @@ -497,6 +495,66 @@ static inline void bitmap_next_set_region(unsigned long *bitmap, *re = find_next_zero_bit(bitmap, end, *rs + 1); } +/** + * 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). + */ +static inline void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) +{ + bitmap_clear(bitmap, pos, BIT(order)); +} + +/** + * 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. + * + * Returns: 0 on success, or %-EBUSY if specified region wasn't + * free (not all bits were zero). + */ +static inline int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) +{ + unsigned int len = BIT(order); + + if (find_next_bit(bitmap, pos + len, pos) < pos + len) + return -EBUSY; + bitmap_set(bitmap, pos, len); + return 0; +} + +/** + * 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. + * + * Returns: the bit offset in bitmap of the allocated region, + * or -errno on failure. + */ +static inline 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 + BIT(order)) <= bits; pos = end) { + if (!bitmap_allocate_region(bitmap, pos, order)) + return pos; + } + return -ENOMEM; +} + /** * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. * @n: u64 value diff --git a/lib/bitmap.c b/lib/bitmap.c index 66da8c33fb1b..09522af227f1 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -8,7 +8,6 @@ #include #include #include -#include #include #include @@ -708,69 +707,6 @@ void bitmap_fold(unsigned long *dst, const unsigned long *orig, } #endif /* CONFIG_NUMA */ -/** - * 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 + BIT(order)) <= bits; pos = end) { - if (!bitmap_allocate_region(bitmap, pos, order)) - 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). - */ -void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) -{ - bitmap_clear(bitmap, pos, BIT(order)); -} -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) -{ - unsigned int len = BIT(order); - - if (find_next_bit(bitmap, pos + len, pos) < pos + len) - return -EBUSY; - bitmap_set(bitmap, pos, len); - return 0; -} -EXPORT_SYMBOL(bitmap_allocate_region); - unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) { return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), -- cgit