diff options
| author | Thierry Reding <treding@nvidia.com> | 2026-04-30 11:07:26 +0200 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2026-04-30 11:07:26 +0200 |
| commit | e6759d98b66fd098b9d9bbf97d7939d6cabd7235 (patch) | |
| tree | c7b5355b9a57d9bfc201edcdbedeb92c0b4607aa | |
| parent | 146cd2e2687ff8d2ea5ee4a14891e1a5ec67ffd5 (diff) | |
| download | linux-next-e6759d98b66fd098b9d9bbf97d7939d6cabd7235.tar.gz | |
Revert "bitmap: drop bitmap_print_to_pagebuf()"
This reverts commit af327141d0dd8037540e7fce8215fec40fb50e88.
| -rw-r--r-- | include/linux/bitmap-str.h | 1 | ||||
| -rw-r--r-- | lib/bitmap-str.c | 42 |
2 files changed, 38 insertions, 5 deletions
diff --git a/include/linux/bitmap-str.h b/include/linux/bitmap-str.h index abe7a69a846fe..53d3e1b32d3d4 100644 --- a/include/linux/bitmap-str.h +++ b/include/linux/bitmap-str.h @@ -5,6 +5,7 @@ #include <linux/types.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); int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, int nmaskbits, loff_t off, size_t count); int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, int nmaskbits, diff --git a/lib/bitmap-str.c b/lib/bitmap-str.c index 2a4d780cdc467..be745209507a4 100644 --- a/lib/bitmap-str.c +++ b/lib/bitmap-str.c @@ -40,6 +40,32 @@ int bitmap_parse_user(const char __user *ubuf, 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 @@ -75,7 +101,7 @@ static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, * @off: in the string from which we are copying, We copy to @buf * @count: the maximum number of bytes to print * - * The sprintf("%*pbl") is used indirectly via its cpumap wrapper + * 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 @@ -85,11 +111,18 @@ static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, * struct device_attribute *attr, char *buf) * { * ... - * return scnprintf(buf, PAGE_SIZE - offest_in_page(buf), nr_trig_max, &mask); + * 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 @@ -116,7 +149,7 @@ static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, * * 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 - * scnprintf("%*pb[l]") mainly serves sysfs attribute with the assumption + * 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, @@ -125,8 +158,7 @@ static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, * * WARNING! * - * This function is not a replacement for sprintf(). - * + * 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: * |