Messages in this thread Patch in this message | | | From | Barry Song <> | Subject | [PATCH v4 1/4] lib: bitmap: introduce bitmap_print_to_buf | Date | Thu, 17 Jun 2021 22:19:07 +1200 |
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From: Tian Tao <tiantao6@hisilicon.com>
New API bitmap_print_to_buf() with bin_attribute to avoid maskp exceeding PAGE_SIZE. bitmap_print_to_pagebuf() is a special case of bitmap_print_to_buf(), so in bitmap_print_to_pagebuf() call bitmap_print_to_buf().
Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stefano Brivio <sbrivio@redhat.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: "Ma, Jianpeng" <jianpeng.ma@intel.com> Cc: Yury Norov <yury.norov@gmail.com> Cc: Valentin Schneider <valentin.schneider@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> --- include/linux/bitmap.h | 2 ++ include/linux/cpumask.h | 21 +++++++++++++++++++++ lib/bitmap.c | 37 +++++++++++++++++++++++++++++++++++-- 3 files changed, 58 insertions(+), 2 deletions(-)
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index a36cfcec4e77..0de6effa2797 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -226,6 +226,8 @@ void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int n unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits); int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits); +int bitmap_print_to_buf(bool list, 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/include/linux/cpumask.h b/include/linux/cpumask.h index bfc4690de4f4..1bef69e4b950 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -983,6 +983,27 @@ cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) nr_cpu_ids); } +/** + * cpumap_print_to_buf - copies the cpumask into the buffer either + * as comma-separated list of cpus or hex values of cpumask + * @list: indicates whether the cpumap must be list + * @mask: the cpumask to copy + * @buf: the buffer to copy into + * @off: in the string from which we are copying, We copy to @buf + off + * @count: the maximum number of bytes to print + * + * The role of cpumap_print_to_buf() and cpumap_print_to_pagebuf() is + * the same, the difference is that buf of bitmap_print_to_buf() + * can be more than one pagesize. + */ +static inline ssize_t +cpumap_print_to_buf(bool list, char *buf, const struct cpumask *mask, + loff_t off, size_t count) +{ + return bitmap_print_to_buf(list, buf, cpumask_bits(mask), + nr_cpu_ids, off, count); +} + #if NR_CPUS <= BITS_PER_LONG #define CPU_MASK_ALL \ (cpumask_t) { { \ diff --git a/lib/bitmap.c b/lib/bitmap.c index 74ceb02f45e3..ed7ef6e2edca 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -461,6 +461,40 @@ int bitmap_parse_user(const char __user *ubuf, } EXPORT_SYMBOL(bitmap_parse_user); +/** + * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string + * @list: indicates whether the bitmap must be list + * @buf: the kernel space buffer to read to + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * @off: offset in data buffer below + * @count: the maximum number of bytes to print + * + * The role of bitmap_print_to_buf() and bitmap_print_to_pagebuf() is + * the same, the difference is that buf of bitmap_print_to_buf() + * can be more than one pagesize. + */ +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; + + if (off == LLONG_MAX && count == PAGE_SIZE - offset_in_page(buf)) + return scnprintf(buf, count, fmt, nmaskbits, maskp); + + 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; +} +EXPORT_SYMBOL(bitmap_print_to_buf); + /** * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string * @list: indicates whether the bitmap must be list @@ -482,8 +516,7 @@ int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, { 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); + return bitmap_print_to_buf(list, buf, maskp, nmaskbits, LLONG_MAX, len); } EXPORT_SYMBOL(bitmap_print_to_pagebuf); -- 2.25.1
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