On Wed, 2 Jun 2021 19:02:48 +0800 Tian Tao <tiantao6@hisilicon.com> wrote:
new API bitmap_print_to_buf with bin_attribute to avoid maskp New API...
Not sure for this particular bit of the kernel, but personally I prefer function names in patch descriptions to have () after them to make it clear that is what they are. Note other people disagree :)
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.
A few comments inline. Mostly editorial, but you also forgot to update your kvfree() to kfree() after moving away from kvmalloc() in this version. Thanks, Jonathan
Signed-off-by: Tian Tao <tiantao6@hisilicon.com> --- include/linux/bitmap.h | 3 +++ include/linux/cpumask.h | 21 +++++++++++++++++++++ lib/bitmap.c | 38 ++++++++++++++++++++++++++++++++++++-- 3 files changed, 60 insertions(+), 2 deletions(-)
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 70a9324..bc401bd9b 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -219,6 +219,9 @@ extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int extern int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits);
+extern int bitmap_print_to_buf(bool list, char *buf, + const unsigned long *maskp, int nmaskbits, loff_t off, size_t count);
Nice to keep this under 80 chars. We can go past that if it hurts readability to keep the line short, but here that isn't the case.
+ #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 383684e..114ed44 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -928,6 +928,27 @@ 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 length that we will copy into
I would use more similar text to below. Nothing stops the buffer being bigger than the copy we ask for after all. "the maximum number of bytes to print"
+ * + * the role of cpumap_print_to_buf and cpumap_print_to_pagebuf is
The...
+ * 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 75006c4..d814b32 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -460,6 +460,40 @@ 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: page which string is placed
No particular reason it should be a page. It's an arbitrary address I think. I would use the text from the memory_read_from_buffer docs. "the kernel space buffer to read to" Whilst here I notice that bitmap_print_to_pagebuf() has @buf: page aligned buffer into which string is places but then uses ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); which seems to suggest that comment for @buf is inaccurate as the buffer does not need to be page aligned.
+ * @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 read + * + * the role of bitmap_print_to_buf and bitmap_print_to_pagebuf is
The... Also, I'm fairly sure kernel-doc referencing will only work if those function names have () after them so please add those.
+ * 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) +{ + int size; + void *data; + const char *fmt = list ? "%*pbl\n" : "%*pb\n"; + + 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)); + kvfree(data);
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 * @buf: page aligned buffer into which string is placed @@ -480,8 +514,8 @@ 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);