Commit 430cd4a2 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab Committed by Yury Norov

lib/bitmap.c make bitmap_print_bitmask_to_buf parseable

The documentation of such function is not on a proper ReST format,
as reported by Sphinx:

    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:532: WARNING: Unexpected indentation.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:526: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:532: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:532: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:533: WARNING: Block quote ends without a blank line; unexpected unindent.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:536: WARNING: Definition list ends without a blank line; unexpected unindent.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:542: WARNING: Unexpected indentation.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:536: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:536: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:543: WARNING: Block quote ends without a blank line; unexpected unindent.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:552: WARNING: Unexpected indentation.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:545: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:545: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:552: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:552: WARNING: Inline emphasis start-string without end-string.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:554: WARNING: Block quote ends without a blank line; unexpected unindent.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:556: WARNING: Definition list ends without a blank line; unexpected unindent.
    Documentation/core-api/kernel-api:81: ./lib/bitmap.c:580: WARNING: Unexpected indentation.

So, the produced output at:

	https://www.kernel.org/doc/html/latest/core-api/kernel-api.html?#c.bitmap_print_bitmask_to_buf

is broken. Fix it by adding spaces and marking the literal blocks.
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
parent c6bc5a3c
......@@ -527,33 +527,39 @@ static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp,
* 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,
* 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,
* 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,
* 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.
......@@ -577,6 +583,7 @@ static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp,
* 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.
......
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