documentation: kernel-api: add more info on bitmap functions

There are some good comments about bitmap operations in lib/bitmap.c
and include/linux/bitmap.h, so format them for document generation and
pull them into core-api/kernel-api.rst.

I converted the "tables" of functions from using tabs to using spaces
so that they are more readable in the source file and in the generated
output.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Randy Dunlap 2017-10-16 16:32:51 -07:00 committed by Jonathan Corbet
parent 718d50ec78
commit 7d7363e403
3 changed files with 74 additions and 51 deletions

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@ -53,6 +53,18 @@ The Linux kernel provides more basic utility functions.
Bitmap Operations
-----------------
.. kernel-doc:: lib/bitmap.c
:doc: bitmap introduction
.. kernel-doc:: include/linux/bitmap.h
:doc: declare bitmap
.. kernel-doc:: include/linux/bitmap.h
:doc: bitmap overview
.. kernel-doc:: include/linux/bitmap.h
:doc: bitmap bitops
.. kernel-doc:: lib/bitmap.c
:export:

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@ -21,13 +21,17 @@
* See lib/bitmap.c for more details.
*/
/*
/**
* DOC: bitmap overview
*
* The available bitmap operations and their rough meaning in the
* case that the bitmap is a single unsigned long are thus:
*
* Note that nbits should be always a compile time evaluable constant.
* Otherwise many inlines will generate horrible code.
*
* ::
*
* bitmap_zero(dst, nbits) *dst = 0UL
* bitmap_fill(dst, nbits) *dst = ~0UL
* bitmap_copy(dst, src, nbits) *dst = *src
@ -61,10 +65,13 @@
* bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
* bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words)
* bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words)
*
*/
/*
* Also the following operations in asm/bitops.h apply to bitmaps.
/**
* DOC: bitmap bitops
*
* Also the following operations in asm/bitops.h apply to bitmaps.::
*
* set_bit(bit, addr) *addr |= bit
* clear_bit(bit, addr) *addr &= ~bit
@ -77,9 +84,11 @@
* find_first_bit(addr, nbits) Position first set bit in *addr
* find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
* find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
*
*/
/*
/**
* DOC: declare bitmap
* The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
* to declare an array named 'name' of just enough unsigned longs to
* contain all bit positions from 0 to 'bits' - 1.

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@ -18,7 +18,9 @@
#include <asm/page.h>
/*
/**
* DOC: bitmap introduction
*
* bitmaps provide an array of bits, implemented using an an
* array of unsigned longs. The number of valid bits in a
* given bitmap does _not_ need to be an exact multiple of