Commit db85eaeb authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390/bitops: fix comment 



Fix some numbers in the comments describing the layout of the bit maps.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent deedabb2

arch/s390/include/asm/bitops.h

+4 −4
Original line number Diff line number Diff line
@@ -13,9 +13,9 @@ 
 *

 * The bitop functions are defined to work on unsigned longs, so for an

 * s390x system the bits end up numbered:

 *   |63..............0|127............64|191...........128|255...........196|

 *   |63..............0|127............64|191...........128|255...........192|

 * and on s390:

 *   |31.....0|63....31|95....64|127...96|159..128|191..160|223..192|255..224|

 *   |31.....0|63....32|95....64|127...96|159..128|191..160|223..192|255..224|

 *

 * There are a few little-endian macros used mostly for filesystem

 * bitmaps, these work on similar bit arrays layouts, but
@@ -30,7 +30,7 @@ 
 * on an s390x system the bits are numbered:

 *   |0..............63|64............127|128...........191|192...........255|

 * and on s390:

 *   |0.....31|31....63|64....95|96...127|128..159|160..191|192..223|224..255|

 *   |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255|

 *

 * The main difference is that bit 0-63 (64b) or 0-31 (32b) in the bit

 * number field needs to be reversed compared to the LSB0 encoded bit
@@ -304,7 +304,7 @@ static inline int test_bit(unsigned long nr, const volatile unsigned long *ptr) 
 * On an s390x system the bits are numbered:

 *   |0..............63|64............127|128...........191|192...........255|

 * and on s390:

 *   |0.....31|31....63|64....95|96...127|128..159|160..191|192..223|224..255|

 *   |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255|

 */

unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);

unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,

arch/s390/lib/find.c

+1 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
 * On s390x the bits are numbered:

 *   |0..............63|64............127|128...........191|192...........255|

 * and on s390:

 *   |0.....31|31....63|64....95|96...127|128..159|160..191|192..223|224..255|

 *   |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255|

 *

 * The reason for this bit numbering is the fact that the hardware sets bits

 * in a bitmap starting at bit 0 (MSB) and we don't want to scan the bitmap