diff options
author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2015-10-08 07:51:44 -0400 |
---|---|---|
committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-10-14 08:32:15 -0400 |
commit | 48002bd5af37c3f6ac4a1484427ac52f7f184950 (patch) | |
tree | 3923e6c81dbee73803fce5319e48186e94ef2003 | |
parent | e4165dcbc087eaf0fa892c6eee7fce8ac0482742 (diff) |
s390/bitops: remove 31 bit related comments
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r-- | arch/s390/include/asm/bitops.h | 31 | ||||
-rw-r--r-- | arch/s390/lib/find.c | 4 |
2 files changed, 13 insertions, 22 deletions
diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h index 47bd0878a006..8043f10da6b5 100644 --- a/arch/s390/include/asm/bitops.h +++ b/arch/s390/include/asm/bitops.h | |||
@@ -11,30 +11,25 @@ | |||
11 | * big-endian system because, unlike little endian, the number of each | 11 | * big-endian system because, unlike little endian, the number of each |
12 | * bit depends on the word size. | 12 | * bit depends on the word size. |
13 | * | 13 | * |
14 | * The bitop functions are defined to work on unsigned longs, so for an | 14 | * The bitop functions are defined to work on unsigned longs, so the bits |
15 | * s390x system the bits end up numbered: | 15 | * end up numbered: |
16 | * |63..............0|127............64|191...........128|255...........192| | 16 | * |63..............0|127............64|191...........128|255...........192| |
17 | * and on s390: | ||
18 | * |31.....0|63....32|95....64|127...96|159..128|191..160|223..192|255..224| | ||
19 | * | 17 | * |
20 | * There are a few little-endian macros used mostly for filesystem | 18 | * There are a few little-endian macros used mostly for filesystem |
21 | * bitmaps, these work on similar bit arrays layouts, but | 19 | * bitmaps, these work on similar bit array layouts, but byte-oriented: |
22 | * byte-oriented: | ||
23 | * |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56| | 20 | * |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56| |
24 | * | 21 | * |
25 | * The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit | 22 | * The main difference is that bit 3-5 in the bit number field needs to be |
26 | * number field needs to be reversed compared to the big-endian bit | 23 | * reversed compared to the big-endian bit fields. This can be achieved by |
27 | * fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b). | 24 | * XOR with 0x38. |
28 | * | 25 | * |
29 | * We also have special functions which work with an MSB0 encoding: | 26 | * We also have special functions which work with an MSB0 encoding. |
30 | * on an s390x system the bits are numbered: | 27 | * The bits are numbered: |
31 | * |0..............63|64............127|128...........191|192...........255| | 28 | * |0..............63|64............127|128...........191|192...........255| |
32 | * and on s390: | ||
33 | * |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255| | ||
34 | * | 29 | * |
35 | * The main difference is that bit 0-63 (64b) or 0-31 (32b) in the bit | 30 | * The main difference is that bit 0-63 in the bit number field needs to be |
36 | * number field needs to be reversed compared to the LSB0 encoded bit | 31 | * reversed compared to the LSB0 encoded bit fields. This can be achieved by |
37 | * fields. This can be achieved by XOR with 0x3f (64b) or 0x1f (32b). | 32 | * XOR with 0x3f. |
38 | * | 33 | * |
39 | */ | 34 | */ |
40 | 35 | ||
@@ -299,10 +294,8 @@ static inline void __clear_bit_unlock(unsigned long nr, | |||
299 | 294 | ||
300 | /* | 295 | /* |
301 | * Functions which use MSB0 bit numbering. | 296 | * Functions which use MSB0 bit numbering. |
302 | * On an s390x system the bits are numbered: | 297 | * The bits are numbered: |
303 | * |0..............63|64............127|128...........191|192...........255| | 298 | * |0..............63|64............127|128...........191|192...........255| |
304 | * and on s390: | ||
305 | * |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255| | ||
306 | */ | 299 | */ |
307 | unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size); | 300 | unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size); |
308 | unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size, | 301 | unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size, |
diff --git a/arch/s390/lib/find.c b/arch/s390/lib/find.c index 922003c1b90d..d90b9245ea41 100644 --- a/arch/s390/lib/find.c +++ b/arch/s390/lib/find.c | |||
@@ -1,10 +1,8 @@ | |||
1 | /* | 1 | /* |
2 | * MSB0 numbered special bitops handling. | 2 | * MSB0 numbered special bitops handling. |
3 | * | 3 | * |
4 | * On s390x the bits are numbered: | 4 | * The bits are numbered: |
5 | * |0..............63|64............127|128...........191|192...........255| | 5 | * |0..............63|64............127|128...........191|192...........255| |
6 | * and on s390: | ||
7 | * |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255| | ||
8 | * | 6 | * |
9 | * The reason for this bit numbering is the fact that the hardware sets bits | 7 | * The reason for this bit numbering is the fact that the hardware sets bits |
10 | * in a bitmap starting at bit 0 (MSB) and we don't want to scan the bitmap | 8 | * in a bitmap starting at bit 0 (MSB) and we don't want to scan the bitmap |