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authorHeiko Carstens <heiko.carstens@de.ibm.com>2013-09-23 12:01:44 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-10-24 17:16:56 +0200
commit7d7c7b24e416afb2637be8447e03ca4457c100fd (patch)
tree3f6df4a49ba2fdaaa01e824d77811777d745cc6d /arch/s390
parentb1cb7e2b6c3e8758e7406422b66c54c066737977 (diff)
downloadlinux-7d7c7b24e416afb2637be8447e03ca4457c100fd.tar.bz2
s390/bitops: rename find_first_bit_left() to find_first_bit_inv()
find_first_bit_left() and friends have nothing to do with the normal LSB0 bit numbering for big endian machines used in Linux (least significant bit has bit number 0). Instead they use MSB0 bit numbering, where the most signficant bit has bit number 0. So rename find_first_bit_left() and friends to find_first_bit_inv(), to avoid any confusion. Also provide inv versions of set_bit, clear_bit and test_bit. This also removes the confusing use of e.g. set_bit() in airq.c which uses a "be_to_le" bit number conversion, which could imply that instead set_bit_le() could be used. But that is entirely wrong since the _le bitops variant uses yet another bit numbering scheme. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/bitops.h39
-rw-r--r--arch/s390/lib/find.c10
2 files changed, 39 insertions, 10 deletions
diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h
index c6dbd6115cc5..6e6ad0680829 100644
--- a/arch/s390/include/asm/bitops.h
+++ b/arch/s390/include/asm/bitops.h
@@ -300,12 +300,41 @@ static inline int test_bit(unsigned long nr, const volatile unsigned long *ptr)
}
/*
- * ATTENTION:
- * find_first_bit_left() and find_next_bit_left() use MSB0 encoding.
+ * Functions which use MSB0 bit numbering.
+ * 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|
*/
-unsigned long find_first_bit_left(const unsigned long *addr, unsigned long size);
-unsigned long find_next_bit_left(const unsigned long *addr, unsigned long size,
- unsigned long offset);
+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,
+ unsigned long offset);
+
+static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
+{
+ return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
+}
+
+static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
+{
+ return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
+}
+
+static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
+{
+ return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
+}
+
+static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
+{
+ return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
+}
+
+static inline int test_bit_inv(unsigned long nr,
+ const volatile unsigned long *ptr)
+{
+ return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
+}
#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
diff --git a/arch/s390/lib/find.c b/arch/s390/lib/find.c
index 8963929b06b9..620d34d6487e 100644
--- a/arch/s390/lib/find.c
+++ b/arch/s390/lib/find.c
@@ -15,7 +15,7 @@
#include <linux/bitops.h>
#include <linux/export.h>
-unsigned long find_first_bit_left(const unsigned long *addr, unsigned long size)
+unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size)
{
const unsigned long *p = addr;
unsigned long result = 0;
@@ -35,10 +35,10 @@ unsigned long find_first_bit_left(const unsigned long *addr, unsigned long size)
found:
return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
}
-EXPORT_SYMBOL(find_first_bit_left);
+EXPORT_SYMBOL(find_first_bit_inv);
-unsigned long find_next_bit_left(const unsigned long *addr, unsigned long size,
- unsigned long offset)
+unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
+ unsigned long offset)
{
const unsigned long *p = addr + (offset / BITS_PER_LONG);
unsigned long result = offset & ~(BITS_PER_LONG - 1);
@@ -74,4 +74,4 @@ found_first:
found_middle:
return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
}
-EXPORT_SYMBOL(find_next_bit_left);
+EXPORT_SYMBOL(find_next_bit_inv);