diff options
Diffstat (limited to 'usr/src/uts/common/sys/bitmap.h')
| -rw-r--r-- | usr/src/uts/common/sys/bitmap.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/usr/src/uts/common/sys/bitmap.h b/usr/src/uts/common/sys/bitmap.h index 8476ba9563..d0dd12b683 100644 --- a/usr/src/uts/common/sys/bitmap.h +++ b/usr/src/uts/common/sys/bitmap.h @@ -20,7 +20,7 @@ */ /* - * Copyright 2005 Sun Microsystems, Inc. All rights reserved. + * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ @@ -124,6 +124,14 @@ extern "C" { #endif /* _LP64 */ +/* + * BIT_ONLYONESET is a private macro not designed for bitmaps of + * arbitrary size. u must be an unsigned integer/long. It returns + * true if one and only one bit is set in u. + */ +#define BIT_ONLYONESET(u) \ + ((((u) == 0) ? 0 : ((u) & ((u) - 1)) == 0)) + #if defined(_KERNEL) && !defined(_ASM) #include <sys/atomic.h> |