From: Olaf Hering Date: Wed, 9 Dec 2020 16:40:00 +0100 Subject: libxc sr bitmap long tools: add API to work with sevaral bits at once Introduce new API to test if a fixed number of bits is clear or set, and clear or set them all at once. The caller has to make sure the input bitnumber is a multiple of BITS_PER_LONG. This API avoids the loop over each bit in a known range just to see if all of them are either clear or set. Signed-off-by: Olaf Hering v02: - change return type from int to bool (jgross) --- tools/libs/ctrl/xc_bitops.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) --- a/tools/libs/ctrl/xc_bitops.h +++ b/tools/libs/ctrl/xc_bitops.h @@ -3,6 +3,7 @@ /* bitmap operations for single threaded access */ +#include #include #include @@ -81,4 +82,31 @@ static inline void bitmap_or(void *_dst, dst[i] |= other[i]; } +static inline bool test_bit_long_set(unsigned long nr_base, const void *_addr) +{ + const unsigned long *addr = _addr; + unsigned long val = addr[nr_base / BITS_PER_LONG]; + + return val == ~0; +} + +static inline bool test_bit_long_clear(unsigned long nr_base, const void *_addr) +{ + const unsigned long *addr = _addr; + unsigned long val = addr[nr_base / BITS_PER_LONG]; + + return val == 0; +} + +static inline void clear_bit_long(unsigned long nr_base, void *_addr) +{ + unsigned long *addr = _addr; + addr[nr_base / BITS_PER_LONG] = 0; +} + +static inline void set_bit_long(unsigned long nr_base, void *_addr) +{ + unsigned long *addr = _addr; + addr[nr_base / BITS_PER_LONG] = ~0; +} #endif /* XC_BITOPS_H */