From cdc66553c4130735f0a2db943a5259e54ff1597a Mon Sep 17 00:00:00 2001 From: Dawei Li Date: Tue, 16 Apr 2024 16:54:48 +0800 Subject: cpumask: Introduce cpumask_first_and_and() Introduce cpumask_first_and_and() to get intersection between 3 cpumasks, free of any intermediate cpumask variable. Instead, cpumask_first_and_and() works in-place with all inputs and produces desired output directly. Signed-off-by: Dawei Li Signed-off-by: Thomas Gleixner Acked-by: Yury Norov Link: https://lore.kernel.org/r/20240416085454.3547175-2-dawei.li@shingroup.cn --- include/linux/cpumask.h | 17 +++++++++++++++++ include/linux/find.h | 27 +++++++++++++++++++++++++++ lib/find_bit.c | 12 ++++++++++++ 3 files changed, 56 insertions(+) diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 1c29947db848..c46f9e9e1d66 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -187,6 +187,23 @@ unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask return find_first_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits); } +/** + * cpumask_first_and_and - return the first cpu from *srcp1 & *srcp2 & *srcp3 + * @srcp1: the first input + * @srcp2: the second input + * @srcp3: the third input + * + * Return: >= nr_cpu_ids if no cpus set in all. + */ +static inline +unsigned int cpumask_first_and_and(const struct cpumask *srcp1, + const struct cpumask *srcp2, + const struct cpumask *srcp3) +{ + return find_first_and_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), + cpumask_bits(srcp3), small_cpumask_bits); +} + /** * cpumask_last - get the last CPU in a cpumask * @srcp: - the cpumask pointer diff --git a/include/linux/find.h b/include/linux/find.h index c69598e383c1..28ec5a03393a 100644 --- a/include/linux/find.h +++ b/include/linux/find.h @@ -29,6 +29,8 @@ unsigned long __find_nth_and_andnot_bit(const unsigned long *addr1, const unsign unsigned long n); extern unsigned long _find_first_and_bit(const unsigned long *addr1, const unsigned long *addr2, unsigned long size); +unsigned long _find_first_and_and_bit(const unsigned long *addr1, const unsigned long *addr2, + const unsigned long *addr3, unsigned long size); extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size); extern unsigned long _find_last_bit(const unsigned long *addr, unsigned long size); @@ -345,6 +347,31 @@ unsigned long find_first_and_bit(const unsigned long *addr1, } #endif +/** + * find_first_and_and_bit - find the first set bit in 3 memory regions + * @addr1: The first address to base the search on + * @addr2: The second address to base the search on + * @addr3: The third address to base the search on + * @size: The bitmap size in bits + * + * Returns the bit number for the first set bit + * If no bits are set, returns @size. + */ +static inline +unsigned long find_first_and_and_bit(const unsigned long *addr1, + const unsigned long *addr2, + const unsigned long *addr3, + unsigned long size) +{ + if (small_const_nbits(size)) { + unsigned long val = *addr1 & *addr2 & *addr3 & GENMASK(size - 1, 0); + + return val ? __ffs(val) : size; + } + + return _find_first_and_and_bit(addr1, addr2, addr3, size); +} + #ifndef find_first_zero_bit /** * find_first_zero_bit - find the first cleared bit in a memory region diff --git a/lib/find_bit.c b/lib/find_bit.c index 32f99e9a670e..dacadd904250 100644 --- a/lib/find_bit.c +++ b/lib/find_bit.c @@ -116,6 +116,18 @@ unsigned long _find_first_and_bit(const unsigned long *addr1, EXPORT_SYMBOL(_find_first_and_bit); #endif +/* + * Find the first set bit in three memory regions. + */ +unsigned long _find_first_and_and_bit(const unsigned long *addr1, + const unsigned long *addr2, + const unsigned long *addr3, + unsigned long size) +{ + return FIND_FIRST_BIT(addr1[idx] & addr2[idx] & addr3[idx], /* nop */, size); +} +EXPORT_SYMBOL(_find_first_and_and_bit); + #ifndef find_first_zero_bit /* * Find the first cleared bit in a memory region. -- cgit v1.2.3