Commit 5da703ef authored by Yury Norov [NVIDIA]'s avatar Yury Norov [NVIDIA] Committed by Borislav Petkov (AMD)
Browse files

cpumask: Add cpumask_{first,next}_andnot() API 



With the lack of the functions, client code has to abuse less efficient
cpumask_nth().

Signed-off-by: default avatarYury Norov [NVIDIA] <yury.norov@gmail.com>
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarJames Morse <james.morse@arm.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Reviewed-by: default avatarFenghua Yu <fenghuay@nvidia.com>
Tested-by: default avatarFenghua Yu <fenghuay@nvidia.com>
Tested-by: default avatarJames Morse <james.morse@arm.com>
Tested-by: default avatarTony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/20250515165855.31452-4-james.morse@arm.com
parent 13f0a02b

include/linux/cpumask.h

+59 −0
Original line number Diff line number Diff line
@@ -178,6 +178,19 @@ 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_andnot - return the first cpu from *srcp1 & ~*srcp2

 * @srcp1: the first input

 * @srcp2: the second input

 *

 * Return: >= nr_cpu_ids if no such cpu found.

 */

static __always_inline

unsigned int cpumask_first_andnot(const struct cpumask *srcp1, const struct cpumask *srcp2)

{

	return find_first_andnot_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
@@ -284,6 +297,25 @@ unsigned int cpumask_next_and(int n, const struct cpumask *src1p, 
		small_cpumask_bits, n + 1);

}



/**

 * cpumask_next_andnot - get the next cpu in *src1p & ~*src2p

 * @n: the cpu prior to the place to search (i.e. return will be > @n)

 * @src1p: the first cpumask pointer

 * @src2p: the second cpumask pointer

 *

 * Return: >= nr_cpu_ids if no further cpus set in both.

 */

static __always_inline

unsigned int cpumask_next_andnot(int n, const struct cpumask *src1p,

				 const struct cpumask *src2p)

{

	/* -1 is a legal arg here. */

	if (n != -1)

		cpumask_check(n);

	return find_next_andnot_bit(cpumask_bits(src1p), cpumask_bits(src2p),

		small_cpumask_bits, n + 1);

}



/**

 * cpumask_next_and_wrap - get the next cpu in *src1p & *src2p, starting from

 *			   @n+1. If nothing found, wrap around and start from
@@ -458,6 +490,33 @@ unsigned int cpumask_any_and_but(const struct cpumask *mask1, 
	return cpumask_next_and(cpu, mask1, mask2);

}



/**

 * cpumask_any_andnot_but - pick an arbitrary cpu from *mask1 & ~*mask2, but not this one.

 * @mask1: the first input cpumask

 * @mask2: the second input cpumask

 * @cpu: the cpu to ignore

 *

 * If @cpu == -1, the function returns the first matching cpu.

 * Returns >= nr_cpu_ids if no cpus set.

 */

static __always_inline

unsigned int cpumask_any_andnot_but(const struct cpumask *mask1,

				    const struct cpumask *mask2,

				    int cpu)

{

	unsigned int i;



	/* -1 is a legal arg here. */

	if (cpu != -1)

		cpumask_check(cpu);



	i = cpumask_first_andnot(mask1, mask2);

	if (i != cpu)

		return i;



	return cpumask_next_andnot(cpu, mask1, mask2);

}



/**

 * cpumask_nth - get the Nth cpu in a cpumask

 * @srcp: the cpumask pointer