The following commit has been merged into the x86/cache branch of tip:
Commit-ID: 189572bf4e005431051319def435ac4b7e4489ca
Gitweb: https://git.kernel.org/tip/189572bf4e005431051319def435ac4b7e4489ca
Author: Yury Norov [NVIDIA] <yury.norov@gmail.com>
AuthorDate: Thu, 15 May 2025 16:58:31
Committer: Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Thu, 15 May 2025 20:24:22 +02:00
cpumask: Relax cpumask_any_but()
Similarly to other cpumask search functions, accept -1, and consider it as
'any CPU' hint. This helps users to avoid coding special cases.
Signed-off-by: Yury Norov [NVIDIA] <yury.norov@gmail.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: James Morse <james.morse@arm.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Link: https://lore.kernel.org/20250515165855.31452-2-james.morse@arm.com
---
include/linux/cpumask.h | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index f9a8683..a3ee875 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -413,14 +413,18 @@ unsigned int cpumask_next_wrap(int n, const struct cpumask *src)
* @cpu: the cpu to ignore.
*
* Often used to find any cpu but smp_processor_id() in a mask.
+ * If @cpu == -1, the function is equivalent to cpumask_any().
* Return: >= nr_cpu_ids if no cpus set.
*/
static __always_inline
-unsigned int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
+unsigned int cpumask_any_but(const struct cpumask *mask, int cpu)
{
unsigned int i;
- cpumask_check(cpu);
+ /* -1 is a legal arg here. */
+ if (cpu != -1)
+ cpumask_check(cpu);
+
for_each_cpu(i, mask)
if (i != cpu)
break;
@@ -433,16 +437,20 @@ unsigned int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
* @mask2: the second input cpumask
* @cpu: the cpu to ignore
*
+ * If @cpu == -1, the function is equivalent to cpumask_any_and().
* Returns >= nr_cpu_ids if no cpus set.
*/
static __always_inline
unsigned int cpumask_any_and_but(const struct cpumask *mask1,
const struct cpumask *mask2,
- unsigned int cpu)
+ int cpu)
{
unsigned int i;
- cpumask_check(cpu);
+ /* -1 is a legal arg here. */
+ if (cpu != -1)
+ cpumask_check(cpu);
+
i = cpumask_first_and(mask1, mask2);
if (i != cpu)
return i;