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-rw-r--r--arch/powerpc/perf/imc-pmu.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index 31fa753e2eb2..dea243185ea4 100644
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* In-Memory Collection (IMC) Performance Monitor counter support.
*
* Copyright (C) 2017 Madhavan Srinivasan, IBM Corporation.
* (C) 2017 Anju T Sudhakar, IBM Corporation.
* (C) 2017 Hemant K Shaw, IBM Corporation.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or later version.
*/
#include <linux/perf_event.h>
#include <linux/slab.h>
@@ -366,7 +362,14 @@ static int ppc_nest_imc_cpu_offline(unsigned int cpu)
*/
nid = cpu_to_node(cpu);
l_cpumask = cpumask_of_node(nid);
- target = cpumask_any_but(l_cpumask, cpu);
+ target = cpumask_last(l_cpumask);
+
+ /*
+ * If this(target) is the last cpu in the cpumask for this chip,
+ * check for any possible online cpu in the chip.
+ */
+ if (unlikely(target == cpu))
+ target = cpumask_any_but(l_cpumask, cpu);
/*
* Update the cpumask with the target cpu and
@@ -671,7 +674,10 @@ static int ppc_core_imc_cpu_offline(unsigned int cpu)
return 0;
/* Find any online cpu in that core except the current "cpu" */
- ncpu = cpumask_any_but(cpu_sibling_mask(cpu), cpu);
+ ncpu = cpumask_last(cpu_sibling_mask(cpu));
+
+ if (unlikely(ncpu == cpu))
+ ncpu = cpumask_any_but(cpu_sibling_mask(cpu), cpu);
if (ncpu >= 0 && ncpu < nr_cpu_ids) {
cpumask_set_cpu(ncpu, &core_imc_cpumask);