perf: arm_pmu: Fix build on arm if !CONFIG_GENERIC_ARCH_TOPOLOGY

The SMT implementation is retrieved by topology_core_has_smt() which depends on CONFIG_GENERIC_ARCH_TOPOLOGY. The config is optional on arm platforms so protect the usage with CONFIG_GENERIC_ARCH_TOPOLOGY.

Fixes c3d78c34ad00 ("perf: arm_pmuv3: Don't use PMCCNTR_EL0 on SMT cores")

Reported-by kernel test robot <[email protected]>

Closes https://lore.kernel.org/oe-kbuild-all/[email protected]/ open here

Signed-off-by Yicong Yang <[email protected]>

---
 drivers/perf/arm_pmu.c | 2 ++
 1 file changed, 2 insertions(+)

drivers/perf/arm_pmu.c +2 -0

index ae437791b5f8..f38bdeb906f0 100644
@@ -925,11 +925,13 @@ int armpmu_register(struct arm_pmu *pmu)
 	if (ret)
 		return ret;
 
+#ifdef CONFIG_GENERIC_ARCH_TOPOLOGY
 	/*
 	 * By this stage we know our supported CPUs on either DT/ACPI platforms,
 	 * detect the SMT implementation.
 	 */
 	pmu->has_smt = topology_core_has_smt(cpumask_first(&pmu->supported_cpus));
+#endif
 
 	if (!pmu->set_event_filter)
 		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;

Signature · 1 line

2.50.1 (Apple Git-155)

Quoted 32 lines · Yicong Yang

The SMT implementation is retrieved by topology_core_has_smt() which depends on CONFIG_GENERIC_ARCH_TOPOLOGY. The config is optional on arm platforms so protect the usage with CONFIG_GENERIC_ARCH_TOPOLOGY.

Fixes c3d78c34ad00 ("perf: arm_pmuv3: Don't use PMCCNTR_EL0 on SMT cores")

Reported-by kernel test robot <[email protected]>

Closes https://lore.kernel.org/oe-kbuild-all/[email protected]/ open here

Signed-off-by Yicong Yang <[email protected]>

---
 drivers/perf/arm_pmu.c | 2 ++
 1 file changed, 2 insertions(+)

drivers/perf/arm_pmu.c +2 -0

index ae437791b5f8..f38bdeb906f0 100644
@@ -925,11 +925,13 @@ int armpmu_register(struct arm_pmu *pmu)
 	if (ret)
 		return ret;
 
+#ifdef CONFIG_GENERIC_ARCH_TOPOLOGY
 	/*
 	 * By this stage we know our supported CPUs on either DT/ACPI platforms,
 	 * detect the SMT implementation.
 	 */
 	pmu->has_smt = topology_core_has_smt(cpumask_first(&pmu->supported_cpus));
+#endif
 
 	if (!pmu->set_event_filter)
 		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;

Signature · 1 line

2.50.1 (Apple Git-155)

Wouldn't we be better off adding something like:

#else
static inline bool topology_core_has_smt(int cpu) { return false; } #endif /* CONFIG_GENERIC_ARCH_TOPOLOGY */

to the bottom of include/linux/arch_topology.h?