perf: arm_pmu: Kill last use of per-CPU cpu_armpmu pointer

Having removed the use of the cpu_armpmu per-CPU variable from the
interrupt handling, the only user left is the BRBE scheduler hook.

It is easy to drop the use of this variable by following the pointer to the
generic PMU structure, and get the arm_pmu structure from there.

Perform the conversion and kill cpu_armpmu altogether.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20251020122944.3074811-27-maz@kernel.org

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 959ceb3d1f556849e8100725a815ac3a0a7a9763..f7abd1333963015f34d299002675b91f97cf844d 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -104,7 +104,6 @@ static const struct pmu_irq_ops percpu_pmunmi_ops = {
        .free_pmuirq = armpmu_free_percpu_pmunmi
 };
 
-DEFINE_PER_CPU(struct arm_pmu *, cpu_armpmu);
 static DEFINE_PER_CPU(int, cpu_irq);
 static DEFINE_PER_CPU(const struct pmu_irq_ops *, cpu_irq_ops);
 
@@ -725,8 +724,6 @@ static int arm_perf_starting_cpu(unsigned int cpu, struct hlist_node *node)
        if (pmu->reset)
                pmu->reset(pmu);
 
-       per_cpu(cpu_armpmu, cpu) = pmu;
-
        irq = armpmu_get_cpu_irq(pmu, cpu);
        if (irq)
                per_cpu(cpu_irq_ops, cpu)->enable_pmuirq(irq);
@@ -746,8 +743,6 @@ static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node)
        if (irq)
                per_cpu(cpu_irq_ops, cpu)->disable_pmuirq(irq);
 
-       per_cpu(cpu_armpmu, cpu) = NULL;
-
        return 0;
 }
 

diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c
index 69c5cc8f56067cd00aba8509d21b984cb8f30d2e..ca8d706d40221f6922e24fc314629b635d47c044 100644 (file)
--- a/drivers/perf/arm_pmuv3.c
+++ b/drivers/perf/arm_pmuv3.c
@@ -1064,7 +1064,7 @@ static int armv8pmu_user_event_idx(struct perf_event *event)
 static void armv8pmu_sched_task(struct perf_event_pmu_context *pmu_ctx,
                                struct task_struct *task, bool sched_in)
 {
-       struct arm_pmu *armpmu = *this_cpu_ptr(&cpu_armpmu);
+       struct arm_pmu *armpmu = to_arm_pmu(pmu_ctx->pmu);
        struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events);
 
        if (!hw_events->branch_users)

diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 6690bd77aa4ee0173af928eb4014f0f0f1699227..bab26a7d79f4cb1ac3e00691a55f9c54b625b0de 100644 (file)
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -132,8 +132,6 @@ struct arm_pmu {
 
 #define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu))
 
-DECLARE_PER_CPU(struct arm_pmu *, cpu_armpmu);
-
 u64 armpmu_event_update(struct perf_event *event);
 
 int armpmu_event_set_period(struct perf_event *event);