drivers: perf: arm_pmu: Drop 'pmu_lock' element from 'struct pmu_hw_events'

As 'pmu_lock' element is not being used in any ARM PMU implementation, just
drop this from 'struct pmu_hw_events'.

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20231115092805.737822-3-anshuman.khandual@arm.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_pmu.c

@@ -893,7 +893,6 @@ struct arm_pmu *armpmu_alloc(void)
 		struct pmu_hw_events *events;
 
 		events = per_cpu_ptr(pmu->hw_events, cpu);
-		raw_spin_lock_init(&events->pmu_lock);
 		events->percpu_pmu = pmu;
 	}
 

include/linux/perf/arm_pmu.h

@@ -59,12 +59,6 @@ struct pmu_hw_events {
 	 */
 	DECLARE_BITMAP(used_mask, ARMPMU_MAX_HWEVENTS);
 
-	/*
-	 * Hardware lock to serialize accesses to PMU registers. Needed for the
-	 * read/modify/write sequences.
-	 */
-	raw_spinlock_t		pmu_lock;
-
 	/*
 	 * When using percpu IRQs, we need a percpu dev_id. Place it here as we
 	 * already have to allocate this struct per cpu.