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Commit e525c37f authored by Alexey Brodkin's avatar Alexey Brodkin Committed by Vineet Gupta
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ARCv2: perf: SMP support 



* split off pmu info into singleton and per-cpu bits
* setup PMU on all cores

Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: default avatarAlexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent e6b1d126

arch/arc/kernel/perf_event.c

+54 −15
Original line number Diff line number Diff line
@@ -21,10 +21,22 @@ 


struct arc_pmu {

	struct pmu	pmu;

	unsigned int	irq;

	int		n_counters;

	unsigned long	used_mask[BITS_TO_LONGS(ARC_PERF_MAX_COUNTERS)];

	u64		max_period;

	int		ev_hw_idx[PERF_COUNT_ARC_HW_MAX];

};



struct arc_pmu_cpu {

	/*

	 * A 1 bit for an index indicates that the counter is being used for

	 * an event. A 0 means that the counter can be used.

	 */

	unsigned long	used_mask[BITS_TO_LONGS(ARC_PERF_MAX_COUNTERS)];



	/*

	 * The events that are active on the PMU for the given index.

	 */

	struct perf_event *act_counter[ARC_PERF_MAX_COUNTERS];

};
@@ -67,6 +79,7 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) 
}



static struct arc_pmu *arc_pmu;

static DEFINE_PER_CPU(struct arc_pmu_cpu, arc_pmu_cpu);



/* read counter #idx; note that counter# != event# on ARC! */

static uint64_t arc_pmu_read_counter(int idx)
@@ -304,10 +317,12 @@ static void arc_pmu_stop(struct perf_event *event, int flags) 


static void arc_pmu_del(struct perf_event *event, int flags)

{

	struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);



	arc_pmu_stop(event, PERF_EF_UPDATE);

	__clear_bit(event->hw.idx, arc_pmu->used_mask);

	__clear_bit(event->hw.idx, pmu_cpu->used_mask);



	arc_pmu->act_counter[event->hw.idx] = 0;

	pmu_cpu->act_counter[event->hw.idx] = 0;



	perf_event_update_userpage(event);

}
@@ -315,22 +330,23 @@ static void arc_pmu_del(struct perf_event *event, int flags) 
/* allocate hardware counter and optionally start counting */

static int arc_pmu_add(struct perf_event *event, int flags)

{

	struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);

	struct hw_perf_event *hwc = &event->hw;

	int idx = hwc->idx;



	if (__test_and_set_bit(idx, arc_pmu->used_mask)) {

		idx = find_first_zero_bit(arc_pmu->used_mask,

	if (__test_and_set_bit(idx, pmu_cpu->used_mask)) {

		idx = find_first_zero_bit(pmu_cpu->used_mask,

					  arc_pmu->n_counters);

		if (idx == arc_pmu->n_counters)

			return -EAGAIN;



		__set_bit(idx, arc_pmu->used_mask);

		__set_bit(idx, pmu_cpu->used_mask);

		hwc->idx = idx;

	}



	write_aux_reg(ARC_REG_PCT_INDEX, idx);



	arc_pmu->act_counter[idx] = event;

	pmu_cpu->act_counter[idx] = event;



	if (is_sampling_event(event)) {

		/* Mimic full counter overflow as other arches do */
@@ -357,7 +373,7 @@ static int arc_pmu_add(struct perf_event *event, int flags) 
static irqreturn_t arc_pmu_intr(int irq, void *dev)

{

	struct perf_sample_data data;

	struct arc_pmu *arc_pmu = (struct arc_pmu *)dev;

	struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);

	struct pt_regs *regs;

	int active_ints;

	int idx;
@@ -369,7 +385,7 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev) 
	regs = get_irq_regs();



	for (idx = 0; idx < arc_pmu->n_counters; idx++) {

		struct perf_event *event = arc_pmu->act_counter[idx];

		struct perf_event *event = pmu_cpu->act_counter[idx];

		struct hw_perf_event *hwc;



		if (!(active_ints & (1 << idx)))
@@ -412,6 +428,17 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev) 


#endif /* CONFIG_ISA_ARCV2 */



void arc_cpu_pmu_irq_init(void)

{

	struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);



	arc_request_percpu_irq(arc_pmu->irq, smp_processor_id(), arc_pmu_intr,

			       "ARC perf counters", pmu_cpu);



	/* Clear all pending interrupt flags */

	write_aux_reg(ARC_REG_PCT_INT_ACT, 0xffffffff);

}



static int arc_pmu_device_probe(struct platform_device *pdev)

{

	struct arc_reg_pct_build pct_bcr;
@@ -488,18 +515,30 @@ static int arc_pmu_device_probe(struct platform_device *pdev) 


	if (has_interrupts) {

		int irq = platform_get_irq(pdev, 0);

		unsigned long flags;



		if (irq < 0) {

			pr_err("Cannot get IRQ number for the platform\n");

			return -ENODEV;

		}



		ret = devm_request_irq(&pdev->dev, irq, arc_pmu_intr, 0,

				       "arc-pmu", arc_pmu);

		if (ret) {

			pr_err("could not allocate PMU IRQ\n");

			return ret;

		}

		arc_pmu->irq = irq;



		/*

		 * arc_cpu_pmu_irq_init() needs to be called on all cores for

		 * their respective local PMU.

		 * However we use opencoded on_each_cpu() to ensure it is called

		 * on core0 first, so that arc_request_percpu_irq() sets up

		 * AUTOEN etc. Otherwise enable_percpu_irq() fails to enable

		 * perf IRQ on non master cores.

		 * see arc_request_percpu_irq()

		 */

		preempt_disable();

		local_irq_save(flags);

		arc_cpu_pmu_irq_init();

		local_irq_restore(flags);

		smp_call_function((smp_call_func_t)arc_cpu_pmu_irq_init, 0, 1);

		preempt_enable();



		/* Clean all pending interrupt flags */

		write_aux_reg(ARC_REG_PCT_INT_ACT, 0xffffffff);