Commit f622fbf2 authored by Mao Han's avatar Mao Han Committed by Guo Ren
Browse files

csky: Add pmu interrupt support 



This patch add interrupt request and handler for csky pmu.
perf can record on hardware event with this patch applied.

Signed-off-by: default avatarMao Han <han_mao@c-sky.com>
Signed-off-by: default avatarGuo Ren <guoren@kernel.org>
parent ccffa1ad

arch/csky/kernel/perf_event.c

+246 −15
Original line number Diff line number Diff line
@@ -12,16 +12,41 @@ 
#define DEFAULT_COUNT_WIDTH 48



#define HPCR		"<0, 0x0>"      /* PMU Control reg */

#define HPSPR		"<0, 0x1>"      /* Start PC reg */

#define HPEPR		"<0, 0x2>"      /* End PC reg */

#define HPSIR		"<0, 0x3>"      /* Soft Counter reg */

#define HPCNTENR	"<0, 0x4>"      /* Count Enable reg */

#define HPINTENR	"<0, 0x5>"      /* Interrupt Enable reg */

#define HPOFSR		"<0, 0x6>"      /* Interrupt Status reg */



/* The events for a given PMU register set. */

struct pmu_hw_events {

	/*

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

	 */

	struct perf_event *events[CSKY_PMU_MAX_EVENTS];



	/*

	 * 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(CSKY_PMU_MAX_EVENTS)];

};



static uint64_t (*hw_raw_read_mapping[CSKY_PMU_MAX_EVENTS])(void);

static void (*hw_raw_write_mapping[CSKY_PMU_MAX_EVENTS])(uint64_t val);



struct csky_pmu_t {

static struct csky_pmu_t {

	struct pmu			pmu;

	struct pmu_hw_events __percpu	*hw_events;

	struct platform_device		*plat_device;

	uint32_t			count_width;

	uint32_t			hpcr;

	u64				max_period;

} csky_pmu;

static int csky_pmu_irq;



#define to_csky_pmu(p)  (container_of(p, struct csky_pmu, pmu))



#define cprgr(reg)				\

({						\
@@ -802,6 +827,47 @@ static const int csky_pmu_cache_map[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = { 
	},

};



int  csky_pmu_event_set_period(struct perf_event *event)

{

	struct hw_perf_event *hwc = &event->hw;

	s64 left = local64_read(&hwc->period_left);

	s64 period = hwc->sample_period;

	int ret = 0;



	if (unlikely(left <= -period)) {

		left = period;

		local64_set(&hwc->period_left, left);

		hwc->last_period = period;

		ret = 1;

	}



	if (unlikely(left <= 0)) {

		left += period;

		local64_set(&hwc->period_left, left);

		hwc->last_period = period;

		ret = 1;

	}



	if (left > (s64)csky_pmu.max_period)

		left = csky_pmu.max_period;



	/*

	 * The hw event starts counting from this event offset,

	 * mark it to be able to extract future "deltas":

	 */

	local64_set(&hwc->prev_count, (u64)(-left));



	if (hw_raw_write_mapping[hwc->idx] != NULL)

		hw_raw_write_mapping[hwc->idx]((u64)(-left) &

						csky_pmu.max_period);



	cpwcr(HPOFSR, ~BIT(hwc->idx) & cprcr(HPOFSR));



	perf_event_update_userpage(event);



	return ret;

}



static void csky_perf_event_update(struct perf_event *event,

				   struct hw_perf_event *hwc)

{
@@ -823,6 +889,11 @@ static void csky_perf_event_update(struct perf_event *event, 
	local64_sub(delta, &hwc->period_left);

}



static void csky_pmu_reset(void *info)

{

	cpwcr(HPCR, BIT(31) | BIT(30) | BIT(1));

}



static void csky_pmu_read(struct perf_event *event)

{

	csky_perf_event_update(event, &event->hw);
@@ -899,6 +970,7 @@ static void csky_pmu_disable(struct pmu *pmu) 


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

{

	unsigned long flg;

	struct hw_perf_event *hwc = &event->hw;

	int idx = hwc->idx;
@@ -910,16 +982,34 @@ static void csky_pmu_start(struct perf_event *event, int flags) 


	hwc->state = 0;



	csky_pmu_event_set_period(event);



	local_irq_save(flg);



	cpwcr(HPINTENR, BIT(idx) | cprcr(HPINTENR));

	cpwcr(HPCNTENR, BIT(idx) | cprcr(HPCNTENR));



	local_irq_restore(flg);

}



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

static void csky_pmu_stop_event(struct perf_event *event)

{

	unsigned long flg;

	struct hw_perf_event *hwc = &event->hw;

	int idx = hwc->idx;



	if (!(event->hw.state & PERF_HES_STOPPED)) {

	local_irq_save(flg);



	cpwcr(HPINTENR, ~BIT(idx) & cprcr(HPINTENR));

	cpwcr(HPCNTENR, ~BIT(idx) & cprcr(HPCNTENR));



	local_irq_restore(flg);

}



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

{

	if (!(event->hw.state & PERF_HES_STOPPED)) {

		csky_pmu_stop_event(event);

		event->hw.state |= PERF_HES_STOPPED;

	}
@@ -932,22 +1022,26 @@ static void csky_pmu_stop(struct perf_event *event, int flags) 


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

{

	struct pmu_hw_events *hw_events = this_cpu_ptr(csky_pmu.hw_events);

	struct hw_perf_event *hwc = &event->hw;



	csky_pmu_stop(event, PERF_EF_UPDATE);



	hw_events->events[hwc->idx] = NULL;



	perf_event_update_userpage(event);

}



/* allocate hardware counter and optionally start counting */

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

{

	struct pmu_hw_events *hw_events = this_cpu_ptr(csky_pmu.hw_events);

	struct hw_perf_event *hwc = &event->hw;



	local64_set(&hwc->prev_count, 0);



	if (hw_raw_write_mapping[hwc->idx] != NULL)

		hw_raw_write_mapping[hwc->idx](0);

	hw_events->events[hwc->idx] = event;



	hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;



	if (flags & PERF_EF_START)

		csky_pmu_start(event, PERF_EF_RELOAD);
@@ -956,8 +1050,110 @@ static int csky_pmu_add(struct perf_event *event, int flags) 
	return 0;

}



static irqreturn_t csky_pmu_handle_irq(int irq_num, void *dev)

{

	struct perf_sample_data data;

	struct pmu_hw_events *cpuc = this_cpu_ptr(csky_pmu.hw_events);

	struct pt_regs *regs;

	int idx;



	/*

	 * Did an overflow occur?

	 */

	if (!cprcr(HPOFSR))

		return IRQ_NONE;



	/*

	 * Handle the counter(s) overflow(s)

	 */

	regs = get_irq_regs();



	csky_pmu_disable(&csky_pmu.pmu);



	for (idx = 0; idx < CSKY_PMU_MAX_EVENTS; ++idx) {

		struct perf_event *event = cpuc->events[idx];

		struct hw_perf_event *hwc;



		/* Ignore if we don't have an event. */

		if (!event)

			continue;

		/*

		 * We have a single interrupt for all counters. Check that

		 * each counter has overflowed before we process it.

		 */

		if (!(cprcr(HPOFSR) & BIT(idx)))

			continue;



		hwc = &event->hw;

		csky_perf_event_update(event, &event->hw);

		perf_sample_data_init(&data, 0, hwc->last_period);

		csky_pmu_event_set_period(event);



		if (perf_event_overflow(event, &data, regs))

			csky_pmu_stop_event(event);

	}



	csky_pmu_enable(&csky_pmu.pmu);



	/*

	 * Handle the pending perf events.

	 *

	 * Note: this call *must* be run with interrupts disabled. For

	 * platforms that can have the PMU interrupts raised as an NMI, this

	 * will not work.

	 */

	irq_work_run();



	return IRQ_HANDLED;

}



static int csky_pmu_request_irq(irq_handler_t handler)

{

	int err, irqs;

	struct platform_device *pmu_device = csky_pmu.plat_device;



	if (!pmu_device)

		return -ENODEV;



	irqs = min(pmu_device->num_resources, num_possible_cpus());

	if (irqs < 1) {

		pr_err("no irqs for PMUs defined\n");

		return -ENODEV;

	}



	csky_pmu_irq = platform_get_irq(pmu_device, 0);

	if (csky_pmu_irq < 0)

		return -ENODEV;

	err = request_percpu_irq(csky_pmu_irq, handler, "csky-pmu",

				 this_cpu_ptr(csky_pmu.hw_events));

	if (err) {

		pr_err("unable to request IRQ%d for CSKY PMU counters\n",

		       csky_pmu_irq);

		return err;

	}



	return 0;

}



static void csky_pmu_free_irq(void)

{

	int irq;

	struct platform_device *pmu_device = csky_pmu.plat_device;



	irq = platform_get_irq(pmu_device, 0);

	if (irq >= 0)

		free_percpu_irq(irq, this_cpu_ptr(csky_pmu.hw_events));

}



int init_hw_perf_events(void)

{

	csky_pmu.hw_events = alloc_percpu_gfp(struct pmu_hw_events,

					      GFP_KERNEL);

	if (!csky_pmu.hw_events) {

		pr_info("failed to allocate per-cpu PMU data.\n");

		return -ENOMEM;

	}



	csky_pmu.pmu = (struct pmu) {

		.pmu_enable	= csky_pmu_enable,

		.pmu_disable	= csky_pmu_disable,
@@ -1029,11 +1225,19 @@ int init_hw_perf_events(void) 
	hw_raw_write_mapping[0x1a] = csky_pmu_write_l2wac;

	hw_raw_write_mapping[0x1b] = csky_pmu_write_l2wmc;



	csky_pmu.pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;

	return 0;

}



	cpwcr(HPCR, BIT(31) | BIT(30) | BIT(1));

static int csky_pmu_starting_cpu(unsigned int cpu)

{

	enable_percpu_irq(csky_pmu_irq, 0);

	return 0;

}



	return perf_pmu_register(&csky_pmu.pmu, "cpu", PERF_TYPE_RAW);

static int csky_pmu_dying_cpu(unsigned int cpu)

{

	disable_percpu_irq(csky_pmu_irq);

	return 0;

}



int csky_pmu_device_probe(struct platform_device *pdev,
@@ -1052,6 +1256,33 @@ int csky_pmu_device_probe(struct platform_device *pdev, 
				 &csky_pmu.count_width)) {

		csky_pmu.count_width = DEFAULT_COUNT_WIDTH;

	}

	csky_pmu.max_period = BIT(csky_pmu.count_width) - 1;



	csky_pmu.plat_device = pdev;



	/* Ensure the PMU has sane values out of reset. */

	on_each_cpu(csky_pmu_reset, &csky_pmu, 1);



	ret = csky_pmu_request_irq(csky_pmu_handle_irq);

	if (ret) {

		csky_pmu.pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;

		pr_notice("[perf] PMU request irq fail!\n");

	}



	ret = cpuhp_setup_state(CPUHP_AP_PERF_ONLINE, "AP_PERF_ONLINE",

				csky_pmu_starting_cpu,

				csky_pmu_dying_cpu);

	if (ret) {

		csky_pmu_free_irq();

		free_percpu(csky_pmu.hw_events);

		return ret;

	}



	ret = perf_pmu_register(&csky_pmu.pmu, "cpu", PERF_TYPE_RAW);

	if (ret) {

		csky_pmu_free_irq();

		free_percpu(csky_pmu.hw_events);

	}



	return ret;

}