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Commit b91c8f28 authored by Punit Agrawal's avatar Punit Agrawal Committed by Will Deacon
Browse files

drivers: CCI: add ARM CCI PMU support



Extend the existing CCI driver to support the PMU by registering a perf
backend for it.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Dave Martin <dave.martin@linaro.org>
Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarPunit Agrawal <punit.agrawal@arm.com>
[will: removed broken __init annotations]
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 83bc10a2
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+632 −4
Original line number Diff line number Diff line
@@ -18,11 +18,21 @@
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <asm/cacheflush.h>
#include <asm/irq_regs.h>
#include <asm/pmu.h>
#include <asm/smp_plat.h>

#define DRIVER_NAME		"CCI-400"
#define DRIVER_NAME_PMU		DRIVER_NAME " PMU"
#define PMU_NAME		"CCI_400"

#define CCI_PORT_CTRL		0x0
#define CCI_CTRL_STATUS		0xc

@@ -54,6 +64,587 @@ static unsigned int nb_cci_ports;
static void __iomem *cci_ctrl_base;
static unsigned long cci_ctrl_phys;

#ifdef CONFIG_HW_PERF_EVENTS

#define CCI_PMCR		0x0100
#define CCI_PID2		0x0fe8

#define CCI_PMCR_CEN		0x00000001
#define CCI_PMCR_NCNT_MASK	0x0000f800
#define CCI_PMCR_NCNT_SHIFT	11

#define CCI_PID2_REV_MASK	0xf0
#define CCI_PID2_REV_SHIFT	4

/* Port ids */
#define CCI_PORT_S0	0
#define CCI_PORT_S1	1
#define CCI_PORT_S2	2
#define CCI_PORT_S3	3
#define CCI_PORT_S4	4
#define CCI_PORT_M0	5
#define CCI_PORT_M1	6
#define CCI_PORT_M2	7

#define CCI_REV_R0		0
#define CCI_REV_R1		1
#define CCI_REV_R0_P4		4
#define CCI_REV_R1_P2		6

#define CCI_PMU_EVT_SEL		0x000
#define CCI_PMU_CNTR		0x004
#define CCI_PMU_CNTR_CTRL	0x008
#define CCI_PMU_OVRFLW		0x00c

#define CCI_PMU_OVRFLW_FLAG	1

#define CCI_PMU_CNTR_BASE(idx)	((idx) * SZ_4K)

/*
 * Instead of an event id to monitor CCI cycles, a dedicated counter is
 * provided. Use 0xff to represent CCI cycles and hope that no future revisions
 * make use of this event in hardware.
 */
enum cci400_perf_events {
	CCI_PMU_CYCLES = 0xff
};

#define CCI_PMU_EVENT_MASK		0xff
#define CCI_PMU_EVENT_SOURCE(event)	((event >> 5) & 0x7)
#define CCI_PMU_EVENT_CODE(event)	(event & 0x1f)

#define CCI_PMU_MAX_HW_EVENTS 5   /* CCI PMU has 4 counters + 1 cycle counter */

#define CCI_PMU_CYCLE_CNTR_IDX		0
#define CCI_PMU_CNTR0_IDX		1
#define CCI_PMU_CNTR_LAST(cci_pmu)	(CCI_PMU_CYCLE_CNTR_IDX + cci_pmu->num_events - 1)

/*
 * CCI PMU event id is an 8-bit value made of two parts - bits 7:5 for one of 8
 * ports and bits 4:0 are event codes. There are different event codes
 * associated with each port type.
 *
 * Additionally, the range of events associated with the port types changed
 * between Rev0 and Rev1.
 *
 * The constants below define the range of valid codes for each port type for
 * the different revisions and are used to validate the event to be monitored.
 */

#define CCI_REV_R0_SLAVE_PORT_MIN_EV	0x00
#define CCI_REV_R0_SLAVE_PORT_MAX_EV	0x13
#define CCI_REV_R0_MASTER_PORT_MIN_EV	0x14
#define CCI_REV_R0_MASTER_PORT_MAX_EV	0x1a

#define CCI_REV_R1_SLAVE_PORT_MIN_EV	0x00
#define CCI_REV_R1_SLAVE_PORT_MAX_EV	0x14
#define CCI_REV_R1_MASTER_PORT_MIN_EV	0x00
#define CCI_REV_R1_MASTER_PORT_MAX_EV	0x11

struct pmu_port_event_ranges {
	u8 slave_min;
	u8 slave_max;
	u8 master_min;
	u8 master_max;
};

static struct pmu_port_event_ranges port_event_range[] = {
	[CCI_REV_R0] = {
		.slave_min = CCI_REV_R0_SLAVE_PORT_MIN_EV,
		.slave_max = CCI_REV_R0_SLAVE_PORT_MAX_EV,
		.master_min = CCI_REV_R0_MASTER_PORT_MIN_EV,
		.master_max = CCI_REV_R0_MASTER_PORT_MAX_EV,
	},
	[CCI_REV_R1] = {
		.slave_min = CCI_REV_R1_SLAVE_PORT_MIN_EV,
		.slave_max = CCI_REV_R1_SLAVE_PORT_MAX_EV,
		.master_min = CCI_REV_R1_MASTER_PORT_MIN_EV,
		.master_max = CCI_REV_R1_MASTER_PORT_MAX_EV,
	},
};

struct cci_pmu_drv_data {
	void __iomem *base;
	struct arm_pmu *cci_pmu;
	int nr_irqs;
	int irqs[CCI_PMU_MAX_HW_EVENTS];
	unsigned long active_irqs;
	struct perf_event *events[CCI_PMU_MAX_HW_EVENTS];
	unsigned long used_mask[BITS_TO_LONGS(CCI_PMU_MAX_HW_EVENTS)];
	struct pmu_port_event_ranges *port_ranges;
	struct pmu_hw_events hw_events;
};
static struct cci_pmu_drv_data *pmu;

static bool is_duplicate_irq(int irq, int *irqs, int nr_irqs)
{
	int i;

	for (i = 0; i < nr_irqs; i++)
		if (irq == irqs[i])
			return true;

	return false;
}

static int probe_cci_revision(void)
{
	int rev;
	rev = readl_relaxed(cci_ctrl_base + CCI_PID2) & CCI_PID2_REV_MASK;
	rev >>= CCI_PID2_REV_SHIFT;

	if (rev <= CCI_REV_R0_P4)
		return CCI_REV_R0;
	else if (rev <= CCI_REV_R1_P2)
		return CCI_REV_R1;

	return -ENOENT;
}

static struct pmu_port_event_ranges *port_range_by_rev(void)
{
	int rev = probe_cci_revision();

	if (rev < 0)
		return NULL;

	return &port_event_range[rev];
}

static int pmu_is_valid_slave_event(u8 ev_code)
{
	return pmu->port_ranges->slave_min <= ev_code &&
		ev_code <= pmu->port_ranges->slave_max;
}

static int pmu_is_valid_master_event(u8 ev_code)
{
	return pmu->port_ranges->master_min <= ev_code &&
		ev_code <= pmu->port_ranges->master_max;
}

static int pmu_validate_hw_event(u8 hw_event)
{
	u8 ev_source = CCI_PMU_EVENT_SOURCE(hw_event);
	u8 ev_code = CCI_PMU_EVENT_CODE(hw_event);

	switch (ev_source) {
	case CCI_PORT_S0:
	case CCI_PORT_S1:
	case CCI_PORT_S2:
	case CCI_PORT_S3:
	case CCI_PORT_S4:
		/* Slave Interface */
		if (pmu_is_valid_slave_event(ev_code))
			return hw_event;
		break;
	case CCI_PORT_M0:
	case CCI_PORT_M1:
	case CCI_PORT_M2:
		/* Master Interface */
		if (pmu_is_valid_master_event(ev_code))
			return hw_event;
		break;
	}

	return -ENOENT;
}

static int pmu_is_valid_counter(struct arm_pmu *cci_pmu, int idx)
{
	return CCI_PMU_CYCLE_CNTR_IDX <= idx &&
		idx <= CCI_PMU_CNTR_LAST(cci_pmu);
}

static u32 pmu_read_register(int idx, unsigned int offset)
{
	return readl_relaxed(pmu->base + CCI_PMU_CNTR_BASE(idx) + offset);
}

static void pmu_write_register(u32 value, int idx, unsigned int offset)
{
	return writel_relaxed(value, pmu->base + CCI_PMU_CNTR_BASE(idx) + offset);
}

static void pmu_disable_counter(int idx)
{
	pmu_write_register(0, idx, CCI_PMU_CNTR_CTRL);
}

static void pmu_enable_counter(int idx)
{
	pmu_write_register(1, idx, CCI_PMU_CNTR_CTRL);
}

static void pmu_set_event(int idx, unsigned long event)
{
	event &= CCI_PMU_EVENT_MASK;
	pmu_write_register(event, idx, CCI_PMU_EVT_SEL);
}

static u32 pmu_get_max_counters(void)
{
	u32 n_cnts = (readl_relaxed(cci_ctrl_base + CCI_PMCR) &
		      CCI_PMCR_NCNT_MASK) >> CCI_PMCR_NCNT_SHIFT;

	/* add 1 for cycle counter */
	return n_cnts + 1;
}

static struct pmu_hw_events *pmu_get_hw_events(void)
{
	return &pmu->hw_events;
}

static int pmu_get_event_idx(struct pmu_hw_events *hw, struct perf_event *event)
{
	struct arm_pmu *cci_pmu = to_arm_pmu(event->pmu);
	struct hw_perf_event *hw_event = &event->hw;
	unsigned long cci_event = hw_event->config_base & CCI_PMU_EVENT_MASK;
	int idx;

	if (cci_event == CCI_PMU_CYCLES) {
		if (test_and_set_bit(CCI_PMU_CYCLE_CNTR_IDX, hw->used_mask))
			return -EAGAIN;

		return CCI_PMU_CYCLE_CNTR_IDX;
	}

	for (idx = CCI_PMU_CNTR0_IDX; idx <= CCI_PMU_CNTR_LAST(cci_pmu); ++idx)
		if (!test_and_set_bit(idx, hw->used_mask))
			return idx;

	/* No counters available */
	return -EAGAIN;
}

static int pmu_map_event(struct perf_event *event)
{
	int mapping;
	u8 config = event->attr.config & CCI_PMU_EVENT_MASK;

	if (event->attr.type < PERF_TYPE_MAX)
		return -ENOENT;

	if (config == CCI_PMU_CYCLES)
		mapping = config;
	else
		mapping = pmu_validate_hw_event(config);

	return mapping;
}

static int pmu_request_irq(struct arm_pmu *cci_pmu, irq_handler_t handler)
{
	int i;
	struct platform_device *pmu_device = cci_pmu->plat_device;

	if (unlikely(!pmu_device))
		return -ENODEV;

	if (pmu->nr_irqs < 1) {
		dev_err(&pmu_device->dev, "no irqs for CCI PMUs defined\n");
		return -ENODEV;
	}

	/*
	 * Register all available CCI PMU interrupts. In the interrupt handler
	 * we iterate over the counters checking for interrupt source (the
	 * overflowing counter) and clear it.
	 *
	 * This should allow handling of non-unique interrupt for the counters.
	 */
	for (i = 0; i < pmu->nr_irqs; i++) {
		int err = request_irq(pmu->irqs[i], handler, IRQF_SHARED,
				"arm-cci-pmu", cci_pmu);
		if (err) {
			dev_err(&pmu_device->dev, "unable to request IRQ%d for ARM CCI PMU counters\n",
				pmu->irqs[i]);
			return err;
		}

		set_bit(i, &pmu->active_irqs);
	}

	return 0;
}

static irqreturn_t pmu_handle_irq(int irq_num, void *dev)
{
	unsigned long flags;
	struct arm_pmu *cci_pmu = (struct arm_pmu *)dev;
	struct pmu_hw_events *events = cci_pmu->get_hw_events();
	struct perf_sample_data data;
	struct pt_regs *regs;
	int idx, handled = IRQ_NONE;

	raw_spin_lock_irqsave(&events->pmu_lock, flags);
	regs = get_irq_regs();
	/*
	 * Iterate over counters and update the corresponding perf events.
	 * This should work regardless of whether we have per-counter overflow
	 * interrupt or a combined overflow interrupt.
	 */
	for (idx = CCI_PMU_CYCLE_CNTR_IDX; idx <= CCI_PMU_CNTR_LAST(cci_pmu); idx++) {
		struct perf_event *event = events->events[idx];
		struct hw_perf_event *hw_counter;

		if (!event)
			continue;

		hw_counter = &event->hw;

		/* Did this counter overflow? */
		if (!pmu_read_register(idx, CCI_PMU_OVRFLW) & CCI_PMU_OVRFLW_FLAG)
			continue;

		pmu_write_register(CCI_PMU_OVRFLW_FLAG, idx, CCI_PMU_OVRFLW);

		handled = IRQ_HANDLED;

		armpmu_event_update(event);
		perf_sample_data_init(&data, 0, hw_counter->last_period);
		if (!armpmu_event_set_period(event))
			continue;

		if (perf_event_overflow(event, &data, regs))
			cci_pmu->disable(event);
	}
	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);

	return IRQ_RETVAL(handled);
}

static void pmu_free_irq(struct arm_pmu *cci_pmu)
{
	int i;

	for (i = 0; i < pmu->nr_irqs; i++) {
		if (!test_and_clear_bit(i, &pmu->active_irqs))
			continue;

		free_irq(pmu->irqs[i], cci_pmu);
	}
}

static void pmu_enable_event(struct perf_event *event)
{
	unsigned long flags;
	struct arm_pmu *cci_pmu = to_arm_pmu(event->pmu);
	struct pmu_hw_events *events = cci_pmu->get_hw_events();
	struct hw_perf_event *hw_counter = &event->hw;
	int idx = hw_counter->idx;

	if (unlikely(!pmu_is_valid_counter(cci_pmu, idx))) {
		dev_err(&cci_pmu->plat_device->dev, "Invalid CCI PMU counter %d\n", idx);
		return;
	}

	raw_spin_lock_irqsave(&events->pmu_lock, flags);

	/* Configure the event to count, unless you are counting cycles */
	if (idx != CCI_PMU_CYCLE_CNTR_IDX)
		pmu_set_event(idx, hw_counter->config_base);

	pmu_enable_counter(idx);

	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}

static void pmu_disable_event(struct perf_event *event)
{
	struct arm_pmu *cci_pmu = to_arm_pmu(event->pmu);
	struct hw_perf_event *hw_counter = &event->hw;
	int idx = hw_counter->idx;

	if (unlikely(!pmu_is_valid_counter(cci_pmu, idx))) {
		dev_err(&cci_pmu->plat_device->dev, "Invalid CCI PMU counter %d\n", idx);
		return;
	}

	pmu_disable_counter(idx);
}

static void pmu_start(struct arm_pmu *cci_pmu)
{
	u32 val;
	unsigned long flags;
	struct pmu_hw_events *events = cci_pmu->get_hw_events();

	raw_spin_lock_irqsave(&events->pmu_lock, flags);

	/* Enable all the PMU counters. */
	val = readl_relaxed(cci_ctrl_base + CCI_PMCR) | CCI_PMCR_CEN;
	writel(val, cci_ctrl_base + CCI_PMCR);

	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}

static void pmu_stop(struct arm_pmu *cci_pmu)
{
	u32 val;
	unsigned long flags;
	struct pmu_hw_events *events = cci_pmu->get_hw_events();

	raw_spin_lock_irqsave(&events->pmu_lock, flags);

	/* Disable all the PMU counters. */
	val = readl_relaxed(cci_ctrl_base + CCI_PMCR) & ~CCI_PMCR_CEN;
	writel(val, cci_ctrl_base + CCI_PMCR);

	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}

static u32 pmu_read_counter(struct perf_event *event)
{
	struct arm_pmu *cci_pmu = to_arm_pmu(event->pmu);
	struct hw_perf_event *hw_counter = &event->hw;
	int idx = hw_counter->idx;
	u32 value;

	if (unlikely(!pmu_is_valid_counter(cci_pmu, idx))) {
		dev_err(&cci_pmu->plat_device->dev, "Invalid CCI PMU counter %d\n", idx);
		return 0;
	}
	value = pmu_read_register(idx, CCI_PMU_CNTR);

	return value;
}

static void pmu_write_counter(struct perf_event *event, u32 value)
{
	struct arm_pmu *cci_pmu = to_arm_pmu(event->pmu);
	struct hw_perf_event *hw_counter = &event->hw;
	int idx = hw_counter->idx;

	if (unlikely(!pmu_is_valid_counter(cci_pmu, idx)))
		dev_err(&cci_pmu->plat_device->dev, "Invalid CCI PMU counter %d\n", idx);
	else
		pmu_write_register(value, idx, CCI_PMU_CNTR);
}

static int cci_pmu_init(struct arm_pmu *cci_pmu, struct platform_device *pdev)
{
	*cci_pmu = (struct arm_pmu){
		.name             = PMU_NAME,
		.max_period       = (1LLU << 32) - 1,
		.get_hw_events    = pmu_get_hw_events,
		.get_event_idx    = pmu_get_event_idx,
		.map_event        = pmu_map_event,
		.request_irq      = pmu_request_irq,
		.handle_irq       = pmu_handle_irq,
		.free_irq         = pmu_free_irq,
		.enable           = pmu_enable_event,
		.disable          = pmu_disable_event,
		.start            = pmu_start,
		.stop             = pmu_stop,
		.read_counter     = pmu_read_counter,
		.write_counter    = pmu_write_counter,
	};

	cci_pmu->plat_device = pdev;
	cci_pmu->num_events = pmu_get_max_counters();

	return armpmu_register(cci_pmu, -1);
}

static const struct of_device_id arm_cci_pmu_matches[] = {
	{
		.compatible = "arm,cci-400-pmu",
	},
	{},
};

static int cci_pmu_probe(struct platform_device *pdev)
{
	struct resource *res;
	int i, ret, irq;

	pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
	if (!pmu)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_warn(&pdev->dev, "Failed to get mem resource\n");
		ret = -EINVAL;
		goto memalloc_err;
	};

	pmu->base = devm_ioremap_resource(&pdev->dev, res);
	if (!pmu->base) {
		dev_warn(&pdev->dev, "Failed to ioremap\n");
		ret = -ENOMEM;
		goto memalloc_err;
	}

	/*
	 * CCI PMU has 5 overflow signals - one per counter; but some may be tied
	 * together to a common interrupt.
	 */
	pmu->nr_irqs = 0;
	for (i = 0; i < CCI_PMU_MAX_HW_EVENTS; i++) {
		irq = platform_get_irq(pdev, i);
		if (irq < 0)
			break;

		if (is_duplicate_irq(irq, pmu->irqs, pmu->nr_irqs))
			continue;

		pmu->irqs[pmu->nr_irqs++] = irq;
	}

	/*
	 * Ensure that the device tree has as many interrupts as the number
	 * of counters.
	 */
	if (i < CCI_PMU_MAX_HW_EVENTS) {
		dev_warn(&pdev->dev, "In-correct number of interrupts: %d, should be %d\n",
			i, CCI_PMU_MAX_HW_EVENTS);
		ret = -EINVAL;
		goto memalloc_err;
	}

	pmu->port_ranges = port_range_by_rev();
	if (!pmu->port_ranges) {
		dev_warn(&pdev->dev, "CCI PMU version not supported\n");
		ret = -EINVAL;
		goto memalloc_err;
	}

	pmu->cci_pmu = devm_kzalloc(&pdev->dev, sizeof(*(pmu->cci_pmu)), GFP_KERNEL);
	if (!pmu->cci_pmu) {
		ret = -ENOMEM;
		goto memalloc_err;
	}

	pmu->hw_events.events = pmu->events;
	pmu->hw_events.used_mask = pmu->used_mask;
	raw_spin_lock_init(&pmu->hw_events.pmu_lock);

	ret = cci_pmu_init(pmu->cci_pmu, pdev);
	if (ret)
		goto pmuinit_err;

	return 0;

pmuinit_err:
	kfree(pmu->cci_pmu);
memalloc_err:
	kfree(pmu);
	return ret;
}

static int cci_platform_probe(struct platform_device *pdev)
{
	if (!cci_probed())
		return -ENODEV;

	return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
}

#endif /* CONFIG_HW_PERF_EVENTS */

struct cpu_port {
	u64 mpidr;
	u32 port;
@@ -120,7 +711,7 @@ int cci_ace_get_port(struct device_node *dn)
}
EXPORT_SYMBOL_GPL(cci_ace_get_port);

static void __init cci_ace_init_ports(void)
static void cci_ace_init_ports(void)
{
	int port, cpu;
	struct device_node *cpun;
@@ -386,7 +977,7 @@ static const struct of_device_id arm_cci_ctrl_if_matches[] = {
	{},
};

static int __init cci_probe(void)
static int cci_probe(void)
{
	struct cci_nb_ports const *cci_config;
	int ret, i, nb_ace = 0, nb_ace_lite = 0;
@@ -490,7 +1081,7 @@ memalloc_err:
static int cci_init_status = -EAGAIN;
static DEFINE_MUTEX(cci_probing);

static int __init cci_init(void)
static int cci_init(void)
{
	if (cci_init_status != -EAGAIN)
		return cci_init_status;
@@ -502,18 +1093,55 @@ static int __init cci_init(void)
	return cci_init_status;
}

#ifdef CONFIG_HW_PERF_EVENTS
static struct platform_driver cci_pmu_driver = {
	.driver = {
		   .name = DRIVER_NAME_PMU,
		   .of_match_table = arm_cci_pmu_matches,
		  },
	.probe = cci_pmu_probe,
};

static struct platform_driver cci_platform_driver = {
	.driver = {
		   .name = DRIVER_NAME,
		   .of_match_table = arm_cci_matches,
		  },
	.probe = cci_platform_probe,
};

static int __init cci_platform_init(void)
{
	int ret;

	ret = platform_driver_register(&cci_pmu_driver);
	if (ret)
		return ret;

	return platform_driver_register(&cci_platform_driver);
}

#else

static int __init cci_platform_init(void)
{
	return 0;
}

#endif
/*
 * To sort out early init calls ordering a helper function is provided to
 * check if the CCI driver has beed initialized. Function check if the driver
 * has been initialized, if not it calls the init function that probes
 * the driver and updates the return value.
 */
bool __init cci_probed(void)
bool cci_probed(void)
{
	return cci_init() == 0;
}
EXPORT_SYMBOL_GPL(cci_probed);

early_initcall(cci_init);
core_initcall(cci_platform_init);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ARM CCI support");