Initial import

1 files changed, 1535 insertions, 0 deletions

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
new file mode 100644
index 000000000..5340604b2
--- /dev/null
+++ b/drivers/bus/arm-cci.c
@@ -0,0 +1,1535 @@
+/*
+ * CCI cache coherent interconnect driver
+ *
+ * Copyright (C) 2013 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/arm-cci.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+
+static void __iomem *cci_ctrl_base;
+static unsigned long cci_ctrl_phys;
+
+#ifdef CONFIG_ARM_CCI400_PORT_CTRL
+struct cci_nb_ports {
+	unsigned int nb_ace;
+	unsigned int nb_ace_lite;
+};
+
+static const struct cci_nb_ports cci400_ports = {
+	.nb_ace = 2,
+	.nb_ace_lite = 3
+};
+
+#define CCI400_PORTS_DATA	(&cci400_ports)
+#else
+#define CCI400_PORTS_DATA	(NULL)
+#endif
+
+static const struct of_device_id arm_cci_matches[] = {
+#ifdef CONFIG_ARM_CCI400_COMMON
+	{.compatible = "arm,cci-400", .data = CCI400_PORTS_DATA },
+#endif
+	{},
+};
+
+#ifdef CONFIG_ARM_CCI400_PMU
+
+#define DRIVER_NAME		"CCI-400"
+#define DRIVER_NAME_PMU		DRIVER_NAME " PMU"
+
+#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
+
+#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)
+
+#define CCI_PMU_CNTR_MASK	((1ULL << 32) -1)
+
+#define CCI_PMU_EVENT_MASK		0xffUL
+#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 */
+
+/* Types of interfaces that can generate events */
+enum {
+	CCI_IF_SLAVE,
+	CCI_IF_MASTER,
+	CCI_IF_MAX,
+};
+
+struct event_range {
+	u32 min;
+	u32 max;
+};
+
+struct cci_pmu_hw_events {
+	struct perf_event *events[CCI_PMU_MAX_HW_EVENTS];
+	unsigned long used_mask[BITS_TO_LONGS(CCI_PMU_MAX_HW_EVENTS)];
+	raw_spinlock_t pmu_lock;
+};
+
+struct cci_pmu_model {
+	char *name;
+	struct event_range event_ranges[CCI_IF_MAX];
+};
+
+static struct cci_pmu_model cci_pmu_models[];
+
+struct cci_pmu {
+	void __iomem *base;
+	struct pmu pmu;
+	int nr_irqs;
+	int irqs[CCI_PMU_MAX_HW_EVENTS];
+	unsigned long active_irqs;
+	const struct cci_pmu_model *model;
+	struct cci_pmu_hw_events hw_events;
+	struct platform_device *plat_device;
+	int num_events;
+	atomic_t active_events;
+	struct mutex reserve_mutex;
+	cpumask_t cpus;
+};
+static struct cci_pmu *pmu;
+
+#define to_cci_pmu(c)	(container_of(c, struct cci_pmu, pmu))
+
+/* 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_R1_PX		5
+
+/*
+ * 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_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
+
+static int pmu_validate_hw_event(unsigned long hw_event)
+{
+	u8 ev_source = CCI_PMU_EVENT_SOURCE(hw_event);
+	u8 ev_code = CCI_PMU_EVENT_CODE(hw_event);
+	int if_type;
+
+	if (hw_event & ~CCI_PMU_EVENT_MASK)
+		return -ENOENT;
+
+	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_type = CCI_IF_SLAVE;
+		break;
+	case CCI_PORT_M0:
+	case CCI_PORT_M1:
+	case CCI_PORT_M2:
+		/* Master Interface */
+		if_type = CCI_IF_MASTER;
+		break;
+	default:
+		return -ENOENT;
+	}
+
+	if (ev_code >= pmu->model->event_ranges[if_type].min &&
+		ev_code <= pmu->model->event_ranges[if_type].max)
+		return hw_event;
+
+	return -ENOENT;
+}
+
+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_R1_PX)
+		return CCI_REV_R0;
+	else
+		return CCI_REV_R1;
+}
+
+static const struct cci_pmu_model *probe_cci_model(struct platform_device *pdev)
+{
+	if (platform_has_secure_cci_access())
+		return &cci_pmu_models[probe_cci_revision()];
+	return NULL;
+}
+
+static int pmu_is_valid_counter(struct cci_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)
+{
+	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 int pmu_get_event_idx(struct cci_pmu_hw_events *hw, struct perf_event *event)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(event->pmu);
+	struct hw_perf_event *hw_event = &event->hw;
+	unsigned long cci_event = hw_event->config_base;
+	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;
+	unsigned long config = event->attr.config;
+
+	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 cci_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 void pmu_free_irq(struct cci_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 u32 pmu_read_counter(struct perf_event *event)
+{
+	struct cci_pmu *cci_pmu = to_cci_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 cci_pmu *cci_pmu = to_cci_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 u64 pmu_event_update(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	u64 delta, prev_raw_count, new_raw_count;
+
+	do {
+		prev_raw_count = local64_read(&hwc->prev_count);
+		new_raw_count = pmu_read_counter(event);
+	} while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
+		 new_raw_count) != prev_raw_count);
+
+	delta = (new_raw_count - prev_raw_count) & CCI_PMU_CNTR_MASK;
+
+	local64_add(delta, &event->count);
+
+	return new_raw_count;
+}
+
+static void pmu_read(struct perf_event *event)
+{
+	pmu_event_update(event);
+}
+
+void pmu_event_set_period(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	/*
+	 * The CCI PMU counters have a period of 2^32. To account for the
+	 * possiblity of extreme interrupt latency we program for a period of
+	 * half that. Hopefully we can handle the interrupt before another 2^31
+	 * events occur and the counter overtakes its previous value.
+	 */
+	u64 val = 1ULL << 31;
+	local64_set(&hwc->prev_count, val);
+	pmu_write_counter(event, val);
+}
+
+static irqreturn_t pmu_handle_irq(int irq_num, void *dev)
+{
+	unsigned long flags;
+	struct cci_pmu *cci_pmu = dev;
+	struct cci_pmu_hw_events *events = &pmu->hw_events;
+	int idx, handled = IRQ_NONE;
+
+	raw_spin_lock_irqsave(&events->pmu_lock, flags);
+	/*
+	 * 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);
+
+		pmu_event_update(event);
+		pmu_event_set_period(event);
+		handled = IRQ_HANDLED;
+	}
+	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
+
+	return IRQ_RETVAL(handled);
+}
+
+static int cci_pmu_get_hw(struct cci_pmu *cci_pmu)
+{
+	int ret = pmu_request_irq(cci_pmu, pmu_handle_irq);
+	if (ret) {
+		pmu_free_irq(cci_pmu);
+		return ret;
+	}
+	return 0;
+}
+
+static void cci_pmu_put_hw(struct cci_pmu *cci_pmu)
+{
+	pmu_free_irq(cci_pmu);
+}
+
+static void hw_perf_event_destroy(struct perf_event *event)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(event->pmu);
+	atomic_t *active_events = &cci_pmu->active_events;
+	struct mutex *reserve_mutex = &cci_pmu->reserve_mutex;
+
+	if (atomic_dec_and_mutex_lock(active_events, reserve_mutex)) {
+		cci_pmu_put_hw(cci_pmu);
+		mutex_unlock(reserve_mutex);
+	}
+}
+
+static void cci_pmu_enable(struct pmu *pmu)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(pmu);
+	struct cci_pmu_hw_events *hw_events = &cci_pmu->hw_events;
+	int enabled = bitmap_weight(hw_events->used_mask, cci_pmu->num_events);
+	unsigned long flags;
+	u32 val;
+
+	if (!enabled)
+		return;
+
+	raw_spin_lock_irqsave(&hw_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(&hw_events->pmu_lock, flags);
+
+}
+
+static void cci_pmu_disable(struct pmu *pmu)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(pmu);
+	struct cci_pmu_hw_events *hw_events = &cci_pmu->hw_events;
+	unsigned long flags;
+	u32 val;
+
+	raw_spin_lock_irqsave(&hw_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(&hw_events->pmu_lock, flags);
+}
+
+static void cci_pmu_start(struct perf_event *event, int pmu_flags)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(event->pmu);
+	struct cci_pmu_hw_events *hw_events = &cci_pmu->hw_events;
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = hwc->idx;
+	unsigned long flags;
+
+	/*
+	 * To handle interrupt latency, we always reprogram the period
+	 * regardlesss of PERF_EF_RELOAD.
+	 */
+	if (pmu_flags & PERF_EF_RELOAD)
+		WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+
+	hwc->state = 0;
+
+	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(&hw_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, hwc->config_base);
+
+	pmu_event_set_period(event);
+	pmu_enable_counter(idx);
+
+	raw_spin_unlock_irqrestore(&hw_events->pmu_lock, flags);
+}
+
+static void cci_pmu_stop(struct perf_event *event, int pmu_flags)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = hwc->idx;
+
+	if (hwc->state & PERF_HES_STOPPED)
+		return;
+
+	if (unlikely(!pmu_is_valid_counter(cci_pmu, idx))) {
+		dev_err(&cci_pmu->plat_device->dev, "Invalid CCI PMU counter %d\n", idx);
+		return;
+	}
+
+	/*
+	 * We always reprogram the counter, so ignore PERF_EF_UPDATE. See
+	 * cci_pmu_start()
+	 */
+	pmu_disable_counter(idx);
+	pmu_event_update(event);
+	hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int cci_pmu_add(struct perf_event *event, int flags)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(event->pmu);
+	struct cci_pmu_hw_events *hw_events = &cci_pmu->hw_events;
+	struct hw_perf_event *hwc = &event->hw;
+	int idx;
+	int err = 0;
+
+	perf_pmu_disable(event->pmu);
+
+	/* If we don't have a space for the counter then finish early. */
+	idx = pmu_get_event_idx(hw_events, event);
+	if (idx < 0) {
+		err = idx;
+		goto out;
+	}
+
+	event->hw.idx = idx;
+	hw_events->events[idx] = event;
+
+	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+	if (flags & PERF_EF_START)
+		cci_pmu_start(event, PERF_EF_RELOAD);
+
+	/* Propagate our changes to the userspace mapping. */
+	perf_event_update_userpage(event);
+
+out:
+	perf_pmu_enable(event->pmu);
+	return err;
+}
+
+static void cci_pmu_del(struct perf_event *event, int flags)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(event->pmu);
+	struct cci_pmu_hw_events *hw_events = &cci_pmu->hw_events;
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = hwc->idx;
+
+	cci_pmu_stop(event, PERF_EF_UPDATE);
+	hw_events->events[idx] = NULL;
+	clear_bit(idx, hw_events->used_mask);
+
+	perf_event_update_userpage(event);
+}
+
+static int
+validate_event(struct pmu *cci_pmu,
+               struct cci_pmu_hw_events *hw_events,
+               struct perf_event *event)
+{
+	if (is_software_event(event))
+		return 1;
+
+	/*
+	 * Reject groups spanning multiple HW PMUs (e.g. CPU + CCI). The
+	 * core perf code won't check that the pmu->ctx == leader->ctx
+	 * until after pmu->event_init(event).
+	 */
+	if (event->pmu != cci_pmu)
+		return 0;
+
+	if (event->state < PERF_EVENT_STATE_OFF)
+		return 1;
+
+	if (event->state == PERF_EVENT_STATE_OFF && !event->attr.enable_on_exec)
+		return 1;
+
+	return pmu_get_event_idx(hw_events, event) >= 0;
+}
+
+static int
+validate_group(struct perf_event *event)
+{
+	struct perf_event *sibling, *leader = event->group_leader;
+	struct cci_pmu_hw_events fake_pmu = {
+		/*
+		 * Initialise the fake PMU. We only need to populate the
+		 * used_mask for the purposes of validation.
+		 */
+		.used_mask = { 0 },
+	};
+
+	if (!validate_event(event->pmu, &fake_pmu, leader))
+		return -EINVAL;
+
+	list_for_each_entry(sibling, &leader->sibling_list, group_entry) {
+		if (!validate_event(event->pmu, &fake_pmu, sibling))
+			return -EINVAL;
+	}
+
+	if (!validate_event(event->pmu, &fake_pmu, event))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int
+__hw_perf_event_init(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	int mapping;
+
+	mapping = pmu_map_event(event);
+
+	if (mapping < 0) {
+		pr_debug("event %x:%llx not supported\n", event->attr.type,
+			 event->attr.config);
+		return mapping;
+	}
+
+	/*
+	 * We don't assign an index until we actually place the event onto
+	 * hardware. Use -1 to signify that we haven't decided where to put it
+	 * yet.
+	 */
+	hwc->idx		= -1;
+	hwc->config_base	= 0;
+	hwc->config		= 0;
+	hwc->event_base		= 0;
+
+	/*
+	 * Store the event encoding into the config_base field.
+	 */
+	hwc->config_base	    |= (unsigned long)mapping;
+
+	/*
+	 * Limit the sample_period to half of the counter width. That way, the
+	 * new counter value is far less likely to overtake the previous one
+	 * unless you have some serious IRQ latency issues.
+	 */
+	hwc->sample_period  = CCI_PMU_CNTR_MASK >> 1;
+	hwc->last_period    = hwc->sample_period;
+	local64_set(&hwc->period_left, hwc->sample_period);
+
+	if (event->group_leader != event) {
+		if (validate_group(event) != 0)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cci_pmu_event_init(struct perf_event *event)
+{
+	struct cci_pmu *cci_pmu = to_cci_pmu(event->pmu);
+	atomic_t *active_events = &cci_pmu->active_events;
+	int err = 0;
+	int cpu;
+
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	/* Shared by all CPUs, no meaningful state to sample */
+	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
+		return -EOPNOTSUPP;
+
+	/* We have no filtering of any kind */
+	if (event->attr.exclude_user	||
+	    event->attr.exclude_kernel	||
+	    event->attr.exclude_hv	||
+	    event->attr.exclude_idle	||
+	    event->attr.exclude_host	||
+	    event->attr.exclude_guest)
+		return -EINVAL;
+
+	/*
+	 * Following the example set by other "uncore" PMUs, we accept any CPU
+	 * and rewrite its affinity dynamically rather than having perf core
+	 * handle cpu == -1 and pid == -1 for this case.
+	 *
+	 * The perf core will pin online CPUs for the duration of this call and
+	 * the event being installed into its context, so the PMU's CPU can't
+	 * change under our feet.
+	 */
+	cpu = cpumask_first(&cci_pmu->cpus);
+	if (event->cpu < 0 || cpu < 0)
+		return -EINVAL;
+	event->cpu = cpu;
+
+	event->destroy = hw_perf_event_destroy;
+	if (!atomic_inc_not_zero(active_events)) {
+		mutex_lock(&cci_pmu->reserve_mutex);
+		if (atomic_read(active_events) == 0)
+			err = cci_pmu_get_hw(cci_pmu);
+		if (!err)
+			atomic_inc(active_events);
+		mutex_unlock(&cci_pmu->reserve_mutex);
+	}
+	if (err)
+		return err;
+
+	err = __hw_perf_event_init(event);
+	if (err)
+		hw_perf_event_destroy(event);
+
+	return err;
+}
+
+static ssize_t pmu_attr_cpumask_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	int n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
+			  cpumask_pr_args(&pmu->cpus));
+	buf[n++] = '\n';
+	buf[n] = '\0';
+	return n;
+}
+
+static DEVICE_ATTR(cpumask, S_IRUGO, pmu_attr_cpumask_show, NULL);
+
+static struct attribute *pmu_attrs[] = {
+	&dev_attr_cpumask.attr,
+	NULL,
+};
+
+static struct attribute_group pmu_attr_group = {
+	.attrs = pmu_attrs,
+};
+
+static const struct attribute_group *pmu_attr_groups[] = {
+	&pmu_attr_group,
+	NULL
+};
+
+static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
+{
+	char *name = cci_pmu->model->name;
+	cci_pmu->pmu = (struct pmu) {
+		.name		= cci_pmu->model->name,
+		.task_ctx_nr	= perf_invalid_context,
+		.pmu_enable	= cci_pmu_enable,
+		.pmu_disable	= cci_pmu_disable,
+		.event_init	= cci_pmu_event_init,
+		.add		= cci_pmu_add,
+		.del		= cci_pmu_del,
+		.start		= cci_pmu_start,
+		.stop		= cci_pmu_stop,
+		.read		= pmu_read,
+		.attr_groups	= pmu_attr_groups,
+	};
+
+	cci_pmu->plat_device = pdev;
+	cci_pmu->num_events = pmu_get_max_counters();
+
+	return perf_pmu_register(&cci_pmu->pmu, name, -1);
+}
+
+static int cci_pmu_cpu_notifier(struct notifier_block *self,
+				unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (long)hcpu;
+	unsigned int target;
+
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_DOWN_PREPARE:
+		if (!cpumask_test_and_clear_cpu(cpu, &pmu->cpus))
+			break;
+		target = cpumask_any_but(cpu_online_mask, cpu);
+		if (target < 0) // UP, last CPU
+			break;
+		/*
+		 * TODO: migrate context once core races on event->ctx have
+		 * been fixed.
+		 */
+		cpumask_set_cpu(target, &pmu->cpus);
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cci_pmu_cpu_nb = {
+	.notifier_call	= cci_pmu_cpu_notifier,
+	/*
+	 * to migrate uncore events, our notifier should be executed
+	 * before perf core's notifier.
+	 */
+	.priority	= CPU_PRI_PERF + 1,
+};
+
+static struct cci_pmu_model cci_pmu_models[] = {
+	[CCI_REV_R0] = {
+		.name = "CCI_400",
+		.event_ranges = {
+			[CCI_IF_SLAVE] = {
+				CCI_REV_R0_SLAVE_PORT_MIN_EV,
+				CCI_REV_R0_SLAVE_PORT_MAX_EV,
+			},
+			[CCI_IF_MASTER] = {
+				CCI_REV_R0_MASTER_PORT_MIN_EV,
+				CCI_REV_R0_MASTER_PORT_MAX_EV,
+			},
+		},
+	},
+	[CCI_REV_R1] = {
+		.name = "CCI_400_r1",
+		.event_ranges = {
+			[CCI_IF_SLAVE] = {
+				CCI_REV_R1_SLAVE_PORT_MIN_EV,
+				CCI_REV_R1_SLAVE_PORT_MAX_EV,
+			},
+			[CCI_IF_MASTER] = {
+				CCI_REV_R1_MASTER_PORT_MIN_EV,
+				CCI_REV_R1_MASTER_PORT_MAX_EV,
+			},
+		},
+	},
+};
+
+static const struct of_device_id arm_cci_pmu_matches[] = {
+	{
+		.compatible = "arm,cci-400-pmu",
+		.data	= NULL,
+	},
+	{
+		.compatible = "arm,cci-400-pmu,r0",
+		.data	= &cci_pmu_models[CCI_REV_R0],
+	},
+	{
+		.compatible = "arm,cci-400-pmu,r1",
+		.data	= &cci_pmu_models[CCI_REV_R1],
+	},
+	{},
+};
+
+static inline const struct cci_pmu_model *get_cci_model(struct platform_device *pdev)
+{
+	const struct of_device_id *match = of_match_node(arm_cci_pmu_matches,
+							pdev->dev.of_node);
+	if (!match)
+		return NULL;
+	if (match->data)
+		return match->data;
+
+	dev_warn(&pdev->dev, "DEPRECATED compatible property,"
+			 "requires secure access to CCI registers");
+	return probe_cci_model(pdev);
+}
+
+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 cci_pmu_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	int i, ret, irq;
+	const struct cci_pmu_model *model;
+
+	model = get_cci_model(pdev);
+	if (!model) {
+		dev_warn(&pdev->dev, "CCI PMU version not supported\n");
+		return -ENODEV;
+	}
+
+	pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
+	if (!pmu)
+		return -ENOMEM;
+
+	pmu->model = model;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pmu->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pmu->base))
+		return -ENOMEM;
+
+	/*
+	 * 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);
+		return -EINVAL;
+	}
+
+	raw_spin_lock_init(&pmu->hw_events.pmu_lock);
+	mutex_init(&pmu->reserve_mutex);
+	atomic_set(&pmu->active_events, 0);
+	cpumask_set_cpu(smp_processor_id(), &pmu->cpus);
+
+	ret = register_cpu_notifier(&cci_pmu_cpu_nb);
+	if (ret)
+		return ret;
+
+	ret = cci_pmu_init(pmu, pdev);
+	if (ret)
+		return ret;
+
+	pr_info("ARM %s PMU driver probed", pmu->model->name);
+	return 0;
+}
+
+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);
+}
+
+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 /* !CONFIG_ARM_CCI400_PMU */
+
+static int __init cci_platform_init(void)
+{
+	return 0;
+}
+
+#endif /* CONFIG_ARM_CCI400_PMU */
+
+#ifdef CONFIG_ARM_CCI400_PORT_CTRL
+
+#define CCI_PORT_CTRL		0x0
+#define CCI_CTRL_STATUS		0xc
+
+#define CCI_ENABLE_SNOOP_REQ	0x1
+#define CCI_ENABLE_DVM_REQ	0x2
+#define CCI_ENABLE_REQ		(CCI_ENABLE_SNOOP_REQ | CCI_ENABLE_DVM_REQ)
+
+enum cci_ace_port_type {
+	ACE_INVALID_PORT = 0x0,
+	ACE_PORT,
+	ACE_LITE_PORT,
+};
+
+struct cci_ace_port {
+	void __iomem *base;
+	unsigned long phys;
+	enum cci_ace_port_type type;
+	struct device_node *dn;
+};
+
+static struct cci_ace_port *ports;
+static unsigned int nb_cci_ports;
+
+struct cpu_port {
+	u64 mpidr;
+	u32 port;
+};
+
+/*
+ * Use the port MSB as valid flag, shift can be made dynamic
+ * by computing number of bits required for port indexes.
+ * Code disabling CCI cpu ports runs with D-cache invalidated
+ * and SCTLR bit clear so data accesses must be kept to a minimum
+ * to improve performance; for now shift is left static to
+ * avoid one more data access while disabling the CCI port.
+ */
+#define PORT_VALID_SHIFT	31
+#define PORT_VALID		(0x1 << PORT_VALID_SHIFT)
+
+static inline void init_cpu_port(struct cpu_port *port, u32 index, u64 mpidr)
+{
+	port->port = PORT_VALID | index;
+	port->mpidr = mpidr;
+}
+
+static inline bool cpu_port_is_valid(struct cpu_port *port)
+{
+	return !!(port->port & PORT_VALID);
+}
+
+static inline bool cpu_port_match(struct cpu_port *port, u64 mpidr)
+{
+	return port->mpidr == (mpidr & MPIDR_HWID_BITMASK);
+}
+
+static struct cpu_port cpu_port[NR_CPUS];
+
+/**
+ * __cci_ace_get_port - Function to retrieve the port index connected to
+ *			a cpu or device.
+ *
+ * @dn: device node of the device to look-up
+ * @type: port type
+ *
+ * Return value:
+ *	- CCI port index if success
+ *	- -ENODEV if failure
+ */
+static int __cci_ace_get_port(struct device_node *dn, int type)
+{
+	int i;
+	bool ace_match;
+	struct device_node *cci_portn;
+
+	cci_portn = of_parse_phandle(dn, "cci-control-port", 0);
+	for (i = 0; i < nb_cci_ports; i++) {
+		ace_match = ports[i].type == type;
+		if (ace_match && cci_portn == ports[i].dn)
+			return i;
+	}
+	return -ENODEV;
+}
+
+int cci_ace_get_port(struct device_node *dn)
+{
+	return __cci_ace_get_port(dn, ACE_LITE_PORT);
+}
+EXPORT_SYMBOL_GPL(cci_ace_get_port);
+
+static void cci_ace_init_ports(void)
+{
+	int port, cpu;
+	struct device_node *cpun;
+
+	/*
+	 * Port index look-up speeds up the function disabling ports by CPU,
+	 * since the logical to port index mapping is done once and does
+	 * not change after system boot.
+	 * The stashed index array is initialized for all possible CPUs
+	 * at probe time.
+	 */
+	for_each_possible_cpu(cpu) {
+		/* too early to use cpu->of_node */
+		cpun = of_get_cpu_node(cpu, NULL);
+
+		if (WARN(!cpun, "Missing cpu device node\n"))
+			continue;
+
+		port = __cci_ace_get_port(cpun, ACE_PORT);
+		if (port < 0)
+			continue;
+
+		init_cpu_port(&cpu_port[cpu], port, cpu_logical_map(cpu));
+	}
+
+	for_each_possible_cpu(cpu) {
+		WARN(!cpu_port_is_valid(&cpu_port[cpu]),
+			"CPU %u does not have an associated CCI port\n",
+			cpu);
+	}
+}
+/*
+ * Functions to enable/disable a CCI interconnect slave port
+ *
+ * They are called by low-level power management code to disable slave
+ * interfaces snoops and DVM broadcast.
+ * Since they may execute with cache data allocation disabled and
+ * after the caches have been cleaned and invalidated the functions provide
+ * no explicit locking since they may run with D-cache disabled, so normal
+ * cacheable kernel locks based on ldrex/strex may not work.
+ * Locking has to be provided by BSP implementations to ensure proper
+ * operations.
+ */
+
+/**
+ * cci_port_control() - function to control a CCI port
+ *
+ * @port: index of the port to setup
+ * @enable: if true enables the port, if false disables it
+ */
+static void notrace cci_port_control(unsigned int port, bool enable)
+{
+	void __iomem *base = ports[port].base;
+
+	writel_relaxed(enable ? CCI_ENABLE_REQ : 0, base + CCI_PORT_CTRL);
+	/*
+	 * This function is called from power down procedures
+	 * and must not execute any instruction that might
+	 * cause the processor to be put in a quiescent state
+	 * (eg wfi). Hence, cpu_relax() can not be added to this
+	 * read loop to optimize power, since it might hide possibly
+	 * disruptive operations.
+	 */
+	while (readl_relaxed(cci_ctrl_base + CCI_CTRL_STATUS) & 0x1)
+			;
+}
+
+/**
+ * cci_disable_port_by_cpu() - function to disable a CCI port by CPU
+ *			       reference
+ *
+ * @mpidr: mpidr of the CPU whose CCI port should be disabled
+ *
+ * Disabling a CCI port for a CPU implies disabling the CCI port
+ * controlling that CPU cluster. Code disabling CPU CCI ports
+ * must make sure that the CPU running the code is the last active CPU
+ * in the cluster ie all other CPUs are quiescent in a low power state.
+ *
+ * Return:
+ *	0 on success
+ *	-ENODEV on port look-up failure
+ */
+int notrace cci_disable_port_by_cpu(u64 mpidr)
+{
+	int cpu;
+	bool is_valid;
+	for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
+		is_valid = cpu_port_is_valid(&cpu_port[cpu]);
+		if (is_valid && cpu_port_match(&cpu_port[cpu], mpidr)) {
+			cci_port_control(cpu_port[cpu].port, false);
+			return 0;
+		}
+	}
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(cci_disable_port_by_cpu);
+
+/**
+ * cci_enable_port_for_self() - enable a CCI port for calling CPU
+ *
+ * Enabling a CCI port for the calling CPU implies enabling the CCI
+ * port controlling that CPU's cluster. Caller must make sure that the
+ * CPU running the code is the first active CPU in the cluster and all
+ * other CPUs are quiescent in a low power state  or waiting for this CPU
+ * to complete the CCI initialization.
+ *
+ * Because this is called when the MMU is still off and with no stack,
+ * the code must be position independent and ideally rely on callee
+ * clobbered registers only.  To achieve this we must code this function
+ * entirely in assembler.
+ *
+ * On success this returns with the proper CCI port enabled.  In case of
+ * any failure this never returns as the inability to enable the CCI is
+ * fatal and there is no possible recovery at this stage.
+ */
+asmlinkage void __naked cci_enable_port_for_self(void)
+{
+	asm volatile ("\n"
+"	.arch armv7-a\n"
+"	mrc	p15, 0, r0, c0, c0, 5	@ get MPIDR value \n"
+"	and	r0, r0, #"__stringify(MPIDR_HWID_BITMASK)" \n"
+"	adr	r1, 5f \n"
+"	ldr	r2, [r1] \n"
+"	add	r1, r1, r2		@ &cpu_port \n"
+"	add	ip, r1, %[sizeof_cpu_port] \n"
+
+	/* Loop over the cpu_port array looking for a matching MPIDR */
+"1:	ldr	r2, [r1, %[offsetof_cpu_port_mpidr_lsb]] \n"
+"	cmp	r2, r0 			@ compare MPIDR \n"
+"	bne	2f \n"
+
+	/* Found a match, now test port validity */
+"	ldr	r3, [r1, %[offsetof_cpu_port_port]] \n"
+"	tst	r3, #"__stringify(PORT_VALID)" \n"
+"	bne	3f \n"
+
+	/* no match, loop with the next cpu_port entry */
+"2:	add	r1, r1, %[sizeof_struct_cpu_port] \n"
+"	cmp	r1, ip			@ done? \n"
+"	blo	1b \n"
+
+	/* CCI port not found -- cheaply try to stall this CPU */
+"cci_port_not_found: \n"
+"	wfi \n"
+"	wfe \n"
+"	b	cci_port_not_found \n"
+
+	/* Use matched port index to look up the corresponding ports entry */
+"3:	bic	r3, r3, #"__stringify(PORT_VALID)" \n"
+"	adr	r0, 6f \n"
+"	ldmia	r0, {r1, r2} \n"
+"	sub	r1, r1, r0 		@ virt - phys \n"
+"	ldr	r0, [r0, r2] 		@ *(&ports) \n"
+"	mov	r2, %[sizeof_struct_ace_port] \n"
+"	mla	r0, r2, r3, r0		@ &ports[index] \n"
+"	sub	r0, r0, r1		@ virt_to_phys() \n"
+
+	/* Enable the CCI port */
+"	ldr	r0, [r0, %[offsetof_port_phys]] \n"
+"	mov	r3, %[cci_enable_req]\n"		   
+"	str	r3, [r0, #"__stringify(CCI_PORT_CTRL)"] \n"
+
+	/* poll the status reg for completion */
+"	adr	r1, 7f \n"
+"	ldr	r0, [r1] \n"
+"	ldr	r0, [r0, r1]		@ cci_ctrl_base \n"
+"4:	ldr	r1, [r0, #"__stringify(CCI_CTRL_STATUS)"] \n"
+"	tst	r1, %[cci_control_status_bits] \n"			
+"	bne	4b \n"
+
+"	mov	r0, #0 \n"
+"	bx	lr \n"
+
+"	.align	2 \n"
+"5:	.word	cpu_port - . \n"
+"6:	.word	. \n"
+"	.word	ports - 6b \n"
+"7:	.word	cci_ctrl_phys - . \n"
+	: :
+	[sizeof_cpu_port] "i" (sizeof(cpu_port)),
+	[cci_enable_req] "i" cpu_to_le32(CCI_ENABLE_REQ),
+	[cci_control_status_bits] "i" cpu_to_le32(1),
+#ifndef __ARMEB__
+	[offsetof_cpu_port_mpidr_lsb] "i" (offsetof(struct cpu_port, mpidr)),
+#else
+	[offsetof_cpu_port_mpidr_lsb] "i" (offsetof(struct cpu_port, mpidr)+4),
+#endif
+	[offsetof_cpu_port_port] "i" (offsetof(struct cpu_port, port)),
+	[sizeof_struct_cpu_port] "i" (sizeof(struct cpu_port)),
+	[sizeof_struct_ace_port] "i" (sizeof(struct cci_ace_port)),
+	[offsetof_port_phys] "i" (offsetof(struct cci_ace_port, phys)) );
+
+	unreachable();
+}
+
+/**
+ * __cci_control_port_by_device() - function to control a CCI port by device
+ *				    reference
+ *
+ * @dn: device node pointer of the device whose CCI port should be
+ *      controlled
+ * @enable: if true enables the port, if false disables it
+ *
+ * Return:
+ *	0 on success
+ *	-ENODEV on port look-up failure
+ */
+int notrace __cci_control_port_by_device(struct device_node *dn, bool enable)
+{
+	int port;
+
+	if (!dn)
+		return -ENODEV;
+
+	port = __cci_ace_get_port(dn, ACE_LITE_PORT);
+	if (WARN_ONCE(port < 0, "node %s ACE lite port look-up failure\n",
+				dn->full_name))
+		return -ENODEV;
+	cci_port_control(port, enable);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__cci_control_port_by_device);
+
+/**
+ * __cci_control_port_by_index() - function to control a CCI port by port index
+ *
+ * @port: port index previously retrieved with cci_ace_get_port()
+ * @enable: if true enables the port, if false disables it
+ *
+ * Return:
+ *	0 on success
+ *	-ENODEV on port index out of range
+ *	-EPERM if operation carried out on an ACE PORT
+ */
+int notrace __cci_control_port_by_index(u32 port, bool enable)
+{
+	if (port >= nb_cci_ports || ports[port].type == ACE_INVALID_PORT)
+		return -ENODEV;
+	/*
+	 * CCI control for ports connected to CPUS is extremely fragile
+	 * and must be made to go through a specific and controlled
+	 * interface (ie cci_disable_port_by_cpu(); control by general purpose
+	 * indexing is therefore disabled for ACE ports.
+	 */
+	if (ports[port].type == ACE_PORT)
+		return -EPERM;
+
+	cci_port_control(port, enable);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__cci_control_port_by_index);
+
+static const struct of_device_id arm_cci_ctrl_if_matches[] = {
+	{.compatible = "arm,cci-400-ctrl-if", },
+	{},
+};
+
+static int cci_probe_ports(struct device_node *np)
+{
+	struct cci_nb_ports const *cci_config;
+	int ret, i, nb_ace = 0, nb_ace_lite = 0;
+	struct device_node *cp;
+	struct resource res;
+	const char *match_str;
+	bool is_ace;
+
+
+	cci_config = of_match_node(arm_cci_matches, np)->data;
+	if (!cci_config)
+		return -ENODEV;
+
+	nb_cci_ports = cci_config->nb_ace + cci_config->nb_ace_lite;
+
+	ports = kcalloc(nb_cci_ports, sizeof(*ports), GFP_KERNEL);
+	if (!ports)
+		return -ENOMEM;
+
+	for_each_child_of_node(np, cp) {
+		if (!of_match_node(arm_cci_ctrl_if_matches, cp))
+			continue;
+
+		i = nb_ace + nb_ace_lite;
+
+		if (i >= nb_cci_ports)
+			break;
+
+		if (of_property_read_string(cp, "interface-type",
+					&match_str)) {
+			WARN(1, "node %s missing interface-type property\n",
+				  cp->full_name);
+			continue;
+		}
+		is_ace = strcmp(match_str, "ace") == 0;
+		if (!is_ace && strcmp(match_str, "ace-lite")) {
+			WARN(1, "node %s containing invalid interface-type property, skipping it\n",
+					cp->full_name);
+			continue;
+		}
+
+		ret = of_address_to_resource(cp, 0, &res);
+		if (!ret) {
+			ports[i].base = ioremap(res.start, resource_size(&res));
+			ports[i].phys = res.start;
+		}
+		if (ret || !ports[i].base) {
+			WARN(1, "unable to ioremap CCI port %d\n", i);
+			continue;
+		}
+
+		if (is_ace) {
+			if (WARN_ON(nb_ace >= cci_config->nb_ace))
+				continue;
+			ports[i].type = ACE_PORT;
+			++nb_ace;
+		} else {
+			if (WARN_ON(nb_ace_lite >= cci_config->nb_ace_lite))
+				continue;
+			ports[i].type = ACE_LITE_PORT;
+			++nb_ace_lite;
+		}
+		ports[i].dn = cp;
+	}
+
+	 /* initialize a stashed array of ACE ports to speed-up look-up */
+	cci_ace_init_ports();
+
+	/*
+	 * Multi-cluster systems may need this data when non-coherent, during
+	 * cluster power-up/power-down. Make sure it reaches main memory.
+	 */
+	sync_cache_w(&cci_ctrl_base);
+	sync_cache_w(&cci_ctrl_phys);
+	sync_cache_w(&ports);
+	sync_cache_w(&cpu_port);
+	__sync_cache_range_w(ports, sizeof(*ports) * nb_cci_ports);
+	pr_info("ARM CCI driver probed\n");
+
+	return 0;
+}
+#else /* !CONFIG_ARM_CCI400_PORT_CTRL */
+static inline int cci_probe_ports(struct device_node *np)
+{
+	return 0;
+}
+#endif /* CONFIG_ARM_CCI400_PORT_CTRL */
+
+static int cci_probe(void)
+{
+	int ret;
+	struct device_node *np;
+	struct resource res;
+
+	np = of_find_matching_node(NULL, arm_cci_matches);
+	if(!np || !of_device_is_available(np))
+		return -ENODEV;
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (!ret) {
+		cci_ctrl_base = ioremap(res.start, resource_size(&res));
+		cci_ctrl_phys =	res.start;
+	}
+	if (ret || !cci_ctrl_base) {
+		WARN(1, "unable to ioremap CCI ctrl\n");
+		return -ENXIO;
+	}
+
+	return cci_probe_ports(np);
+}
+
+static int cci_init_status = -EAGAIN;
+static DEFINE_MUTEX(cci_probing);
+
+static int cci_init(void)
+{
+	if (cci_init_status != -EAGAIN)
+		return cci_init_status;
+
+	mutex_lock(&cci_probing);
+	if (cci_init_status == -EAGAIN)
+		cci_init_status = cci_probe();
+	mutex_unlock(&cci_probing);
+	return cci_init_status;
+}
+
+/*
+ * 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 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");