Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / bus / arm-cci.c
diff --git a/kernel/drivers/bus/arm-cci.c b/kernel/drivers/bus/arm-cci.c
new file mode 100644 (file)
index 0000000..5340604
--- /dev/null
@@ -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");