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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/perf/arm_dsu_pmu.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/perf/arm_dsu_pmu.c')
-rw-r--r--drivers/perf/arm_dsu_pmu.c879
1 files changed, 879 insertions, 0 deletions
diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c
new file mode 100644
index 0000000000..8223c49bd0
--- /dev/null
+++ b/drivers/perf/arm_dsu_pmu.c
@@ -0,0 +1,879 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARM DynamIQ Shared Unit (DSU) PMU driver
+ *
+ * Copyright (C) ARM Limited, 2017.
+ *
+ * Based on ARM CCI-PMU, ARMv8 PMU-v3 drivers.
+ */
+
+#define PMUNAME "arm_dsu"
+#define DRVNAME PMUNAME "_pmu"
+#define pr_fmt(fmt) DRVNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/bug.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include <asm/arm_dsu_pmu.h>
+#include <asm/local64.h>
+
+/* PMU event codes */
+#define DSU_PMU_EVT_CYCLES 0x11
+#define DSU_PMU_EVT_CHAIN 0x1e
+
+#define DSU_PMU_MAX_COMMON_EVENTS 0x40
+
+#define DSU_PMU_MAX_HW_CNTRS 32
+#define DSU_PMU_HW_COUNTER_MASK (DSU_PMU_MAX_HW_CNTRS - 1)
+
+#define CLUSTERPMCR_E BIT(0)
+#define CLUSTERPMCR_P BIT(1)
+#define CLUSTERPMCR_C BIT(2)
+#define CLUSTERPMCR_N_SHIFT 11
+#define CLUSTERPMCR_N_MASK 0x1f
+#define CLUSTERPMCR_IDCODE_SHIFT 16
+#define CLUSTERPMCR_IDCODE_MASK 0xff
+#define CLUSTERPMCR_IMP_SHIFT 24
+#define CLUSTERPMCR_IMP_MASK 0xff
+#define CLUSTERPMCR_RES_MASK 0x7e8
+#define CLUSTERPMCR_RES_VAL 0x40
+
+#define DSU_ACTIVE_CPU_MASK 0x0
+#define DSU_ASSOCIATED_CPU_MASK 0x1
+
+/*
+ * We use the index of the counters as they appear in the counter
+ * bit maps in the PMU registers (e.g CLUSTERPMSELR).
+ * i.e,
+ * counter 0 - Bit 0
+ * counter 1 - Bit 1
+ * ...
+ * Cycle counter - Bit 31
+ */
+#define DSU_PMU_IDX_CYCLE_COUNTER 31
+
+/* All event counters are 32bit, with a 64bit Cycle counter */
+#define DSU_PMU_COUNTER_WIDTH(idx) \
+ (((idx) == DSU_PMU_IDX_CYCLE_COUNTER) ? 64 : 32)
+
+#define DSU_PMU_COUNTER_MASK(idx) \
+ GENMASK_ULL((DSU_PMU_COUNTER_WIDTH((idx)) - 1), 0)
+
+#define DSU_EXT_ATTR(_name, _func, _config) \
+ (&((struct dev_ext_attribute[]) { \
+ { \
+ .attr = __ATTR(_name, 0444, _func, NULL), \
+ .var = (void *)_config \
+ } \
+ })[0].attr.attr)
+
+#define DSU_EVENT_ATTR(_name, _config) \
+ DSU_EXT_ATTR(_name, dsu_pmu_sysfs_event_show, (unsigned long)_config)
+
+#define DSU_FORMAT_ATTR(_name, _config) \
+ DSU_EXT_ATTR(_name, dsu_pmu_sysfs_format_show, (char *)_config)
+
+#define DSU_CPUMASK_ATTR(_name, _config) \
+ DSU_EXT_ATTR(_name, dsu_pmu_cpumask_show, (unsigned long)_config)
+
+struct dsu_hw_events {
+ DECLARE_BITMAP(used_mask, DSU_PMU_MAX_HW_CNTRS);
+ struct perf_event *events[DSU_PMU_MAX_HW_CNTRS];
+};
+
+/*
+ * struct dsu_pmu - DSU PMU descriptor
+ *
+ * @pmu_lock : Protects accesses to DSU PMU register from normal vs
+ * interrupt handler contexts.
+ * @hw_events : Holds the event counter state.
+ * @associated_cpus : CPUs attached to the DSU.
+ * @active_cpu : CPU to which the PMU is bound for accesses.
+ * @cpuhp_node : Node for CPU hotplug notifier link.
+ * @num_counters : Number of event counters implemented by the PMU,
+ * excluding the cycle counter.
+ * @irq : Interrupt line for counter overflow.
+ * @cpmceid_bitmap : Bitmap for the availability of architected common
+ * events (event_code < 0x40).
+ */
+struct dsu_pmu {
+ struct pmu pmu;
+ struct device *dev;
+ raw_spinlock_t pmu_lock;
+ struct dsu_hw_events hw_events;
+ cpumask_t associated_cpus;
+ cpumask_t active_cpu;
+ struct hlist_node cpuhp_node;
+ s8 num_counters;
+ int irq;
+ DECLARE_BITMAP(cpmceid_bitmap, DSU_PMU_MAX_COMMON_EVENTS);
+};
+
+static unsigned long dsu_pmu_cpuhp_state;
+
+static inline struct dsu_pmu *to_dsu_pmu(struct pmu *pmu)
+{
+ return container_of(pmu, struct dsu_pmu, pmu);
+}
+
+static ssize_t dsu_pmu_sysfs_event_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct dev_ext_attribute *eattr = container_of(attr,
+ struct dev_ext_attribute, attr);
+ return sysfs_emit(buf, "event=0x%lx\n", (unsigned long)eattr->var);
+}
+
+static ssize_t dsu_pmu_sysfs_format_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct dev_ext_attribute *eattr = container_of(attr,
+ struct dev_ext_attribute, attr);
+ return sysfs_emit(buf, "%s\n", (char *)eattr->var);
+}
+
+static ssize_t dsu_pmu_cpumask_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct pmu *pmu = dev_get_drvdata(dev);
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(pmu);
+ struct dev_ext_attribute *eattr = container_of(attr,
+ struct dev_ext_attribute, attr);
+ unsigned long mask_id = (unsigned long)eattr->var;
+ const cpumask_t *cpumask;
+
+ switch (mask_id) {
+ case DSU_ACTIVE_CPU_MASK:
+ cpumask = &dsu_pmu->active_cpu;
+ break;
+ case DSU_ASSOCIATED_CPU_MASK:
+ cpumask = &dsu_pmu->associated_cpus;
+ break;
+ default:
+ return 0;
+ }
+ return cpumap_print_to_pagebuf(true, buf, cpumask);
+}
+
+static struct attribute *dsu_pmu_format_attrs[] = {
+ DSU_FORMAT_ATTR(event, "config:0-31"),
+ NULL,
+};
+
+static const struct attribute_group dsu_pmu_format_attr_group = {
+ .name = "format",
+ .attrs = dsu_pmu_format_attrs,
+};
+
+static struct attribute *dsu_pmu_event_attrs[] = {
+ DSU_EVENT_ATTR(cycles, 0x11),
+ DSU_EVENT_ATTR(bus_access, 0x19),
+ DSU_EVENT_ATTR(memory_error, 0x1a),
+ DSU_EVENT_ATTR(bus_cycles, 0x1d),
+ DSU_EVENT_ATTR(l3d_cache_allocate, 0x29),
+ DSU_EVENT_ATTR(l3d_cache_refill, 0x2a),
+ DSU_EVENT_ATTR(l3d_cache, 0x2b),
+ DSU_EVENT_ATTR(l3d_cache_wb, 0x2c),
+ NULL,
+};
+
+static umode_t
+dsu_pmu_event_attr_is_visible(struct kobject *kobj, struct attribute *attr,
+ int unused)
+{
+ struct pmu *pmu = dev_get_drvdata(kobj_to_dev(kobj));
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(pmu);
+ struct dev_ext_attribute *eattr = container_of(attr,
+ struct dev_ext_attribute, attr.attr);
+ unsigned long evt = (unsigned long)eattr->var;
+
+ return test_bit(evt, dsu_pmu->cpmceid_bitmap) ? attr->mode : 0;
+}
+
+static const struct attribute_group dsu_pmu_events_attr_group = {
+ .name = "events",
+ .attrs = dsu_pmu_event_attrs,
+ .is_visible = dsu_pmu_event_attr_is_visible,
+};
+
+static struct attribute *dsu_pmu_cpumask_attrs[] = {
+ DSU_CPUMASK_ATTR(cpumask, DSU_ACTIVE_CPU_MASK),
+ DSU_CPUMASK_ATTR(associated_cpus, DSU_ASSOCIATED_CPU_MASK),
+ NULL,
+};
+
+static const struct attribute_group dsu_pmu_cpumask_attr_group = {
+ .attrs = dsu_pmu_cpumask_attrs,
+};
+
+static const struct attribute_group *dsu_pmu_attr_groups[] = {
+ &dsu_pmu_cpumask_attr_group,
+ &dsu_pmu_events_attr_group,
+ &dsu_pmu_format_attr_group,
+ NULL,
+};
+
+static int dsu_pmu_get_online_cpu_any_but(struct dsu_pmu *dsu_pmu, int cpu)
+{
+ struct cpumask online_supported;
+
+ cpumask_and(&online_supported,
+ &dsu_pmu->associated_cpus, cpu_online_mask);
+ return cpumask_any_but(&online_supported, cpu);
+}
+
+static inline bool dsu_pmu_counter_valid(struct dsu_pmu *dsu_pmu, u32 idx)
+{
+ return (idx < dsu_pmu->num_counters) ||
+ (idx == DSU_PMU_IDX_CYCLE_COUNTER);
+}
+
+static inline u64 dsu_pmu_read_counter(struct perf_event *event)
+{
+ u64 val;
+ unsigned long flags;
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(event->pmu);
+ int idx = event->hw.idx;
+
+ if (WARN_ON(!cpumask_test_cpu(smp_processor_id(),
+ &dsu_pmu->associated_cpus)))
+ return 0;
+
+ if (!dsu_pmu_counter_valid(dsu_pmu, idx)) {
+ dev_err(event->pmu->dev,
+ "Trying reading invalid counter %d\n", idx);
+ return 0;
+ }
+
+ raw_spin_lock_irqsave(&dsu_pmu->pmu_lock, flags);
+ if (idx == DSU_PMU_IDX_CYCLE_COUNTER)
+ val = __dsu_pmu_read_pmccntr();
+ else
+ val = __dsu_pmu_read_counter(idx);
+ raw_spin_unlock_irqrestore(&dsu_pmu->pmu_lock, flags);
+
+ return val;
+}
+
+static void dsu_pmu_write_counter(struct perf_event *event, u64 val)
+{
+ unsigned long flags;
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(event->pmu);
+ int idx = event->hw.idx;
+
+ if (WARN_ON(!cpumask_test_cpu(smp_processor_id(),
+ &dsu_pmu->associated_cpus)))
+ return;
+
+ if (!dsu_pmu_counter_valid(dsu_pmu, idx)) {
+ dev_err(event->pmu->dev,
+ "writing to invalid counter %d\n", idx);
+ return;
+ }
+
+ raw_spin_lock_irqsave(&dsu_pmu->pmu_lock, flags);
+ if (idx == DSU_PMU_IDX_CYCLE_COUNTER)
+ __dsu_pmu_write_pmccntr(val);
+ else
+ __dsu_pmu_write_counter(idx, val);
+ raw_spin_unlock_irqrestore(&dsu_pmu->pmu_lock, flags);
+}
+
+static int dsu_pmu_get_event_idx(struct dsu_hw_events *hw_events,
+ struct perf_event *event)
+{
+ int idx;
+ unsigned long evtype = event->attr.config;
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(event->pmu);
+ unsigned long *used_mask = hw_events->used_mask;
+
+ if (evtype == DSU_PMU_EVT_CYCLES) {
+ if (test_and_set_bit(DSU_PMU_IDX_CYCLE_COUNTER, used_mask))
+ return -EAGAIN;
+ return DSU_PMU_IDX_CYCLE_COUNTER;
+ }
+
+ idx = find_first_zero_bit(used_mask, dsu_pmu->num_counters);
+ if (idx >= dsu_pmu->num_counters)
+ return -EAGAIN;
+ set_bit(idx, hw_events->used_mask);
+ return idx;
+}
+
+static void dsu_pmu_enable_counter(struct dsu_pmu *dsu_pmu, int idx)
+{
+ __dsu_pmu_counter_interrupt_enable(idx);
+ __dsu_pmu_enable_counter(idx);
+}
+
+static void dsu_pmu_disable_counter(struct dsu_pmu *dsu_pmu, int idx)
+{
+ __dsu_pmu_disable_counter(idx);
+ __dsu_pmu_counter_interrupt_disable(idx);
+}
+
+static inline void dsu_pmu_set_event(struct dsu_pmu *dsu_pmu,
+ struct perf_event *event)
+{
+ int idx = event->hw.idx;
+ unsigned long flags;
+
+ if (!dsu_pmu_counter_valid(dsu_pmu, idx)) {
+ dev_err(event->pmu->dev,
+ "Trying to set invalid counter %d\n", idx);
+ return;
+ }
+
+ raw_spin_lock_irqsave(&dsu_pmu->pmu_lock, flags);
+ __dsu_pmu_set_event(idx, event->hw.config_base);
+ raw_spin_unlock_irqrestore(&dsu_pmu->pmu_lock, flags);
+}
+
+static void dsu_pmu_event_update(struct perf_event *event)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ u64 delta, prev_count, new_count;
+
+ do {
+ /* We may also be called from the irq handler */
+ prev_count = local64_read(&hwc->prev_count);
+ new_count = dsu_pmu_read_counter(event);
+ } while (local64_cmpxchg(&hwc->prev_count, prev_count, new_count) !=
+ prev_count);
+ delta = (new_count - prev_count) & DSU_PMU_COUNTER_MASK(hwc->idx);
+ local64_add(delta, &event->count);
+}
+
+static void dsu_pmu_read(struct perf_event *event)
+{
+ dsu_pmu_event_update(event);
+}
+
+static inline u32 dsu_pmu_get_reset_overflow(void)
+{
+ return __dsu_pmu_get_reset_overflow();
+}
+
+/**
+ * dsu_pmu_set_event_period: Set the period for the counter.
+ *
+ * All DSU PMU event counters, except the cycle counter are 32bit
+ * counters. To handle cases of extreme interrupt latency, we program
+ * the counter with half of the max count for the counters.
+ */
+static void dsu_pmu_set_event_period(struct perf_event *event)
+{
+ int idx = event->hw.idx;
+ u64 val = DSU_PMU_COUNTER_MASK(idx) >> 1;
+
+ local64_set(&event->hw.prev_count, val);
+ dsu_pmu_write_counter(event, val);
+}
+
+static irqreturn_t dsu_pmu_handle_irq(int irq_num, void *dev)
+{
+ int i;
+ bool handled = false;
+ struct dsu_pmu *dsu_pmu = dev;
+ struct dsu_hw_events *hw_events = &dsu_pmu->hw_events;
+ unsigned long overflow;
+
+ overflow = dsu_pmu_get_reset_overflow();
+ if (!overflow)
+ return IRQ_NONE;
+
+ for_each_set_bit(i, &overflow, DSU_PMU_MAX_HW_CNTRS) {
+ struct perf_event *event = hw_events->events[i];
+
+ if (!event)
+ continue;
+ dsu_pmu_event_update(event);
+ dsu_pmu_set_event_period(event);
+ handled = true;
+ }
+
+ return IRQ_RETVAL(handled);
+}
+
+static void dsu_pmu_start(struct perf_event *event, int pmu_flags)
+{
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(event->pmu);
+
+ /* We always reprogram the counter */
+ if (pmu_flags & PERF_EF_RELOAD)
+ WARN_ON(!(event->hw.state & PERF_HES_UPTODATE));
+ dsu_pmu_set_event_period(event);
+ if (event->hw.idx != DSU_PMU_IDX_CYCLE_COUNTER)
+ dsu_pmu_set_event(dsu_pmu, event);
+ event->hw.state = 0;
+ dsu_pmu_enable_counter(dsu_pmu, event->hw.idx);
+}
+
+static void dsu_pmu_stop(struct perf_event *event, int pmu_flags)
+{
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(event->pmu);
+
+ if (event->hw.state & PERF_HES_STOPPED)
+ return;
+ dsu_pmu_disable_counter(dsu_pmu, event->hw.idx);
+ dsu_pmu_event_update(event);
+ event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int dsu_pmu_add(struct perf_event *event, int flags)
+{
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(event->pmu);
+ struct dsu_hw_events *hw_events = &dsu_pmu->hw_events;
+ struct hw_perf_event *hwc = &event->hw;
+ int idx;
+
+ if (WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(),
+ &dsu_pmu->associated_cpus)))
+ return -ENOENT;
+
+ idx = dsu_pmu_get_event_idx(hw_events, event);
+ if (idx < 0)
+ return idx;
+
+ hwc->idx = idx;
+ hw_events->events[idx] = event;
+ hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+
+ if (flags & PERF_EF_START)
+ dsu_pmu_start(event, PERF_EF_RELOAD);
+
+ perf_event_update_userpage(event);
+ return 0;
+}
+
+static void dsu_pmu_del(struct perf_event *event, int flags)
+{
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(event->pmu);
+ struct dsu_hw_events *hw_events = &dsu_pmu->hw_events;
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+
+ dsu_pmu_stop(event, PERF_EF_UPDATE);
+ hw_events->events[idx] = NULL;
+ clear_bit(idx, hw_events->used_mask);
+ perf_event_update_userpage(event);
+}
+
+static void dsu_pmu_enable(struct pmu *pmu)
+{
+ u32 pmcr;
+ unsigned long flags;
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(pmu);
+
+ /* If no counters are added, skip enabling the PMU */
+ if (bitmap_empty(dsu_pmu->hw_events.used_mask, DSU_PMU_MAX_HW_CNTRS))
+ return;
+
+ raw_spin_lock_irqsave(&dsu_pmu->pmu_lock, flags);
+ pmcr = __dsu_pmu_read_pmcr();
+ pmcr |= CLUSTERPMCR_E;
+ __dsu_pmu_write_pmcr(pmcr);
+ raw_spin_unlock_irqrestore(&dsu_pmu->pmu_lock, flags);
+}
+
+static void dsu_pmu_disable(struct pmu *pmu)
+{
+ u32 pmcr;
+ unsigned long flags;
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(pmu);
+
+ raw_spin_lock_irqsave(&dsu_pmu->pmu_lock, flags);
+ pmcr = __dsu_pmu_read_pmcr();
+ pmcr &= ~CLUSTERPMCR_E;
+ __dsu_pmu_write_pmcr(pmcr);
+ raw_spin_unlock_irqrestore(&dsu_pmu->pmu_lock, flags);
+}
+
+static bool dsu_pmu_validate_event(struct pmu *pmu,
+ struct dsu_hw_events *hw_events,
+ struct perf_event *event)
+{
+ if (is_software_event(event))
+ return true;
+ /* Reject groups spanning multiple HW PMUs. */
+ if (event->pmu != pmu)
+ return false;
+ return dsu_pmu_get_event_idx(hw_events, event) >= 0;
+}
+
+/*
+ * Make sure the group of events can be scheduled at once
+ * on the PMU.
+ */
+static bool dsu_pmu_validate_group(struct perf_event *event)
+{
+ struct perf_event *sibling, *leader = event->group_leader;
+ struct dsu_hw_events fake_hw;
+
+ if (event->group_leader == event)
+ return true;
+
+ memset(fake_hw.used_mask, 0, sizeof(fake_hw.used_mask));
+ if (!dsu_pmu_validate_event(event->pmu, &fake_hw, leader))
+ return false;
+ for_each_sibling_event(sibling, leader) {
+ if (!dsu_pmu_validate_event(event->pmu, &fake_hw, sibling))
+ return false;
+ }
+ return dsu_pmu_validate_event(event->pmu, &fake_hw, event);
+}
+
+static int dsu_pmu_event_init(struct perf_event *event)
+{
+ struct dsu_pmu *dsu_pmu = to_dsu_pmu(event->pmu);
+
+ if (event->attr.type != event->pmu->type)
+ return -ENOENT;
+
+ /* We don't support sampling */
+ if (is_sampling_event(event)) {
+ dev_dbg(dsu_pmu->pmu.dev, "Can't support sampling events\n");
+ return -EOPNOTSUPP;
+ }
+
+ /* We cannot support task bound events */
+ if (event->cpu < 0 || event->attach_state & PERF_ATTACH_TASK) {
+ dev_dbg(dsu_pmu->pmu.dev, "Can't support per-task counters\n");
+ return -EINVAL;
+ }
+
+ if (has_branch_stack(event)) {
+ dev_dbg(dsu_pmu->pmu.dev, "Can't support filtering\n");
+ return -EINVAL;
+ }
+
+ if (!cpumask_test_cpu(event->cpu, &dsu_pmu->associated_cpus)) {
+ dev_dbg(dsu_pmu->pmu.dev,
+ "Requested cpu is not associated with the DSU\n");
+ return -EINVAL;
+ }
+ /*
+ * Choose the current active CPU to read the events. We don't want
+ * to migrate the event contexts, irq handling etc to the requested
+ * CPU. As long as the requested CPU is within the same DSU, we
+ * are fine.
+ */
+ event->cpu = cpumask_first(&dsu_pmu->active_cpu);
+ if (event->cpu >= nr_cpu_ids)
+ return -EINVAL;
+ if (!dsu_pmu_validate_group(event))
+ return -EINVAL;
+
+ event->hw.config_base = event->attr.config;
+ return 0;
+}
+
+static struct dsu_pmu *dsu_pmu_alloc(struct platform_device *pdev)
+{
+ struct dsu_pmu *dsu_pmu;
+
+ dsu_pmu = devm_kzalloc(&pdev->dev, sizeof(*dsu_pmu), GFP_KERNEL);
+ if (!dsu_pmu)
+ return ERR_PTR(-ENOMEM);
+
+ raw_spin_lock_init(&dsu_pmu->pmu_lock);
+ /*
+ * Initialise the number of counters to -1, until we probe
+ * the real number on a connected CPU.
+ */
+ dsu_pmu->num_counters = -1;
+ return dsu_pmu;
+}
+
+/**
+ * dsu_pmu_dt_get_cpus: Get the list of CPUs in the cluster
+ * from device tree.
+ */
+static int dsu_pmu_dt_get_cpus(struct device *dev, cpumask_t *mask)
+{
+ int i = 0, n, cpu;
+ struct device_node *cpu_node;
+
+ n = of_count_phandle_with_args(dev->of_node, "cpus", NULL);
+ if (n <= 0)
+ return -ENODEV;
+ for (; i < n; i++) {
+ cpu_node = of_parse_phandle(dev->of_node, "cpus", i);
+ if (!cpu_node)
+ break;
+ cpu = of_cpu_node_to_id(cpu_node);
+ of_node_put(cpu_node);
+ /*
+ * We have to ignore the failures here and continue scanning
+ * the list to handle cases where the nr_cpus could be capped
+ * in the running kernel.
+ */
+ if (cpu < 0)
+ continue;
+ cpumask_set_cpu(cpu, mask);
+ }
+ return 0;
+}
+
+/**
+ * dsu_pmu_acpi_get_cpus: Get the list of CPUs in the cluster
+ * from ACPI.
+ */
+static int dsu_pmu_acpi_get_cpus(struct device *dev, cpumask_t *mask)
+{
+#ifdef CONFIG_ACPI
+ struct acpi_device *parent_adev = acpi_dev_parent(ACPI_COMPANION(dev));
+ int cpu;
+
+ /*
+ * A dsu pmu node is inside a cluster parent node along with cpu nodes.
+ * We need to find out all cpus that have the same parent with this pmu.
+ */
+ for_each_possible_cpu(cpu) {
+ struct acpi_device *acpi_dev;
+ struct device *cpu_dev = get_cpu_device(cpu);
+
+ if (!cpu_dev)
+ continue;
+
+ acpi_dev = ACPI_COMPANION(cpu_dev);
+ if (acpi_dev && acpi_dev_parent(acpi_dev) == parent_adev)
+ cpumask_set_cpu(cpu, mask);
+ }
+#endif
+
+ return 0;
+}
+
+/*
+ * dsu_pmu_probe_pmu: Probe the PMU details on a CPU in the cluster.
+ */
+static void dsu_pmu_probe_pmu(struct dsu_pmu *dsu_pmu)
+{
+ u64 num_counters;
+ u32 cpmceid[2];
+
+ num_counters = (__dsu_pmu_read_pmcr() >> CLUSTERPMCR_N_SHIFT) &
+ CLUSTERPMCR_N_MASK;
+ /* We can only support up to 31 independent counters */
+ if (WARN_ON(num_counters > 31))
+ num_counters = 31;
+ dsu_pmu->num_counters = num_counters;
+ if (!dsu_pmu->num_counters)
+ return;
+ cpmceid[0] = __dsu_pmu_read_pmceid(0);
+ cpmceid[1] = __dsu_pmu_read_pmceid(1);
+ bitmap_from_arr32(dsu_pmu->cpmceid_bitmap, cpmceid,
+ DSU_PMU_MAX_COMMON_EVENTS);
+}
+
+static void dsu_pmu_set_active_cpu(int cpu, struct dsu_pmu *dsu_pmu)
+{
+ cpumask_set_cpu(cpu, &dsu_pmu->active_cpu);
+ if (irq_set_affinity(dsu_pmu->irq, &dsu_pmu->active_cpu))
+ pr_warn("Failed to set irq affinity to %d\n", cpu);
+}
+
+/*
+ * dsu_pmu_init_pmu: Initialise the DSU PMU configurations if
+ * we haven't done it already.
+ */
+static void dsu_pmu_init_pmu(struct dsu_pmu *dsu_pmu)
+{
+ if (dsu_pmu->num_counters == -1)
+ dsu_pmu_probe_pmu(dsu_pmu);
+ /* Reset the interrupt overflow mask */
+ dsu_pmu_get_reset_overflow();
+}
+
+static int dsu_pmu_device_probe(struct platform_device *pdev)
+{
+ int irq, rc;
+ struct dsu_pmu *dsu_pmu;
+ struct fwnode_handle *fwnode = dev_fwnode(&pdev->dev);
+ char *name;
+ static atomic_t pmu_idx = ATOMIC_INIT(-1);
+
+ dsu_pmu = dsu_pmu_alloc(pdev);
+ if (IS_ERR(dsu_pmu))
+ return PTR_ERR(dsu_pmu);
+
+ if (is_of_node(fwnode))
+ rc = dsu_pmu_dt_get_cpus(&pdev->dev, &dsu_pmu->associated_cpus);
+ else if (is_acpi_device_node(fwnode))
+ rc = dsu_pmu_acpi_get_cpus(&pdev->dev, &dsu_pmu->associated_cpus);
+ else
+ return -ENOENT;
+
+ if (rc) {
+ dev_warn(&pdev->dev, "Failed to parse the CPUs\n");
+ return rc;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return -EINVAL;
+
+ name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s_%d",
+ PMUNAME, atomic_inc_return(&pmu_idx));
+ if (!name)
+ return -ENOMEM;
+ rc = devm_request_irq(&pdev->dev, irq, dsu_pmu_handle_irq,
+ IRQF_NOBALANCING, name, dsu_pmu);
+ if (rc) {
+ dev_warn(&pdev->dev, "Failed to request IRQ %d\n", irq);
+ return rc;
+ }
+
+ dsu_pmu->irq = irq;
+ platform_set_drvdata(pdev, dsu_pmu);
+ rc = cpuhp_state_add_instance(dsu_pmu_cpuhp_state,
+ &dsu_pmu->cpuhp_node);
+ if (rc)
+ return rc;
+
+ dsu_pmu->pmu = (struct pmu) {
+ .task_ctx_nr = perf_invalid_context,
+ .module = THIS_MODULE,
+ .pmu_enable = dsu_pmu_enable,
+ .pmu_disable = dsu_pmu_disable,
+ .event_init = dsu_pmu_event_init,
+ .add = dsu_pmu_add,
+ .del = dsu_pmu_del,
+ .start = dsu_pmu_start,
+ .stop = dsu_pmu_stop,
+ .read = dsu_pmu_read,
+
+ .attr_groups = dsu_pmu_attr_groups,
+ .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
+ };
+
+ rc = perf_pmu_register(&dsu_pmu->pmu, name, -1);
+ if (rc) {
+ cpuhp_state_remove_instance(dsu_pmu_cpuhp_state,
+ &dsu_pmu->cpuhp_node);
+ }
+
+ return rc;
+}
+
+static int dsu_pmu_device_remove(struct platform_device *pdev)
+{
+ struct dsu_pmu *dsu_pmu = platform_get_drvdata(pdev);
+
+ perf_pmu_unregister(&dsu_pmu->pmu);
+ cpuhp_state_remove_instance(dsu_pmu_cpuhp_state, &dsu_pmu->cpuhp_node);
+
+ return 0;
+}
+
+static const struct of_device_id dsu_pmu_of_match[] = {
+ { .compatible = "arm,dsu-pmu", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, dsu_pmu_of_match);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id dsu_pmu_acpi_match[] = {
+ { "ARMHD500", 0},
+ {},
+};
+MODULE_DEVICE_TABLE(acpi, dsu_pmu_acpi_match);
+#endif
+
+static struct platform_driver dsu_pmu_driver = {
+ .driver = {
+ .name = DRVNAME,
+ .of_match_table = of_match_ptr(dsu_pmu_of_match),
+ .acpi_match_table = ACPI_PTR(dsu_pmu_acpi_match),
+ .suppress_bind_attrs = true,
+ },
+ .probe = dsu_pmu_device_probe,
+ .remove = dsu_pmu_device_remove,
+};
+
+static int dsu_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)
+{
+ struct dsu_pmu *dsu_pmu = hlist_entry_safe(node, struct dsu_pmu,
+ cpuhp_node);
+
+ if (!cpumask_test_cpu(cpu, &dsu_pmu->associated_cpus))
+ return 0;
+
+ /* If the PMU is already managed, there is nothing to do */
+ if (!cpumask_empty(&dsu_pmu->active_cpu))
+ return 0;
+
+ dsu_pmu_init_pmu(dsu_pmu);
+ dsu_pmu_set_active_cpu(cpu, dsu_pmu);
+
+ return 0;
+}
+
+static int dsu_pmu_cpu_teardown(unsigned int cpu, struct hlist_node *node)
+{
+ int dst;
+ struct dsu_pmu *dsu_pmu = hlist_entry_safe(node, struct dsu_pmu,
+ cpuhp_node);
+
+ if (!cpumask_test_and_clear_cpu(cpu, &dsu_pmu->active_cpu))
+ return 0;
+
+ dst = dsu_pmu_get_online_cpu_any_but(dsu_pmu, cpu);
+ /* If there are no active CPUs in the DSU, leave IRQ disabled */
+ if (dst >= nr_cpu_ids)
+ return 0;
+
+ perf_pmu_migrate_context(&dsu_pmu->pmu, cpu, dst);
+ dsu_pmu_set_active_cpu(dst, dsu_pmu);
+
+ return 0;
+}
+
+static int __init dsu_pmu_init(void)
+{
+ int ret;
+
+ ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+ DRVNAME,
+ dsu_pmu_cpu_online,
+ dsu_pmu_cpu_teardown);
+ if (ret < 0)
+ return ret;
+ dsu_pmu_cpuhp_state = ret;
+ ret = platform_driver_register(&dsu_pmu_driver);
+ if (ret)
+ cpuhp_remove_multi_state(dsu_pmu_cpuhp_state);
+
+ return ret;
+}
+
+static void __exit dsu_pmu_exit(void)
+{
+ platform_driver_unregister(&dsu_pmu_driver);
+ cpuhp_remove_multi_state(dsu_pmu_cpuhp_state);
+}
+
+module_init(dsu_pmu_init);
+module_exit(dsu_pmu_exit);
+
+MODULE_DESCRIPTION("Perf driver for ARM DynamIQ Shared Unit");
+MODULE_AUTHOR("Suzuki K Poulose <suzuki.poulose@arm.com>");
+MODULE_LICENSE("GPL v2");