diff options
Diffstat (limited to 'drivers/perf/arm_dsu_pmu.c')
| -rw-r--r-- | drivers/perf/arm_dsu_pmu.c | 843 |
1 files changed, 843 insertions, 0 deletions
diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c new file mode 100644 index 000000000000..93c50e377507 --- /dev/null +++ b/drivers/perf/arm_dsu_pmu.c @@ -0,0 +1,843 @@ +/* + * ARM DynamIQ Shared Unit (DSU) PMU driver + * + * Copyright (C) ARM Limited, 2017. + * + * Based on ARM CCI-PMU, ARMv8 PMU-v3 drivers. + * + * 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. + */ + +#define PMUNAME "arm_dsu" +#define DRVNAME PMUNAME "_pmu" +#define pr_fmt(fmt) DRVNAME ": " fmt + +#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_device.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 snprintf(buf, PAGE_SIZE, "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 snprintf(buf, PAGE_SIZE, "%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; + list_for_each_entry(sibling, &leader->sibling_list, group_entry) { + 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) || + event->attr.exclude_user || + event->attr.exclude_kernel || + event->attr.exclude_hv || + event->attr.exclude_idle || + event->attr.exclude_host || + event->attr.exclude_guest) { + 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. + */ +static int dsu_pmu_dt_get_cpus(struct device_node *dev, cpumask_t *mask) +{ + int i = 0, n, cpu; + struct device_node *cpu_node; + + n = of_count_phandle_with_args(dev, "cpus", NULL); + if (n <= 0) + return -ENODEV; + for (; i < n; i++) { + cpu_node = of_parse_phandle(dev, "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_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_u32array(dsu_pmu->cpmceid_bitmap, + DSU_PMU_MAX_COMMON_EVENTS, + cpmceid, + ARRAY_SIZE(cpmceid)); +} + +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_hint(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; + 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); + + rc = dsu_pmu_dt_get_cpus(pdev->dev.of_node, &dsu_pmu->associated_cpus); + if (rc) { + dev_warn(&pdev->dev, "Failed to parse the CPUs\n"); + return rc; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_warn(&pdev->dev, "Failed to find IRQ\n"); + 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, + }; + + rc = perf_pmu_register(&dsu_pmu->pmu, name, -1); + if (rc) { + cpuhp_state_remove_instance(dsu_pmu_cpuhp_state, + &dsu_pmu->cpuhp_node); + irq_set_affinity_hint(dsu_pmu->irq, NULL); + } + + 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); + irq_set_affinity_hint(dsu_pmu->irq, NULL); + + return 0; +} + +static const struct of_device_id dsu_pmu_of_match[] = { + { .compatible = "arm,dsu-pmu", }, + {}, +}; + +static struct platform_driver dsu_pmu_driver = { + .driver = { + .name = DRVNAME, + .of_match_table = of_match_ptr(dsu_pmu_of_match), + }, + .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) { + irq_set_affinity_hint(dsu_pmu->irq, NULL); + 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; + return platform_driver_register(&dsu_pmu_driver); +} + +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_DEVICE_TABLE(of, dsu_pmu_of_match); +MODULE_DESCRIPTION("Perf driver for ARM DynamIQ Shared Unit"); +MODULE_AUTHOR("Suzuki K Poulose <suzuki.poulose@arm.com>"); +MODULE_LICENSE("GPL v2"); |