diff options
Diffstat (limited to 'drivers/perf/arm_dmc620_pmu.c')
| -rw-r--r-- | drivers/perf/arm_dmc620_pmu.c | 748 |
1 files changed, 748 insertions, 0 deletions
diff --git a/drivers/perf/arm_dmc620_pmu.c b/drivers/perf/arm_dmc620_pmu.c new file mode 100644 index 000000000000..004930eb4bbb --- /dev/null +++ b/drivers/perf/arm_dmc620_pmu.c @@ -0,0 +1,748 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ARM DMC-620 memory controller PMU driver + * + * Copyright (C) 2020 Ampere Computing LLC. + */ + +#define DMC620_PMUNAME "arm_dmc620" +#define DMC620_DRVNAME DMC620_PMUNAME "_pmu" +#define pr_fmt(fmt) DMC620_DRVNAME ": " fmt + +#include <linux/acpi.h> +#include <linux/bitfield.h> +#include <linux/bitops.h> +#include <linux/cpuhotplug.h> +#include <linux/cpumask.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/perf_event.h> +#include <linux/platform_device.h> +#include <linux/printk.h> +#include <linux/rculist.h> +#include <linux/refcount.h> + +#define DMC620_PA_SHIFT 12 +#define DMC620_CNT_INIT 0x80000000 +#define DMC620_CNT_MAX_PERIOD 0xffffffff +#define DMC620_PMU_CLKDIV2_MAX_COUNTERS 8 +#define DMC620_PMU_CLK_MAX_COUNTERS 2 +#define DMC620_PMU_MAX_COUNTERS \ + (DMC620_PMU_CLKDIV2_MAX_COUNTERS + DMC620_PMU_CLK_MAX_COUNTERS) + +/* + * The PMU registers start at 0xA00 in the DMC-620 memory map, and these + * offsets are relative to that base. + * + * Each counter has a group of control/value registers, and the + * DMC620_PMU_COUNTERn offsets are within a counter group. + * + * The counter registers groups start at 0xA10. + */ +#define DMC620_PMU_OVERFLOW_STATUS_CLKDIV2 0x8 +#define DMC620_PMU_OVERFLOW_STATUS_CLKDIV2_MASK \ + (DMC620_PMU_CLKDIV2_MAX_COUNTERS - 1) +#define DMC620_PMU_OVERFLOW_STATUS_CLK 0xC +#define DMC620_PMU_OVERFLOW_STATUS_CLK_MASK \ + (DMC620_PMU_CLK_MAX_COUNTERS - 1) +#define DMC620_PMU_COUNTERS_BASE 0x10 +#define DMC620_PMU_COUNTERn_MASK_31_00 0x0 +#define DMC620_PMU_COUNTERn_MASK_63_32 0x4 +#define DMC620_PMU_COUNTERn_MATCH_31_00 0x8 +#define DMC620_PMU_COUNTERn_MATCH_63_32 0xC +#define DMC620_PMU_COUNTERn_CONTROL 0x10 +#define DMC620_PMU_COUNTERn_CONTROL_ENABLE BIT(0) +#define DMC620_PMU_COUNTERn_CONTROL_INVERT BIT(1) +#define DMC620_PMU_COUNTERn_CONTROL_EVENT_MUX GENMASK(6, 2) +#define DMC620_PMU_COUNTERn_CONTROL_INCR_MUX GENMASK(8, 7) +#define DMC620_PMU_COUNTERn_VALUE 0x20 +/* Offset of the registers for a given counter, relative to 0xA00 */ +#define DMC620_PMU_COUNTERn_OFFSET(n) \ + (DMC620_PMU_COUNTERS_BASE + 0x28 * (n)) + +static LIST_HEAD(dmc620_pmu_irqs); +static DEFINE_MUTEX(dmc620_pmu_irqs_lock); + +struct dmc620_pmu_irq { + struct hlist_node node; + struct list_head pmus_node; + struct list_head irqs_node; + refcount_t refcount; + unsigned int irq_num; + unsigned int cpu; +}; + +struct dmc620_pmu { + struct pmu pmu; + + void __iomem *base; + struct dmc620_pmu_irq *irq; + struct list_head pmus_node; + + /* + * We put all clkdiv2 and clk counters to a same array. + * The first DMC620_PMU_CLKDIV2_MAX_COUNTERS bits belong to + * clkdiv2 counters, the last DMC620_PMU_CLK_MAX_COUNTERS + * belong to clk counters. + */ + DECLARE_BITMAP(used_mask, DMC620_PMU_MAX_COUNTERS); + struct perf_event *events[DMC620_PMU_MAX_COUNTERS]; +}; + +#define to_dmc620_pmu(p) (container_of(p, struct dmc620_pmu, pmu)) + +static int cpuhp_state_num; + +struct dmc620_pmu_event_attr { + struct device_attribute attr; + u8 clkdiv2; + u8 eventid; +}; + +static ssize_t +dmc620_pmu_event_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + struct dmc620_pmu_event_attr *eattr; + + eattr = container_of(attr, typeof(*eattr), attr); + + return sprintf(page, "event=0x%x,clkdiv2=0x%x\n", eattr->eventid, eattr->clkdiv2); +} + +#define DMC620_PMU_EVENT_ATTR(_name, _eventid, _clkdiv2) \ + (&((struct dmc620_pmu_event_attr[]) {{ \ + .attr = __ATTR(_name, 0444, dmc620_pmu_event_show, NULL), \ + .clkdiv2 = _clkdiv2, \ + .eventid = _eventid, \ + }})[0].attr.attr) + +static struct attribute *dmc620_pmu_events_attrs[] = { + /* clkdiv2 events list */ + DMC620_PMU_EVENT_ATTR(clkdiv2_cycle_count, 0x0, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_allocate, 0x1, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_queue_depth, 0x2, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_waiting_for_wr_data, 0x3, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_read_backlog, 0x4, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_waiting_for_mi, 0x5, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_hazard_resolution, 0x6, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_enqueue, 0x7, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_arbitrate, 0x8, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_lrank_turnaround_activate, 0x9, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_prank_turnaround_activate, 0xa, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_read_depth, 0xb, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_write_depth, 0xc, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_highigh_qos_depth, 0xd, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_high_qos_depth, 0xe, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_medium_qos_depth, 0xf, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_low_qos_depth, 0x10, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_activate, 0x11, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_rdwr, 0x12, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_refresh, 0x13, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_training_request, 0x14, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_t_mac_tracker, 0x15, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_bk_fsm_tracker, 0x16, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_bk_open_tracker, 0x17, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_ranks_in_pwr_down, 0x18, 1), + DMC620_PMU_EVENT_ATTR(clkdiv2_ranks_in_sref, 0x19, 1), + + /* clk events list */ + DMC620_PMU_EVENT_ATTR(clk_cycle_count, 0x0, 0), + DMC620_PMU_EVENT_ATTR(clk_request, 0x1, 0), + DMC620_PMU_EVENT_ATTR(clk_upload_stall, 0x2, 0), + NULL, +}; + +static struct attribute_group dmc620_pmu_events_attr_group = { + .name = "events", + .attrs = dmc620_pmu_events_attrs, +}; + +/* User ABI */ +#define ATTR_CFG_FLD_mask_CFG config +#define ATTR_CFG_FLD_mask_LO 0 +#define ATTR_CFG_FLD_mask_HI 44 +#define ATTR_CFG_FLD_match_CFG config1 +#define ATTR_CFG_FLD_match_LO 0 +#define ATTR_CFG_FLD_match_HI 44 +#define ATTR_CFG_FLD_invert_CFG config2 +#define ATTR_CFG_FLD_invert_LO 0 +#define ATTR_CFG_FLD_invert_HI 0 +#define ATTR_CFG_FLD_incr_CFG config2 +#define ATTR_CFG_FLD_incr_LO 1 +#define ATTR_CFG_FLD_incr_HI 2 +#define ATTR_CFG_FLD_event_CFG config2 +#define ATTR_CFG_FLD_event_LO 3 +#define ATTR_CFG_FLD_event_HI 8 +#define ATTR_CFG_FLD_clkdiv2_CFG config2 +#define ATTR_CFG_FLD_clkdiv2_LO 9 +#define ATTR_CFG_FLD_clkdiv2_HI 9 + +#define __GEN_PMU_FORMAT_ATTR(cfg, lo, hi) \ + (lo) == (hi) ? #cfg ":" #lo "\n" : #cfg ":" #lo "-" #hi + +#define _GEN_PMU_FORMAT_ATTR(cfg, lo, hi) \ + __GEN_PMU_FORMAT_ATTR(cfg, lo, hi) + +#define GEN_PMU_FORMAT_ATTR(name) \ + PMU_FORMAT_ATTR(name, \ + _GEN_PMU_FORMAT_ATTR(ATTR_CFG_FLD_##name##_CFG, \ + ATTR_CFG_FLD_##name##_LO, \ + ATTR_CFG_FLD_##name##_HI)) + +#define _ATTR_CFG_GET_FLD(attr, cfg, lo, hi) \ + ((((attr)->cfg) >> lo) & GENMASK_ULL(hi - lo, 0)) + +#define ATTR_CFG_GET_FLD(attr, name) \ + _ATTR_CFG_GET_FLD(attr, \ + ATTR_CFG_FLD_##name##_CFG, \ + ATTR_CFG_FLD_##name##_LO, \ + ATTR_CFG_FLD_##name##_HI) + +GEN_PMU_FORMAT_ATTR(mask); +GEN_PMU_FORMAT_ATTR(match); +GEN_PMU_FORMAT_ATTR(invert); +GEN_PMU_FORMAT_ATTR(incr); +GEN_PMU_FORMAT_ATTR(event); +GEN_PMU_FORMAT_ATTR(clkdiv2); + +static struct attribute *dmc620_pmu_formats_attrs[] = { + &format_attr_mask.attr, + &format_attr_match.attr, + &format_attr_invert.attr, + &format_attr_incr.attr, + &format_attr_event.attr, + &format_attr_clkdiv2.attr, + NULL, +}; + +static struct attribute_group dmc620_pmu_format_attr_group = { + .name = "format", + .attrs = dmc620_pmu_formats_attrs, +}; + +static const struct attribute_group *dmc620_pmu_attr_groups[] = { + &dmc620_pmu_events_attr_group, + &dmc620_pmu_format_attr_group, + NULL, +}; + +static inline +u32 dmc620_pmu_creg_read(struct dmc620_pmu *dmc620_pmu, + unsigned int idx, unsigned int reg) +{ + return readl(dmc620_pmu->base + DMC620_PMU_COUNTERn_OFFSET(idx) + reg); +} + +static inline +void dmc620_pmu_creg_write(struct dmc620_pmu *dmc620_pmu, + unsigned int idx, unsigned int reg, u32 val) +{ + writel(val, dmc620_pmu->base + DMC620_PMU_COUNTERn_OFFSET(idx) + reg); +} + +static +unsigned int dmc620_event_to_counter_control(struct perf_event *event) +{ + struct perf_event_attr *attr = &event->attr; + unsigned int reg = 0; + + reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_INVERT, + ATTR_CFG_GET_FLD(attr, invert)); + reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_EVENT_MUX, + ATTR_CFG_GET_FLD(attr, event)); + reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_INCR_MUX, + ATTR_CFG_GET_FLD(attr, incr)); + + return reg; +} + +static int dmc620_get_event_idx(struct perf_event *event) +{ + struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); + int idx, start_idx, end_idx; + + if (ATTR_CFG_GET_FLD(&event->attr, clkdiv2)) { + start_idx = 0; + end_idx = DMC620_PMU_CLKDIV2_MAX_COUNTERS; + } else { + start_idx = DMC620_PMU_CLKDIV2_MAX_COUNTERS; + end_idx = DMC620_PMU_MAX_COUNTERS; + } + + for (idx = start_idx; idx < end_idx; ++idx) { + if (!test_and_set_bit(idx, dmc620_pmu->used_mask)) + return idx; + } + + /* The counters are all in use. */ + return -EAGAIN; +} + +static inline +u64 dmc620_pmu_read_counter(struct perf_event *event) +{ + struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); + + return dmc620_pmu_creg_read(dmc620_pmu, + event->hw.idx, DMC620_PMU_COUNTERn_VALUE); +} + +static void dmc620_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 = dmc620_pmu_read_counter(event); + } while (local64_cmpxchg(&hwc->prev_count, + prev_count, new_count) != prev_count); + delta = (new_count - prev_count) & DMC620_CNT_MAX_PERIOD; + local64_add(delta, &event->count); +} + +static void dmc620_pmu_event_set_period(struct perf_event *event) +{ + struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); + + local64_set(&event->hw.prev_count, DMC620_CNT_INIT); + dmc620_pmu_creg_write(dmc620_pmu, + event->hw.idx, DMC620_PMU_COUNTERn_VALUE, DMC620_CNT_INIT); +} + +static void dmc620_pmu_enable_counter(struct perf_event *event) +{ + struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); + u32 reg; + + reg = dmc620_event_to_counter_control(event) | DMC620_PMU_COUNTERn_CONTROL_ENABLE; + dmc620_pmu_creg_write(dmc620_pmu, + event->hw.idx, DMC620_PMU_COUNTERn_CONTROL, reg); +} + +static void dmc620_pmu_disable_counter(struct perf_event *event) +{ + struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); + + dmc620_pmu_creg_write(dmc620_pmu, + event->hw.idx, DMC620_PMU_COUNTERn_CONTROL, 0); +} + +static irqreturn_t dmc620_pmu_handle_irq(int irq_num, void *data) +{ + struct dmc620_pmu_irq *irq = data; + struct dmc620_pmu *dmc620_pmu; + irqreturn_t ret = IRQ_NONE; + + rcu_read_lock(); + list_for_each_entry_rcu(dmc620_pmu, &irq->pmus_node, pmus_node) { + unsigned long status; + struct perf_event *event; + unsigned int idx; + + /* + * HW doesn't provide a control to atomically disable all counters. + * To prevent race condition (overflow happens while clearing status register), + * disable all events before continuing + */ + for (idx = 0; idx < DMC620_PMU_MAX_COUNTERS; idx++) { + event = dmc620_pmu->events[idx]; + if (!event) + continue; + dmc620_pmu_disable_counter(event); + } + + status = readl(dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2); + status |= (readl(dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK) << + DMC620_PMU_CLKDIV2_MAX_COUNTERS); + if (status) { + for_each_set_bit(idx, &status, + DMC620_PMU_MAX_COUNTERS) { + event = dmc620_pmu->events[idx]; + if (WARN_ON_ONCE(!event)) + continue; + dmc620_pmu_event_update(event); + dmc620_pmu_event_set_period(event); + } + + if (status & DMC620_PMU_OVERFLOW_STATUS_CLKDIV2_MASK) + writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2); + + if ((status >> DMC620_PMU_CLKDIV2_MAX_COUNTERS) & + DMC620_PMU_OVERFLOW_STATUS_CLK_MASK) + writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK); + } + + for (idx = 0; idx < DMC620_PMU_MAX_COUNTERS; idx++) { + event = dmc620_pmu->events[idx]; + if (!event) + continue; + if (!(event->hw.state & PERF_HES_STOPPED)) + dmc620_pmu_enable_counter(event); + } + + ret = IRQ_HANDLED; + } + rcu_read_unlock(); + + return ret; +} + +static struct dmc620_pmu_irq *__dmc620_pmu_get_irq(int irq_num) +{ + struct dmc620_pmu_irq *irq; + int ret; + + list_for_each_entry(irq, &dmc620_pmu_irqs, irqs_node) + if (irq->irq_num == irq_num && refcount_inc_not_zero(&irq->refcount)) + return irq; + + irq = kzalloc(sizeof(*irq), GFP_KERNEL); + if (!irq) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&irq->pmus_node); + + /* Pick one CPU to be the preferred one to use */ + irq->cpu = raw_smp_processor_id(); + refcount_set(&irq->refcount, 1); + + ret = request_irq(irq_num, dmc620_pmu_handle_irq, + IRQF_NOBALANCING | IRQF_NO_THREAD, + "dmc620-pmu", irq); + if (ret) + goto out_free_aff; + + ret = irq_set_affinity_hint(irq_num, cpumask_of(irq->cpu)); + if (ret) + goto out_free_irq; + + ret = cpuhp_state_add_instance_nocalls(cpuhp_state_num, &irq->node); + if (ret) + goto out_free_irq; + + irq->irq_num = irq_num; + list_add(&irq->irqs_node, &dmc620_pmu_irqs); + + return irq; + +out_free_irq: + free_irq(irq_num, irq); +out_free_aff: + kfree(irq); + return ERR_PTR(ret); +} + +static int dmc620_pmu_get_irq(struct dmc620_pmu *dmc620_pmu, int irq_num) +{ + struct dmc620_pmu_irq *irq; + + mutex_lock(&dmc620_pmu_irqs_lock); + irq = __dmc620_pmu_get_irq(irq_num); + mutex_unlock(&dmc620_pmu_irqs_lock); + + if (IS_ERR(irq)) + return PTR_ERR(irq); + + dmc620_pmu->irq = irq; + mutex_lock(&dmc620_pmu_irqs_lock); + list_add_rcu(&dmc620_pmu->pmus_node, &irq->pmus_node); + mutex_unlock(&dmc620_pmu_irqs_lock); + + return 0; +} + +static void dmc620_pmu_put_irq(struct dmc620_pmu *dmc620_pmu) +{ + struct dmc620_pmu_irq *irq = dmc620_pmu->irq; + + mutex_lock(&dmc620_pmu_irqs_lock); + list_del_rcu(&dmc620_pmu->pmus_node); + + if (!refcount_dec_and_test(&irq->refcount)) { + mutex_unlock(&dmc620_pmu_irqs_lock); + return; + } + + list_del(&irq->irqs_node); + mutex_unlock(&dmc620_pmu_irqs_lock); + + WARN_ON(irq_set_affinity_hint(irq->irq_num, NULL)); + free_irq(irq->irq_num, irq); + cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &irq->node); + kfree(irq); +} + +static int dmc620_pmu_event_init(struct perf_event *event) +{ + struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); + struct hw_perf_event *hwc = &event->hw; + struct perf_event *sibling; + + if (event->attr.type != event->pmu->type) + return -ENOENT; + + /* + * DMC 620 PMUs are shared across all cpus and cannot + * support task bound and sampling events. + */ + if (is_sampling_event(event) || + event->attach_state & PERF_ATTACH_TASK) { + dev_dbg(dmc620_pmu->pmu.dev, + "Can't support per-task counters\n"); + return -EOPNOTSUPP; + } + + /* + * Many perf core operations (eg. events rotation) operate on a + * single CPU context. This is obvious for CPU PMUs, where one + * expects the same sets of events being observed on all CPUs, + * but can lead to issues for off-core PMUs, where each + * event could be theoretically assigned to a different CPU. To + * mitigate this, we enforce CPU assignment to one, selected + * processor. + */ + event->cpu = dmc620_pmu->irq->cpu; + if (event->cpu < 0) + return -EINVAL; + + /* + * We can't atomically disable all HW counters so only one event allowed, + * although software events are acceptable. + */ + if (event->group_leader != event && + !is_software_event(event->group_leader)) + return -EINVAL; + + for_each_sibling_event(sibling, event->group_leader) { + if (sibling != event && + !is_software_event(sibling)) + return -EINVAL; + } + + hwc->idx = -1; + return 0; +} + +static void dmc620_pmu_read(struct perf_event *event) +{ + dmc620_pmu_event_update(event); +} + +static void dmc620_pmu_start(struct perf_event *event, int flags) +{ + event->hw.state = 0; + dmc620_pmu_event_set_period(event); + dmc620_pmu_enable_counter(event); +} + +static void dmc620_pmu_stop(struct perf_event *event, int flags) +{ + if (event->hw.state & PERF_HES_STOPPED) + return; + + dmc620_pmu_disable_counter(event); + dmc620_pmu_event_update(event); + event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; +} + +static int dmc620_pmu_add(struct perf_event *event, int flags) +{ + struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); + struct perf_event_attr *attr = &event->attr; + struct hw_perf_event *hwc = &event->hw; + int idx; + u64 reg; + + idx = dmc620_get_event_idx(event); + if (idx < 0) + return idx; + + hwc->idx = idx; + dmc620_pmu->events[idx] = event; + hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; + + reg = ATTR_CFG_GET_FLD(attr, mask); + dmc620_pmu_creg_write(dmc620_pmu, + idx, DMC620_PMU_COUNTERn_MASK_31_00, lower_32_bits(reg)); + dmc620_pmu_creg_write(dmc620_pmu, + idx, DMC620_PMU_COUNTERn_MASK_63_32, upper_32_bits(reg)); + + reg = ATTR_CFG_GET_FLD(attr, match); + dmc620_pmu_creg_write(dmc620_pmu, + idx, DMC620_PMU_COUNTERn_MATCH_31_00, lower_32_bits(reg)); + dmc620_pmu_creg_write(dmc620_pmu, + idx, DMC620_PMU_COUNTERn_MATCH_63_32, upper_32_bits(reg)); + + if (flags & PERF_EF_START) + dmc620_pmu_start(event, PERF_EF_RELOAD); + + perf_event_update_userpage(event); + return 0; +} + +static void dmc620_pmu_del(struct perf_event *event, int flags) +{ + struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu); + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + + dmc620_pmu_stop(event, PERF_EF_UPDATE); + dmc620_pmu->events[idx] = NULL; + clear_bit(idx, dmc620_pmu->used_mask); + perf_event_update_userpage(event); +} + +static int dmc620_pmu_cpu_teardown(unsigned int cpu, + struct hlist_node *node) +{ + struct dmc620_pmu_irq *irq; + struct dmc620_pmu *dmc620_pmu; + unsigned int target; + + irq = hlist_entry_safe(node, struct dmc620_pmu_irq, node); + if (cpu != irq->cpu) + return 0; + + target = cpumask_any_but(cpu_online_mask, cpu); + if (target >= nr_cpu_ids) + return 0; + + /* We're only reading, but this isn't the place to be involving RCU */ + mutex_lock(&dmc620_pmu_irqs_lock); + list_for_each_entry(dmc620_pmu, &irq->pmus_node, pmus_node) + perf_pmu_migrate_context(&dmc620_pmu->pmu, irq->cpu, target); + mutex_unlock(&dmc620_pmu_irqs_lock); + + WARN_ON(irq_set_affinity_hint(irq->irq_num, cpumask_of(target))); + irq->cpu = target; + + return 0; +} + +static int dmc620_pmu_device_probe(struct platform_device *pdev) +{ + struct dmc620_pmu *dmc620_pmu; + struct resource *res; + char *name; + int irq_num; + int i, ret; + + dmc620_pmu = devm_kzalloc(&pdev->dev, + sizeof(struct dmc620_pmu), GFP_KERNEL); + if (!dmc620_pmu) + return -ENOMEM; + + platform_set_drvdata(pdev, dmc620_pmu); + + dmc620_pmu->pmu = (struct pmu) { + .module = THIS_MODULE, + .capabilities = PERF_PMU_CAP_NO_EXCLUDE, + .task_ctx_nr = perf_invalid_context, + .event_init = dmc620_pmu_event_init, + .add = dmc620_pmu_add, + .del = dmc620_pmu_del, + .start = dmc620_pmu_start, + .stop = dmc620_pmu_stop, + .read = dmc620_pmu_read, + .attr_groups = dmc620_pmu_attr_groups, + }; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dmc620_pmu->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dmc620_pmu->base)) + return PTR_ERR(dmc620_pmu->base); + + /* Make sure device is reset before enabling interrupt */ + for (i = 0; i < DMC620_PMU_MAX_COUNTERS; i++) + dmc620_pmu_creg_write(dmc620_pmu, i, DMC620_PMU_COUNTERn_CONTROL, 0); + writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2); + writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK); + + irq_num = platform_get_irq(pdev, 0); + if (irq_num < 0) + return irq_num; + + ret = dmc620_pmu_get_irq(dmc620_pmu, irq_num); + if (ret) + return ret; + + name = devm_kasprintf(&pdev->dev, GFP_KERNEL, + "%s_%llx", DMC620_PMUNAME, + (u64)(res->start >> DMC620_PA_SHIFT)); + if (!name) { + dev_err(&pdev->dev, + "Create name failed, PMU @%pa\n", &res->start); + goto out_teardown_dev; + } + + ret = perf_pmu_register(&dmc620_pmu->pmu, name, -1); + if (ret) + goto out_teardown_dev; + + return 0; + +out_teardown_dev: + dmc620_pmu_put_irq(dmc620_pmu); + synchronize_rcu(); + return ret; +} + +static int dmc620_pmu_device_remove(struct platform_device *pdev) +{ + struct dmc620_pmu *dmc620_pmu = platform_get_drvdata(pdev); + + dmc620_pmu_put_irq(dmc620_pmu); + + /* perf will synchronise RCU before devres can free dmc620_pmu */ + perf_pmu_unregister(&dmc620_pmu->pmu); + + return 0; +} + +static const struct acpi_device_id dmc620_acpi_match[] = { + { "ARMHD620", 0}, + {}, +}; +MODULE_DEVICE_TABLE(acpi, dmc620_acpi_match); +static struct platform_driver dmc620_pmu_driver = { + .driver = { + .name = DMC620_DRVNAME, + .acpi_match_table = dmc620_acpi_match, + }, + .probe = dmc620_pmu_device_probe, + .remove = dmc620_pmu_device_remove, +}; + +static int __init dmc620_pmu_init(void) +{ + cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, + DMC620_DRVNAME, + NULL, + dmc620_pmu_cpu_teardown); + if (cpuhp_state_num < 0) + return cpuhp_state_num; + + return platform_driver_register(&dmc620_pmu_driver); +} + +static void __exit dmc620_pmu_exit(void) +{ + platform_driver_unregister(&dmc620_pmu_driver); + cpuhp_remove_multi_state(cpuhp_state_num); +} + +module_init(dmc620_pmu_init); +module_exit(dmc620_pmu_exit); + +MODULE_DESCRIPTION("Perf driver for the ARM DMC-620 memory controller"); +MODULE_AUTHOR("Tuan Phan <tuanphan@os.amperecomputing.com"); +MODULE_LICENSE("GPL v2"); |