From 21bdbb7102edeaebb5ec4ef530c8f442f7562c96 Mon Sep 17 00:00:00 2001 From: Neil Leeder Date: Tue, 7 Feb 2017 13:14:04 -0500 Subject: [PATCH] perf: add qcom l2 cache perf events driver Adds perf events support for L2 cache PMU. The L2 cache PMU driver is named 'l2cache_0' and can be used with perf events to profile L2 events such as cache hits and misses on Qualcomm Technologies processors. Reviewed-by: Mark Rutland Signed-off-by: Neil Leeder [will: minimise nesting in l2_cache_associate_cpu_with_cluster] [will: use kstrtoul for unsigned long, remove redunant .owner setting] Signed-off-by: Will Deacon --- Documentation/perf/qcom_l2_pmu.txt | 38 ++ drivers/perf/Kconfig | 9 + drivers/perf/Makefile | 1 + drivers/perf/qcom_l2_pmu.c | 1013 ++++++++++++++++++++++++++++ include/linux/cpuhotplug.h | 1 + 5 files changed, 1062 insertions(+) create mode 100644 Documentation/perf/qcom_l2_pmu.txt create mode 100644 drivers/perf/qcom_l2_pmu.c diff --git a/Documentation/perf/qcom_l2_pmu.txt b/Documentation/perf/qcom_l2_pmu.txt new file mode 100644 index 000000000000..b25b97659ab9 --- /dev/null +++ b/Documentation/perf/qcom_l2_pmu.txt @@ -0,0 +1,38 @@ +Qualcomm Technologies Level-2 Cache Performance Monitoring Unit (PMU) +===================================================================== + +This driver supports the L2 cache clusters found in Qualcomm Technologies +Centriq SoCs. There are multiple physical L2 cache clusters, each with their +own PMU. Each cluster has one or more CPUs associated with it. + +There is one logical L2 PMU exposed, which aggregates the results from +the physical PMUs. + +The driver provides a description of its available events and configuration +options in sysfs, see /sys/devices/l2cache_0. + +The "format" directory describes the format of the events. + +Events can be envisioned as a 2-dimensional array. Each column represents +a group of events. There are 8 groups. Only one entry from each +group can be in use at a time. If multiple events from the same group +are specified, the conflicting events cannot be counted at the same time. + +Events are specified as 0xCCG, where CC is 2 hex digits specifying +the code (array row) and G specifies the group (column) 0-7. + +In addition there is a cycle counter event specified by the value 0xFE +which is outside the above scheme. + +The driver provides a "cpumask" sysfs attribute which contains a mask +consisting of one CPU per cluster which will be used to handle all the PMU +events on that cluster. + +Examples for use with perf: + + perf stat -e l2cache_0/config=0x001/,l2cache_0/config=0x042/ -a sleep 1 + + perf stat -e l2cache_0/config=0xfe/ -C 2 sleep 1 + +The driver does not support sampling, therefore "perf record" will +not work. Per-task perf sessions are not supported. diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig index 4d5c5f9f0dbd..93651907874f 100644 --- a/drivers/perf/Kconfig +++ b/drivers/perf/Kconfig @@ -12,6 +12,15 @@ config ARM_PMU Say y if you want to use CPU performance monitors on ARM-based systems. +config QCOM_L2_PMU + bool "Qualcomm Technologies L2-cache PMU" + depends on ARCH_QCOM && ARM64 && PERF_EVENTS && ACPI + help + Provides support for the L2 cache performance monitor unit (PMU) + in Qualcomm Technologies processors. + Adds the L2 cache PMU into the perf events subsystem for + monitoring L2 cache events. + config XGENE_PMU depends on PERF_EVENTS && ARCH_XGENE bool "APM X-Gene SoC PMU" diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile index b116e982810b..ef24833c94a8 100644 --- a/drivers/perf/Makefile +++ b/drivers/perf/Makefile @@ -1,2 +1,3 @@ obj-$(CONFIG_ARM_PMU) += arm_pmu.o +obj-$(CONFIG_QCOM_L2_PMU) += qcom_l2_pmu.o obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o diff --git a/drivers/perf/qcom_l2_pmu.c b/drivers/perf/qcom_l2_pmu.c new file mode 100644 index 000000000000..c259848228b4 --- /dev/null +++ b/drivers/perf/qcom_l2_pmu.c @@ -0,0 +1,1013 @@ +/* Copyright (c) 2015-2017 The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#define MAX_L2_CTRS 9 + +#define L2PMCR_NUM_EV_SHIFT 11 +#define L2PMCR_NUM_EV_MASK 0x1F + +#define L2PMCR 0x400 +#define L2PMCNTENCLR 0x403 +#define L2PMCNTENSET 0x404 +#define L2PMINTENCLR 0x405 +#define L2PMINTENSET 0x406 +#define L2PMOVSCLR 0x407 +#define L2PMOVSSET 0x408 +#define L2PMCCNTCR 0x409 +#define L2PMCCNTR 0x40A +#define L2PMCCNTSR 0x40C +#define L2PMRESR 0x410 +#define IA_L2PMXEVCNTCR_BASE 0x420 +#define IA_L2PMXEVCNTR_BASE 0x421 +#define IA_L2PMXEVFILTER_BASE 0x423 +#define IA_L2PMXEVTYPER_BASE 0x424 + +#define IA_L2_REG_OFFSET 0x10 + +#define L2PMXEVFILTER_SUFILTER_ALL 0x000E0000 +#define L2PMXEVFILTER_ORGFILTER_IDINDEP 0x00000004 +#define L2PMXEVFILTER_ORGFILTER_ALL 0x00000003 + +#define L2EVTYPER_REG_SHIFT 3 + +#define L2PMRESR_GROUP_BITS 8 +#define L2PMRESR_GROUP_MASK GENMASK(7, 0) + +#define L2CYCLE_CTR_BIT 31 +#define L2CYCLE_CTR_RAW_CODE 0xFE + +#define L2PMCR_RESET_ALL 0x6 +#define L2PMCR_COUNTERS_ENABLE 0x1 +#define L2PMCR_COUNTERS_DISABLE 0x0 + +#define L2PMRESR_EN BIT_ULL(63) + +#define L2_EVT_MASK 0x00000FFF +#define L2_EVT_CODE_MASK 0x00000FF0 +#define L2_EVT_GRP_MASK 0x0000000F +#define L2_EVT_CODE_SHIFT 4 +#define L2_EVT_GRP_SHIFT 0 + +#define L2_EVT_CODE(event) (((event) & L2_EVT_CODE_MASK) >> L2_EVT_CODE_SHIFT) +#define L2_EVT_GROUP(event) (((event) & L2_EVT_GRP_MASK) >> L2_EVT_GRP_SHIFT) + +#define L2_EVT_GROUP_MAX 7 + +#define L2_COUNTER_RELOAD BIT_ULL(31) +#define L2_CYCLE_COUNTER_RELOAD BIT_ULL(63) + +#define L2CPUSRSELR_EL1 sys_reg(3, 3, 15, 0, 6) +#define L2CPUSRDR_EL1 sys_reg(3, 3, 15, 0, 7) + +#define reg_idx(reg, i) (((i) * IA_L2_REG_OFFSET) + reg##_BASE) + +static DEFINE_RAW_SPINLOCK(l2_access_lock); + +/** + * set_l2_indirect_reg: write value to an L2 register + * @reg: Address of L2 register. + * @value: Value to be written to register. + * + * Use architecturally required barriers for ordering between system register + * accesses + */ +static void set_l2_indirect_reg(u64 reg, u64 val) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&l2_access_lock, flags); + write_sysreg_s(reg, L2CPUSRSELR_EL1); + isb(); + write_sysreg_s(val, L2CPUSRDR_EL1); + isb(); + raw_spin_unlock_irqrestore(&l2_access_lock, flags); +} + +/** + * get_l2_indirect_reg: read an L2 register value + * @reg: Address of L2 register. + * + * Use architecturally required barriers for ordering between system register + * accesses + */ +static u64 get_l2_indirect_reg(u64 reg) +{ + u64 val; + unsigned long flags; + + raw_spin_lock_irqsave(&l2_access_lock, flags); + write_sysreg_s(reg, L2CPUSRSELR_EL1); + isb(); + val = read_sysreg_s(L2CPUSRDR_EL1); + raw_spin_unlock_irqrestore(&l2_access_lock, flags); + + return val; +} + +struct cluster_pmu; + +/* + * Aggregate PMU. Implements the core pmu functions and manages + * the hardware PMUs. + */ +struct l2cache_pmu { + struct hlist_node node; + u32 num_pmus; + struct pmu pmu; + int num_counters; + cpumask_t cpumask; + struct platform_device *pdev; + struct cluster_pmu * __percpu *pmu_cluster; + struct list_head clusters; +}; + +/* + * The cache is made up of one or more clusters, each cluster has its own PMU. + * Each cluster is associated with one or more CPUs. + * This structure represents one of the hardware PMUs. + * + * Events can be envisioned as a 2-dimensional array. Each column represents + * a group of events. There are 8 groups. Only one entry from each + * group can be in use at a time. + * + * Events are specified as 0xCCG, where CC is 2 hex digits specifying + * the code (array row) and G specifies the group (column). + * + * In addition there is a cycle counter event specified by L2CYCLE_CTR_RAW_CODE + * which is outside the above scheme. + */ +struct cluster_pmu { + struct list_head next; + struct perf_event *events[MAX_L2_CTRS]; + struct l2cache_pmu *l2cache_pmu; + DECLARE_BITMAP(used_counters, MAX_L2_CTRS); + DECLARE_BITMAP(used_groups, L2_EVT_GROUP_MAX + 1); + int irq; + int cluster_id; + /* The CPU that is used for collecting events on this cluster */ + int on_cpu; + /* All the CPUs associated with this cluster */ + cpumask_t cluster_cpus; + spinlock_t pmu_lock; +}; + +#define to_l2cache_pmu(p) (container_of(p, struct l2cache_pmu, pmu)) + +static u32 l2_cycle_ctr_idx; +static u32 l2_counter_present_mask; + +static inline u32 idx_to_reg_bit(u32 idx) +{ + if (idx == l2_cycle_ctr_idx) + return BIT(L2CYCLE_CTR_BIT); + + return BIT(idx); +} + +static inline struct cluster_pmu *get_cluster_pmu( + struct l2cache_pmu *l2cache_pmu, int cpu) +{ + return *per_cpu_ptr(l2cache_pmu->pmu_cluster, cpu); +} + +static void cluster_pmu_reset(void) +{ + /* Reset all counters */ + set_l2_indirect_reg(L2PMCR, L2PMCR_RESET_ALL); + set_l2_indirect_reg(L2PMCNTENCLR, l2_counter_present_mask); + set_l2_indirect_reg(L2PMINTENCLR, l2_counter_present_mask); + set_l2_indirect_reg(L2PMOVSCLR, l2_counter_present_mask); +} + +static inline void cluster_pmu_enable(void) +{ + set_l2_indirect_reg(L2PMCR, L2PMCR_COUNTERS_ENABLE); +} + +static inline void cluster_pmu_disable(void) +{ + set_l2_indirect_reg(L2PMCR, L2PMCR_COUNTERS_DISABLE); +} + +static inline void cluster_pmu_counter_set_value(u32 idx, u64 value) +{ + if (idx == l2_cycle_ctr_idx) + set_l2_indirect_reg(L2PMCCNTR, value); + else + set_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTR, idx), value); +} + +static inline u64 cluster_pmu_counter_get_value(u32 idx) +{ + u64 value; + + if (idx == l2_cycle_ctr_idx) + value = get_l2_indirect_reg(L2PMCCNTR); + else + value = get_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTR, idx)); + + return value; +} + +static inline void cluster_pmu_counter_enable(u32 idx) +{ + set_l2_indirect_reg(L2PMCNTENSET, idx_to_reg_bit(idx)); +} + +static inline void cluster_pmu_counter_disable(u32 idx) +{ + set_l2_indirect_reg(L2PMCNTENCLR, idx_to_reg_bit(idx)); +} + +static inline void cluster_pmu_counter_enable_interrupt(u32 idx) +{ + set_l2_indirect_reg(L2PMINTENSET, idx_to_reg_bit(idx)); +} + +static inline void cluster_pmu_counter_disable_interrupt(u32 idx) +{ + set_l2_indirect_reg(L2PMINTENCLR, idx_to_reg_bit(idx)); +} + +static inline void cluster_pmu_set_evccntcr(u32 val) +{ + set_l2_indirect_reg(L2PMCCNTCR, val); +} + +static inline void cluster_pmu_set_evcntcr(u32 ctr, u32 val) +{ + set_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTCR, ctr), val); +} + +static inline void cluster_pmu_set_evtyper(u32 ctr, u32 val) +{ + set_l2_indirect_reg(reg_idx(IA_L2PMXEVTYPER, ctr), val); +} + +static void cluster_pmu_set_resr(struct cluster_pmu *cluster, + u32 event_group, u32 event_cc) +{ + u64 field; + u64 resr_val; + u32 shift; + unsigned long flags; + + shift = L2PMRESR_GROUP_BITS * event_group; + field = ((u64)(event_cc & L2PMRESR_GROUP_MASK) << shift); + + spin_lock_irqsave(&cluster->pmu_lock, flags); + + resr_val = get_l2_indirect_reg(L2PMRESR); + resr_val &= ~(L2PMRESR_GROUP_MASK << shift); + resr_val |= field; + resr_val |= L2PMRESR_EN; + set_l2_indirect_reg(L2PMRESR, resr_val); + + spin_unlock_irqrestore(&cluster->pmu_lock, flags); +} + +/* + * Hardware allows filtering of events based on the originating + * CPU. Turn this off by setting filter bits to allow events from + * all CPUS, subunits and ID independent events in this cluster. + */ +static inline void cluster_pmu_set_evfilter_sys_mode(u32 ctr) +{ + u32 val = L2PMXEVFILTER_SUFILTER_ALL | + L2PMXEVFILTER_ORGFILTER_IDINDEP | + L2PMXEVFILTER_ORGFILTER_ALL; + + set_l2_indirect_reg(reg_idx(IA_L2PMXEVFILTER, ctr), val); +} + +static inline u32 cluster_pmu_getreset_ovsr(void) +{ + u32 result = get_l2_indirect_reg(L2PMOVSSET); + + set_l2_indirect_reg(L2PMOVSCLR, result); + return result; +} + +static inline bool cluster_pmu_has_overflowed(u32 ovsr) +{ + return !!(ovsr & l2_counter_present_mask); +} + +static inline bool cluster_pmu_counter_has_overflowed(u32 ovsr, u32 idx) +{ + return !!(ovsr & idx_to_reg_bit(idx)); +} + +static void l2_cache_event_update(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + u64 delta, prev, now; + u32 idx = hwc->idx; + + do { + prev = local64_read(&hwc->prev_count); + now = cluster_pmu_counter_get_value(idx); + } while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev); + + /* + * The cycle counter is 64-bit, but all other counters are + * 32-bit, and we must handle 32-bit overflow explicitly. + */ + delta = now - prev; + if (idx != l2_cycle_ctr_idx) + delta &= 0xffffffff; + + local64_add(delta, &event->count); +} + +static void l2_cache_cluster_set_period(struct cluster_pmu *cluster, + struct hw_perf_event *hwc) +{ + u32 idx = hwc->idx; + u64 new; + + /* + * We limit the max period to half the max counter value so + * that even in the case of extreme interrupt latency the + * counter will (hopefully) not wrap past its initial value. + */ + if (idx == l2_cycle_ctr_idx) + new = L2_CYCLE_COUNTER_RELOAD; + else + new = L2_COUNTER_RELOAD; + + local64_set(&hwc->prev_count, new); + cluster_pmu_counter_set_value(idx, new); +} + +static int l2_cache_get_event_idx(struct cluster_pmu *cluster, + struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + int idx; + int num_ctrs = cluster->l2cache_pmu->num_counters - 1; + unsigned int group; + + if (hwc->config_base == L2CYCLE_CTR_RAW_CODE) { + if (test_and_set_bit(l2_cycle_ctr_idx, cluster->used_counters)) + return -EAGAIN; + + return l2_cycle_ctr_idx; + } + + idx = find_first_zero_bit(cluster->used_counters, num_ctrs); + if (idx == num_ctrs) + /* The counters are all in use. */ + return -EAGAIN; + + /* + * Check for column exclusion: event column already in use by another + * event. This is for events which are not in the same group. + * Conflicting events in the same group are detected in event_init. + */ + group = L2_EVT_GROUP(hwc->config_base); + if (test_bit(group, cluster->used_groups)) + return -EAGAIN; + + set_bit(idx, cluster->used_counters); + set_bit(group, cluster->used_groups); + + return idx; +} + +static void l2_cache_clear_event_idx(struct cluster_pmu *cluster, + struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + + clear_bit(idx, cluster->used_counters); + if (hwc->config_base != L2CYCLE_CTR_RAW_CODE) + clear_bit(L2_EVT_GROUP(hwc->config_base), cluster->used_groups); +} + +static irqreturn_t l2_cache_handle_irq(int irq_num, void *data) +{ + struct cluster_pmu *cluster = data; + int num_counters = cluster->l2cache_pmu->num_counters; + u32 ovsr; + int idx; + + ovsr = cluster_pmu_getreset_ovsr(); + if (!cluster_pmu_has_overflowed(ovsr)) + return IRQ_NONE; + + for_each_set_bit(idx, cluster->used_counters, num_counters) { + struct perf_event *event = cluster->events[idx]; + struct hw_perf_event *hwc; + + if (WARN_ON_ONCE(!event)) + continue; + + if (!cluster_pmu_counter_has_overflowed(ovsr, idx)) + continue; + + l2_cache_event_update(event); + hwc = &event->hw; + + l2_cache_cluster_set_period(cluster, hwc); + } + + return IRQ_HANDLED; +} + +/* + * Implementation of abstract pmu functionality required by + * the core perf events code. + */ + +static void l2_cache_pmu_enable(struct pmu *pmu) +{ + /* + * Although there is only one PMU (per socket) controlling multiple + * physical PMUs (per cluster), because we do not support per-task mode + * each event is associated with a CPU. Each event has pmu_enable + * called on its CPU, so here it is only necessary to enable the + * counters for the current CPU. + */ + + cluster_pmu_enable(); +} + +static void l2_cache_pmu_disable(struct pmu *pmu) +{ + cluster_pmu_disable(); +} + +static int l2_cache_event_init(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + struct cluster_pmu *cluster; + struct perf_event *sibling; + struct l2cache_pmu *l2cache_pmu; + + if (event->attr.type != event->pmu->type) + return -ENOENT; + + l2cache_pmu = to_l2cache_pmu(event->pmu); + + if (hwc->sample_period) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Sampling not supported\n"); + return -EOPNOTSUPP; + } + + if (event->cpu < 0) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Per-task mode not supported\n"); + return -EOPNOTSUPP; + } + + /* We cannot filter accurately so we just don't allow it. */ + if (event->attr.exclude_user || event->attr.exclude_kernel || + event->attr.exclude_hv || event->attr.exclude_idle) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Can't exclude execution levels\n"); + return -EOPNOTSUPP; + } + + if (((L2_EVT_GROUP(event->attr.config) > L2_EVT_GROUP_MAX) || + ((event->attr.config & ~L2_EVT_MASK) != 0)) && + (event->attr.config != L2CYCLE_CTR_RAW_CODE)) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Invalid config %llx\n", + event->attr.config); + return -EINVAL; + } + + /* Don't allow groups with mixed PMUs, except for s/w events */ + if (event->group_leader->pmu != event->pmu && + !is_software_event(event->group_leader)) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Can't create mixed PMU group\n"); + return -EINVAL; + } + + list_for_each_entry(sibling, &event->group_leader->sibling_list, + group_entry) + if (sibling->pmu != event->pmu && + !is_software_event(sibling)) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Can't create mixed PMU group\n"); + return -EINVAL; + } + + cluster = get_cluster_pmu(l2cache_pmu, event->cpu); + if (!cluster) { + /* CPU has not been initialised */ + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "CPU%d not associated with L2 cluster\n", event->cpu); + return -EINVAL; + } + + /* Ensure all events in a group are on the same cpu */ + if ((event->group_leader != event) && + (cluster->on_cpu != event->group_leader->cpu)) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Can't create group on CPUs %d and %d", + event->cpu, event->group_leader->cpu); + return -EINVAL; + } + + if ((event != event->group_leader) && + (L2_EVT_GROUP(event->group_leader->attr.config) == + L2_EVT_GROUP(event->attr.config))) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Column exclusion: conflicting events %llx %llx\n", + event->group_leader->attr.config, + event->attr.config); + return -EINVAL; + } + + list_for_each_entry(sibling, &event->group_leader->sibling_list, + group_entry) { + if ((sibling != event) && + (L2_EVT_GROUP(sibling->attr.config) == + L2_EVT_GROUP(event->attr.config))) { + dev_dbg_ratelimited(&l2cache_pmu->pdev->dev, + "Column exclusion: conflicting events %llx %llx\n", + sibling->attr.config, + event->attr.config); + return -EINVAL; + } + } + + hwc->idx = -1; + hwc->config_base = event->attr.config; + + /* + * Ensure all events are on the same cpu so all events are in the + * same cpu context, to avoid races on pmu_enable etc. + */ + event->cpu = cluster->on_cpu; + + return 0; +} + +static void l2_cache_event_start(struct perf_event *event, int flags) +{ + struct cluster_pmu *cluster; + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + u32 config; + u32 event_cc, event_group; + + hwc->state = 0; + + cluster = get_cluster_pmu(to_l2cache_pmu(event->pmu), event->cpu); + + l2_cache_cluster_set_period(cluster, hwc); + + if (hwc->config_base == L2CYCLE_CTR_RAW_CODE) { + cluster_pmu_set_evccntcr(0); + } else { + config = hwc->config_base; + event_cc = L2_EVT_CODE(config); + event_group = L2_EVT_GROUP(config); + + cluster_pmu_set_evcntcr(idx, 0); + cluster_pmu_set_evtyper(idx, event_group); + cluster_pmu_set_resr(cluster, event_group, event_cc); + cluster_pmu_set_evfilter_sys_mode(idx); + } + + cluster_pmu_counter_enable_interrupt(idx); + cluster_pmu_counter_enable(idx); +} + +static void l2_cache_event_stop(struct perf_event *event, int flags) +{ + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + + if (hwc->state & PERF_HES_STOPPED) + return; + + cluster_pmu_counter_disable_interrupt(idx); + cluster_pmu_counter_disable(idx); + + if (flags & PERF_EF_UPDATE) + l2_cache_event_update(event); + hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; +} + +static int l2_cache_event_add(struct perf_event *event, int flags) +{ + struct hw_perf_event *hwc = &event->hw; + int idx; + int err = 0; + struct cluster_pmu *cluster; + + cluster = get_cluster_pmu(to_l2cache_pmu(event->pmu), event->cpu); + + idx = l2_cache_get_event_idx(cluster, event); + if (idx < 0) + return idx; + + hwc->idx = idx; + hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; + cluster->events[idx] = event; + local64_set(&hwc->prev_count, 0); + + if (flags & PERF_EF_START) + l2_cache_event_start(event, flags); + + /* Propagate changes to the userspace mapping. */ + perf_event_update_userpage(event); + + return err; +} + +static void l2_cache_event_del(struct perf_event *event, int flags) +{ + struct hw_perf_event *hwc = &event->hw; + struct cluster_pmu *cluster; + int idx = hwc->idx; + + cluster = get_cluster_pmu(to_l2cache_pmu(event->pmu), event->cpu); + + l2_cache_event_stop(event, flags | PERF_EF_UPDATE); + cluster->events[idx] = NULL; + l2_cache_clear_event_idx(cluster, event); + + perf_event_update_userpage(event); +} + +static void l2_cache_event_read(struct perf_event *event) +{ + l2_cache_event_update(event); +} + +static ssize_t l2_cache_pmu_cpumask_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct l2cache_pmu *l2cache_pmu = to_l2cache_pmu(dev_get_drvdata(dev)); + + return cpumap_print_to_pagebuf(true, buf, &l2cache_pmu->cpumask); +} + +static struct device_attribute l2_cache_pmu_cpumask_attr = + __ATTR(cpumask, S_IRUGO, l2_cache_pmu_cpumask_show, NULL); + +static struct attribute *l2_cache_pmu_cpumask_attrs[] = { + &l2_cache_pmu_cpumask_attr.attr, + NULL, +}; + +static struct attribute_group l2_cache_pmu_cpumask_group = { + .attrs = l2_cache_pmu_cpumask_attrs, +}; + +/* CCG format for perf RAW codes. */ +PMU_FORMAT_ATTR(l2_code, "config:4-11"); +PMU_FORMAT_ATTR(l2_group, "config:0-3"); +static struct attribute *l2_cache_pmu_formats[] = { + &format_attr_l2_code.attr, + &format_attr_l2_group.attr, + NULL, +}; + +static struct attribute_group l2_cache_pmu_format_group = { + .name = "format", + .attrs = l2_cache_pmu_formats, +}; + +static const struct attribute_group *l2_cache_pmu_attr_grps[] = { + &l2_cache_pmu_format_group, + &l2_cache_pmu_cpumask_group, + NULL, +}; + +/* + * Generic device handlers + */ + +static const struct acpi_device_id l2_cache_pmu_acpi_match[] = { + { "QCOM8130", }, + { } +}; + +static int get_num_counters(void) +{ + int val; + + val = get_l2_indirect_reg(L2PMCR); + + /* + * Read number of counters from L2PMCR and add 1 + * for the cycle counter. + */ + return ((val >> L2PMCR_NUM_EV_SHIFT) & L2PMCR_NUM_EV_MASK) + 1; +} + +static struct cluster_pmu *l2_cache_associate_cpu_with_cluster( + struct l2cache_pmu *l2cache_pmu, int cpu) +{ + u64 mpidr; + int cpu_cluster_id; + struct cluster_pmu *cluster = NULL; + + /* + * This assumes that the cluster_id is in MPIDR[aff1] for + * single-threaded cores, and MPIDR[aff2] for multi-threaded + * cores. This logic will have to be updated if this changes. + */ + mpidr = read_cpuid_mpidr(); + if (mpidr & MPIDR_MT_BITMASK) + cpu_cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2); + else + cpu_cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1); + + list_for_each_entry(cluster, &l2cache_pmu->clusters, next) { + if (cluster->cluster_id != cpu_cluster_id) + continue; + + dev_info(&l2cache_pmu->pdev->dev, + "CPU%d associated with cluster %d\n", cpu, + cluster->cluster_id); + cpumask_set_cpu(cpu, &cluster->cluster_cpus); + *per_cpu_ptr(l2cache_pmu->pmu_cluster, cpu) = cluster; + break; + } + + return cluster; +} + +static int l2cache_pmu_online_cpu(unsigned int cpu, struct hlist_node *node) +{ + struct cluster_pmu *cluster; + struct l2cache_pmu *l2cache_pmu; + + l2cache_pmu = hlist_entry_safe(node, struct l2cache_pmu, node); + cluster = get_cluster_pmu(l2cache_pmu, cpu); + if (!cluster) { + /* First time this CPU has come online */ + cluster = l2_cache_associate_cpu_with_cluster(l2cache_pmu, cpu); + if (!cluster) { + /* Only if broken firmware doesn't list every cluster */ + WARN_ONCE(1, "No L2 cache cluster for CPU%d\n", cpu); + return 0; + } + } + + /* If another CPU is managing this cluster, we're done */ + if (cluster->on_cpu != -1) + return 0; + + /* + * All CPUs on this cluster were down, use this one. + * Reset to put it into sane state. + */ + cluster->on_cpu = cpu; + cpumask_set_cpu(cpu, &l2cache_pmu->cpumask); + cluster_pmu_reset(); + + WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(cpu))); + enable_irq(cluster->irq); + + return 0; +} + +static int l2cache_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) +{ + struct cluster_pmu *cluster; + struct l2cache_pmu *l2cache_pmu; + cpumask_t cluster_online_cpus; + unsigned int target; + + l2cache_pmu = hlist_entry_safe(node, struct l2cache_pmu, node); + cluster = get_cluster_pmu(l2cache_pmu, cpu); + if (!cluster) + return 0; + + /* If this CPU is not managing the cluster, we're done */ + if (cluster->on_cpu != cpu) + return 0; + + /* Give up ownership of cluster */ + cpumask_clear_cpu(cpu, &l2cache_pmu->cpumask); + cluster->on_cpu = -1; + + /* Any other CPU for this cluster which is still online */ + cpumask_and(&cluster_online_cpus, &cluster->cluster_cpus, + cpu_online_mask); + target = cpumask_any_but(&cluster_online_cpus, cpu); + if (target >= nr_cpu_ids) { + disable_irq(cluster->irq); + return 0; + } + + perf_pmu_migrate_context(&l2cache_pmu->pmu, cpu, target); + cluster->on_cpu = target; + cpumask_set_cpu(target, &l2cache_pmu->cpumask); + WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(target))); + + return 0; +} + +static int l2_cache_pmu_probe_cluster(struct device *dev, void *data) +{ + struct platform_device *pdev = to_platform_device(dev->parent); + struct platform_device *sdev = to_platform_device(dev); + struct l2cache_pmu *l2cache_pmu = data; + struct cluster_pmu *cluster; + struct acpi_device *device; + unsigned long fw_cluster_id; + int err; + int irq; + + if (acpi_bus_get_device(ACPI_HANDLE(dev), &device)) + return -ENODEV; + + if (kstrtoul(device->pnp.unique_id, 10, &fw_cluster_id) < 0) { + dev_err(&pdev->dev, "unable to read ACPI uid\n"); + return -ENODEV; + } + + cluster = devm_kzalloc(&pdev->dev, sizeof(*cluster), GFP_KERNEL); + if (!cluster) + return -ENOMEM; + + INIT_LIST_HEAD(&cluster->next); + list_add(&cluster->next, &l2cache_pmu->clusters); + cluster->cluster_id = fw_cluster_id; + + irq = platform_get_irq(sdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, + "Failed to get valid irq for cluster %ld\n", + fw_cluster_id); + return irq; + } + irq_set_status_flags(irq, IRQ_NOAUTOEN); + cluster->irq = irq; + + cluster->l2cache_pmu = l2cache_pmu; + cluster->on_cpu = -1; + + err = devm_request_irq(&pdev->dev, irq, l2_cache_handle_irq, + IRQF_NOBALANCING | IRQF_NO_THREAD, + "l2-cache-pmu", cluster); + if (err) { + dev_err(&pdev->dev, + "Unable to request IRQ%d for L2 PMU counters\n", irq); + return err; + } + + dev_info(&pdev->dev, + "Registered L2 cache PMU cluster %ld\n", fw_cluster_id); + + spin_lock_init(&cluster->pmu_lock); + + l2cache_pmu->num_pmus++; + + return 0; +} + +static int l2_cache_pmu_probe(struct platform_device *pdev) +{ + int err; + struct l2cache_pmu *l2cache_pmu; + + l2cache_pmu = + devm_kzalloc(&pdev->dev, sizeof(*l2cache_pmu), GFP_KERNEL); + if (!l2cache_pmu) + return -ENOMEM; + + INIT_LIST_HEAD(&l2cache_pmu->clusters); + + platform_set_drvdata(pdev, l2cache_pmu); + l2cache_pmu->pmu = (struct pmu) { + /* suffix is instance id for future use with multiple sockets */ + .name = "l2cache_0", + .task_ctx_nr = perf_invalid_context, + .pmu_enable = l2_cache_pmu_enable, + .pmu_disable = l2_cache_pmu_disable, + .event_init = l2_cache_event_init, + .add = l2_cache_event_add, + .del = l2_cache_event_del, + .start = l2_cache_event_start, + .stop = l2_cache_event_stop, + .read = l2_cache_event_read, + .attr_groups = l2_cache_pmu_attr_grps, + }; + + l2cache_pmu->num_counters = get_num_counters(); + l2cache_pmu->pdev = pdev; + l2cache_pmu->pmu_cluster = devm_alloc_percpu(&pdev->dev, + struct cluster_pmu *); + if (!l2cache_pmu->pmu_cluster) + return -ENOMEM; + + l2_cycle_ctr_idx = l2cache_pmu->num_counters - 1; + l2_counter_present_mask = GENMASK(l2cache_pmu->num_counters - 2, 0) | + BIT(L2CYCLE_CTR_BIT); + + cpumask_clear(&l2cache_pmu->cpumask); + + /* Read cluster info and initialize each cluster */ + err = device_for_each_child(&pdev->dev, l2cache_pmu, + l2_cache_pmu_probe_cluster); + if (err) + return err; + + if (l2cache_pmu->num_pmus == 0) { + dev_err(&pdev->dev, "No hardware L2 cache PMUs found\n"); + return -ENODEV; + } + + err = cpuhp_state_add_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE, + &l2cache_pmu->node); + if (err) { + dev_err(&pdev->dev, "Error %d registering hotplug", err); + return err; + } + + err = perf_pmu_register(&l2cache_pmu->pmu, l2cache_pmu->pmu.name, -1); + if (err) { + dev_err(&pdev->dev, "Error %d registering L2 cache PMU\n", err); + goto out_unregister; + } + + dev_info(&pdev->dev, "Registered L2 cache PMU using %d HW PMUs\n", + l2cache_pmu->num_pmus); + + return err; + +out_unregister: + cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE, + &l2cache_pmu->node); + return err; +} + +static int l2_cache_pmu_remove(struct platform_device *pdev) +{ + struct l2cache_pmu *l2cache_pmu = + to_l2cache_pmu(platform_get_drvdata(pdev)); + + perf_pmu_unregister(&l2cache_pmu->pmu); + cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE, + &l2cache_pmu->node); + return 0; +} + +static struct platform_driver l2_cache_pmu_driver = { + .driver = { + .name = "qcom-l2cache-pmu", + .acpi_match_table = ACPI_PTR(l2_cache_pmu_acpi_match), + }, + .probe = l2_cache_pmu_probe, + .remove = l2_cache_pmu_remove, +}; + +static int __init register_l2_cache_pmu_driver(void) +{ + int err; + + err = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE, + "AP_PERF_ARM_QCOM_L2_ONLINE", + l2cache_pmu_online_cpu, + l2cache_pmu_offline_cpu); + if (err) + return err; + + return platform_driver_register(&l2_cache_pmu_driver); +} +device_initcall(register_l2_cache_pmu_driver); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 20bfefbe7594..1b7b2075b9cd 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -138,6 +138,7 @@ enum cpuhp_state { CPUHP_AP_PERF_ARM_CCI_ONLINE, CPUHP_AP_PERF_ARM_CCN_ONLINE, CPUHP_AP_PERF_ARM_L2X0_ONLINE, + CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE, CPUHP_AP_WORKQUEUE_ONLINE, CPUHP_AP_RCUTREE_ONLINE, CPUHP_AP_ONLINE_DYN, -- 2.20.1