[PATCH v6] soc: qcom: add l2 cache perf events driver
Neil Leeder
nleeder at codeaurora.org
Wed Sep 21 14:12:54 PDT 2016
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.
Signed-off-by: Neil Leeder <nleeder at codeaurora.org>
---
v6: restore accidentally dropped Kconfig dependencies
v5:
Fold the header and l2-accessors into .c file
Use multi-instance framework for hotplug
Change terminology from slice to cluster for clarity
Remove unnecessary rmw sequence for enable registers
Use prev_count in hwc rather than in slice
Enforce all events in same group on same CPU
Add comments, rename variables for clarity
v4:
Replace notifier with hotplug statemachine
Allocate PMU struct dynamically
v3:
Remove exports from l2-accessors
Change l2-accessors Kconfig to make it not user-selectable
Reorder and remove unnecessary includes
v2:
Add the l2-accessors patch to this patchset, previously posted separately.
Remove sampling and per-task functionality for this uncore PMU.
Use cpumask to replace code which filtered events to one cpu per slice.
Replace manual event filtering with filter_match callback.
Use a separate used_mask for event groups.
Add hotplug notifier for CPU and irq migration.
Remove extraneous synchronisation instructions.
Other miscellaneous cleanup.
drivers/soc/qcom/Kconfig | 9 +
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/perf_event_l2.c | 948 +++++++++++++++++++++++++++++++++++++++
include/linux/cpuhotplug.h | 1 +
4 files changed, 959 insertions(+)
create mode 100644 drivers/soc/qcom/perf_event_l2.c
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 461b387..3fa27a8 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -10,6 +10,15 @@ config QCOM_GSBI
functions for connecting the underlying serial UART, SPI, and I2C
devices to the output pins.
+config QCOM_PERF_EVENTS_L2
+ bool "Qualcomm Technologies L2-cache perf events"
+ depends on ARCH_QCOM && ARM64 && HW_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 QCOM_PM
bool "Qualcomm Power Management"
depends on ARCH_QCOM && !ARM64
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index fdd664e..4c9df3b 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o
+obj-$(CONFIG_QCOM_PERF_EVENTS_L2) += perf_event_l2.o
obj-$(CONFIG_QCOM_PM) += spm.o
obj-$(CONFIG_QCOM_SMD) += smd.o
obj-$(CONFIG_QCOM_SMD_RPM) += smd-rpm.o
diff --git a/drivers/soc/qcom/perf_event_l2.c b/drivers/soc/qcom/perf_event_l2.c
new file mode 100644
index 0000000..bbf47c9
--- /dev/null
+++ b/drivers/soc/qcom/perf_event_l2.c
@@ -0,0 +1,948 @@
+/* Copyright (c) 2015,2016 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 <linux/acpi.h>
+#include <linux/interrupt.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+
+#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 L2PM_CC_ENABLE 0x80000000
+
+#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 ((u64)1 << 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_MAX_PERIOD U32_MAX
+#define L2_CNT_PERIOD (U32_MAX - GENMASK(26, 0))
+
+#define L2CPUSRSELR_EL1 S3_3_c15_c0_6
+#define L2CPUSRDR_EL1 S3_3_c15_c0_7
+
+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(reg, L2CPUSRSELR_EL1);
+ isb();
+ write_sysreg(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(reg, L2CPUSRSELR_EL1);
+ isb();
+ val = read_sysreg(L2CPUSRDR_EL1);
+ raw_spin_unlock_irqrestore(&l2_access_lock, flags);
+
+ return val;
+}
+
+/*
+ * 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;
+};
+
+/*
+ * 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. When an event is assigned a counter
+ * by *_event_add(), the counter index is assigned to group_to_counter[group].
+ * This allows *filter_match() to detect and reject conflicting events in
+ * the same group.
+ * 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 hml2_pmu {
+ 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 group_to_counter[L2_EVT_GROUP_MAX + 1];
+ int irq;
+ /* 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 DEFINE_PER_CPU(struct hml2_pmu *, pmu_cluster);
+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 hml2_pmu *get_hml2_pmu(int cpu)
+{
+ return per_cpu(pmu_cluster, cpu);
+}
+
+static void hml2_pmu__reset_on_cluster(void *x)
+{
+ /* Reset all ctrs */
+ 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 hml2_pmu__reset(struct hml2_pmu *cluster)
+{
+ cpumask_t *mask = &cluster->cluster_cpus;
+
+ if (smp_call_function_any(mask, hml2_pmu__reset_on_cluster, NULL, 1))
+ dev_err(&cluster->l2cache_pmu->pdev->dev,
+ "Failed to reset on cluster with cpu %d\n",
+ cpumask_first(&cluster->cluster_cpus));
+}
+
+static inline void hml2_pmu__enable(void)
+{
+ set_l2_indirect_reg(L2PMCR, L2PMCR_COUNTERS_ENABLE);
+}
+
+static inline void hml2_pmu__disable(void)
+{
+ set_l2_indirect_reg(L2PMCR, L2PMCR_COUNTERS_DISABLE);
+}
+
+static inline void hml2_pmu__counter_set_value(u32 idx, u64 value)
+{
+ u32 counter_reg;
+
+ if (idx == l2_cycle_ctr_idx) {
+ set_l2_indirect_reg(L2PMCCNTR, value);
+ } else {
+ counter_reg = (idx * IA_L2_REG_OFFSET) + IA_L2PMXEVCNTR_BASE;
+ set_l2_indirect_reg(counter_reg, value & GENMASK(31, 0));
+ }
+}
+
+static inline u64 hml2_pmu__counter_get_value(u32 idx)
+{
+ u64 value;
+ u32 counter_reg;
+
+ if (idx == l2_cycle_ctr_idx) {
+ value = get_l2_indirect_reg(L2PMCCNTR);
+ } else {
+ counter_reg = (idx * IA_L2_REG_OFFSET) + IA_L2PMXEVCNTR_BASE;
+ value = get_l2_indirect_reg(counter_reg);
+ }
+
+ return value;
+}
+
+static inline void hml2_pmu__counter_enable(u32 idx)
+{
+ set_l2_indirect_reg(L2PMCNTENSET, idx_to_reg_bit(idx));
+}
+
+static inline void hml2_pmu__counter_disable(u32 idx)
+{
+ set_l2_indirect_reg(L2PMCNTENCLR, idx_to_reg_bit(idx));
+}
+
+static inline void hml2_pmu__counter_enable_interrupt(u32 idx)
+{
+ set_l2_indirect_reg(L2PMINTENSET, idx_to_reg_bit(idx));
+}
+
+static inline void hml2_pmu__counter_disable_interrupt(u32 idx)
+{
+ set_l2_indirect_reg(L2PMINTENCLR, idx_to_reg_bit(idx));
+}
+
+static inline void hml2_pmu__set_evccntcr(u32 val)
+{
+ set_l2_indirect_reg(L2PMCCNTCR, val);
+}
+
+static inline void hml2_pmu__set_evcntcr(u32 ctr, u32 val)
+{
+ u32 evtcr_reg = (ctr * IA_L2_REG_OFFSET) + IA_L2PMXEVCNTCR_BASE;
+
+ set_l2_indirect_reg(evtcr_reg, val);
+}
+
+static inline void hml2_pmu__set_evtyper(u32 ctr, u32 val)
+{
+ u32 evtype_reg = (ctr * IA_L2_REG_OFFSET) + IA_L2PMXEVTYPER_BASE;
+
+ set_l2_indirect_reg(evtype_reg, val);
+}
+
+static void hml2_pmu__set_resr(struct hml2_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) | L2PMRESR_EN;
+
+ spin_lock_irqsave(&cluster->pmu_lock, flags);
+
+ resr_val = get_l2_indirect_reg(L2PMRESR);
+ resr_val &= ~(L2PMRESR_GROUP_MASK << shift);
+ resr_val |= field;
+ 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 hml2_pmu__set_evfilter_sys_mode(u32 ctr)
+{
+ u32 reg = (ctr * IA_L2_REG_OFFSET) + IA_L2PMXEVFILTER_BASE;
+ u32 val = L2PMXEVFILTER_SUFILTER_ALL |
+ L2PMXEVFILTER_ORGFILTER_IDINDEP |
+ L2PMXEVFILTER_ORGFILTER_ALL;
+
+ set_l2_indirect_reg(reg, val);
+}
+
+static inline u32 hml2_pmu__getreset_ovsr(void)
+{
+ u32 result = get_l2_indirect_reg(L2PMOVSSET);
+
+ set_l2_indirect_reg(L2PMOVSCLR, result);
+ return result;
+}
+
+static inline bool hml2_pmu__has_overflowed(u32 ovsr)
+{
+ return !!(ovsr & l2_counter_present_mask);
+}
+
+static inline bool hml2_pmu__counter_has_overflowed(u32 ovsr, u32 idx)
+{
+ return !!(ovsr & idx_to_reg_bit(idx));
+}
+
+static void l2_cache__event_update_from_cluster(struct perf_event *event,
+ struct hml2_pmu *cluster)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ u64 delta64, prev, now;
+ u32 delta;
+ u32 idx = hwc->idx;
+
+ do {
+ prev = local64_read(&hwc->prev_count);
+ now = hml2_pmu__counter_get_value(idx);
+ } while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev);
+
+ if (idx == l2_cycle_ctr_idx) {
+ /*
+ * The cycle counter is 64-bit so needs separate handling
+ * of 64-bit delta.
+ */
+ delta64 = now - prev;
+ local64_add(delta64, &event->count);
+ } else {
+ /*
+ * 32-bit counters need the unsigned 32-bit math to handle
+ * overflow and now < prev
+ */
+ delta = now - prev;
+ local64_add(delta, &event->count);
+ }
+}
+
+static void l2_cache__cluster_set_period(struct hml2_pmu *cluster,
+ struct hw_perf_event *hwc)
+{
+ u64 base = L2_MAX_PERIOD - (L2_CNT_PERIOD - 1);
+ u32 idx = hwc->idx;
+ u64 prev = local64_read(&hwc->prev_count);
+ u64 value;
+
+ /*
+ * Limit the maximum period to prevent the counter value
+ * from overtaking the one we are about to program.
+ * Use a starting value which is high enough that after
+ * an overflow, interrupt latency will not cause the count
+ * to reach the base value. If the previous value
+ * is below the base, increase it to be above the base
+ * and update prev_count accordingly. Otherwise if
+ * the previous value is already above the base
+ * nothing needs to be done to prev_count.
+ */
+ if (prev < base) {
+ value = base + prev;
+ local64_set(&hwc->prev_count, value);
+ } else {
+ value = prev;
+ }
+
+ hml2_pmu__counter_set_value(idx, value);
+}
+
+static int l2_cache__get_event_idx(struct hml2_pmu *cluster,
+ struct perf_event *event)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int idx;
+
+ 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;
+ }
+
+ for (idx = 0; idx < cluster->l2cache_pmu->num_counters - 1; idx++) {
+ if (!test_and_set_bit(idx, cluster->used_counters)) {
+ set_bit(L2_EVT_GROUP(hwc->config_base),
+ cluster->used_groups);
+ return idx;
+ }
+ }
+
+ /* The counters are all in use. */
+ return -EAGAIN;
+}
+
+static void l2_cache__clear_event_idx(struct hml2_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 hml2_pmu *cluster = data;
+ int num_counters = cluster->l2cache_pmu->num_counters;
+ u32 ovsr;
+ int idx;
+
+ ovsr = hml2_pmu__getreset_ovsr();
+ if (!hml2_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 (!hml2_pmu__counter_has_overflowed(ovsr, idx))
+ continue;
+
+ l2_cache__event_update_from_cluster(event, cluster);
+ 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.
+ */
+
+ hml2_pmu__enable();
+}
+
+static void l2_cache__pmu_disable(struct pmu *pmu)
+{
+ hml2_pmu__disable();
+}
+
+static int l2_cache__event_init(struct perf_event *event)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct hml2_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_warn(&l2cache_pmu->pdev->dev, "Sampling not supported\n");
+ return -EOPNOTSUPP;
+ }
+
+ if (event->cpu < 0) {
+ dev_warn(&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_warn(&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_warn(&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_warn(&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_warn(&l2cache_pmu->pdev->dev,
+ "Can't create mixed PMU group\n");
+ return -EINVAL;
+ }
+
+ /* Ensure all events in a group are on the same cpu */
+ cluster = get_hml2_pmu(event->cpu);
+ if ((event->group_leader != event) &&
+ (cluster->on_cpu != event->group_leader->cpu)) {
+ dev_warn(&l2cache_pmu->pdev->dev,
+ "Can't create group on CPUs %d and %d",
+ event->cpu, event->group_leader->cpu);
+ 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 hml2_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_hml2_pmu(event->cpu);
+ l2_cache__cluster_set_period(cluster, hwc);
+
+ if (hwc->config_base == L2CYCLE_CTR_RAW_CODE) {
+ hml2_pmu__set_evccntcr(0x0);
+ } else {
+ config = hwc->config_base;
+ event_cc = L2_EVT_CODE(config);
+ event_group = L2_EVT_GROUP(config);
+
+ hml2_pmu__set_evcntcr(idx, 0x0);
+ hml2_pmu__set_evtyper(idx, event_group);
+ hml2_pmu__set_resr(cluster, event_group, event_cc);
+ hml2_pmu__set_evfilter_sys_mode(idx);
+ }
+
+ hml2_pmu__counter_enable_interrupt(idx);
+ hml2_pmu__counter_enable(idx);
+}
+
+static void l2_cache__event_stop(struct perf_event *event, int flags)
+{
+ struct hml2_pmu *cluster;
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+
+ if (!(hwc->state & PERF_HES_STOPPED)) {
+ cluster = get_hml2_pmu(event->cpu);
+ hml2_pmu__counter_disable_interrupt(idx);
+ hml2_pmu__counter_disable(idx);
+
+ if (flags & PERF_EF_UPDATE)
+ l2_cache__event_update_from_cluster(event, cluster);
+ 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 hml2_pmu *cluster;
+
+ cluster = get_hml2_pmu(event->cpu);
+
+ idx = l2_cache__get_event_idx(cluster, event);
+ if (idx < 0) {
+ err = idx;
+ return err;
+ }
+
+ hwc->idx = idx;
+ hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ cluster->events[idx] = event;
+ cluster->group_to_counter[L2_EVT_GROUP(hwc->config_base)] = idx;
+ local64_set(&hwc->prev_count, 0ULL);
+
+ 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 hml2_pmu *cluster;
+ int idx = hwc->idx;
+
+ cluster = get_hml2_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_from_cluster(event, get_hml2_pmu(event->cpu));
+}
+
+static int l2_cache_filter_match(struct perf_event *event)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct hml2_pmu *cluster = get_hml2_pmu(event->cpu);
+ unsigned int group = L2_EVT_GROUP(hwc->config_base);
+
+ /* check for column exclusion: group already in use by another event */
+ if (test_bit(group, cluster->used_groups) &&
+ cluster->events[cluster->group_to_counter[group]] != event)
+ return 0;
+
+ return 1;
+}
+
+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 int l2cache_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
+{
+ struct hml2_pmu *cluster;
+ cpumask_t cluster_online_cpus;
+ struct l2cache_pmu *l2cache_pmu;
+
+ l2cache_pmu = hlist_entry_safe(node, struct l2cache_pmu, node);
+ cluster = get_hml2_pmu(cpu);
+ cpumask_and(&cluster_online_cpus, &cluster->cluster_cpus,
+ cpu_online_mask);
+
+ if (cpumask_weight(&cluster_online_cpus) == 1) {
+ /* all CPUs on this cluster were down, use this one */
+ cluster->on_cpu = cpu;
+ cpumask_set_cpu(cpu, &l2cache_pmu->cpumask);
+ WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(cpu)));
+ }
+
+ return 0;
+}
+
+static int l2cache_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+ struct hml2_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);
+
+ if (!cpumask_test_and_clear_cpu(cpu, &l2cache_pmu->cpumask))
+ return 0;
+ cluster = get_hml2_pmu(cpu);
+ cpumask_and(&cluster_online_cpus, &cluster->cluster_cpus,
+ cpu_online_mask);
+
+ /* Any other CPU for this cluster which is still online */
+ target = cpumask_any_but(&cluster_online_cpus, cpu);
+ if (target >= nr_cpu_ids)
+ 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 hml2_pmu *cluster;
+ struct acpi_device *device;
+ unsigned long fw_cluster_id;
+ int cpu;
+ int err;
+ int irq;
+
+ if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
+ return -ENODEV;
+
+ if (kstrtol(device->pnp.unique_id, 10, &fw_cluster_id) < 0) {
+ dev_err(&pdev->dev, "unable to read ACPI uid\n");
+ return -ENODEV;
+ }
+
+ 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;
+ }
+
+ cluster = devm_kzalloc(&pdev->dev, sizeof(*cluster), GFP_KERNEL);
+ if (!cluster)
+ return -ENOMEM;
+
+ cluster->l2cache_pmu = l2cache_pmu;
+ for_each_present_cpu(cpu) {
+ if (topology_physical_package_id(cpu) == fw_cluster_id) {
+ cpumask_set_cpu(cpu, &cluster->cluster_cpus);
+ per_cpu(pmu_cluster, cpu) = cluster;
+ }
+ }
+ cluster->irq = irq;
+
+ if (cpumask_empty(&cluster->cluster_cpus)) {
+ dev_err(&pdev->dev, "No CPUs found for L2 cache instance %ld\n",
+ fw_cluster_id);
+ return -ENODEV;
+ }
+
+ /* Pick one CPU to be the preferred one to use in the cluster */
+ cluster->on_cpu = cpumask_first(&cluster->cluster_cpus);
+
+ if (irq_set_affinity(irq, cpumask_of(cluster->on_cpu))) {
+ dev_err(&pdev->dev,
+ "Unable to set irq affinity (irq=%d, cpu=%d)\n",
+ irq, cluster->on_cpu);
+ return -ENODEV;
+ }
+
+ err = devm_request_irq(&pdev->dev, irq, l2_cache__handle_irq,
+ IRQF_NOBALANCING, "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 instance %ld with %d CPUs\n",
+ fw_cluster_id, cpumask_weight(&cluster->cluster_cpus));
+
+ cluster->pmu_lock = __SPIN_LOCK_UNLOCKED(cluster->pmu_lock);
+ cpumask_set_cpu(cluster->on_cpu, &l2cache_pmu->cpumask);
+
+ hml2_pmu__reset(cluster);
+ 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;
+
+ 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,
+ .filter_match = l2_cache_filter_match,
+ };
+
+ l2cache_pmu->num_counters = get_num_counters();
+ l2cache_pmu->pdev = pdev;
+ l2_cycle_ctr_idx = l2cache_pmu->num_counters - 1;
+ l2_counter_present_mask = GENMASK(l2cache_pmu->num_counters - 2, 0) |
+ L2PM_CC_ENABLE;
+
+ 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 < 0)
+ return err;
+
+ if (l2cache_pmu->num_pmus == 0) {
+ dev_err(&pdev->dev, "No hardware L2 cache PMUs found\n");
+ return -ENODEV;
+ }
+
+ err = perf_pmu_register(&l2cache_pmu->pmu, l2cache_pmu->pmu.name, -1);
+ if (err < 0) {
+ dev_err(&pdev->dev, "Error %d registering L2 cache PMU\n", err);
+ return err;
+ }
+
+ dev_info(&pdev->dev, "Registered L2 cache PMU using %d HW PMUs\n",
+ l2cache_pmu->num_pmus);
+
+ err = cpuhp_state_add_instance_nocalls(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));
+
+ cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
+ &l2cache_pmu->node);
+ perf_pmu_unregister(&l2cache_pmu->pmu);
+ return 0;
+}
+
+static struct platform_driver l2_cache_pmu_driver = {
+ .driver = {
+ .name = "qcom-l2cache-pmu",
+ .owner = THIS_MODULE,
+ .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 45a4287..f342842 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -113,6 +113,7 @@ 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_NOTIFY_ONLINE,
--
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.
More information about the linux-arm-kernel
mailing list