[PATCH v9] perf: add qcom l2 cache perf events driver
From: Neil Leeder
Date: Fri Feb 03 2017 - 17:32:00 EST
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.
Signed-off-by: Neil Leeder <nleeder@xxxxxxxxxxxxxx>
---
v9:
Add support for maxcpus < all cpus:
Move some of probe functionality to hotplug online callback
Call hotplug callbacks from probe
Make percpu cpu->cluster map dynamic and associated with PMU instead of global
Use *sysreg_s() for portability reasons
Add documentation file
Rebase on 4.10-rc6
Misc cleanups
v8:
Various style changes for function names & code restructuring
Replace dev_warn with ratelimited debug prints
Move hotplug registration before PMU registration
Reload counters with a fixed value
Add column-exclusion check for events in same group
Rebase on 4.10-rc3
v7:
Move to drivers/perf
Rebased on 4.9-rc1
Ran perf fuzzer against driver for 4 hours with no crashes
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.
Documentation/perf/qcom_l2_pmu.txt | 38 ++
drivers/perf/Kconfig | 9 +
drivers/perf/Makefile | 1 +
drivers/perf/qcom_l2_pmu.c | 1031 ++++++++++++++++++++++++++++++++++++
include/linux/cpuhotplug.h | 1 +
5 files changed, 1080 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 0000000..b25b976
--- /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 4d5c5f9..9365190 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 b116e98..ef24833 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 0000000..3dfe7d3
--- /dev/null
+++ b/drivers/perf/qcom_l2_pmu.c
@@ -0,0 +1,1031 @@
+/* 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 <linux/acpi.h>
+#include <linux/bitops.h>
+#include <linux/bug.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/percpu.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include <asm/barrier.h>
+#include <asm/local64.h>
+#include <asm/sysreg.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 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_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 cluster_pmu_reset(struct cluster_pmu *cluster)
+{
+ cpumask_t *mask = &cluster->cluster_cpus;
+
+ if (smp_call_function_any(mask, cluster_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 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;
+
+ 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;
+
+ set_bit(idx, cluster->used_counters);
+ set_bit(L2_EVT_GROUP(hwc->config_base), 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 (!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 int l2_cache_filter_match(struct perf_event *event)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct l2cache_pmu *l2cache_pmu = to_l2cache_pmu(event->pmu);
+ struct cluster_pmu *cluster = get_cluster_pmu(l2cache_pmu, event->cpu);
+ unsigned int group = L2_EVT_GROUP(hwc->config_base);
+
+ if (hwc->config_base == L2CYCLE_CTR_RAW_CODE)
+ return 1;
+
+ /*
+ * 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.
+ */
+ if (test_bit(group, cluster->used_groups))
+ 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 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;
+
+ /*
+ * 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) {
+ 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;
+ return cluster;
+ }
+ }
+ return 0;
+}
+
+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(cluster);
+
+ 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 (kstrtol(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,
+ .filter_match = l2_cache_filter_match,
+ };
+
+ 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 < 0)
+ 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",
+ .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 d936a00..b7d100e 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -140,6 +140,7 @@ 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,
--
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Qualcomm Technologies, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.