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-rw-r--r--arch/arm/mm/cache-l2x0-pmu.c584
1 files changed, 584 insertions, 0 deletions
diff --git a/arch/arm/mm/cache-l2x0-pmu.c b/arch/arm/mm/cache-l2x0-pmu.c
new file mode 100644
index 000000000..afe5b4c7b
--- /dev/null
+++ b/arch/arm/mm/cache-l2x0-pmu.c
@@ -0,0 +1,584 @@
+/*
+ * L220/L310 cache controller support
+ *
+ * Copyright (C) 2016 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <linux/errno.h>
+#include <linux/hrtimer.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/perf_event.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <asm/hardware/cache-l2x0.h>
+
+#define PMU_NR_COUNTERS 2
+
+static void __iomem *l2x0_base;
+static struct pmu *l2x0_pmu;
+static cpumask_t pmu_cpu;
+
+static const char *l2x0_name;
+
+static ktime_t l2x0_pmu_poll_period;
+static struct hrtimer l2x0_pmu_hrtimer;
+
+/*
+ * The L220/PL310 PMU has two equivalent counters, Counter1 and Counter0.
+ * Registers controlling these are laid out in pairs, in descending order, i.e.
+ * the register for Counter1 comes first, followed by the register for
+ * Counter0.
+ * We ensure that idx 0 -> Counter0, and idx1 -> Counter1.
+ */
+static struct perf_event *events[PMU_NR_COUNTERS];
+
+/* Find an unused counter */
+static int l2x0_pmu_find_idx(void)
+{
+ int i;
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++) {
+ if (!events[i])
+ return i;
+ }
+
+ return -1;
+}
+
+/* How many counters are allocated? */
+static int l2x0_pmu_num_active_counters(void)
+{
+ int i, cnt = 0;
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++) {
+ if (events[i])
+ cnt++;
+ }
+
+ return cnt;
+}
+
+static void l2x0_pmu_counter_config_write(int idx, u32 val)
+{
+ writel_relaxed(val, l2x0_base + L2X0_EVENT_CNT0_CFG - 4 * idx);
+}
+
+static u32 l2x0_pmu_counter_read(int idx)
+{
+ return readl_relaxed(l2x0_base + L2X0_EVENT_CNT0_VAL - 4 * idx);
+}
+
+static void l2x0_pmu_counter_write(int idx, u32 val)
+{
+ writel_relaxed(val, l2x0_base + L2X0_EVENT_CNT0_VAL - 4 * idx);
+}
+
+static void __l2x0_pmu_enable(void)
+{
+ u32 val = readl_relaxed(l2x0_base + L2X0_EVENT_CNT_CTRL);
+ val |= L2X0_EVENT_CNT_CTRL_ENABLE;
+ writel_relaxed(val, l2x0_base + L2X0_EVENT_CNT_CTRL);
+}
+
+static void __l2x0_pmu_disable(void)
+{
+ u32 val = readl_relaxed(l2x0_base + L2X0_EVENT_CNT_CTRL);
+ val &= ~L2X0_EVENT_CNT_CTRL_ENABLE;
+ writel_relaxed(val, l2x0_base + L2X0_EVENT_CNT_CTRL);
+}
+
+static void l2x0_pmu_enable(struct pmu *pmu)
+{
+ if (l2x0_pmu_num_active_counters() == 0)
+ return;
+
+ __l2x0_pmu_enable();
+}
+
+static void l2x0_pmu_disable(struct pmu *pmu)
+{
+ if (l2x0_pmu_num_active_counters() == 0)
+ return;
+
+ __l2x0_pmu_disable();
+}
+
+static void warn_if_saturated(u32 count)
+{
+ if (count != 0xffffffff)
+ return;
+
+ pr_warn_ratelimited("L2X0 counter saturated. Poll period too long\n");
+}
+
+static void l2x0_pmu_event_read(struct perf_event *event)
+{
+ struct hw_perf_event *hw = &event->hw;
+ u64 prev_count, new_count, mask;
+
+ do {
+ prev_count = local64_read(&hw->prev_count);
+ new_count = l2x0_pmu_counter_read(hw->idx);
+ } while (local64_xchg(&hw->prev_count, new_count) != prev_count);
+
+ mask = GENMASK_ULL(31, 0);
+ local64_add((new_count - prev_count) & mask, &event->count);
+
+ warn_if_saturated(new_count);
+}
+
+static void l2x0_pmu_event_configure(struct perf_event *event)
+{
+ struct hw_perf_event *hw = &event->hw;
+
+ /*
+ * The L2X0 counters saturate at 0xffffffff rather than wrapping, so we
+ * will *always* lose some number of events when a counter saturates,
+ * and have no way of detecting how many were lost.
+ *
+ * To minimize the impact of this, we try to maximize the period by
+ * always starting counters at zero. To ensure that group ratios are
+ * representative, we poll periodically to avoid counters saturating.
+ * See l2x0_pmu_poll().
+ */
+ local64_set(&hw->prev_count, 0);
+ l2x0_pmu_counter_write(hw->idx, 0);
+}
+
+static enum hrtimer_restart l2x0_pmu_poll(struct hrtimer *hrtimer)
+{
+ unsigned long flags;
+ int i;
+
+ local_irq_save(flags);
+ __l2x0_pmu_disable();
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++) {
+ struct perf_event *event = events[i];
+
+ if (!event)
+ continue;
+
+ l2x0_pmu_event_read(event);
+ l2x0_pmu_event_configure(event);
+ }
+
+ __l2x0_pmu_enable();
+ local_irq_restore(flags);
+
+ hrtimer_forward_now(hrtimer, l2x0_pmu_poll_period);
+ return HRTIMER_RESTART;
+}
+
+
+static void __l2x0_pmu_event_enable(int idx, u32 event)
+{
+ u32 val;
+
+ val = event << L2X0_EVENT_CNT_CFG_SRC_SHIFT;
+ val |= L2X0_EVENT_CNT_CFG_INT_DISABLED;
+ l2x0_pmu_counter_config_write(idx, val);
+}
+
+static void l2x0_pmu_event_start(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hw = &event->hw;
+
+ if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
+ return;
+
+ if (flags & PERF_EF_RELOAD) {
+ WARN_ON_ONCE(!(hw->state & PERF_HES_UPTODATE));
+ l2x0_pmu_event_configure(event);
+ }
+
+ hw->state = 0;
+
+ __l2x0_pmu_event_enable(hw->idx, hw->config_base);
+}
+
+static void __l2x0_pmu_event_disable(int idx)
+{
+ u32 val;
+
+ val = L2X0_EVENT_CNT_CFG_SRC_DISABLED << L2X0_EVENT_CNT_CFG_SRC_SHIFT;
+ val |= L2X0_EVENT_CNT_CFG_INT_DISABLED;
+ l2x0_pmu_counter_config_write(idx, val);
+}
+
+static void l2x0_pmu_event_stop(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hw = &event->hw;
+
+ if (WARN_ON_ONCE(event->hw.state & PERF_HES_STOPPED))
+ return;
+
+ __l2x0_pmu_event_disable(hw->idx);
+
+ hw->state |= PERF_HES_STOPPED;
+
+ if (flags & PERF_EF_UPDATE) {
+ l2x0_pmu_event_read(event);
+ hw->state |= PERF_HES_UPTODATE;
+ }
+}
+
+static int l2x0_pmu_event_add(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hw = &event->hw;
+ int idx = l2x0_pmu_find_idx();
+
+ if (idx == -1)
+ return -EAGAIN;
+
+ /*
+ * Pin the timer, so that the overflows are handled by the chosen
+ * event->cpu (this is the same one as presented in "cpumask"
+ * attribute).
+ */
+ if (l2x0_pmu_num_active_counters() == 0)
+ hrtimer_start(&l2x0_pmu_hrtimer, l2x0_pmu_poll_period,
+ HRTIMER_MODE_REL_PINNED);
+
+ events[idx] = event;
+ hw->idx = idx;
+
+ l2x0_pmu_event_configure(event);
+
+ hw->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+
+ if (flags & PERF_EF_START)
+ l2x0_pmu_event_start(event, 0);
+
+ return 0;
+}
+
+static void l2x0_pmu_event_del(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hw = &event->hw;
+
+ l2x0_pmu_event_stop(event, PERF_EF_UPDATE);
+
+ events[hw->idx] = NULL;
+ hw->idx = -1;
+
+ if (l2x0_pmu_num_active_counters() == 0)
+ hrtimer_cancel(&l2x0_pmu_hrtimer);
+}
+
+static bool l2x0_pmu_group_is_valid(struct perf_event *event)
+{
+ struct pmu *pmu = event->pmu;
+ struct perf_event *leader = event->group_leader;
+ struct perf_event *sibling;
+ int num_hw = 0;
+
+ if (leader->pmu == pmu)
+ num_hw++;
+ else if (!is_software_event(leader))
+ return false;
+
+ for_each_sibling_event(sibling, leader) {
+ if (sibling->pmu == pmu)
+ num_hw++;
+ else if (!is_software_event(sibling))
+ return false;
+ }
+
+ return num_hw <= PMU_NR_COUNTERS;
+}
+
+static int l2x0_pmu_event_init(struct perf_event *event)
+{
+ struct hw_perf_event *hw = &event->hw;
+
+ if (event->attr.type != l2x0_pmu->type)
+ return -ENOENT;
+
+ if (is_sampling_event(event) ||
+ event->attach_state & PERF_ATTACH_TASK)
+ return -EINVAL;
+
+ if (event->attr.exclude_user ||
+ event->attr.exclude_kernel ||
+ event->attr.exclude_hv ||
+ event->attr.exclude_idle ||
+ event->attr.exclude_host ||
+ event->attr.exclude_guest)
+ return -EINVAL;
+
+ if (event->cpu < 0)
+ return -EINVAL;
+
+ if (event->attr.config & ~L2X0_EVENT_CNT_CFG_SRC_MASK)
+ return -EINVAL;
+
+ hw->config_base = event->attr.config;
+
+ if (!l2x0_pmu_group_is_valid(event))
+ return -EINVAL;
+
+ event->cpu = cpumask_first(&pmu_cpu);
+
+ return 0;
+}
+
+struct l2x0_event_attribute {
+ struct device_attribute attr;
+ unsigned int config;
+ bool pl310_only;
+};
+
+#define L2X0_EVENT_ATTR(_name, _config, _pl310_only) \
+ (&((struct l2x0_event_attribute[]) {{ \
+ .attr = __ATTR(_name, S_IRUGO, l2x0_pmu_event_show, NULL), \
+ .config = _config, \
+ .pl310_only = _pl310_only, \
+ }})[0].attr.attr)
+
+#define L220_PLUS_EVENT_ATTR(_name, _config) \
+ L2X0_EVENT_ATTR(_name, _config, false)
+
+#define PL310_EVENT_ATTR(_name, _config) \
+ L2X0_EVENT_ATTR(_name, _config, true)
+
+static ssize_t l2x0_pmu_event_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct l2x0_event_attribute *lattr;
+
+ lattr = container_of(attr, typeof(*lattr), attr);
+ return snprintf(buf, PAGE_SIZE, "config=0x%x\n", lattr->config);
+}
+
+static umode_t l2x0_pmu_event_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr,
+ int unused)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct pmu *pmu = dev_get_drvdata(dev);
+ struct l2x0_event_attribute *lattr;
+
+ lattr = container_of(attr, typeof(*lattr), attr.attr);
+
+ if (!lattr->pl310_only || strcmp("l2c_310", pmu->name) == 0)
+ return attr->mode;
+
+ return 0;
+}
+
+static struct attribute *l2x0_pmu_event_attrs[] = {
+ L220_PLUS_EVENT_ATTR(co, 0x1),
+ L220_PLUS_EVENT_ATTR(drhit, 0x2),
+ L220_PLUS_EVENT_ATTR(drreq, 0x3),
+ L220_PLUS_EVENT_ATTR(dwhit, 0x4),
+ L220_PLUS_EVENT_ATTR(dwreq, 0x5),
+ L220_PLUS_EVENT_ATTR(dwtreq, 0x6),
+ L220_PLUS_EVENT_ATTR(irhit, 0x7),
+ L220_PLUS_EVENT_ATTR(irreq, 0x8),
+ L220_PLUS_EVENT_ATTR(wa, 0x9),
+ PL310_EVENT_ATTR(ipfalloc, 0xa),
+ PL310_EVENT_ATTR(epfhit, 0xb),
+ PL310_EVENT_ATTR(epfalloc, 0xc),
+ PL310_EVENT_ATTR(srrcvd, 0xd),
+ PL310_EVENT_ATTR(srconf, 0xe),
+ PL310_EVENT_ATTR(epfrcvd, 0xf),
+ NULL
+};
+
+static struct attribute_group l2x0_pmu_event_attrs_group = {
+ .name = "events",
+ .attrs = l2x0_pmu_event_attrs,
+ .is_visible = l2x0_pmu_event_attr_is_visible,
+};
+
+static ssize_t l2x0_pmu_cpumask_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return cpumap_print_to_pagebuf(true, buf, &pmu_cpu);
+}
+
+static struct device_attribute l2x0_pmu_cpumask_attr =
+ __ATTR(cpumask, S_IRUGO, l2x0_pmu_cpumask_show, NULL);
+
+static struct attribute *l2x0_pmu_cpumask_attrs[] = {
+ &l2x0_pmu_cpumask_attr.attr,
+ NULL,
+};
+
+static struct attribute_group l2x0_pmu_cpumask_attr_group = {
+ .attrs = l2x0_pmu_cpumask_attrs,
+};
+
+static const struct attribute_group *l2x0_pmu_attr_groups[] = {
+ &l2x0_pmu_event_attrs_group,
+ &l2x0_pmu_cpumask_attr_group,
+ NULL,
+};
+
+static void l2x0_pmu_reset(void)
+{
+ int i;
+
+ __l2x0_pmu_disable();
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++)
+ __l2x0_pmu_event_disable(i);
+}
+
+static int l2x0_pmu_offline_cpu(unsigned int cpu)
+{
+ unsigned int target;
+
+ if (!cpumask_test_and_clear_cpu(cpu, &pmu_cpu))
+ return 0;
+
+ target = cpumask_any_but(cpu_online_mask, cpu);
+ if (target >= nr_cpu_ids)
+ return 0;
+
+ perf_pmu_migrate_context(l2x0_pmu, cpu, target);
+ cpumask_set_cpu(target, &pmu_cpu);
+
+ return 0;
+}
+
+void l2x0_pmu_suspend(void)
+{
+ int i;
+
+ if (!l2x0_pmu)
+ return;
+
+ l2x0_pmu_disable(l2x0_pmu);
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++) {
+ if (events[i])
+ l2x0_pmu_event_stop(events[i], PERF_EF_UPDATE);
+ }
+
+}
+
+void l2x0_pmu_resume(void)
+{
+ int i;
+
+ if (!l2x0_pmu)
+ return;
+
+ l2x0_pmu_reset();
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++) {
+ if (events[i])
+ l2x0_pmu_event_start(events[i], PERF_EF_RELOAD);
+ }
+
+ l2x0_pmu_enable(l2x0_pmu);
+}
+
+void __init l2x0_pmu_register(void __iomem *base, u32 part)
+{
+ /*
+ * Determine whether we support the PMU, and choose the name for sysfs.
+ * This is also used by l2x0_pmu_event_attr_is_visible to determine
+ * which events to display, as the PL310 PMU supports a superset of
+ * L220 events.
+ *
+ * The L210 PMU has a different programmer's interface, and is not
+ * supported by this driver.
+ *
+ * We must defer registering the PMU until the perf subsystem is up and
+ * running, so just stash the name and base, and leave that to another
+ * initcall.
+ */
+ switch (part & L2X0_CACHE_ID_PART_MASK) {
+ case L2X0_CACHE_ID_PART_L220:
+ l2x0_name = "l2c_220";
+ break;
+ case L2X0_CACHE_ID_PART_L310:
+ l2x0_name = "l2c_310";
+ break;
+ default:
+ return;
+ }
+
+ l2x0_base = base;
+}
+
+static __init int l2x0_pmu_init(void)
+{
+ int ret;
+
+ if (!l2x0_base)
+ return 0;
+
+ l2x0_pmu = kzalloc(sizeof(*l2x0_pmu), GFP_KERNEL);
+ if (!l2x0_pmu) {
+ pr_warn("Unable to allocate L2x0 PMU\n");
+ return -ENOMEM;
+ }
+
+ *l2x0_pmu = (struct pmu) {
+ .task_ctx_nr = perf_invalid_context,
+ .pmu_enable = l2x0_pmu_enable,
+ .pmu_disable = l2x0_pmu_disable,
+ .read = l2x0_pmu_event_read,
+ .start = l2x0_pmu_event_start,
+ .stop = l2x0_pmu_event_stop,
+ .add = l2x0_pmu_event_add,
+ .del = l2x0_pmu_event_del,
+ .event_init = l2x0_pmu_event_init,
+ .attr_groups = l2x0_pmu_attr_groups,
+ };
+
+ l2x0_pmu_reset();
+
+ /*
+ * We always use a hrtimer rather than an interrupt.
+ * See comments in l2x0_pmu_event_configure and l2x0_pmu_poll.
+ *
+ * Polling once a second allows the counters to fill up to 1/128th on a
+ * quad-core test chip with cores clocked at 400MHz. Hopefully this
+ * leaves sufficient headroom to avoid overflow on production silicon
+ * at higher frequencies.
+ */
+ l2x0_pmu_poll_period = ms_to_ktime(1000);
+ hrtimer_init(&l2x0_pmu_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ l2x0_pmu_hrtimer.function = l2x0_pmu_poll;
+
+ cpumask_set_cpu(0, &pmu_cpu);
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_L2X0_ONLINE,
+ "perf/arm/l2x0:online", NULL,
+ l2x0_pmu_offline_cpu);
+ if (ret)
+ goto out_pmu;
+
+ ret = perf_pmu_register(l2x0_pmu, l2x0_name, -1);
+ if (ret)
+ goto out_cpuhp;
+
+ return 0;
+
+out_cpuhp:
+ cpuhp_remove_state_nocalls(CPUHP_AP_PERF_ARM_L2X0_ONLINE);
+out_pmu:
+ kfree(l2x0_pmu);
+ l2x0_pmu = NULL;
+ return ret;
+}
+device_initcall(l2x0_pmu_init);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 04:04:27 +0000