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- /*
- * Performance events - AMD Processor Power Reporting Mechanism
- *
- * Copyright (C) 2016 Advanced Micro Devices, Inc.
- *
- * Author: Huang Rui <ray.huang@amd.com>
- *
- * 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.
- */
- #include <linux/module.h>
- #include <linux/slab.h>
- #include <linux/perf_event.h>
- #include <asm/cpu_device_id.h>
- #include "../perf_event.h"
- #define MSR_F15H_CU_PWR_ACCUMULATOR 0xc001007a
- #define MSR_F15H_CU_MAX_PWR_ACCUMULATOR 0xc001007b
- #define MSR_F15H_PTSC 0xc0010280
- /* Event code: LSB 8 bits, passed in attr->config any other bit is reserved. */
- #define AMD_POWER_EVENT_MASK 0xFFULL
- /*
- * Accumulated power status counters.
- */
- #define AMD_POWER_EVENTSEL_PKG 1
- /*
- * The ratio of compute unit power accumulator sample period to the
- * PTSC period.
- */
- static unsigned int cpu_pwr_sample_ratio;
- /* Maximum accumulated power of a compute unit. */
- static u64 max_cu_acc_power;
- static struct pmu pmu_class;
- /*
- * Accumulated power represents the sum of each compute unit's (CU) power
- * consumption. On any core of each CU we read the total accumulated power from
- * MSR_F15H_CU_PWR_ACCUMULATOR. cpu_mask represents CPU bit map of all cores
- * which are picked to measure the power for the CUs they belong to.
- */
- static cpumask_t cpu_mask;
- static void event_update(struct perf_event *event)
- {
- struct hw_perf_event *hwc = &event->hw;
- u64 prev_pwr_acc, new_pwr_acc, prev_ptsc, new_ptsc;
- u64 delta, tdelta;
- prev_pwr_acc = hwc->pwr_acc;
- prev_ptsc = hwc->ptsc;
- rdmsrl(MSR_F15H_CU_PWR_ACCUMULATOR, new_pwr_acc);
- rdmsrl(MSR_F15H_PTSC, new_ptsc);
- /*
- * Calculate the CU power consumption over a time period, the unit of
- * final value (delta) is micro-Watts. Then add it to the event count.
- */
- if (new_pwr_acc < prev_pwr_acc) {
- delta = max_cu_acc_power + new_pwr_acc;
- delta -= prev_pwr_acc;
- } else
- delta = new_pwr_acc - prev_pwr_acc;
- delta *= cpu_pwr_sample_ratio * 1000;
- tdelta = new_ptsc - prev_ptsc;
- do_div(delta, tdelta);
- local64_add(delta, &event->count);
- }
- static void __pmu_event_start(struct perf_event *event)
- {
- if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
- return;
- event->hw.state = 0;
- rdmsrl(MSR_F15H_PTSC, event->hw.ptsc);
- rdmsrl(MSR_F15H_CU_PWR_ACCUMULATOR, event->hw.pwr_acc);
- }
- static void pmu_event_start(struct perf_event *event, int mode)
- {
- __pmu_event_start(event);
- }
- static void pmu_event_stop(struct perf_event *event, int mode)
- {
- struct hw_perf_event *hwc = &event->hw;
- /* Mark event as deactivated and stopped. */
- if (!(hwc->state & PERF_HES_STOPPED))
- hwc->state |= PERF_HES_STOPPED;
- /* Check if software counter update is necessary. */
- if ((mode & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
- /*
- * Drain the remaining delta count out of an event
- * that we are disabling:
- */
- event_update(event);
- hwc->state |= PERF_HES_UPTODATE;
- }
- }
- static int pmu_event_add(struct perf_event *event, int mode)
- {
- struct hw_perf_event *hwc = &event->hw;
- hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
- if (mode & PERF_EF_START)
- __pmu_event_start(event);
- return 0;
- }
- static void pmu_event_del(struct perf_event *event, int flags)
- {
- pmu_event_stop(event, PERF_EF_UPDATE);
- }
- static int pmu_event_init(struct perf_event *event)
- {
- u64 cfg = event->attr.config & AMD_POWER_EVENT_MASK;
- /* Only look at AMD power events. */
- if (event->attr.type != pmu_class.type)
- return -ENOENT;
- /* Unsupported modes and filters. */
- 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 ||
- /* no sampling */
- event->attr.sample_period)
- return -EINVAL;
- if (cfg != AMD_POWER_EVENTSEL_PKG)
- return -EINVAL;
- return 0;
- }
- static void pmu_event_read(struct perf_event *event)
- {
- event_update(event);
- }
- static ssize_t
- get_attr_cpumask(struct device *dev, struct device_attribute *attr, char *buf)
- {
- return cpumap_print_to_pagebuf(true, buf, &cpu_mask);
- }
- static DEVICE_ATTR(cpumask, S_IRUGO, get_attr_cpumask, NULL);
- static struct attribute *pmu_attrs[] = {
- &dev_attr_cpumask.attr,
- NULL,
- };
- static struct attribute_group pmu_attr_group = {
- .attrs = pmu_attrs,
- };
- /*
- * Currently it only supports to report the power of each
- * processor/package.
- */
- EVENT_ATTR_STR(power-pkg, power_pkg, "event=0x01");
- EVENT_ATTR_STR(power-pkg.unit, power_pkg_unit, "mWatts");
- /* Convert the count from micro-Watts to milli-Watts. */
- EVENT_ATTR_STR(power-pkg.scale, power_pkg_scale, "1.000000e-3");
- static struct attribute *events_attr[] = {
- EVENT_PTR(power_pkg),
- EVENT_PTR(power_pkg_unit),
- EVENT_PTR(power_pkg_scale),
- NULL,
- };
- static struct attribute_group pmu_events_group = {
- .name = "events",
- .attrs = events_attr,
- };
- PMU_FORMAT_ATTR(event, "config:0-7");
- static struct attribute *formats_attr[] = {
- &format_attr_event.attr,
- NULL,
- };
- static struct attribute_group pmu_format_group = {
- .name = "format",
- .attrs = formats_attr,
- };
- static const struct attribute_group *attr_groups[] = {
- &pmu_attr_group,
- &pmu_format_group,
- &pmu_events_group,
- NULL,
- };
- static struct pmu pmu_class = {
- .attr_groups = attr_groups,
- /* system-wide only */
- .task_ctx_nr = perf_invalid_context,
- .event_init = pmu_event_init,
- .add = pmu_event_add,
- .del = pmu_event_del,
- .start = pmu_event_start,
- .stop = pmu_event_stop,
- .read = pmu_event_read,
- };
- static int power_cpu_exit(unsigned int cpu)
- {
- int target;
- if (!cpumask_test_and_clear_cpu(cpu, &cpu_mask))
- return 0;
- /*
- * Find a new CPU on the same compute unit, if was set in cpumask
- * and still some CPUs on compute unit. Then migrate event and
- * context to new CPU.
- */
- target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu);
- if (target < nr_cpumask_bits) {
- cpumask_set_cpu(target, &cpu_mask);
- perf_pmu_migrate_context(&pmu_class, cpu, target);
- }
- return 0;
- }
- static int power_cpu_init(unsigned int cpu)
- {
- int target;
- /*
- * 1) If any CPU is set at cpu_mask in the same compute unit, do
- * nothing.
- * 2) If no CPU is set at cpu_mask in the same compute unit,
- * set current ONLINE CPU.
- *
- * Note: if there is a CPU aside of the new one already in the
- * sibling mask, then it is also in cpu_mask.
- */
- target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu);
- if (target >= nr_cpumask_bits)
- cpumask_set_cpu(cpu, &cpu_mask);
- return 0;
- }
- static const struct x86_cpu_id cpu_match[] = {
- { .vendor = X86_VENDOR_AMD, .family = 0x15 },
- {},
- };
- static int __init amd_power_pmu_init(void)
- {
- int ret;
- if (!x86_match_cpu(cpu_match))
- return -ENODEV;
- if (!boot_cpu_has(X86_FEATURE_ACC_POWER))
- return -ENODEV;
- cpu_pwr_sample_ratio = cpuid_ecx(0x80000007);
- if (rdmsrl_safe(MSR_F15H_CU_MAX_PWR_ACCUMULATOR, &max_cu_acc_power)) {
- pr_err("Failed to read max compute unit power accumulator MSR\n");
- return -ENODEV;
- }
- cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
- "AP_PERF_X86_AMD_POWER_ONLINE",
- power_cpu_init, power_cpu_exit);
- ret = perf_pmu_register(&pmu_class, "power", -1);
- if (WARN_ON(ret)) {
- pr_warn("AMD Power PMU registration failed\n");
- return ret;
- }
- pr_info("AMD Power PMU detected\n");
- return ret;
- }
- module_init(amd_power_pmu_init);
- static void __exit amd_power_pmu_exit(void)
- {
- cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_AMD_POWER_ONLINE);
- perf_pmu_unregister(&pmu_class);
- }
- module_exit(amd_power_pmu_exit);
- MODULE_AUTHOR("Huang Rui <ray.huang@amd.com>");
- MODULE_DESCRIPTION("AMD Processor Power Reporting Mechanism");
- MODULE_LICENSE("GPL v2");
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