1/*
  2 * This program is free software; you can redistribute it and/or modify
  3 * it under the terms of the GNU General Public License version 2 as
  4 * published by the Free Software Foundation.
  5 *
  6 * This program is distributed in the hope that it will be useful,
  7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  9 * GNU General Public License for more details.
 10 *
 11 * You should have received a copy of the GNU General Public License
 12 * along with this program; if not, write to the Free Software
 13 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 14 *
 15 * Copyright (C) 2012 ARM Limited
 16 *
 17 * Author: Will Deacon <will.deacon@arm.com>
 18 */
 19#define pr_fmt(fmt) "CPU PMU: " fmt
 20
 21#include <linux/bitmap.h>
 22#include <linux/export.h>
 23#include <linux/kernel.h>
 24#include <linux/of.h>
 25#include <linux/platform_device.h>
 26#include <linux/slab.h>
 27#include <linux/spinlock.h>
 28#include <linux/irq.h>
 29#include <linux/irqdesc.h>
 30
 31#include <asm/cputype.h>
 32#include <asm/irq_regs.h>
 33#include <asm/pmu.h>
 34
 35/* Set at runtime when we know what CPU type we are. */
 36static struct arm_pmu *cpu_pmu;
 37
 38static DEFINE_PER_CPU(struct arm_pmu *, percpu_pmu);
 39static DEFINE_PER_CPU(struct perf_event * [ARMPMU_MAX_HWEVENTS], hw_events);
 40static DEFINE_PER_CPU(unsigned long [BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)], used_mask);
 41static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
 42
 43/*
 44 * Despite the names, these two functions are CPU-specific and are used
 45 * by the OProfile/perf code.
 46 */
 47const char *perf_pmu_name(void)
 48{
 49	if (!cpu_pmu)
 50		return NULL;
 51
 52	return cpu_pmu->name;
 53}
 54EXPORT_SYMBOL_GPL(perf_pmu_name);
 55
 56int perf_num_counters(void)
 57{
 58	int max_events = 0;
 59
 60	if (cpu_pmu != NULL)
 61		max_events = cpu_pmu->num_events;
 62
 63	return max_events;
 64}
 65EXPORT_SYMBOL_GPL(perf_num_counters);
 66
 67/* Include the PMU-specific implementations. */
 68#include "perf_event_xscale.c"
 69#include "perf_event_v6.c"
 70#include "perf_event_v7.c"
 71
 72static struct pmu_hw_events *cpu_pmu_get_cpu_events(void)
 73{
 74	return this_cpu_ptr(&cpu_hw_events);
 75}
 76
 77static void cpu_pmu_enable_percpu_irq(void *data)
 78{
 79	struct arm_pmu *cpu_pmu = data;
 80	struct platform_device *pmu_device = cpu_pmu->plat_device;
 81	int irq = platform_get_irq(pmu_device, 0);
 82
 83	enable_percpu_irq(irq, IRQ_TYPE_NONE);
 84	cpumask_set_cpu(smp_processor_id(), &cpu_pmu->active_irqs);
 85}
 86
 87static void cpu_pmu_disable_percpu_irq(void *data)
 88{
 89	struct arm_pmu *cpu_pmu = data;
 90	struct platform_device *pmu_device = cpu_pmu->plat_device;
 91	int irq = platform_get_irq(pmu_device, 0);
 92
 93	cpumask_clear_cpu(smp_processor_id(), &cpu_pmu->active_irqs);
 94	disable_percpu_irq(irq);
 95}
 96
 97static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
 98{
 99	int i, irq, irqs;
100	struct platform_device *pmu_device = cpu_pmu->plat_device;
101
102	irqs = min(pmu_device->num_resources, num_possible_cpus());
103
104	irq = platform_get_irq(pmu_device, 0);
105	if (irq >= 0 && irq_is_percpu(irq)) {
106		on_each_cpu(cpu_pmu_disable_percpu_irq, cpu_pmu, 1);
107		free_percpu_irq(irq, &percpu_pmu);
108	} else {
109		for (i = 0; i < irqs; ++i) {
110			if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs))
111				continue;
112			irq = platform_get_irq(pmu_device, i);
113			if (irq >= 0)
114				free_irq(irq, cpu_pmu);
115		}
116	}
117}
118
119static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
120{
121	int i, err, irq, irqs;
122	struct platform_device *pmu_device = cpu_pmu->plat_device;
123
124	if (!pmu_device)
125		return -ENODEV;
126
127	irqs = min(pmu_device->num_resources, num_possible_cpus());
128	if (irqs < 1) {
129		pr_err("no irqs for PMUs defined\n");
130		return -ENODEV;
131	}
132
133	irq = platform_get_irq(pmu_device, 0);
134	if (irq >= 0 && irq_is_percpu(irq)) {
135		err = request_percpu_irq(irq, handler, "arm-pmu", &percpu_pmu);
136		if (err) {
137			pr_err("unable to request IRQ%d for ARM PMU counters\n",
138				irq);
139			return err;
140		}
141		on_each_cpu(cpu_pmu_enable_percpu_irq, cpu_pmu, 1);
142	} else {
143		for (i = 0; i < irqs; ++i) {
144			err = 0;
145			irq = platform_get_irq(pmu_device, i);
146			if (irq < 0)
147				continue;
148
149			/*
150			 * If we have a single PMU interrupt that we can't shift,
151			 * assume that we're running on a uniprocessor machine and
152			 * continue. Otherwise, continue without this interrupt.
153			 */
154			if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) {
155				pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n",
156					    irq, i);
157				continue;
158			}
159
160			err = request_irq(irq, handler,
161					  IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu",
162					  cpu_pmu);
163			if (err) {
164				pr_err("unable to request IRQ%d for ARM PMU counters\n",
165					irq);
166				return err;
167			}
168
169			cpumask_set_cpu(i, &cpu_pmu->active_irqs);
170		}
171	}
172
173	return 0;
174}
175
176static void cpu_pmu_init(struct arm_pmu *cpu_pmu)
177{
178	int cpu;
179	for_each_possible_cpu(cpu) {
180		struct pmu_hw_events *events = &per_cpu(cpu_hw_events, cpu);
181		events->events = per_cpu(hw_events, cpu);
182		events->used_mask = per_cpu(used_mask, cpu);
183		raw_spin_lock_init(&events->pmu_lock);
184		per_cpu(percpu_pmu, cpu) = cpu_pmu;
185	}
186
187	cpu_pmu->get_hw_events	= cpu_pmu_get_cpu_events;
188	cpu_pmu->request_irq	= cpu_pmu_request_irq;
189	cpu_pmu->free_irq	= cpu_pmu_free_irq;
190
191	/* Ensure the PMU has sane values out of reset. */
192	if (cpu_pmu->reset)
193		on_each_cpu(cpu_pmu->reset, cpu_pmu, 1);
194}
195
196/*
197 * PMU hardware loses all context when a CPU goes offline.
198 * When a CPU is hotplugged back in, since some hardware registers are
199 * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
200 * junk values out of them.
201 */
202static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,
203			  void *hcpu)
204{
205	if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
206		return NOTIFY_DONE;
207
208	if (cpu_pmu && cpu_pmu->reset)
209		cpu_pmu->reset(cpu_pmu);
210	else
211		return NOTIFY_DONE;
212
213	return NOTIFY_OK;
214}
215
216static struct notifier_block cpu_pmu_hotplug_notifier = {
217	.notifier_call = cpu_pmu_notify,
218};
219
220/*
221 * PMU platform driver and devicetree bindings.
222 */
223static struct of_device_id cpu_pmu_of_device_ids[] = {
224	{.compatible = "arm,cortex-a15-pmu",	.data = armv7_a15_pmu_init},
225	{.compatible = "arm,cortex-a12-pmu",	.data = armv7_a12_pmu_init},
226	{.compatible = "arm,cortex-a9-pmu",	.data = armv7_a9_pmu_init},
227	{.compatible = "arm,cortex-a8-pmu",	.data = armv7_a8_pmu_init},
228	{.compatible = "arm,cortex-a7-pmu",	.data = armv7_a7_pmu_init},
229	{.compatible = "arm,cortex-a5-pmu",	.data = armv7_a5_pmu_init},
230	{.compatible = "arm,arm11mpcore-pmu",	.data = armv6mpcore_pmu_init},
231	{.compatible = "arm,arm1176-pmu",	.data = armv6pmu_init},
232	{.compatible = "arm,arm1136-pmu",	.data = armv6pmu_init},
233	{.compatible = "qcom,krait-pmu",	.data = krait_pmu_init},
234	{},
235};
236
237static struct platform_device_id cpu_pmu_plat_device_ids[] = {
238	{.name = "arm-pmu"},
239	{},
240};
241
242/*
243 * CPU PMU identification and probing.
244 */
245static int probe_current_pmu(struct arm_pmu *pmu)
246{
247	int cpu = get_cpu();
248	unsigned long implementor = read_cpuid_implementor();
249	unsigned long part_number = read_cpuid_part_number();
250	int ret = -ENODEV;
251
252	pr_info("probing PMU on CPU %d\n", cpu);
253
254	/* ARM Ltd CPUs. */
255	if (implementor == ARM_CPU_IMP_ARM) {
256		switch (part_number) {
257		case ARM_CPU_PART_ARM1136:
258		case ARM_CPU_PART_ARM1156:
259		case ARM_CPU_PART_ARM1176:
260			ret = armv6pmu_init(pmu);
261			break;
262		case ARM_CPU_PART_ARM11MPCORE:
263			ret = armv6mpcore_pmu_init(pmu);
264			break;
265		case ARM_CPU_PART_CORTEX_A8:
266			ret = armv7_a8_pmu_init(pmu);
267			break;
268		case ARM_CPU_PART_CORTEX_A9:
269			ret = armv7_a9_pmu_init(pmu);
270			break;
271		}
272	/* Intel CPUs [xscale]. */
273	} else if (implementor == ARM_CPU_IMP_INTEL) {
274		switch (xscale_cpu_arch_version()) {
275		case ARM_CPU_XSCALE_ARCH_V1:
276			ret = xscale1pmu_init(pmu);
277			break;
278		case ARM_CPU_XSCALE_ARCH_V2:
279			ret = xscale2pmu_init(pmu);
280			break;
281		}
282	}
283
284	put_cpu();
285	return ret;
286}
287
288static int cpu_pmu_device_probe(struct platform_device *pdev)
289{
290	const struct of_device_id *of_id;
291	const int (*init_fn)(struct arm_pmu *);
292	struct device_node *node = pdev->dev.of_node;
293	struct arm_pmu *pmu;
294	int ret = -ENODEV;
295
296	if (cpu_pmu) {
297		pr_info("attempt to register multiple PMU devices!");
298		return -ENOSPC;
299	}
300
301	pmu = kzalloc(sizeof(struct arm_pmu), GFP_KERNEL);
302	if (!pmu) {
303		pr_info("failed to allocate PMU device!");
304		return -ENOMEM;
305	}
306
307	cpu_pmu = pmu;
308	cpu_pmu->plat_device = pdev;
309
310	if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
311		init_fn = of_id->data;
312		ret = init_fn(pmu);
313	} else {
314		ret = probe_current_pmu(pmu);
315	}
316
317	if (ret) {
318		pr_info("failed to probe PMU!");
319		goto out_free;
320	}
321
322	cpu_pmu_init(cpu_pmu);
323	ret = armpmu_register(cpu_pmu, PERF_TYPE_RAW);
324
325	if (!ret)
326		return 0;
327
328out_free:
329	pr_info("failed to register PMU devices!");
330	kfree(pmu);
331	return ret;
332}
333
334static struct platform_driver cpu_pmu_driver = {
335	.driver		= {
336		.name	= "arm-pmu",
337		.pm	= &armpmu_dev_pm_ops,
338		.of_match_table = cpu_pmu_of_device_ids,
339	},
340	.probe		= cpu_pmu_device_probe,
341	.id_table	= cpu_pmu_plat_device_ids,
342};
343
344static int __init register_pmu_driver(void)
345{
346	int err;
347
348	err = register_cpu_notifier(&cpu_pmu_hotplug_notifier);
349	if (err)
350		return err;
351
352	err = platform_driver_register(&cpu_pmu_driver);
353	if (err)
354		unregister_cpu_notifier(&cpu_pmu_hotplug_notifier);
355
356	return err;
357}
358device_initcall(register_pmu_driver);