summaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/pmu.c
blob: c53474fe84dfe1851df72fd7428fccf02ea33c4f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/*
 *  linux/arch/arm/kernel/pmu.c
 *
 *  Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
 *  Copyright (C) 2010 ARM Ltd, Will Deacon
 *
 * 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.
 *
 */

#define pr_fmt(fmt) "PMU: " fmt

#include <linux/cpumask.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>

#include <asm/pmu.h>

static volatile long pmu_lock;

static struct platform_device *pmu_devices[ARM_NUM_PMU_DEVICES];

static int __devinit pmu_register(struct platform_device *pdev,
					enum arm_pmu_type type)
{
	if (type < 0 || type >= ARM_NUM_PMU_DEVICES) {
		pr_warning("received registration request for unknown "
				"PMU device type %d\n", type);
		return -EINVAL;
	}

	if (pmu_devices[type]) {
		pr_warning("rejecting duplicate registration of PMU device "
			"type %d.", type);
		return -ENOSPC;
	}

	pr_info("registered new PMU device of type %d\n", type);
	pmu_devices[type] = pdev;
	return 0;
}

#define OF_MATCH_PMU(_name, _type) {	\
	.compatible = _name,		\
	.data = (void *)_type,		\
}

#define OF_MATCH_CPU(name)	OF_MATCH_PMU(name, ARM_PMU_DEVICE_CPU)

static struct of_device_id armpmu_of_device_ids[] = {
	OF_MATCH_CPU("arm,cortex-a9-pmu"),
	OF_MATCH_CPU("arm,cortex-a8-pmu"),
	OF_MATCH_CPU("arm,arm1136-pmu"),
	OF_MATCH_CPU("arm,arm1176-pmu"),
	{},
};

#define PLAT_MATCH_PMU(_name, _type) {	\
	.name		= _name,	\
	.driver_data	= _type,	\
}

#define PLAT_MATCH_CPU(_name)	PLAT_MATCH_PMU(_name, ARM_PMU_DEVICE_CPU)

static struct platform_device_id armpmu_plat_device_ids[] = {
	PLAT_MATCH_CPU("arm-pmu"),
	{},
};

enum arm_pmu_type armpmu_device_type(struct platform_device *pdev)
{
	const struct of_device_id	*of_id;
	const struct platform_device_id *pdev_id;

	/* provided by of_device_id table */
	if (pdev->dev.of_node) {
		of_id = of_match_device(armpmu_of_device_ids, &pdev->dev);
		BUG_ON(!of_id);
		return (enum arm_pmu_type)of_id->data;
	}

	/* Provided by platform_device_id table */
	pdev_id = platform_get_device_id(pdev);
	BUG_ON(!pdev_id);
	return pdev_id->driver_data;
}

static int __devinit armpmu_device_probe(struct platform_device *pdev)
{
	return pmu_register(pdev, armpmu_device_type(pdev));
}

static struct platform_driver armpmu_driver = {
	.driver		= {
		.name	= "arm-pmu",
		.of_match_table = armpmu_of_device_ids,
	},
	.probe		= armpmu_device_probe,
	.id_table	= armpmu_plat_device_ids,
};

static int __init register_pmu_driver(void)
{
	return platform_driver_register(&armpmu_driver);
}
device_initcall(register_pmu_driver);

struct platform_device *
reserve_pmu(enum arm_pmu_type type)
{
	struct platform_device *pdev;

	if (test_and_set_bit_lock(type, &pmu_lock)) {
		pdev = ERR_PTR(-EBUSY);
	} else if (pmu_devices[type] == NULL) {
		clear_bit_unlock(type, &pmu_lock);
		pdev = ERR_PTR(-ENODEV);
	} else {
		pdev = pmu_devices[type];
	}

	return pdev;
}
EXPORT_SYMBOL_GPL(reserve_pmu);

int
release_pmu(enum arm_pmu_type type)
{
	if (WARN_ON(!pmu_devices[type]))
		return -EINVAL;
	clear_bit_unlock(type, &pmu_lock);
	return 0;
}
EXPORT_SYMBOL_GPL(release_pmu);

static int
set_irq_affinity(int irq,
		 unsigned int cpu)
{
#ifdef CONFIG_SMP
	int err = irq_set_affinity(irq, cpumask_of(cpu));
	if (err)
		pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n",
			   irq, cpu);
	return err;
#else
	return -EINVAL;
#endif
}

static int
init_cpu_pmu(void)
{
	int i, irqs, err = 0;
	struct platform_device *pdev = pmu_devices[ARM_PMU_DEVICE_CPU];

	if (!pdev)
		return -ENODEV;

	irqs = pdev->num_resources;

	/*
	 * If we have a single PMU interrupt that we can't shift, assume that
	 * we're running on a uniprocessor machine and continue.
	 */
	if (irqs == 1 && !irq_can_set_affinity(platform_get_irq(pdev, 0)))
		return 0;

	for (i = 0; i < irqs; ++i) {
		err = set_irq_affinity(platform_get_irq(pdev, i), i);
		if (err)
			break;
	}

	return err;
}

int
init_pmu(enum arm_pmu_type type)
{
	int err = 0;

	switch (type) {
	case ARM_PMU_DEVICE_CPU:
		err = init_cpu_pmu();
		break;
	default:
		pr_warning("attempt to initialise PMU of unknown "
			   "type %d\n", type);
		err = -EINVAL;
	}

	return err;
}
EXPORT_SYMBOL_GPL(init_pmu);
OpenPOWER on IntegriCloud