summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/perf_cpum_cf_common.c
blob: 6d53215c8484ba633524eebb0e494814e833e0a0 (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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
// SPDX-License-Identifier: GPL-2.0
/*
 * CPU-Measurement Counter Facility Support - Common Layer
 *
 *  Copyright IBM Corp. 2019
 *  Author(s): Hendrik Brueckner <brueckner@linux.ibm.com>
 */
#define KMSG_COMPONENT	"cpum_cf_common"
#define pr_fmt(fmt)	KMSG_COMPONENT ": " fmt

#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/init.h>
#include <linux/export.h>
#include <asm/ctl_reg.h>
#include <asm/irq.h>
#include <asm/cpu_mcf.h>

/* Per-CPU event structure for the counter facility */
DEFINE_PER_CPU(struct cpu_cf_events, cpu_cf_events) = {
	.ctr_set = {
		[CPUMF_CTR_SET_BASIC]	= ATOMIC_INIT(0),
		[CPUMF_CTR_SET_USER]	= ATOMIC_INIT(0),
		[CPUMF_CTR_SET_CRYPTO]	= ATOMIC_INIT(0),
		[CPUMF_CTR_SET_EXT]	= ATOMIC_INIT(0),
		[CPUMF_CTR_SET_MT_DIAG] = ATOMIC_INIT(0),
	},
	.alert = ATOMIC64_INIT(0),
	.state = 0,
	.flags = 0,
	.txn_flags = 0,
};
/* Indicator whether the CPU-Measurement Counter Facility Support is ready */
static bool cpum_cf_initalized;

/* CPU-measurement alerts for the counter facility */
static void cpumf_measurement_alert(struct ext_code ext_code,
				    unsigned int alert, unsigned long unused)
{
	struct cpu_cf_events *cpuhw;

	if (!(alert & CPU_MF_INT_CF_MASK))
		return;

	inc_irq_stat(IRQEXT_CMC);
	cpuhw = this_cpu_ptr(&cpu_cf_events);

	/* Measurement alerts are shared and might happen when the PMU
	 * is not reserved.  Ignore these alerts in this case. */
	if (!(cpuhw->flags & PMU_F_RESERVED))
		return;

	/* counter authorization change alert */
	if (alert & CPU_MF_INT_CF_CACA)
		qctri(&cpuhw->info);

	/* loss of counter data alert */
	if (alert & CPU_MF_INT_CF_LCDA)
		pr_err("CPU[%i] Counter data was lost\n", smp_processor_id());

	/* loss of MT counter data alert */
	if (alert & CPU_MF_INT_CF_MTDA)
		pr_warn("CPU[%i] MT counter data was lost\n",
			smp_processor_id());

	/* store alert for special handling by in-kernel users */
	atomic64_or(alert, &cpuhw->alert);
}

#define PMC_INIT      0
#define PMC_RELEASE   1
static void cpum_cf_setup_cpu(void *flags)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);

	switch (*((int *) flags)) {
	case PMC_INIT:
		memset(&cpuhw->info, 0, sizeof(cpuhw->info));
		qctri(&cpuhw->info);
		cpuhw->flags |= PMU_F_RESERVED;
		break;

	case PMC_RELEASE:
		cpuhw->flags &= ~PMU_F_RESERVED;
		break;
	}

	/* Disable CPU counter sets */
	lcctl(0);
}

bool kernel_cpumcf_avail(void)
{
	return cpum_cf_initalized;
}
EXPORT_SYMBOL(kernel_cpumcf_avail);


/* Reserve/release functions for sharing perf hardware */
static DEFINE_SPINLOCK(cpumcf_owner_lock);
static void *cpumcf_owner;

/* Initialize the CPU-measurement counter facility */
int __kernel_cpumcf_begin(void)
{
	int flags = PMC_INIT;
	int err = 0;

	spin_lock(&cpumcf_owner_lock);
	if (cpumcf_owner)
		err = -EBUSY;
	else
		cpumcf_owner = __builtin_return_address(0);
	spin_unlock(&cpumcf_owner_lock);
	if (err)
		return err;

	on_each_cpu(cpum_cf_setup_cpu, &flags, 1);
	irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT);

	return 0;
}
EXPORT_SYMBOL(__kernel_cpumcf_begin);

/* Obtain the CPU-measurement alerts for the counter facility */
unsigned long kernel_cpumcf_alert(int clear)
{
	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
	unsigned long alert;

	alert = atomic64_read(&cpuhw->alert);
	if (clear)
		atomic64_set(&cpuhw->alert, 0);

	return alert;
}
EXPORT_SYMBOL(kernel_cpumcf_alert);

/* Release the CPU-measurement counter facility */
void __kernel_cpumcf_end(void)
{
	int flags = PMC_RELEASE;

	on_each_cpu(cpum_cf_setup_cpu, &flags, 1);
	irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);

	spin_lock(&cpumcf_owner_lock);
	cpumcf_owner = NULL;
	spin_unlock(&cpumcf_owner_lock);
}
EXPORT_SYMBOL(__kernel_cpumcf_end);

static int cpum_cf_setup(unsigned int cpu, int flags)
{
	local_irq_disable();
	cpum_cf_setup_cpu(&flags);
	local_irq_enable();
	return 0;
}

static int cpum_cf_online_cpu(unsigned int cpu)
{
	return cpum_cf_setup(cpu, PMC_INIT);
}

static int cpum_cf_offline_cpu(unsigned int cpu)
{
	return cpum_cf_setup(cpu, PMC_RELEASE);
}

/* Return the maximum possible counter set size (in number of 8 byte counters)
 * depending on type and model number.
 */
size_t cpum_cf_ctrset_size(enum cpumf_ctr_set ctrset,
			   struct cpumf_ctr_info *info)
{
	size_t ctrset_size = 0;

	switch (ctrset) {
	case CPUMF_CTR_SET_BASIC:
		if (info->cfvn >= 1)
			ctrset_size = 6;
		break;
	case CPUMF_CTR_SET_USER:
		if (info->cfvn == 1)
			ctrset_size = 6;
		else if (info->cfvn >= 3)
			ctrset_size = 2;
		break;
	case CPUMF_CTR_SET_CRYPTO:
		if (info->csvn >= 1 && info->csvn <= 5)
			ctrset_size = 16;
		else if (info->csvn == 6)
			ctrset_size = 20;
		break;
	case CPUMF_CTR_SET_EXT:
		if (info->csvn == 1)
			ctrset_size = 32;
		else if (info->csvn == 2)
			ctrset_size = 48;
		else if (info->csvn >= 3 && info->csvn <= 5)
			ctrset_size = 128;
		else if (info->csvn == 6)
			ctrset_size = 160;
		break;
	case CPUMF_CTR_SET_MT_DIAG:
		if (info->csvn > 3)
			ctrset_size = 48;
		break;
	case CPUMF_CTR_SET_MAX:
		break;
	}

	return ctrset_size;
}

static int __init cpum_cf_init(void)
{
	int rc;

	if (!cpum_cf_avail())
		return -ENODEV;

	/* clear bit 15 of cr0 to unauthorize problem-state to
	 * extract measurement counters */
	ctl_clear_bit(0, 48);

	/* register handler for measurement-alert interruptions */
	rc = register_external_irq(EXT_IRQ_MEASURE_ALERT,
				   cpumf_measurement_alert);
	if (rc) {
		pr_err("Registering for CPU-measurement alerts "
		       "failed with rc=%i\n", rc);
		return rc;
	}

	rc = cpuhp_setup_state(CPUHP_AP_PERF_S390_CF_ONLINE,
				"perf/s390/cf:online",
				cpum_cf_online_cpu, cpum_cf_offline_cpu);
	if (!rc)
		cpum_cf_initalized = true;

	return rc;
}
early_initcall(cpum_cf_init);