summaryrefslogtreecommitdiff
path: root/arch/i386/oprofile/nmi_int.c
blob: 0493e8b8ec49266618b155fb3490f02854dc70db (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
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
/**
 * @file nmi_int.c
 *
 * @remark Copyright 2002 OProfile authors
 * @remark Read the file COPYING
 *
 * @author John Levon <levon@movementarian.org>
 */

#include <linux/init.h>
#include <linux/notifier.h>
#include <linux/smp.h>
#include <linux/oprofile.h>
#include <linux/sysdev.h>
#include <linux/slab.h>
#include <asm/nmi.h>
#include <asm/msr.h>
#include <asm/apic.h>
 
#include "op_counter.h"
#include "op_x86_model.h"
 
static struct op_x86_model_spec const * model;
static struct op_msrs cpu_msrs[NR_CPUS];
static unsigned long saved_lvtpc[NR_CPUS];
 
static int nmi_start(void);
static void nmi_stop(void);

/* 0 == registered but off, 1 == registered and on */
static int nmi_enabled = 0;

#ifdef CONFIG_PM

static int nmi_suspend(struct sys_device *dev, pm_message_t state)
{
	if (nmi_enabled == 1)
		nmi_stop();
	return 0;
}


static int nmi_resume(struct sys_device *dev)
{
	if (nmi_enabled == 1)
		nmi_start();
	return 0;
}


static struct sysdev_class oprofile_sysclass = {
	set_kset_name("oprofile"),
	.resume		= nmi_resume,
	.suspend	= nmi_suspend,
};


static struct sys_device device_oprofile = {
	.id	= 0,
	.cls	= &oprofile_sysclass,
};


static int __init init_driverfs(void)
{
	int error;
	if (!(error = sysdev_class_register(&oprofile_sysclass)))
		error = sysdev_register(&device_oprofile);
	return error;
}


static void exit_driverfs(void)
{
	sysdev_unregister(&device_oprofile);
	sysdev_class_unregister(&oprofile_sysclass);
}

#else
#define init_driverfs() do { } while (0)
#define exit_driverfs() do { } while (0)
#endif /* CONFIG_PM */


static int nmi_callback(struct pt_regs * regs, int cpu)
{
	return model->check_ctrs(regs, &cpu_msrs[cpu]);
}
 
 
static void nmi_cpu_save_registers(struct op_msrs * msrs)
{
	unsigned int const nr_ctrs = model->num_counters;
	unsigned int const nr_ctrls = model->num_controls; 
	struct op_msr * counters = msrs->counters;
	struct op_msr * controls = msrs->controls;
	unsigned int i;

	for (i = 0; i < nr_ctrs; ++i) {
		rdmsr(counters[i].addr,
			counters[i].saved.low,
			counters[i].saved.high);
	}
 
	for (i = 0; i < nr_ctrls; ++i) {
		rdmsr(controls[i].addr,
			controls[i].saved.low,
			controls[i].saved.high);
	}
}


static void nmi_save_registers(void * dummy)
{
	int cpu = smp_processor_id();
	struct op_msrs * msrs = &cpu_msrs[cpu];
	model->fill_in_addresses(msrs);
	nmi_cpu_save_registers(msrs);
}


static void free_msrs(void)
{
	int i;
	for (i = 0; i < NR_CPUS; ++i) {
		kfree(cpu_msrs[i].counters);
		cpu_msrs[i].counters = NULL;
		kfree(cpu_msrs[i].controls);
		cpu_msrs[i].controls = NULL;
	}
}


static int allocate_msrs(void)
{
	int success = 1;
	size_t controls_size = sizeof(struct op_msr) * model->num_controls;
	size_t counters_size = sizeof(struct op_msr) * model->num_counters;

	int i;
	for (i = 0; i < NR_CPUS; ++i) {
		if (!cpu_online(i))
			continue;

		cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
		if (!cpu_msrs[i].counters) {
			success = 0;
			break;
		}
		cpu_msrs[i].controls = kmalloc(controls_size, GFP_KERNEL);
		if (!cpu_msrs[i].controls) {
			success = 0;
			break;
		}
	}

	if (!success)
		free_msrs();

	return success;
}


static void nmi_cpu_setup(void * dummy)
{
	int cpu = smp_processor_id();
	struct op_msrs * msrs = &cpu_msrs[cpu];
	spin_lock(&oprofilefs_lock);
	model->setup_ctrs(msrs);
	spin_unlock(&oprofilefs_lock);
	saved_lvtpc[cpu] = apic_read(APIC_LVTPC);
	apic_write(APIC_LVTPC, APIC_DM_NMI);
}


static int nmi_setup(void)
{
	if (!allocate_msrs())
		return -ENOMEM;

	/* We walk a thin line between law and rape here.
	 * We need to be careful to install our NMI handler
	 * without actually triggering any NMIs as this will
	 * break the core code horrifically.
	 */
	if (reserve_lapic_nmi() < 0) {
		free_msrs();
		return -EBUSY;
	}
	/* We need to serialize save and setup for HT because the subset
	 * of msrs are distinct for save and setup operations
	 */
	on_each_cpu(nmi_save_registers, NULL, 0, 1);
	on_each_cpu(nmi_cpu_setup, NULL, 0, 1);
	set_nmi_callback(nmi_callback);
	nmi_enabled = 1;
	return 0;
}


static void nmi_restore_registers(struct op_msrs * msrs)
{
	unsigned int const nr_ctrs = model->num_counters;
	unsigned int const nr_ctrls = model->num_controls; 
	struct op_msr * counters = msrs->counters;
	struct op_msr * controls = msrs->controls;
	unsigned int i;

	for (i = 0; i < nr_ctrls; ++i) {
		wrmsr(controls[i].addr,
			controls[i].saved.low,
			controls[i].saved.high);
	}
 
	for (i = 0; i < nr_ctrs; ++i) {
		wrmsr(counters[i].addr,
			counters[i].saved.low,
			counters[i].saved.high);
	}
}
 

static void nmi_cpu_shutdown(void * dummy)
{
	unsigned int v;
	int cpu = smp_processor_id();
	struct op_msrs * msrs = &cpu_msrs[cpu];
 
	/* restoring APIC_LVTPC can trigger an apic error because the delivery
	 * mode and vector nr combination can be illegal. That's by design: on
	 * power on apic lvt contain a zero vector nr which are legal only for
	 * NMI delivery mode. So inhibit apic err before restoring lvtpc
	 */
	v = apic_read(APIC_LVTERR);
	apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
	apic_write(APIC_LVTPC, saved_lvtpc[cpu]);
	apic_write(APIC_LVTERR, v);
	nmi_restore_registers(msrs);
}

 
static void nmi_shutdown(void)
{
	nmi_enabled = 0;
	on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
	unset_nmi_callback();
	release_lapic_nmi();
	free_msrs();
}

 
static void nmi_cpu_start(void * dummy)
{
	struct op_msrs const * msrs = &cpu_msrs[smp_processor_id()];
	model->start(msrs);
}
 

static int nmi_start(void)
{
	on_each_cpu(nmi_cpu_start, NULL, 0, 1);
	return 0;
}
 
 
static void nmi_cpu_stop(void * dummy)
{
	struct op_msrs const * msrs = &cpu_msrs[smp_processor_id()];
	model->stop(msrs);
}
 
 
static void nmi_stop(void)
{
	on_each_cpu(nmi_cpu_stop, NULL, 0, 1);
}


struct op_counter_config counter_config[OP_MAX_COUNTER];

static int nmi_create_files(struct super_block * sb, struct dentry * root)
{
	unsigned int i;

	for (i = 0; i < model->num_counters; ++i) {
		struct dentry * dir;
		char buf[2];
 
		snprintf(buf, 2, "%d", i);
		dir = oprofilefs_mkdir(sb, root, buf);
		oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled); 
		oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event); 
		oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count); 
		oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask); 
		oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel); 
		oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user); 
	}

	return 0;
}
 
 
static int __init p4_init(char ** cpu_type)
{
	__u8 cpu_model = boot_cpu_data.x86_model;

	if (cpu_model > 4)
		return 0;

#ifndef CONFIG_SMP
	*cpu_type = "i386/p4";
	model = &op_p4_spec;
	return 1;
#else
	switch (smp_num_siblings) {
		case 1:
			*cpu_type = "i386/p4";
			model = &op_p4_spec;
			return 1;

		case 2:
			*cpu_type = "i386/p4-ht";
			model = &op_p4_ht2_spec;
			return 1;
	}
#endif

	printk(KERN_INFO "oprofile: P4 HyperThreading detected with > 2 threads\n");
	printk(KERN_INFO "oprofile: Reverting to timer mode.\n");
	return 0;
}


static int __init ppro_init(char ** cpu_type)
{
	__u8 cpu_model = boot_cpu_data.x86_model;

	if (cpu_model > 0xd)
		return 0;

	if (cpu_model == 9) {
		*cpu_type = "i386/p6_mobile";
	} else if (cpu_model > 5) {
		*cpu_type = "i386/piii";
	} else if (cpu_model > 2) {
		*cpu_type = "i386/pii";
	} else {
		*cpu_type = "i386/ppro";
	}

	model = &op_ppro_spec;
	return 1;
}

/* in order to get driverfs right */
static int using_nmi;

int __init op_nmi_init(struct oprofile_operations *ops)
{
	__u8 vendor = boot_cpu_data.x86_vendor;
	__u8 family = boot_cpu_data.x86;
	char *cpu_type;

	if (!cpu_has_apic)
		return -ENODEV;
 
	switch (vendor) {
		case X86_VENDOR_AMD:
			/* Needs to be at least an Athlon (or hammer in 32bit mode) */

			switch (family) {
			default:
				return -ENODEV;
			case 6:
				model = &op_athlon_spec;
				cpu_type = "i386/athlon";
				break;
			case 0xf:
				model = &op_athlon_spec;
				/* Actually it could be i386/hammer too, but give
				   user space an consistent name. */
				cpu_type = "x86-64/hammer";
				break;
			}
			break;
 
		case X86_VENDOR_INTEL:
			switch (family) {
				/* Pentium IV */
				case 0xf:
					if (!p4_init(&cpu_type))
						return -ENODEV;
					break;

				/* A P6-class processor */
				case 6:
					if (!ppro_init(&cpu_type))
						return -ENODEV;
					break;

				default:
					return -ENODEV;
			}
			break;

		default:
			return -ENODEV;
	}

	init_driverfs();
	using_nmi = 1;
	ops->create_files = nmi_create_files;
	ops->setup = nmi_setup;
	ops->shutdown = nmi_shutdown;
	ops->start = nmi_start;
	ops->stop = nmi_stop;
	ops->cpu_type = cpu_type;
	printk(KERN_INFO "oprofile: using NMI interrupt.\n");
	return 0;
}


void op_nmi_exit(void)
{
	if (using_nmi)
		exit_driverfs();
}