aboutsummaryrefslogtreecommitdiff
path: root/sys/kern/subr_pcpu.c
blob: ba76bb249ecb5acf836820839f12af8e0c3a06e5 (plain) (blame)
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
/*-
 * Copyright (c) 2001 Wind River Systems, Inc.
 * All rights reserved.
 * Written by: John Baldwin <jhb@FreeBSD.org>
 *
 * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * This module provides MI support for per-cpu data.
 *
 * Each architecture determines the mapping of logical CPU IDs to physical
 * CPUs.  The requirements of this mapping are as follows:
 *  - Logical CPU IDs must reside in the range 0 ... MAXCPU - 1.
 *  - The mapping is not required to be dense.  That is, there may be
 *    gaps in the mappings.
 *  - The platform sets the value of MAXCPU in <machine/param.h>.
 *  - It is suggested, but not required, that in the non-SMP case, the
 *    platform define MAXCPU to be 1 and define the logical ID of the
 *    sole CPU as 0.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/smp.h>
#include <sys/sx.h>
#include <ddb/ddb.h>

MALLOC_DEFINE(M_PCPU, "Per-cpu", "Per-cpu resource accouting.");

struct dpcpu_free {
	uintptr_t	df_start;
	int		df_len;
	TAILQ_ENTRY(dpcpu_free) df_link;
};

static DPCPU_DEFINE(char, modspace[DPCPU_MODMIN]);
static TAILQ_HEAD(, dpcpu_free) dpcpu_head = TAILQ_HEAD_INITIALIZER(dpcpu_head);
static struct sx dpcpu_lock;
uintptr_t dpcpu_off[MAXCPU];
struct pcpu *cpuid_to_pcpu[MAXCPU];
struct cpuhead cpuhead = STAILQ_HEAD_INITIALIZER(cpuhead);

/*
 * Initialize the MI portions of a struct pcpu.
 */
void
pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
{

	bzero(pcpu, size);
	KASSERT(cpuid >= 0 && cpuid < MAXCPU,
	    ("pcpu_init: invalid cpuid %d", cpuid));
	pcpu->pc_cpuid = cpuid;
	cpuid_to_pcpu[cpuid] = pcpu;
	STAILQ_INSERT_TAIL(&cpuhead, pcpu, pc_allcpu);
	cpu_pcpu_init(pcpu, cpuid, size);
	pcpu->pc_rm_queue.rmq_next = &pcpu->pc_rm_queue;
	pcpu->pc_rm_queue.rmq_prev = &pcpu->pc_rm_queue;
}

void
dpcpu_init(void *dpcpu, int cpuid)
{
	struct pcpu *pcpu;

	pcpu = pcpu_find(cpuid);
	pcpu->pc_dynamic = (uintptr_t)dpcpu - DPCPU_START;

	/*
	 * Initialize defaults from our linker section.
	 */
	memcpy(dpcpu, (void *)DPCPU_START, DPCPU_BYTES);

	/*
	 * Place it in the global pcpu offset array.
	 */
	dpcpu_off[cpuid] = pcpu->pc_dynamic;
}

static void
dpcpu_startup(void *dummy __unused)
{
	struct dpcpu_free *df;

	df = malloc(sizeof(*df), M_PCPU, M_WAITOK | M_ZERO);
	df->df_start = (uintptr_t)&DPCPU_NAME(modspace);
	df->df_len = DPCPU_MODMIN;
	TAILQ_INSERT_HEAD(&dpcpu_head, df, df_link);
	sx_init(&dpcpu_lock, "dpcpu alloc lock");
}
SYSINIT(dpcpu, SI_SUB_KLD, SI_ORDER_FIRST, dpcpu_startup, 0);

/*
 * First-fit extent based allocator for allocating space in the per-cpu
 * region reserved for modules.  This is only intended for use by the
 * kernel linkers to place module linker sets.
 */
void *
dpcpu_alloc(int size)
{
	struct dpcpu_free *df;
	void *s;

	s = NULL;
	size = roundup2(size, sizeof(void *));
	sx_xlock(&dpcpu_lock);
	TAILQ_FOREACH(df, &dpcpu_head, df_link) {
		if (df->df_len < size)
			continue;
		if (df->df_len == size) {
			s = (void *)df->df_start;
			TAILQ_REMOVE(&dpcpu_head, df, df_link);
			free(df, M_PCPU);
			break;
		}
		s = (void *)df->df_start;
		df->df_len -= size;
		df->df_start = df->df_start + size;
		break;
	}
	sx_xunlock(&dpcpu_lock);

	return (s);
}

/*
 * Free dynamic per-cpu space at module unload time. 
 */
void
dpcpu_free(void *s, int size)
{
	struct dpcpu_free *df;
	struct dpcpu_free *dn;
	uintptr_t start;
	uintptr_t end;

	size = roundup2(size, sizeof(void *));
	start = (uintptr_t)s;
	end = start + size;
	/*
	 * Free a region of space and merge it with as many neighbors as
	 * possible.  Keeping the list sorted simplifies this operation.
	 */
	sx_xlock(&dpcpu_lock);
	TAILQ_FOREACH(df, &dpcpu_head, df_link) {
		if (df->df_start > end)
			break;
		/*
		 * If we expand at the end of an entry we may have to
		 * merge it with the one following it as well.
		 */
		if (df->df_start + df->df_len == start) {
			df->df_len += size;
			dn = TAILQ_NEXT(df, df_link);
			if (df->df_start + df->df_len == dn->df_start) {
				df->df_len += dn->df_len;
				TAILQ_REMOVE(&dpcpu_head, dn, df_link);
				free(dn, M_PCPU);
			}
			sx_xunlock(&dpcpu_lock);
			return;
		}
		if (df->df_start == end) {
			df->df_start = start;
			df->df_len += size;
			sx_xunlock(&dpcpu_lock);
			return;
		}
	}
	dn = malloc(sizeof(*df), M_PCPU, M_WAITOK | M_ZERO);
	dn->df_start = start;
	dn->df_len = size;
	if (df)
		TAILQ_INSERT_BEFORE(df, dn, df_link);
	else
		TAILQ_INSERT_TAIL(&dpcpu_head, dn, df_link);
	sx_xunlock(&dpcpu_lock);
}

/*
 * Initialize the per-cpu storage from an updated linker-set region.
 */
void
dpcpu_copy(void *s, int size)
{
#ifdef SMP
	uintptr_t dpcpu;
	int i;

	for (i = 0; i < mp_ncpus; ++i) {
		dpcpu = dpcpu_off[i];
		if (dpcpu == 0)
			continue;
		memcpy((void *)(dpcpu + (uintptr_t)s), s, size);
	}
#else
	memcpy((void *)(dpcpu_off[0] + (uintptr_t)s), s, size);
#endif
}

/*
 * Destroy a struct pcpu.
 */
void
pcpu_destroy(struct pcpu *pcpu)
{

	STAILQ_REMOVE(&cpuhead, pcpu, pcpu, pc_allcpu);
	cpuid_to_pcpu[pcpu->pc_cpuid] = NULL;
	dpcpu_off[pcpu->pc_cpuid] = 0;
}

/*
 * Locate a struct pcpu by cpu id.
 */
struct pcpu *
pcpu_find(u_int cpuid)
{

	return (cpuid_to_pcpu[cpuid]);
}

int
sysctl_dpcpu_quad(SYSCTL_HANDLER_ARGS)
{
	uintptr_t dpcpu;
	int64_t count;
	int i;

	count = 0;
	for (i = 0; i < mp_ncpus; ++i) {
		dpcpu = dpcpu_off[i];
		if (dpcpu == 0)
			continue;
		count += *(int64_t *)(dpcpu + (uintptr_t)arg1);
	}
	return (SYSCTL_OUT(req, &count, sizeof(count)));
}

int
sysctl_dpcpu_long(SYSCTL_HANDLER_ARGS)
{
	uintptr_t dpcpu;
	long count;
	int i;

	count = 0;
	for (i = 0; i < mp_ncpus; ++i) {
		dpcpu = dpcpu_off[i];
		if (dpcpu == 0)
			continue;
		count += *(long *)(dpcpu + (uintptr_t)arg1);
	}
	return (SYSCTL_OUT(req, &count, sizeof(count)));
}

int
sysctl_dpcpu_int(SYSCTL_HANDLER_ARGS)
{
	uintptr_t dpcpu;
	int count;
	int i;

	count = 0;
	for (i = 0; i < mp_ncpus; ++i) {
		dpcpu = dpcpu_off[i];
		if (dpcpu == 0)
			continue;
		count += *(int *)(dpcpu + (uintptr_t)arg1);
	}
	return (SYSCTL_OUT(req, &count, sizeof(count)));
}

#ifdef DDB
DB_SHOW_COMMAND(dpcpu_off, db_show_dpcpu_off)
{
	int id;

	CPU_FOREACH(id) {
		db_printf("dpcpu_off[%2d] = 0x%jx (+ DPCPU_START = %p)\n",
		    id, (uintmax_t)dpcpu_off[id],
		    (void *)(uintptr_t)(dpcpu_off[id] + DPCPU_START));
	}
}

static void
show_pcpu(struct pcpu *pc)
{
	struct thread *td;

	db_printf("cpuid        = %d\n", pc->pc_cpuid);
	db_printf("dynamic pcpu = %p\n", (void *)pc->pc_dynamic);
	db_printf("curthread    = ");
	td = pc->pc_curthread;
	if (td != NULL)
		db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
		    td->td_name);
	else
		db_printf("none\n");
	db_printf("curpcb       = %p\n", pc->pc_curpcb);
	db_printf("fpcurthread  = ");
	td = pc->pc_fpcurthread;
	if (td != NULL)
		db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
		    td->td_name);
	else
		db_printf("none\n");
	db_printf("idlethread   = ");
	td = pc->pc_idlethread;
	if (td != NULL)
		db_printf("%p: tid %d \"%s\"\n", td, td->td_tid, td->td_name);
	else
		db_printf("none\n");
	db_show_mdpcpu(pc);

#ifdef VIMAGE
	db_printf("curvnet      = %p\n", pc->pc_curthread->td_vnet);
#endif

#ifdef WITNESS
	db_printf("spin locks held:\n");
	witness_list_locks(&pc->pc_spinlocks, db_printf);
#endif
}

DB_SHOW_COMMAND(pcpu, db_show_pcpu)
{
	struct pcpu *pc;
	int id;

	if (have_addr)
		id = ((addr >> 4) % 16) * 10 + (addr % 16);
	else
		id = PCPU_GET(cpuid);
	pc = pcpu_find(id);
	if (pc == NULL) {
		db_printf("CPU %d not found\n", id);
		return;
	}
	show_pcpu(pc);
}

DB_SHOW_ALL_COMMAND(pcpu, db_show_cpu_all)
{
	struct pcpu *pc;
	int id;

	db_printf("Current CPU: %d\n\n", PCPU_GET(cpuid));
	for (id = 0; id <= mp_maxid; id++) {
		pc = pcpu_find(id);
		if (pc != NULL) {
			show_pcpu(pc);
			db_printf("\n");
		}
	}
}
DB_SHOW_ALIAS(allpcpu, db_show_cpu_all);
#endif