FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_pcpu.c
1 /*-
2 * Copyright (c) 2001 Wind River Systems, Inc.
3 * All rights reserved.
4 * Written by: John Baldwin <jhb@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 4. Neither the name of the author nor the names of any co-contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 /*
32 * This module provides MI support for per-cpu data.
33 *
34 * Each architecture determines the mapping of logical CPU IDs to physical
35 * CPUs. The requirements of this mapping are as follows:
36 * - Logical CPU IDs must reside in the range 0 ... MAXCPU - 1.
37 * - The mapping is not required to be dense. That is, there may be
38 * gaps in the mappings.
39 * - The platform sets the value of MAXCPU in <machine/param.h>.
40 * - It is suggested, but not required, that in the non-SMP case, the
41 * platform define MAXCPU to be 1 and define the logical ID of the
42 * sole CPU as 0.
43 */
44
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47
48 #include "opt_ddb.h"
49
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/linker_set.h>
53 #include <sys/lock.h>
54 #include <sys/pcpu.h>
55 #include <sys/proc.h>
56 #include <sys/smp.h>
57 #include <ddb/ddb.h>
58
59 static struct pcpu *cpuid_to_pcpu[MAXCPU];
60 struct cpuhead cpuhead = SLIST_HEAD_INITIALIZER(cpuhead);
61
62 /*
63 * Initialize the MI portions of a struct pcpu.
64 */
65 void
66 pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
67 {
68
69 bzero(pcpu, size);
70 KASSERT(cpuid >= 0 && cpuid < MAXCPU,
71 ("pcpu_init: invalid cpuid %d", cpuid));
72 pcpu->pc_cpuid = cpuid;
73 pcpu->pc_cpumask = 1 << cpuid;
74 cpuid_to_pcpu[cpuid] = pcpu;
75 SLIST_INSERT_HEAD(&cpuhead, pcpu, pc_allcpu);
76 cpu_pcpu_init(pcpu, cpuid, size);
77 }
78
79 /*
80 * Destroy a struct pcpu.
81 */
82 void
83 pcpu_destroy(struct pcpu *pcpu)
84 {
85
86 SLIST_REMOVE(&cpuhead, pcpu, pcpu, pc_allcpu);
87 cpuid_to_pcpu[pcpu->pc_cpuid] = NULL;
88 }
89
90 /*
91 * Locate a struct pcpu by cpu id.
92 */
93 struct pcpu *
94 pcpu_find(u_int cpuid)
95 {
96
97 return (cpuid_to_pcpu[cpuid]);
98 }
99
100 #ifdef DDB
101
102 static void
103 show_pcpu(struct pcpu *pc)
104 {
105 struct thread *td;
106
107 db_printf("cpuid = %d\n", pc->pc_cpuid);
108 db_printf("curthread = ");
109 td = pc->pc_curthread;
110 if (td != NULL)
111 db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
112 td->td_proc->p_comm);
113 else
114 db_printf("none\n");
115 db_printf("curpcb = %p\n", pc->pc_curpcb);
116 db_printf("fpcurthread = ");
117 td = pc->pc_fpcurthread;
118 if (td != NULL)
119 db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
120 td->td_proc->p_comm);
121 else
122 db_printf("none\n");
123 db_printf("idlethread = ");
124 td = pc->pc_idlethread;
125 if (td != NULL)
126 db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
127 td->td_proc->p_comm);
128 else
129 db_printf("none\n");
130 db_show_mdpcpu(pc);
131
132 #ifdef WITNESS
133 db_printf("spin locks held:\n");
134 witness_list_locks(&pc->pc_spinlocks);
135 #endif
136 }
137
138 DB_SHOW_COMMAND(pcpu, db_show_pcpu)
139 {
140 struct pcpu *pc;
141 int id;
142
143 if (have_addr)
144 id = ((addr >> 4) % 16) * 10 + (addr % 16);
145 else
146 id = PCPU_GET(cpuid);
147 pc = pcpu_find(id);
148 if (pc == NULL) {
149 db_printf("CPU %d not found\n", id);
150 return;
151 }
152 show_pcpu(pc);
153 }
154
155 DB_SHOW_COMMAND(allpcpu, db_show_cpu_all)
156 {
157 struct pcpu *pc;
158 int id;
159
160 db_printf("Current CPU: %d\n\n", PCPU_GET(cpuid));
161 for (id = 0; id <= mp_maxid; id++) {
162 pc = pcpu_find(id);
163 if (pc != NULL) {
164 show_pcpu(pc);
165 db_printf("\n");
166 }
167 }
168 }
169 #endif
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