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 * $FreeBSD: releng/5.0/sys/kern/subr_pcpu.c 88901 2002-01-05 09:35:50Z peter $
31 */
32
33 /*
34 * This module provides MI support for per-cpu data.
35 *
36 * Each architecture determines the mapping of logical CPU IDs to physical
37 * CPUs. The requirements of this mapping are as follows:
38 * - Logical CPU IDs must reside in the range 0 ... MAXCPU - 1.
39 * - The mapping is not required to be dense. That is, there may be
40 * gaps in the mappings.
41 * - The platform sets the value of MAXCPU in <machine/param.h>.
42 * - It is suggested, but not required, that in the non-SMP case, the
43 * platform define MAXCPU to be 1 and define the logical ID of the
44 * sole CPU as 0.
45 */
46
47 #include "opt_ddb.h"
48
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/linker_set.h>
52 #include <sys/lock.h>
53 #include <sys/pcpu.h>
54 #include <sys/proc.h>
55 #include <ddb/ddb.h>
56
57 static struct pcpu *cpuid_to_pcpu[MAXCPU];
58 struct cpuhead cpuhead = SLIST_HEAD_INITIALIZER(cpuhead);
59
60 /*
61 * Initialize the MI portions of a struct pcpu.
62 */
63 void
64 pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
65 {
66
67 bzero(pcpu, size);
68 KASSERT(cpuid >= 0 && cpuid < MAXCPU,
69 ("pcpu_init: invalid cpuid %d", cpuid));
70 pcpu->pc_cpuid = cpuid;
71 pcpu->pc_cpumask = 1 << cpuid;
72 cpuid_to_pcpu[cpuid] = pcpu;
73 SLIST_INSERT_HEAD(&cpuhead, pcpu, pc_allcpu);
74 cpu_pcpu_init(pcpu, cpuid, size);
75 }
76
77 /*
78 * Destroy a struct pcpu.
79 */
80 void
81 pcpu_destroy(struct pcpu *pcpu)
82 {
83
84 SLIST_REMOVE(&cpuhead, pcpu, pcpu, pc_allcpu);
85 cpuid_to_pcpu[pcpu->pc_cpuid] = NULL;
86 }
87
88 /*
89 * Locate a struct pcpu by cpu id.
90 */
91 struct pcpu *
92 pcpu_find(u_int cpuid)
93 {
94
95 return (cpuid_to_pcpu[cpuid]);
96 }
97
98 #ifdef DDB
99 DB_SHOW_COMMAND(pcpu, db_show_pcpu)
100 {
101 struct pcpu *pc;
102 struct thread *td;
103 int id;
104
105 if (have_addr)
106 id = ((addr >> 4) % 16) * 10 + (addr % 16);
107 else
108 id = PCPU_GET(cpuid);
109 pc = pcpu_find(id);
110 if (pc == NULL) {
111 db_printf("CPU %d not found\n", id);
112 return;
113 }
114 db_printf("cpuid = %d\n", pc->pc_cpuid);
115 db_printf("curthread = ");
116 td = pc->pc_curthread;
117 if (td != NULL)
118 db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
119 td->td_proc->p_comm);
120 else
121 db_printf("none\n");
122 db_printf("curpcb = %p\n", pc->pc_curpcb);
123 db_printf("fpcurthread = ");
124 td = pc->pc_fpcurthread;
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_printf("idlethread = ");
131 td = pc->pc_idlethread;
132 if (td != NULL)
133 db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
134 td->td_proc->p_comm);
135 else
136 db_printf("none\n");
137 db_show_mdpcpu(pc);
138
139 #ifdef WITNESS
140 db_printf("spin locks held:\n");
141 witness_list_locks(&pc->pc_spinlocks);
142 #endif
143 }
144 #endif
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