xref: /freebsd/sys/kern/subr_pcpu.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
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 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 	pcpu->pc_rm_queue.rmq_next = &pcpu->pc_rm_queue;
78 	pcpu->pc_rm_queue.rmq_prev = &pcpu->pc_rm_queue;
79 #ifdef KTR
80 	snprintf(pcpu->pc_name, sizeof(pcpu->pc_name), "CPU %d", cpuid);
81 #endif
82 
83 }
84 
85 /*
86  * Destroy a struct pcpu.
87  */
88 void
89 pcpu_destroy(struct pcpu *pcpu)
90 {
91 
92 	SLIST_REMOVE(&cpuhead, pcpu, pcpu, pc_allcpu);
93 	cpuid_to_pcpu[pcpu->pc_cpuid] = NULL;
94 }
95 
96 /*
97  * Locate a struct pcpu by cpu id.
98  */
99 struct pcpu *
100 pcpu_find(u_int cpuid)
101 {
102 
103 	return (cpuid_to_pcpu[cpuid]);
104 }
105 
106 #ifdef DDB
107 
108 static void
109 show_pcpu(struct pcpu *pc)
110 {
111 	struct thread *td;
112 
113 	db_printf("cpuid        = %d\n", pc->pc_cpuid);
114 	db_printf("curthread    = ");
115 	td = pc->pc_curthread;
116 	if (td != NULL)
117 		db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
118 		    td->td_name);
119 	else
120 		db_printf("none\n");
121 	db_printf("curpcb       = %p\n", pc->pc_curpcb);
122 	db_printf("fpcurthread  = ");
123 	td = pc->pc_fpcurthread;
124 	if (td != NULL)
125 		db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
126 		    td->td_name);
127 	else
128 		db_printf("none\n");
129 	db_printf("idlethread   = ");
130 	td = pc->pc_idlethread;
131 	if (td != NULL)
132 		db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
133 		    td->td_name);
134 	else
135 		db_printf("none\n");
136 	db_show_mdpcpu(pc);
137 
138 #ifdef VIMAGE
139 	db_printf("curvnet      = %p\n", pc->pc_curthread->td_vnet);
140 #endif
141 
142 #ifdef WITNESS
143 	db_printf("spin locks held:\n");
144 	witness_list_locks(&pc->pc_spinlocks);
145 #endif
146 }
147 
148 DB_SHOW_COMMAND(pcpu, db_show_pcpu)
149 {
150 	struct pcpu *pc;
151 	int id;
152 
153 	if (have_addr)
154 		id = ((addr >> 4) % 16) * 10 + (addr % 16);
155 	else
156 		id = PCPU_GET(cpuid);
157 	pc = pcpu_find(id);
158 	if (pc == NULL) {
159 		db_printf("CPU %d not found\n", id);
160 		return;
161 	}
162 	show_pcpu(pc);
163 }
164 
165 DB_SHOW_ALL_COMMAND(pcpu, db_show_cpu_all)
166 {
167 	struct pcpu *pc;
168 	int id;
169 
170 	db_printf("Current CPU: %d\n\n", PCPU_GET(cpuid));
171 	for (id = 0; id <= mp_maxid; id++) {
172 		pc = pcpu_find(id);
173 		if (pc != NULL) {
174 			show_pcpu(pc);
175 			db_printf("\n");
176 		}
177 	}
178 }
179 DB_SHOW_ALIAS(allpcpu, db_show_cpu_all);
180 #endif
181