xref: /freebsd/sys/kern/subr_pcpu.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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 
80 }
81 
82 /*
83  * Destroy a struct pcpu.
84  */
85 void
86 pcpu_destroy(struct pcpu *pcpu)
87 {
88 
89 	SLIST_REMOVE(&cpuhead, pcpu, pcpu, pc_allcpu);
90 	cpuid_to_pcpu[pcpu->pc_cpuid] = NULL;
91 }
92 
93 /*
94  * Locate a struct pcpu by cpu id.
95  */
96 struct pcpu *
97 pcpu_find(u_int cpuid)
98 {
99 
100 	return (cpuid_to_pcpu[cpuid]);
101 }
102 
103 #ifdef DDB
104 
105 static void
106 show_pcpu(struct pcpu *pc)
107 {
108 	struct thread *td;
109 
110 	db_printf("cpuid        = %d\n", pc->pc_cpuid);
111 	db_printf("curthread    = ");
112 	td = pc->pc_curthread;
113 	if (td != NULL)
114 		db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
115 		    td->td_name);
116 	else
117 		db_printf("none\n");
118 	db_printf("curpcb       = %p\n", pc->pc_curpcb);
119 	db_printf("fpcurthread  = ");
120 	td = pc->pc_fpcurthread;
121 	if (td != NULL)
122 		db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
123 		    td->td_name);
124 	else
125 		db_printf("none\n");
126 	db_printf("idlethread   = ");
127 	td = pc->pc_idlethread;
128 	if (td != NULL)
129 		db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
130 		    td->td_name);
131 	else
132 		db_printf("none\n");
133 	db_show_mdpcpu(pc);
134 
135 #ifdef WITNESS
136 	db_printf("spin locks held:\n");
137 	witness_list_locks(&pc->pc_spinlocks);
138 #endif
139 }
140 
141 DB_SHOW_COMMAND(pcpu, db_show_pcpu)
142 {
143 	struct pcpu *pc;
144 	int id;
145 
146 	if (have_addr)
147 		id = ((addr >> 4) % 16) * 10 + (addr % 16);
148 	else
149 		id = PCPU_GET(cpuid);
150 	pc = pcpu_find(id);
151 	if (pc == NULL) {
152 		db_printf("CPU %d not found\n", id);
153 		return;
154 	}
155 	show_pcpu(pc);
156 }
157 
158 DB_SHOW_COMMAND(allpcpu, db_show_cpu_all)
159 {
160 	struct pcpu *pc;
161 	int id;
162 
163 	db_printf("Current CPU: %d\n\n", PCPU_GET(cpuid));
164 	for (id = 0; id <= mp_maxid; id++) {
165 		pc = pcpu_find(id);
166 		if (pc != NULL) {
167 			show_pcpu(pc);
168 			db_printf("\n");
169 		}
170 	}
171 }
172 #endif
173