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 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