FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_pcpu.c

     /*
      * Copyright (c) 2001 Wind River Systems, Inc.
      * All rights reserved.
      * Written by: John Baldwin <jhb@FreeBSD.org>
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 4. Neither the name of the author nor the names of any co-contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     * $FreeBSD: releng/5.1/sys/kern/subr_pcpu.c 88901 2002-01-05 09:35:50Z peter $
     */
    
    /*
     * This module provides MI support for per-cpu data.
     *
     * Each architecture determines the mapping of logical CPU IDs to physical
     * CPUs.  The requirements of this mapping are as follows:
     *  - Logical CPU IDs must reside in the range 0 ... MAXCPU - 1.
     *  - The mapping is not required to be dense.  That is, there may be
     *    gaps in the mappings.
     *  - The platform sets the value of MAXCPU in <machine/param.h>.
     *  - It is suggested, but not required, that in the non-SMP case, the
     *    platform define MAXCPU to be 1 and define the logical ID of the
     *    sole CPU as 0.
     */
    
    #include "opt_ddb.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/linker_set.h>
    #include <sys/lock.h>
    #include <sys/pcpu.h>
    #include <sys/proc.h>
    #include <ddb/ddb.h>
    
    static struct pcpu *cpuid_to_pcpu[MAXCPU];
    struct cpuhead cpuhead = SLIST_HEAD_INITIALIZER(cpuhead);
    
    /*
     * Initialize the MI portions of a struct pcpu.
     */
    void
    pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
    {
    
            bzero(pcpu, size);
            KASSERT(cpuid >= 0 && cpuid < MAXCPU,
                ("pcpu_init: invalid cpuid %d", cpuid));
            pcpu->pc_cpuid = cpuid;
            pcpu->pc_cpumask = 1 << cpuid;
            cpuid_to_pcpu[cpuid] = pcpu;
            SLIST_INSERT_HEAD(&cpuhead, pcpu, pc_allcpu);
            cpu_pcpu_init(pcpu, cpuid, size);
    }
    
    /*
     * Destroy a struct pcpu.
     */
    void
    pcpu_destroy(struct pcpu *pcpu)
    {
    
            SLIST_REMOVE(&cpuhead, pcpu, pcpu, pc_allcpu);
            cpuid_to_pcpu[pcpu->pc_cpuid] = NULL;
    }
    
    /*
     * Locate a struct pcpu by cpu id.
     */
    struct pcpu *
    pcpu_find(u_int cpuid)
    {
    
            return (cpuid_to_pcpu[cpuid]);
    }
    
    #ifdef DDB
    DB_SHOW_COMMAND(pcpu, db_show_pcpu)
   {
           struct pcpu *pc;
           struct thread *td;
           int id;
   
           if (have_addr)
                   id = ((addr >> 4) % 16) * 10 + (addr % 16);
           else
                   id = PCPU_GET(cpuid);
           pc = pcpu_find(id);
           if (pc == NULL) {
                   db_printf("CPU %d not found\n", id);
                   return;
           }
           db_printf("cpuid        = %d\n", pc->pc_cpuid);
           db_printf("curthread    = ");
           td = pc->pc_curthread;
           if (td != NULL)
                   db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
                       td->td_proc->p_comm);
           else
                   db_printf("none\n");
           db_printf("curpcb       = %p\n", pc->pc_curpcb);
           db_printf("fpcurthread  = ");
           td = pc->pc_fpcurthread;
           if (td != NULL)
                   db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
                       td->td_proc->p_comm);
           else
                   db_printf("none\n");
           db_printf("idlethread   = ");
           td = pc->pc_idlethread;
           if (td != NULL)
                   db_printf("%p: pid %d \"%s\"\n", td, td->td_proc->p_pid,
                       td->td_proc->p_comm);
           else
                   db_printf("none\n");
           db_show_mdpcpu(pc);
                   
   #ifdef WITNESS
           db_printf("spin locks held:\n");
           witness_list_locks(&pc->pc_spinlocks);
   #endif
   }
   #endif

Cache object: 6d8a6115e4e6b9e988c7cd0599a3e637