FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_init.c

     /*-
      * Copyright (c) 1991, 1993
      *      The Regents of the University of California.  All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
      * The Mach Operating System project at Carnegie-Mellon University.
      *
      * 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 University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
     *
     *      from: @(#)vm_init.c     8.1 (Berkeley) 6/11/93
     *
     *
     * Copyright (c) 1987, 1990 Carnegie-Mellon University.
     * All rights reserved.
     *
     * Authors: Avadis Tevanian, Jr., Michael Wayne Young
     *
     * Permission to use, copy, modify and distribute this software and
     * its documentation is hereby granted, provided that both the copyright
     * notice and this permission notice appear in all copies of the
     * software, derivative works or modified versions, and any portions
     * thereof, and that both notices appear in supporting documentation.
     *
     * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     *
     * Carnegie Mellon requests users of this software to return to
     *
     *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
     *  School of Computer Science
     *  Carnegie Mellon University
     *  Pittsburgh PA 15213-3890
     *
     * any improvements or extensions that they make and grant Carnegie the
     * rights to redistribute these changes.
     */
    
    /*
     *      Initialize the Virtual Memory subsystem.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/proc.h>
    #include <sys/rwlock.h>
    #include <sys/malloc.h>
    #include <sys/sysctl.h>
    #include <sys/systm.h>
    #include <sys/selinfo.h>
    #include <sys/pipe.h>
    #include <sys/bio.h>
    #include <sys/buf.h>
    #include <sys/vmem.h>
    
    #include <vm/vm.h>
    #include <vm/vm_param.h>
    #include <vm/vm_kern.h>
    #include <vm/vm_object.h>
    #include <vm/vm_page.h>
    #include <vm/vm_map.h>
    #include <vm/vm_pager.h>
    #include <vm/vm_extern.h>
    
    long physmem;
    
    static int exec_map_entries = 16;
    TUNABLE_INT("vm.exec_map_entries", &exec_map_entries);
    SYSCTL_INT(_vm, OID_AUTO, exec_map_entries, CTLFLAG_RD, &exec_map_entries, 0,
        "Maximum number of simultaneous execs");
    
    /*
     * System initialization
    */
   static void vm_mem_init(void *);
   SYSINIT(vm_mem, SI_SUB_VM, SI_ORDER_FIRST, vm_mem_init, NULL);
   
   /*
    * Import kva into the kernel arena.
    */
   static int
   kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp)
   {
           vm_offset_t addr;
           int result;
    
           addr = vm_map_min(kernel_map);
           result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0,
               VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
           if (result != KERN_SUCCESS)
                   return (ENOMEM);
   
           *addrp = addr;
   
           return (0);
   }
   
   /*
    *      vm_init initializes the virtual memory system.
    *      This is done only by the first cpu up.
    *
    *      The start and end address of physical memory is passed in.
    */
   /* ARGSUSED*/
   static void
   vm_mem_init(dummy)
           void *dummy;
   {
   
           /*
            * Initializes resident memory structures. From here on, all physical
            * memory is accounted for, and we use only virtual addresses.
            */
           vm_set_page_size();
           virtual_avail = vm_page_startup(virtual_avail);
           
           /*
            * Initialize other VM packages
            */
           vmem_startup();
           vm_object_init();
           vm_map_startup();
           kmem_init(virtual_avail, virtual_end);
   
           /*
            * Initialize the kernel_arena.  This can grow on demand.
            */
           vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0);
           vmem_set_import(kernel_arena, kva_import, NULL, NULL,
   #if VM_NRESERVLEVEL > 0
               1 << (VM_LEVEL_0_ORDER + PAGE_SHIFT));
   #else
               /* On non-superpage architectures want large import sizes. */
               PAGE_SIZE * 1024);
   #endif
   
           kmem_init_zero_region();
           pmap_init();
           vm_pager_init();
   }
   
   void
   vm_ksubmap_init(struct kva_md_info *kmi)
   {
           vm_offset_t firstaddr;
           caddr_t v;
           vm_size_t size = 0;
           long physmem_est;
           vm_offset_t minaddr;
           vm_offset_t maxaddr;
   
           /*
            * Allocate space for system data structures.
            * The first available kernel virtual address is in "v".
            * As pages of kernel virtual memory are allocated, "v" is incremented.
            * As pages of memory are allocated and cleared,
            * "firstaddr" is incremented.
            */
   
           /*
            * Make two passes.  The first pass calculates how much memory is
            * needed and allocates it.  The second pass assigns virtual
            * addresses to the various data structures.
            */
           firstaddr = 0;
   again:
           v = (caddr_t)firstaddr;
   
           /*
            * Discount the physical memory larger than the size of kernel_map
            * to avoid eating up all of KVA space.
            */
           physmem_est = lmin(physmem, btoc(kernel_map->max_offset -
               kernel_map->min_offset));
   
           v = kern_vfs_bio_buffer_alloc(v, physmem_est);
   
           /*
            * End of first pass, size has been calculated so allocate memory
            */
           if (firstaddr == 0) {
                   size = (vm_size_t)v;
                   firstaddr = kmem_malloc(kernel_arena, round_page(size),
                       M_ZERO | M_WAITOK);
                   if (firstaddr == 0)
                           panic("startup: no room for tables");
                   goto again;
           }
   
           /*
            * End of second pass, addresses have been assigned
            */
           if ((vm_size_t)((char *)v - firstaddr) != size)
                   panic("startup: table size inconsistency");
   
           /*
            * Allocate the clean map to hold all of the paging and I/O virtual
            * memory.
            */
           size = (long)nbuf * BKVASIZE + (long)nswbuf * MAXPHYS +
               (long)bio_transient_maxcnt * MAXPHYS;
           kmi->clean_sva = firstaddr = kva_alloc(size);
           kmi->clean_eva = firstaddr + size;
   
           /*
            * Allocate the buffer arena.
            */
           size = (long)nbuf * BKVASIZE;
           kmi->buffer_sva = firstaddr;
           kmi->buffer_eva = kmi->buffer_sva + size;
           vmem_init(buffer_arena, "buffer arena", kmi->buffer_sva, size,
               PAGE_SIZE, 0, 0);
           firstaddr += size;
   
           /*
            * Now swap kva.
            */
           swapbkva = firstaddr;
           size = (long)nswbuf * MAXPHYS;
           firstaddr += size;
   
           /*
            * And optionally transient bio space.
            */
           if (bio_transient_maxcnt != 0) {
                   size = (long)bio_transient_maxcnt * MAXPHYS;
                   vmem_init(transient_arena, "transient arena",
                       firstaddr, size, PAGE_SIZE, 0, 0);
                   firstaddr += size;
           }
           if (firstaddr != kmi->clean_eva)
                   panic("Clean map calculation incorrect");
   
           /*
            * Allocate the pageable submaps.
            */
           exec_map = kmem_suballoc(kernel_map, &minaddr, &maxaddr,
               exec_map_entries * round_page(PATH_MAX + ARG_MAX), FALSE);
           pipe_map = kmem_suballoc(kernel_map, &minaddr, &maxaddr, maxpipekva,
               FALSE);
   }

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