1994-05-24 10:09:53 +00:00
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/*
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* The Mach Operating System project at Carnegie-Mellon University.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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1994-08-02 07:55:43 +00:00
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* from: @(#)vm_kern.c 8.3 (Berkeley) 1/12/94
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1994-05-24 10:09:53 +00:00
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*
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*
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* Copyright (c) 1987, 1990 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Authors: Avadis Tevanian, Jr., Michael Wayne Young
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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1994-08-02 07:55:43 +00:00
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*
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1994-08-07 14:53:27 +00:00
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* $Id: vm_kern.c,v 1.5 1994/08/07 13:10:39 davidg Exp $
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1994-05-24 10:09:53 +00:00
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*/
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/*
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* Kernel memory management.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <vm/vm.h>
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#include <vm/vm_page.h>
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#include <vm/vm_pageout.h>
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#include <vm/vm_kern.h>
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/*
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* kmem_alloc_pageable:
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*
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* Allocate pageable memory to the kernel's address map.
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* map must be "kernel_map" below.
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*/
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vm_offset_t kmem_alloc_pageable(map, size)
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vm_map_t map;
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register vm_size_t size;
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{
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vm_offset_t addr;
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register int result;
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#if 0
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if (map != kernel_map)
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panic("kmem_alloc_pageable: not called with kernel_map");
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#endif
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size = round_page(size);
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addr = vm_map_min(map);
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result = vm_map_find(map, NULL, (vm_offset_t) 0,
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&addr, size, TRUE);
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if (result != KERN_SUCCESS) {
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return(0);
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}
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return(addr);
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}
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/*
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* Allocate wired-down memory in the kernel's address map
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* or a submap.
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*/
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vm_offset_t kmem_alloc(map, size)
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register vm_map_t map;
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register vm_size_t size;
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{
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vm_offset_t addr;
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register vm_offset_t offset;
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extern vm_object_t kernel_object;
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vm_offset_t i;
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size = round_page(size);
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/*
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* Use the kernel object for wired-down kernel pages.
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* Assume that no region of the kernel object is
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* referenced more than once.
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*/
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/*
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* Locate sufficient space in the map. This will give us the
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* final virtual address for the new memory, and thus will tell
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* us the offset within the kernel map.
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*/
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vm_map_lock(map);
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if (vm_map_findspace(map, 0, size, &addr)) {
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vm_map_unlock(map);
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return (0);
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}
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offset = addr - VM_MIN_KERNEL_ADDRESS;
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vm_object_reference(kernel_object);
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vm_map_insert(map, kernel_object, offset, addr, addr + size);
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vm_map_unlock(map);
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/*
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* Guarantee that there are pages already in this object
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* before calling vm_map_pageable. This is to prevent the
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* following scenario:
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*
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* 1) Threads have swapped out, so that there is a
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* pager for the kernel_object.
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* 2) The kmsg zone is empty, and so we are kmem_allocing
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* a new page for it.
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* 3) vm_map_pageable calls vm_fault; there is no page,
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* but there is a pager, so we call
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* pager_data_request. But the kmsg zone is empty,
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* so we must kmem_alloc.
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* 4) goto 1
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* 5) Even if the kmsg zone is not empty: when we get
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* the data back from the pager, it will be (very
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* stale) non-zero data. kmem_alloc is defined to
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* return zero-filled memory.
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*
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* We're intentionally not activating the pages we allocate
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* to prevent a race with page-out. vm_map_pageable will wire
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* the pages.
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*/
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vm_object_lock(kernel_object);
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for (i = 0 ; i < size; i+= PAGE_SIZE) {
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vm_page_t mem;
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while ((mem = vm_page_alloc(kernel_object, offset+i)) == NULL) {
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vm_object_unlock(kernel_object);
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VM_WAIT;
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vm_object_lock(kernel_object);
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}
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vm_page_zero_fill(mem);
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mem->flags &= ~PG_BUSY;
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}
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vm_object_unlock(kernel_object);
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/*
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* And finally, mark the data as non-pageable.
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*/
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(void) vm_map_pageable(map, (vm_offset_t) addr, addr + size, FALSE);
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/*
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* Try to coalesce the map
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*/
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vm_map_simplify(map, addr);
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return(addr);
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}
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/*
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* kmem_free:
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*
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* Release a region of kernel virtual memory allocated
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* with kmem_alloc, and return the physical pages
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* associated with that region.
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*/
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void kmem_free(map, addr, size)
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vm_map_t map;
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register vm_offset_t addr;
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vm_size_t size;
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{
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(void) vm_map_remove(map, trunc_page(addr), round_page(addr + size));
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}
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/*
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* kmem_suballoc:
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*
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* Allocates a map to manage a subrange
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* of the kernel virtual address space.
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*
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* Arguments are as follows:
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*
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* parent Map to take range from
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* size Size of range to find
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* min, max Returned endpoints of map
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* pageable Can the region be paged
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*/
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vm_map_t kmem_suballoc(parent, min, max, size, pageable)
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register vm_map_t parent;
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vm_offset_t *min, *max;
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register vm_size_t size;
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boolean_t pageable;
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{
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register int ret;
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vm_map_t result;
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size = round_page(size);
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*min = (vm_offset_t) vm_map_min(parent);
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ret = vm_map_find(parent, NULL, (vm_offset_t) 0,
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min, size, TRUE);
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if (ret != KERN_SUCCESS) {
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printf("kmem_suballoc: bad status return of %d.\n", ret);
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panic("kmem_suballoc");
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}
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*max = *min + size;
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pmap_reference(vm_map_pmap(parent));
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result = vm_map_create(vm_map_pmap(parent), *min, *max, pageable);
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if (result == NULL)
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panic("kmem_suballoc: cannot create submap");
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if ((ret = vm_map_submap(parent, *min, *max, result)) != KERN_SUCCESS)
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panic("kmem_suballoc: unable to change range to submap");
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return(result);
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}
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/*
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* Allocate wired-down memory in the kernel's address map for the higher
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* level kernel memory allocator (kern/kern_malloc.c). We cannot use
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* kmem_alloc() because we may need to allocate memory at interrupt
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* level where we cannot block (canwait == FALSE).
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*
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* This routine has its own private kernel submap (kmem_map) and object
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* (kmem_object). This, combined with the fact that only malloc uses
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* this routine, ensures that we will never block in map or object waits.
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*
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* Note that this still only works in a uni-processor environment and
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* when called at splhigh().
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*
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* We don't worry about expanding the map (adding entries) since entries
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* for wired maps are statically allocated.
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*/
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vm_offset_t
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kmem_malloc(map, size, canwait)
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register vm_map_t map;
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register vm_size_t size;
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boolean_t canwait;
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{
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register vm_offset_t offset, i;
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vm_map_entry_t entry;
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vm_offset_t addr;
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vm_page_t m;
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extern vm_object_t kmem_object;
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if (map != kmem_map && map != mb_map)
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panic("kern_malloc_alloc: map != {kmem,mb}_map");
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size = round_page(size);
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addr = vm_map_min(map);
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/*
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* Locate sufficient space in the map. This will give us the
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* final virtual address for the new memory, and thus will tell
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* us the offset within the kernel map.
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*/
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vm_map_lock(map);
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if (vm_map_findspace(map, 0, size, &addr)) {
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vm_map_unlock(map);
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1994-05-25 09:21:21 +00:00
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#if 0
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1994-05-24 10:09:53 +00:00
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if (canwait) /* XXX should wait */
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panic("kmem_malloc: %s too small",
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map == kmem_map ? "kmem_map" : "mb_map");
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1994-05-25 09:21:21 +00:00
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#endif
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if (canwait)
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panic("kmem_malloc: map too small");
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1994-05-24 10:09:53 +00:00
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return (0);
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}
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offset = addr - vm_map_min(kmem_map);
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vm_object_reference(kmem_object);
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vm_map_insert(map, kmem_object, offset, addr, addr + size);
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/*
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* If we can wait, just mark the range as wired
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* (will fault pages as necessary).
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*/
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if (canwait) {
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vm_map_unlock(map);
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(void) vm_map_pageable(map, (vm_offset_t) addr, addr + size,
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FALSE);
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vm_map_simplify(map, addr);
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return(addr);
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}
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/*
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* If we cannot wait then we must allocate all memory up front,
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* pulling it off the active queue to prevent pageout.
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*/
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vm_object_lock(kmem_object);
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for (i = 0; i < size; i += PAGE_SIZE) {
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m = vm_page_alloc(kmem_object, offset + i);
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/*
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* Ran out of space, free everything up and return.
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* Don't need to lock page queues here as we know
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* that the pages we got aren't on any queues.
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*/
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if (m == NULL) {
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while (i != 0) {
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i -= PAGE_SIZE;
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m = vm_page_lookup(kmem_object, offset + i);
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vm_page_free(m);
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}
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vm_object_unlock(kmem_object);
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vm_map_delete(map, addr, addr + size);
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vm_map_unlock(map);
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return(0);
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}
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#if 0
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vm_page_zero_fill(m);
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#endif
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m->flags &= ~PG_BUSY;
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}
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vm_object_unlock(kmem_object);
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/*
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* Mark map entry as non-pageable.
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* Assert: vm_map_insert() will never be able to extend the previous
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* entry so there will be a new entry exactly corresponding to this
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* address range and it will have wired_count == 0.
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*/
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if (!vm_map_lookup_entry(map, addr, &entry) ||
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entry->start != addr || entry->end != addr + size ||
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entry->wired_count)
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panic("kmem_malloc: entry not found or misaligned");
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entry->wired_count++;
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/*
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* Loop thru pages, entering them in the pmap.
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* (We cannot add them to the wired count without
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|
|
* wrapping the vm_page_queue_lock in splimp...)
|
|
|
|
*/
|
|
|
|
for (i = 0; i < size; i += PAGE_SIZE) {
|
|
|
|
vm_object_lock(kmem_object);
|
|
|
|
m = vm_page_lookup(kmem_object, offset + i);
|
|
|
|
vm_object_unlock(kmem_object);
|
1994-08-06 09:15:42 +00:00
|
|
|
pmap_kenter( addr + i, VM_PAGE_TO_PHYS(m));
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
vm_map_unlock(map);
|
|
|
|
|
|
|
|
vm_map_simplify(map, addr);
|
|
|
|
return(addr);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* kmem_alloc_wait
|
|
|
|
*
|
|
|
|
* Allocates pageable memory from a sub-map of the kernel. If the submap
|
|
|
|
* has no room, the caller sleeps waiting for more memory in the submap.
|
|
|
|
*
|
|
|
|
*/
|
|
|
|
vm_offset_t kmem_alloc_wait(map, size)
|
|
|
|
vm_map_t map;
|
|
|
|
vm_size_t size;
|
|
|
|
{
|
|
|
|
vm_offset_t addr;
|
|
|
|
|
|
|
|
size = round_page(size);
|
|
|
|
|
|
|
|
for (;;) {
|
|
|
|
/*
|
|
|
|
* To make this work for more than one map,
|
|
|
|
* use the map's lock to lock out sleepers/wakers.
|
|
|
|
*/
|
|
|
|
vm_map_lock(map);
|
|
|
|
if (vm_map_findspace(map, 0, size, &addr) == 0)
|
|
|
|
break;
|
|
|
|
/* no space now; see if we can ever get space */
|
|
|
|
if (vm_map_max(map) - vm_map_min(map) < size) {
|
|
|
|
vm_map_unlock(map);
|
|
|
|
return (0);
|
|
|
|
}
|
|
|
|
assert_wait((int)map, TRUE);
|
|
|
|
vm_map_unlock(map);
|
1994-05-25 09:21:21 +00:00
|
|
|
thread_block("kmaw");
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
vm_map_insert(map, NULL, (vm_offset_t)0, addr, addr + size);
|
|
|
|
vm_map_unlock(map);
|
|
|
|
return (addr);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* kmem_free_wakeup
|
|
|
|
*
|
|
|
|
* Returns memory to a submap of the kernel, and wakes up any threads
|
|
|
|
* waiting for memory in that map.
|
|
|
|
*/
|
|
|
|
void kmem_free_wakeup(map, addr, size)
|
|
|
|
vm_map_t map;
|
|
|
|
vm_offset_t addr;
|
|
|
|
vm_size_t size;
|
|
|
|
{
|
|
|
|
vm_map_lock(map);
|
|
|
|
(void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
|
|
|
|
thread_wakeup((int)map);
|
|
|
|
vm_map_unlock(map);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Create the kernel map; insert a mapping covering kernel text, data, bss,
|
|
|
|
* and all space allocated thus far (`boostrap' data). The new map will thus
|
|
|
|
* map the range between VM_MIN_KERNEL_ADDRESS and `start' as allocated, and
|
|
|
|
* the range between `start' and `end' as free.
|
|
|
|
*/
|
|
|
|
void kmem_init(start, end)
|
|
|
|
vm_offset_t start, end;
|
|
|
|
{
|
|
|
|
register vm_map_t m;
|
|
|
|
|
|
|
|
m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end, FALSE);
|
|
|
|
vm_map_lock(m);
|
|
|
|
/* N.B.: cannot use kgdb to debug, starting with this assignment ... */
|
|
|
|
kernel_map = m;
|
|
|
|
(void) vm_map_insert(m, NULL, (vm_offset_t)0,
|
|
|
|
VM_MIN_KERNEL_ADDRESS, start);
|
|
|
|
/* ... and ending with the completion of the above `insert' */
|
|
|
|
vm_map_unlock(m);
|
|
|
|
}
|