974 lines
27 KiB
C
974 lines
27 KiB
C
/* $OpenBSD: uvm_km.c,v 1.152 2024/03/27 15:41:40 kurt Exp $ */
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/* $NetBSD: uvm_km.c,v 1.42 2001/01/14 02:10:01 thorpej Exp $ */
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/*
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* Copyright (c) 1997 Charles D. Cranor and Washington University.
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* Copyright (c) 1991, 1993, The Regents of the University of California.
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*
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* 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. 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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* @(#)vm_kern.c 8.3 (Berkeley) 1/12/94
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* from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp
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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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* 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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*/
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/*
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* uvm_km.c: handle kernel memory allocation and management
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*/
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/*
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* overview of kernel memory management:
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*
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* the kernel virtual address space is mapped by "kernel_map." kernel_map
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* starts at a machine-dependent address and is VM_KERNEL_SPACE_SIZE bytes
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* large.
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*
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* the kernel_map has several "submaps." submaps can only appear in
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* the kernel_map (user processes can't use them). submaps "take over"
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* the management of a sub-range of the kernel's address space. submaps
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* are typically allocated at boot time and are never released. kernel
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* virtual address space that is mapped by a submap is locked by the
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* submap's lock -- not the kernel_map's lock.
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*
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* thus, the useful feature of submaps is that they allow us to break
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* up the locking and protection of the kernel address space into smaller
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* chunks.
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*
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* The VM system has several standard kernel submaps:
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* kmem_map: Contains only wired kernel memory for malloc(9).
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* Note: All access to this map must be protected by splvm as
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* calls to malloc(9) are allowed in interrupt handlers.
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* exec_map: Memory to hold arguments to system calls are allocated from
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* this map.
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* XXX: This is primeraly used to artificially limit the number
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* of concurrent processes doing an exec.
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* phys_map: Buffers for vmapbuf (physio) are allocated from this map.
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*
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* the kernel allocates its private memory out of special uvm_objects whose
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* reference count is set to UVM_OBJ_KERN (thus indicating that the objects
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* are "special" and never die). all kernel objects should be thought of
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* as large, fixed-sized, sparsely populated uvm_objects. each kernel
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* object is equal to the size of kernel virtual address space (i.e.
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* VM_KERNEL_SPACE_SIZE).
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*
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* most kernel private memory lives in kernel_object. the only exception
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* to this is for memory that belongs to submaps that must be protected
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* by splvm(). each of these submaps manages their own pages.
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*
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* note that just because a kernel object spans the entire kernel virtual
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* address space doesn't mean that it has to be mapped into the entire space.
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* large chunks of a kernel object's space go unused either because
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* that area of kernel VM is unmapped, or there is some other type of
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* object mapped into that range (e.g. a vnode). for submap's kernel
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* objects, the only part of the object that can ever be populated is the
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* offsets that are managed by the submap.
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*
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* note that the "offset" in a kernel object is always the kernel virtual
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* address minus the vm_map_min(kernel_map).
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* example:
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* suppose kernel_map starts at 0xf8000000 and the kernel does a
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* uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the
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* kernel map]. if uvm_km_alloc returns virtual address 0xf8235000,
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* then that means that the page at offset 0x235000 in kernel_object is
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* mapped at 0xf8235000.
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*
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* kernel objects have one other special property: when the kernel virtual
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* memory mapping them is unmapped, the backing memory in the object is
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* freed right away. this is done with the uvm_km_pgremove() function.
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* this has to be done because there is no backing store for kernel pages
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* and no need to save them after they are no longer referenced.
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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 <sys/proc.h>
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#include <sys/kthread.h>
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#include <uvm/uvm.h>
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/*
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* global data structures
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*/
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struct vm_map *kernel_map = NULL;
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/* Unconstraint range. */
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struct uvm_constraint_range no_constraint = { 0x0, (paddr_t)-1 };
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/*
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* local data structures
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*/
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static struct vm_map kernel_map_store;
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/*
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* uvm_km_init: init kernel maps and objects to reflect reality (i.e.
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* KVM already allocated for text, data, bss, and static data structures).
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*
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* => KVM is defined by [base.. base + VM_KERNEL_SPACE_SIZE].
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* we assume that [base -> start] has already been allocated and that
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* "end" is the end of the kernel image span.
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*/
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void
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uvm_km_init(vaddr_t base, vaddr_t start, vaddr_t end)
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{
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/* kernel_object: for pageable anonymous kernel memory */
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uao_init();
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uvm.kernel_object = uao_create(VM_KERNEL_SPACE_SIZE, UAO_FLAG_KERNOBJ);
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/*
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* init the map and reserve already allocated kernel space
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* before installing.
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*/
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uvm_map_setup(&kernel_map_store, pmap_kernel(), base, end,
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#ifdef KVA_GUARDPAGES
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VM_MAP_PAGEABLE | VM_MAP_GUARDPAGES
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#else
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VM_MAP_PAGEABLE
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#endif
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);
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if (base != start && uvm_map(&kernel_map_store, &base, start - base,
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NULL, UVM_UNKNOWN_OFFSET, 0,
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UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE,
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MAP_INHERIT_NONE, MADV_RANDOM, UVM_FLAG_FIXED)) != 0)
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panic("uvm_km_init: could not reserve space for kernel");
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kernel_map = &kernel_map_store;
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#ifndef __HAVE_PMAP_DIRECT
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/* allow km_alloc calls before uvm_km_thread starts */
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mtx_init(&uvm_km_pages.mtx, IPL_VM);
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#endif
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}
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/*
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* uvm_km_suballoc: allocate a submap in the kernel map. once a submap
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* is allocated all references to that area of VM must go through it. this
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* allows the locking of VAs in kernel_map to be broken up into regions.
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*
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* => if `fixed' is true, *min specifies where the region described
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* by the submap must start
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* => if submap is non NULL we use that as the submap, otherwise we
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* alloc a new map
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*/
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struct vm_map *
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uvm_km_suballoc(struct vm_map *map, vaddr_t *min, vaddr_t *max, vsize_t size,
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int flags, boolean_t fixed, struct vm_map *submap)
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{
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int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0);
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size = round_page(size); /* round up to pagesize */
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/* first allocate a blank spot in the parent map */
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if (uvm_map(map, min, size, NULL, UVM_UNKNOWN_OFFSET, 0,
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UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE,
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MAP_INHERIT_NONE, MADV_RANDOM, mapflags)) != 0) {
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panic("uvm_km_suballoc: unable to allocate space in parent map");
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}
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/* set VM bounds (min is filled in by uvm_map) */
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*max = *min + size;
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/* add references to pmap and create or init the submap */
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pmap_reference(vm_map_pmap(map));
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if (submap == NULL) {
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submap = uvm_map_create(vm_map_pmap(map), *min, *max, flags);
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if (submap == NULL)
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panic("uvm_km_suballoc: unable to create submap");
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} else {
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uvm_map_setup(submap, vm_map_pmap(map), *min, *max, flags);
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}
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/*
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* now let uvm_map_submap plug in it...
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*/
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if (uvm_map_submap(map, *min, *max, submap) != 0)
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panic("uvm_km_suballoc: submap allocation failed");
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return(submap);
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}
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/*
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* uvm_km_pgremove: remove pages from a kernel uvm_object.
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*
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* => when you unmap a part of anonymous kernel memory you want to toss
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* the pages right away. (this gets called from uvm_unmap_...).
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*/
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void
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uvm_km_pgremove(struct uvm_object *uobj, vaddr_t startva, vaddr_t endva)
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{
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const voff_t start = startva - vm_map_min(kernel_map);
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const voff_t end = endva - vm_map_min(kernel_map);
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struct vm_page *pp;
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voff_t curoff;
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int slot;
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int swpgonlydelta = 0;
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KASSERT(UVM_OBJ_IS_AOBJ(uobj));
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KASSERT(rw_write_held(uobj->vmobjlock));
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pmap_remove(pmap_kernel(), startva, endva);
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for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) {
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pp = uvm_pagelookup(uobj, curoff);
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if (pp && pp->pg_flags & PG_BUSY) {
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uvm_pagewait(pp, uobj->vmobjlock, "km_pgrm");
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rw_enter(uobj->vmobjlock, RW_WRITE);
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curoff -= PAGE_SIZE; /* loop back to us */
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continue;
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}
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/* free the swap slot, then the page */
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slot = uao_dropswap(uobj, curoff >> PAGE_SHIFT);
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if (pp != NULL) {
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uvm_lock_pageq();
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uvm_pagefree(pp);
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uvm_unlock_pageq();
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} else if (slot != 0) {
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swpgonlydelta++;
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}
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}
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if (swpgonlydelta > 0) {
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KASSERT(uvmexp.swpgonly >= swpgonlydelta);
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atomic_add_int(&uvmexp.swpgonly, -swpgonlydelta);
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}
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}
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/*
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* uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for "intrsafe"
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* objects
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*
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* => when you unmap a part of anonymous kernel memory you want to toss
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* the pages right away. (this gets called from uvm_unmap_...).
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* => none of the pages will ever be busy, and none of them will ever
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* be on the active or inactive queues (because these objects are
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* never allowed to "page").
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*/
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void
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uvm_km_pgremove_intrsafe(vaddr_t start, vaddr_t end)
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{
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struct vm_page *pg;
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vaddr_t va;
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paddr_t pa;
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for (va = start; va < end; va += PAGE_SIZE) {
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if (!pmap_extract(pmap_kernel(), va, &pa))
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continue;
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pg = PHYS_TO_VM_PAGE(pa);
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if (pg == NULL)
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panic("uvm_km_pgremove_intrsafe: no page");
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uvm_pagefree(pg);
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}
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pmap_kremove(start, end - start);
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}
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/*
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* uvm_km_kmemalloc: lower level kernel memory allocator for malloc()
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*
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* => we map wired memory into the specified map using the obj passed in
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* => NOTE: we can return NULL even if we can wait if there is not enough
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* free VM space in the map... caller should be prepared to handle
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* this case.
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* => we return KVA of memory allocated
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* => flags: NOWAIT, VALLOC - just allocate VA, TRYLOCK - fail if we can't
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* lock the map
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* => low, high, alignment, boundary, nsegs are the corresponding parameters
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* to uvm_pglistalloc
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* => flags: ZERO - correspond to uvm_pglistalloc flags
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*/
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vaddr_t
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uvm_km_kmemalloc_pla(struct vm_map *map, struct uvm_object *obj, vsize_t size,
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vsize_t valign, int flags, paddr_t low, paddr_t high, paddr_t alignment,
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paddr_t boundary, int nsegs)
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{
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vaddr_t kva, loopva;
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voff_t offset;
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struct vm_page *pg;
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struct pglist pgl;
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int pla_flags;
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KASSERT(vm_map_pmap(map) == pmap_kernel());
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/* UVM_KMF_VALLOC => !UVM_KMF_ZERO */
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KASSERT(!(flags & UVM_KMF_VALLOC) ||
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!(flags & UVM_KMF_ZERO));
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/* setup for call */
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size = round_page(size);
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kva = vm_map_min(map); /* hint */
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if (nsegs == 0)
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nsegs = atop(size);
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/* allocate some virtual space */
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if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET,
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valign, UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE,
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MAP_INHERIT_NONE, MADV_RANDOM, (flags & UVM_KMF_TRYLOCK))) != 0)) {
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return 0;
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}
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/* if all we wanted was VA, return now */
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if (flags & UVM_KMF_VALLOC) {
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return kva;
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}
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/* recover object offset from virtual address */
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if (obj != NULL)
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offset = kva - vm_map_min(kernel_map);
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else
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offset = 0;
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/*
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* now allocate and map in the memory... note that we are the only ones
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* whom should ever get a handle on this area of VM.
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*/
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TAILQ_INIT(&pgl);
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pla_flags = 0;
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KASSERT(uvmexp.swpgonly <= uvmexp.swpages);
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if ((flags & UVM_KMF_NOWAIT) ||
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((flags & UVM_KMF_CANFAIL) &&
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uvmexp.swpages - uvmexp.swpgonly <= atop(size)))
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pla_flags |= UVM_PLA_NOWAIT;
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else
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pla_flags |= UVM_PLA_WAITOK;
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if (flags & UVM_KMF_ZERO)
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pla_flags |= UVM_PLA_ZERO;
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if (uvm_pglistalloc(size, low, high, alignment, boundary, &pgl, nsegs,
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pla_flags) != 0) {
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/* Failed. */
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uvm_unmap(map, kva, kva + size);
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return (0);
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}
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if (obj != NULL)
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rw_enter(obj->vmobjlock, RW_WRITE);
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loopva = kva;
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while (loopva != kva + size) {
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pg = TAILQ_FIRST(&pgl);
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TAILQ_REMOVE(&pgl, pg, pageq);
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uvm_pagealloc_pg(pg, obj, offset, NULL);
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atomic_clearbits_int(&pg->pg_flags, PG_BUSY);
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UVM_PAGE_OWN(pg, NULL);
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/*
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* map it in: note that we call pmap_enter with the map and
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* object unlocked in case we are kmem_map.
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*/
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if (obj == NULL) {
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pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg),
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PROT_READ | PROT_WRITE);
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} else {
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pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg),
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PROT_READ | PROT_WRITE,
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PROT_READ | PROT_WRITE | PMAP_WIRED);
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}
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loopva += PAGE_SIZE;
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offset += PAGE_SIZE;
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}
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KASSERT(TAILQ_EMPTY(&pgl));
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pmap_update(pmap_kernel());
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if (obj != NULL)
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rw_exit(obj->vmobjlock);
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return kva;
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}
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/*
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* uvm_km_free: free an area of kernel memory
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*/
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void
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uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size)
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{
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uvm_unmap(map, trunc_page(addr), round_page(addr+size));
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}
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/*
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* uvm_km_alloc1: allocate wired down memory in the kernel map.
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*
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* => we can sleep if needed
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*/
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vaddr_t
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uvm_km_alloc1(struct vm_map *map, vsize_t size, vsize_t align, boolean_t zeroit)
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{
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vaddr_t kva, loopva;
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voff_t offset;
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struct vm_page *pg;
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KASSERT(vm_map_pmap(map) == pmap_kernel());
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size = round_page(size);
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kva = vm_map_min(map); /* hint */
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/* allocate some virtual space */
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if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object,
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UVM_UNKNOWN_OFFSET, align,
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UVM_MAPFLAG(PROT_READ | PROT_WRITE,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_INHERIT_NONE, MADV_RANDOM, 0)) != 0)) {
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return 0;
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}
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/* recover object offset from virtual address */
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offset = kva - vm_map_min(kernel_map);
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/* now allocate the memory. we must be careful about released pages. */
|
|
loopva = kva;
|
|
while (size) {
|
|
rw_enter(uvm.kernel_object->vmobjlock, RW_WRITE);
|
|
/* allocate ram */
|
|
pg = uvm_pagealloc(uvm.kernel_object, offset, NULL, 0);
|
|
if (pg) {
|
|
atomic_clearbits_int(&pg->pg_flags, PG_BUSY);
|
|
UVM_PAGE_OWN(pg, NULL);
|
|
}
|
|
rw_exit(uvm.kernel_object->vmobjlock);
|
|
if (__predict_false(pg == NULL)) {
|
|
if (curproc == uvm.pagedaemon_proc) {
|
|
/*
|
|
* It is unfeasible for the page daemon to
|
|
* sleep for memory, so free what we have
|
|
* allocated and fail.
|
|
*/
|
|
uvm_unmap(map, kva, loopva - kva);
|
|
return (0);
|
|
} else {
|
|
uvm_wait("km_alloc1w"); /* wait for memory */
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* map it in; note we're never called with an intrsafe
|
|
* object, so we always use regular old pmap_enter().
|
|
*/
|
|
pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg),
|
|
PROT_READ | PROT_WRITE,
|
|
PROT_READ | PROT_WRITE | PMAP_WIRED);
|
|
|
|
loopva += PAGE_SIZE;
|
|
offset += PAGE_SIZE;
|
|
size -= PAGE_SIZE;
|
|
}
|
|
pmap_update(map->pmap);
|
|
|
|
/*
|
|
* zero on request (note that "size" is now zero due to the above loop
|
|
* so we need to subtract kva from loopva to reconstruct the size).
|
|
*/
|
|
if (zeroit)
|
|
memset((caddr_t)kva, 0, loopva - kva);
|
|
|
|
return kva;
|
|
}
|
|
|
|
#if defined(__HAVE_PMAP_DIRECT)
|
|
/*
|
|
* uvm_km_page allocator, __HAVE_PMAP_DIRECT arch
|
|
* On architectures with machine memory direct mapped into a portion
|
|
* of KVM, we have very little work to do. Just get a physical page,
|
|
* and find and return its VA.
|
|
*/
|
|
void
|
|
uvm_km_page_init(void)
|
|
{
|
|
/* nothing */
|
|
}
|
|
|
|
void
|
|
uvm_km_page_lateinit(void)
|
|
{
|
|
/* nothing */
|
|
}
|
|
|
|
#else
|
|
/*
|
|
* uvm_km_page allocator, non __HAVE_PMAP_DIRECT archs
|
|
* This is a special allocator that uses a reserve of free pages
|
|
* to fulfill requests. It is fast and interrupt safe, but can only
|
|
* return page sized regions. Its primary use is as a backend for pool.
|
|
*
|
|
* The memory returned is allocated from the larger kernel_map, sparing
|
|
* pressure on the small interrupt-safe kmem_map. It is wired, but
|
|
* not zero filled.
|
|
*/
|
|
|
|
struct uvm_km_pages uvm_km_pages;
|
|
|
|
void uvm_km_createthread(void *);
|
|
void uvm_km_thread(void *);
|
|
struct uvm_km_free_page *uvm_km_doputpage(struct uvm_km_free_page *);
|
|
|
|
/*
|
|
* Allocate the initial reserve, and create the thread which will
|
|
* keep the reserve full. For bootstrapping, we allocate more than
|
|
* the lowat amount, because it may be a while before the thread is
|
|
* running.
|
|
*/
|
|
void
|
|
uvm_km_page_init(void)
|
|
{
|
|
int lowat_min;
|
|
int i;
|
|
int len, bulk;
|
|
vaddr_t addr;
|
|
|
|
if (!uvm_km_pages.lowat) {
|
|
/* based on physmem, calculate a good value here */
|
|
uvm_km_pages.lowat = physmem / 256;
|
|
lowat_min = physmem < atop(16 * 1024 * 1024) ? 32 : 128;
|
|
if (uvm_km_pages.lowat < lowat_min)
|
|
uvm_km_pages.lowat = lowat_min;
|
|
}
|
|
if (uvm_km_pages.lowat > UVM_KM_PAGES_LOWAT_MAX)
|
|
uvm_km_pages.lowat = UVM_KM_PAGES_LOWAT_MAX;
|
|
uvm_km_pages.hiwat = 4 * uvm_km_pages.lowat;
|
|
if (uvm_km_pages.hiwat > UVM_KM_PAGES_HIWAT_MAX)
|
|
uvm_km_pages.hiwat = UVM_KM_PAGES_HIWAT_MAX;
|
|
|
|
/* Allocate all pages in as few allocations as possible. */
|
|
len = 0;
|
|
bulk = uvm_km_pages.hiwat;
|
|
while (len < uvm_km_pages.hiwat && bulk > 0) {
|
|
bulk = MIN(bulk, uvm_km_pages.hiwat - len);
|
|
addr = vm_map_min(kernel_map);
|
|
if (uvm_map(kernel_map, &addr, (vsize_t)bulk << PAGE_SHIFT,
|
|
NULL, UVM_UNKNOWN_OFFSET, 0,
|
|
UVM_MAPFLAG(PROT_READ | PROT_WRITE,
|
|
PROT_READ | PROT_WRITE, MAP_INHERIT_NONE,
|
|
MADV_RANDOM, UVM_KMF_TRYLOCK)) != 0) {
|
|
bulk /= 2;
|
|
continue;
|
|
}
|
|
|
|
for (i = len; i < len + bulk; i++, addr += PAGE_SIZE)
|
|
uvm_km_pages.page[i] = addr;
|
|
len += bulk;
|
|
}
|
|
|
|
uvm_km_pages.free = len;
|
|
for (i = len; i < UVM_KM_PAGES_HIWAT_MAX; i++)
|
|
uvm_km_pages.page[i] = 0;
|
|
|
|
/* tone down if really high */
|
|
if (uvm_km_pages.lowat > 512)
|
|
uvm_km_pages.lowat = 512;
|
|
}
|
|
|
|
void
|
|
uvm_km_page_lateinit(void)
|
|
{
|
|
kthread_create_deferred(uvm_km_createthread, NULL);
|
|
}
|
|
|
|
void
|
|
uvm_km_createthread(void *arg)
|
|
{
|
|
kthread_create(uvm_km_thread, NULL, &uvm_km_pages.km_proc, "kmthread");
|
|
}
|
|
|
|
/*
|
|
* Endless loop. We grab pages in increments of 16 pages, then
|
|
* quickly swap them into the list.
|
|
*/
|
|
void
|
|
uvm_km_thread(void *arg)
|
|
{
|
|
vaddr_t pg[16];
|
|
int i;
|
|
int allocmore = 0;
|
|
int flags;
|
|
struct uvm_km_free_page *fp = NULL;
|
|
|
|
KERNEL_UNLOCK();
|
|
|
|
for (;;) {
|
|
mtx_enter(&uvm_km_pages.mtx);
|
|
if (uvm_km_pages.free >= uvm_km_pages.lowat &&
|
|
uvm_km_pages.freelist == NULL) {
|
|
msleep_nsec(&uvm_km_pages.km_proc, &uvm_km_pages.mtx,
|
|
PVM, "kmalloc", INFSLP);
|
|
}
|
|
allocmore = uvm_km_pages.free < uvm_km_pages.lowat;
|
|
fp = uvm_km_pages.freelist;
|
|
uvm_km_pages.freelist = NULL;
|
|
uvm_km_pages.freelistlen = 0;
|
|
mtx_leave(&uvm_km_pages.mtx);
|
|
|
|
if (allocmore) {
|
|
/*
|
|
* If there was nothing on the freelist, then we
|
|
* must obtain at least one page to make progress.
|
|
* So, only use UVM_KMF_TRYLOCK for the first page
|
|
* if fp != NULL
|
|
*/
|
|
flags = UVM_MAPFLAG(PROT_READ | PROT_WRITE,
|
|
PROT_READ | PROT_WRITE, MAP_INHERIT_NONE,
|
|
MADV_RANDOM, fp != NULL ? UVM_KMF_TRYLOCK : 0);
|
|
memset(pg, 0, sizeof(pg));
|
|
for (i = 0; i < nitems(pg); i++) {
|
|
pg[i] = vm_map_min(kernel_map);
|
|
if (uvm_map(kernel_map, &pg[i], PAGE_SIZE,
|
|
NULL, UVM_UNKNOWN_OFFSET, 0, flags) != 0) {
|
|
pg[i] = 0;
|
|
break;
|
|
}
|
|
|
|
/* made progress, so don't sleep for more */
|
|
flags = UVM_MAPFLAG(PROT_READ | PROT_WRITE,
|
|
PROT_READ | PROT_WRITE, MAP_INHERIT_NONE,
|
|
MADV_RANDOM, UVM_KMF_TRYLOCK);
|
|
}
|
|
|
|
mtx_enter(&uvm_km_pages.mtx);
|
|
for (i = 0; i < nitems(pg); i++) {
|
|
if (uvm_km_pages.free ==
|
|
nitems(uvm_km_pages.page))
|
|
break;
|
|
else if (pg[i] != 0)
|
|
uvm_km_pages.page[uvm_km_pages.free++]
|
|
= pg[i];
|
|
}
|
|
wakeup(&uvm_km_pages.free);
|
|
mtx_leave(&uvm_km_pages.mtx);
|
|
|
|
/* Cleanup left-over pages (if any). */
|
|
for (; i < nitems(pg); i++) {
|
|
if (pg[i] != 0) {
|
|
uvm_unmap(kernel_map,
|
|
pg[i], pg[i] + PAGE_SIZE);
|
|
}
|
|
}
|
|
}
|
|
while (fp) {
|
|
fp = uvm_km_doputpage(fp);
|
|
}
|
|
}
|
|
}
|
|
|
|
struct uvm_km_free_page *
|
|
uvm_km_doputpage(struct uvm_km_free_page *fp)
|
|
{
|
|
vaddr_t va = (vaddr_t)fp;
|
|
struct vm_page *pg;
|
|
int freeva = 1;
|
|
struct uvm_km_free_page *nextfp = fp->next;
|
|
|
|
pg = uvm_atopg(va);
|
|
|
|
pmap_kremove(va, PAGE_SIZE);
|
|
pmap_update(kernel_map->pmap);
|
|
|
|
mtx_enter(&uvm_km_pages.mtx);
|
|
if (uvm_km_pages.free < uvm_km_pages.hiwat) {
|
|
uvm_km_pages.page[uvm_km_pages.free++] = va;
|
|
freeva = 0;
|
|
}
|
|
mtx_leave(&uvm_km_pages.mtx);
|
|
|
|
if (freeva)
|
|
uvm_unmap(kernel_map, va, va + PAGE_SIZE);
|
|
|
|
uvm_pagefree(pg);
|
|
return (nextfp);
|
|
}
|
|
#endif /* !__HAVE_PMAP_DIRECT */
|
|
|
|
void *
|
|
km_alloc(size_t sz, const struct kmem_va_mode *kv,
|
|
const struct kmem_pa_mode *kp, const struct kmem_dyn_mode *kd)
|
|
{
|
|
struct vm_map *map;
|
|
struct vm_page *pg;
|
|
struct pglist pgl;
|
|
int mapflags = 0;
|
|
vm_prot_t prot;
|
|
paddr_t pla_align;
|
|
int pla_flags;
|
|
int pla_maxseg;
|
|
vaddr_t va, sva = 0;
|
|
|
|
KASSERT(sz == round_page(sz));
|
|
|
|
TAILQ_INIT(&pgl);
|
|
|
|
if (kp->kp_nomem || kp->kp_pageable)
|
|
goto alloc_va;
|
|
|
|
pla_flags = kd->kd_waitok ? UVM_PLA_WAITOK : UVM_PLA_NOWAIT;
|
|
pla_flags |= UVM_PLA_TRYCONTIG;
|
|
if (kp->kp_zero)
|
|
pla_flags |= UVM_PLA_ZERO;
|
|
|
|
pla_align = kp->kp_align;
|
|
#ifdef __HAVE_PMAP_DIRECT
|
|
if (pla_align < kv->kv_align)
|
|
pla_align = kv->kv_align;
|
|
#endif
|
|
pla_maxseg = kp->kp_maxseg;
|
|
if (pla_maxseg == 0)
|
|
pla_maxseg = sz / PAGE_SIZE;
|
|
|
|
if (uvm_pglistalloc(sz, kp->kp_constraint->ucr_low,
|
|
kp->kp_constraint->ucr_high, pla_align, kp->kp_boundary,
|
|
&pgl, pla_maxseg, pla_flags)) {
|
|
return (NULL);
|
|
}
|
|
|
|
#ifdef __HAVE_PMAP_DIRECT
|
|
/*
|
|
* Only use direct mappings for single page or single segment
|
|
* allocations.
|
|
*/
|
|
if (kv->kv_singlepage || kp->kp_maxseg == 1) {
|
|
TAILQ_FOREACH(pg, &pgl, pageq) {
|
|
va = pmap_map_direct(pg);
|
|
if (pg == TAILQ_FIRST(&pgl))
|
|
sva = va;
|
|
}
|
|
return ((void *)sva);
|
|
}
|
|
#endif
|
|
alloc_va:
|
|
prot = PROT_READ | PROT_WRITE;
|
|
|
|
if (kp->kp_pageable) {
|
|
KASSERT(kp->kp_object);
|
|
KASSERT(!kv->kv_singlepage);
|
|
} else {
|
|
KASSERT(kp->kp_object == NULL);
|
|
}
|
|
|
|
if (kv->kv_singlepage) {
|
|
KASSERT(sz == PAGE_SIZE);
|
|
#ifdef __HAVE_PMAP_DIRECT
|
|
panic("km_alloc: DIRECT single page");
|
|
#else
|
|
mtx_enter(&uvm_km_pages.mtx);
|
|
while (uvm_km_pages.free == 0) {
|
|
if (kd->kd_waitok == 0) {
|
|
mtx_leave(&uvm_km_pages.mtx);
|
|
uvm_pglistfree(&pgl);
|
|
return NULL;
|
|
}
|
|
msleep_nsec(&uvm_km_pages.free, &uvm_km_pages.mtx,
|
|
PVM, "getpage", INFSLP);
|
|
}
|
|
va = uvm_km_pages.page[--uvm_km_pages.free];
|
|
if (uvm_km_pages.free < uvm_km_pages.lowat &&
|
|
curproc != uvm_km_pages.km_proc) {
|
|
if (kd->kd_slowdown)
|
|
*kd->kd_slowdown = 1;
|
|
wakeup(&uvm_km_pages.km_proc);
|
|
}
|
|
mtx_leave(&uvm_km_pages.mtx);
|
|
#endif
|
|
} else {
|
|
struct uvm_object *uobj = NULL;
|
|
|
|
if (kd->kd_trylock)
|
|
mapflags |= UVM_KMF_TRYLOCK;
|
|
|
|
if (kp->kp_object)
|
|
uobj = *kp->kp_object;
|
|
try_map:
|
|
map = *kv->kv_map;
|
|
va = vm_map_min(map);
|
|
if (uvm_map(map, &va, sz, uobj, kd->kd_prefer,
|
|
kv->kv_align, UVM_MAPFLAG(prot, prot, MAP_INHERIT_NONE,
|
|
MADV_RANDOM, mapflags))) {
|
|
if (kv->kv_wait && kd->kd_waitok) {
|
|
tsleep_nsec(map, PVM, "km_allocva", INFSLP);
|
|
goto try_map;
|
|
}
|
|
uvm_pglistfree(&pgl);
|
|
return (NULL);
|
|
}
|
|
}
|
|
sva = va;
|
|
TAILQ_FOREACH(pg, &pgl, pageq) {
|
|
if (kp->kp_pageable)
|
|
pmap_enter(pmap_kernel(), va, VM_PAGE_TO_PHYS(pg),
|
|
prot, prot | PMAP_WIRED);
|
|
else
|
|
pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), prot);
|
|
va += PAGE_SIZE;
|
|
}
|
|
pmap_update(pmap_kernel());
|
|
return ((void *)sva);
|
|
}
|
|
|
|
void
|
|
km_free(void *v, size_t sz, const struct kmem_va_mode *kv,
|
|
const struct kmem_pa_mode *kp)
|
|
{
|
|
vaddr_t sva, eva, va;
|
|
struct vm_page *pg;
|
|
struct pglist pgl;
|
|
|
|
sva = (vaddr_t)v;
|
|
eva = sva + sz;
|
|
|
|
if (kp->kp_nomem)
|
|
goto free_va;
|
|
|
|
#ifdef __HAVE_PMAP_DIRECT
|
|
if (kv->kv_singlepage || kp->kp_maxseg == 1) {
|
|
TAILQ_INIT(&pgl);
|
|
for (va = sva; va < eva; va += PAGE_SIZE) {
|
|
pg = pmap_unmap_direct(va);
|
|
TAILQ_INSERT_TAIL(&pgl, pg, pageq);
|
|
}
|
|
uvm_pglistfree(&pgl);
|
|
return;
|
|
}
|
|
#else
|
|
if (kv->kv_singlepage) {
|
|
struct uvm_km_free_page *fp = v;
|
|
|
|
mtx_enter(&uvm_km_pages.mtx);
|
|
fp->next = uvm_km_pages.freelist;
|
|
uvm_km_pages.freelist = fp;
|
|
if (uvm_km_pages.freelistlen++ > 16)
|
|
wakeup(&uvm_km_pages.km_proc);
|
|
mtx_leave(&uvm_km_pages.mtx);
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
if (kp->kp_pageable) {
|
|
pmap_remove(pmap_kernel(), sva, eva);
|
|
pmap_update(pmap_kernel());
|
|
} else {
|
|
TAILQ_INIT(&pgl);
|
|
for (va = sva; va < eva; va += PAGE_SIZE) {
|
|
paddr_t pa;
|
|
|
|
if (!pmap_extract(pmap_kernel(), va, &pa))
|
|
continue;
|
|
|
|
pg = PHYS_TO_VM_PAGE(pa);
|
|
if (pg == NULL) {
|
|
panic("km_free: unmanaged page 0x%lx", pa);
|
|
}
|
|
TAILQ_INSERT_TAIL(&pgl, pg, pageq);
|
|
}
|
|
pmap_kremove(sva, sz);
|
|
pmap_update(pmap_kernel());
|
|
uvm_pglistfree(&pgl);
|
|
}
|
|
free_va:
|
|
uvm_unmap(*kv->kv_map, sva, eva);
|
|
if (kv->kv_wait)
|
|
wakeup(*kv->kv_map);
|
|
}
|
|
|
|
const struct kmem_va_mode kv_any = {
|
|
.kv_map = &kernel_map,
|
|
};
|
|
|
|
const struct kmem_va_mode kv_intrsafe = {
|
|
.kv_map = &kmem_map,
|
|
};
|
|
|
|
const struct kmem_va_mode kv_page = {
|
|
.kv_singlepage = 1
|
|
};
|
|
|
|
const struct kmem_pa_mode kp_dirty = {
|
|
.kp_constraint = &no_constraint
|
|
};
|
|
|
|
const struct kmem_pa_mode kp_dma = {
|
|
.kp_constraint = &dma_constraint
|
|
};
|
|
|
|
const struct kmem_pa_mode kp_dma_contig = {
|
|
.kp_constraint = &dma_constraint,
|
|
.kp_maxseg = 1
|
|
};
|
|
|
|
const struct kmem_pa_mode kp_dma_zero = {
|
|
.kp_constraint = &dma_constraint,
|
|
.kp_zero = 1
|
|
};
|
|
|
|
const struct kmem_pa_mode kp_zero = {
|
|
.kp_constraint = &no_constraint,
|
|
.kp_zero = 1
|
|
};
|
|
|
|
const struct kmem_pa_mode kp_pageable = {
|
|
.kp_object = &uvm.kernel_object,
|
|
.kp_pageable = 1
|
|
/* XXX - kp_nomem, maybe, but we'll need to fix km_free. */
|
|
};
|
|
|
|
const struct kmem_pa_mode kp_none = {
|
|
.kp_nomem = 1
|
|
};
|
|
|
|
const struct kmem_dyn_mode kd_waitok = {
|
|
.kd_waitok = 1,
|
|
.kd_prefer = UVM_UNKNOWN_OFFSET
|
|
};
|
|
|
|
const struct kmem_dyn_mode kd_nowait = {
|
|
.kd_prefer = UVM_UNKNOWN_OFFSET
|
|
};
|
|
|
|
const struct kmem_dyn_mode kd_trylock = {
|
|
.kd_trylock = 1,
|
|
.kd_prefer = UVM_UNKNOWN_OFFSET
|
|
};
|