Add a new example kernel module: mapper
Basic implementation of mmap. Submitted by Akul Pillai.
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kamil
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@ -1,4 +1,4 @@
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# $NetBSD: Makefile,v 1.6 2018/05/29 16:53:56 kamil Exp $
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# $NetBSD: Makefile,v 1.7 2019/01/17 20:47:42 kamil Exp $
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.include <bsd.own.mk>
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@ -6,6 +6,7 @@ SUBDIR+= executor
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SUBDIR+= hello
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#SUBDIR+= luahello # Nothing to build here, only text files
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SUBDIR+= luareadhappy # Needs an additional Lua script
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SUBDIR+= mapper # Needs an additional helper program
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SUBDIR+= panic_string # Crashes the system
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SUBDIR+= ping # Needs an additional helper program
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SUBDIR+= properties
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@ -1,4 +1,4 @@
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$NetBSD: README,v 1.8 2018/05/29 16:53:56 kamil Exp $
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$NetBSD: README,v 1.9 2019/01/17 20:47:42 kamil Exp $
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Kernel Developer's Manual
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@ -10,6 +10,7 @@ DESCRIPTION
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* hello - the simplest `hello world' module
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* luahello - the simplest `hello world' Lua module
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* luareadhappy - demonstrates calling Lua code from C
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* mapper - basic implementation of mmap
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* panic_string - shows how panic is being called through a device
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* ping - basic ioctl(9)
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* properties - handle incoming properties during the module load
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@ -66,5 +67,8 @@ HISTORY
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The panic_string module first appeared in NetBSD 9.0 and was authored by
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Harry Pantazis.
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The mapper module first appeared in NetBSD 9.0 and was authored by
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Akul Pillai.
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AUTHORS
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This document was written by Kamil Rytarowski.
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17
sys/modules/examples/mapper/Makefile
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17
sys/modules/examples/mapper/Makefile
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# $NetBSD: Makefile,v 1.1 2019/01/17 20:47:42 kamil Exp $
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.include "../Makefile.inc"
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#S?= /usr/src/sys
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KMOD= mapper
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SRCS= mapper.c
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.include <bsd.kmodule.mk>
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# To make use of this module, you'll need to separately build the
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# cmd_mapper program, with a Makefile similar to
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#
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# MKMAN= NO
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# PROG= cmd_mapper
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# .include <bsd.prog.mk>
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64
sys/modules/examples/mapper/cmd_mapper.c
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64
sys/modules/examples/mapper/cmd_mapper.c
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/* $NetBSD: cmd_mapper.c,v 1.1 2019/01/17 20:47:42 kamil Exp $ */
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/*-
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* Copyright (c) 2019 The NetBSD Foundation, Inc.
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* All rights reserved.
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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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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__RCSID("$NetBSD: cmd_mapper.c,v 1.1 2019/01/17 20:47:42 kamil Exp $");
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#include <sys/mman.h>
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#include <err.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#define _PATH_DEV_MAPPER "/dev/mapper"
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int main(int argc, char **argv)
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{
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int devfd;
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char *map = NULL;
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if ((devfd = open(_PATH_DEV_MAPPER, O_RDONLY)) == -1)
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err(EXIT_FAILURE, "Cannot open %s", _PATH_DEV_MAPPER);
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map = (char *)(mmap(0, sysconf(_SC_PAGESIZE), PROT_READ, MAP_SHARED,
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devfd, 0));
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if (map == MAP_FAILED)
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err(EXIT_FAILURE, "Mapping failed");
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printf("Message from device: %s\n",map);
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if (munmap(map, sysconf(_SC_PAGESIZE)) == -1)
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err(EXIT_FAILURE, "Unmap failed");
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if (close(devfd) == -1)
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err(EXIT_FAILURE, "Cannot close %s", _PATH_DEV_MAPPER);
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return EXIT_SUCCESS;
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}
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141
sys/modules/examples/mapper/mapper.c
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141
sys/modules/examples/mapper/mapper.c
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/* $NetBSD: mapper.c,v 1.1 2019/01/17 20:47:42 kamil Exp $ */
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/*-
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* Copyright (c) 2019 The NetBSD Foundation, Inc.
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* All rights reserved.
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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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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: mapper.c,v 1.1 2019/01/17 20:47:42 kamil Exp $");
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#include <sys/param.h>
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#include <sys/conf.h>
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#include <sys/device.h>
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#include <sys/kernel.h>
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#include <sys/kmem.h>
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#include <sys/module.h>
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#include <sys/systm.h>
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#include <uvm/uvm.h>
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/*
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* Creating a device /dev/mapper for demonstration.
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* To use this device you need to do:
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* mknod /dev/mapper c 210 0
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*
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*/
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dev_type_open(mapper_open);
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dev_type_close(mapper_close);
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dev_type_mmap(mapper_mmap);
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static struct cdevsw mapper_cdevsw = {
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.d_open = mapper_open,
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.d_close = mapper_close,
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.d_read = noread,
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.d_write = nowrite,
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.d_ioctl = noioctl,
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.d_stop = nostop,
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.d_tty = notty,
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.d_poll = nopoll,
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.d_mmap = mapper_mmap,
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.d_kqfilter = nokqfilter,
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.d_discard = nodiscard,
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.d_flag = D_OTHER
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};
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struct mapper_softc {
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int refcnt;
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char *buffer;
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};
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static struct mapper_softc sc;
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int
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mapper_open(dev_t self __unused, int flag __unused, int mode __unused,
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struct lwp *l __unused)
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{
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if (sc.refcnt > 0)
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return EBUSY;
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++sc.refcnt;
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sc.buffer = kmem_zalloc(PAGE_SIZE, KM_SLEEP);
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snprintf(sc.buffer, PAGE_SIZE, "Hey There!");
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return 0;
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}
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int
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mapper_close(dev_t self __unused, int flag __unused, int mode __unused,
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struct lwp *l __unused)
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{
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kmem_free(sc.buffer, PAGE_SIZE);
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--sc.refcnt;
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return 0;
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}
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/*
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* Here, pmap_extract() is used to extract the mapping from the specified
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* physical map for the provided virtual address, where pmap_kernel() points
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* to the kernel pmap.
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*/
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paddr_t
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mapper_mmap(dev_t dev, off_t off, int prot)
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{
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paddr_t pa;
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if (off & PAGE_MASK)
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return (paddr_t)-1;
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if (prot != VM_PROT_READ)
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return (paddr_t)-1;
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if (pmap_extract(pmap_kernel(), (vaddr_t)sc.buffer, &pa))
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return (paddr_t)atop(pa);
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return (paddr_t)-1;
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}
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MODULE(MODULE_CLASS_MISC, mapper, NULL);
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static int
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mapper_modcmd(modcmd_t cmd, void *arg __unused)
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{
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/* The major should be verified and changed if needed to avoid
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* conflicts with other devices. */
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int cmajor = 210, bmajor = -1;
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switch (cmd) {
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case MODULE_CMD_INIT:
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if (devsw_attach("mapper", NULL, &bmajor, &mapper_cdevsw,
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&cmajor))
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return ENXIO;
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return 0;
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case MODULE_CMD_FINI:
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if (sc.refcnt > 0)
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return EBUSY;
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devsw_detach(NULL, &mapper_cdevsw);
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return 0;
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default:
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return ENOTTY;
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}
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return 0;
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}
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