cacdd70cc7
There is no need to mark this device node to use Giant. The only architectures that use io(4) (i386 and amd64) only change a flag in td->td_frame, which is only accessed by curthread. Apart from this change, I think some fishy things may happen when using /dev/io in multithreaded applications. I haven't tested, but looking at the code, the flag doesn't get cleared when close() is called from another thread, but this may not be this important. I'm not removing D_NEEDGIANT from mem(4), because this driver isn't Giant safe at all (it calls GIANT_REQUIRED).
90 lines
2.3 KiB
C
90 lines
2.3 KiB
C
/*-
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* Copyright (c) 2004 Mark R V Murray
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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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* in this position and unchanged.
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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 AUTHORS ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/conf.h>
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#include <sys/fcntl.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/signalvar.h>
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#include <sys/systm.h>
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#include <sys/uio.h>
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#include <machine/specialreg.h>
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#include <vm/vm.h>
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#include <vm/pmap.h>
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#include <machine/iodev.h>
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static struct cdev *iodev;
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static struct cdevsw io_cdevsw = {
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.d_version = D_VERSION,
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.d_open = ioopen,
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.d_close = ioclose,
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.d_name = "io",
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};
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/* ARGSUSED */
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static int
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io_modevent(module_t mod __unused, int type, void *data __unused)
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{
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switch(type) {
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case MOD_LOAD:
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if (bootverbose)
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printf("io: <I/O>\n");
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iodev = make_dev(&io_cdevsw, 0,
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UID_ROOT, GID_WHEEL, 0600, "io");
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break;
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case MOD_UNLOAD:
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destroy_dev(iodev);
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break;
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case MOD_SHUTDOWN:
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break;
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default:
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return(EOPNOTSUPP);
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break;
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}
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return (0);
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}
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DEV_MODULE(io, io_modevent, NULL);
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MODULE_VERSION(io, 1);
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