text: /*
   * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
   * Copyright (c) 1982, 1986, 1991, 1993
   *	The Regents of the University of California.  All rights reserved.
   * (c) UNIX System Laboratories, Inc.
   * All or some portions of this file are derived from material licensed
   * to the University of California by American Telephone and Telegraph
   * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   * the permission of UNIX System Laboratories, Inc.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   *	@(#)kern_subr.c	8.3 (Berkeley) 1/21/94
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD: src/sys/amd64/amd64/uio_machdep.c,v 1.5 2004/06/03 10:22:45 tjr Exp $");
  
  #include <sys/param.h>
  #include <sys/kernel.h>
  #include <sys/lock.h>
  #include <sys/mutex.h>
  #include <sys/proc.h>
  #include <sys/systm.h>
  #include <sys/uio.h>
  
  #include <vm/vm.h>
  #include <vm/vm_page.h>
  
  #include <machine/vmparam.h>
  
  /*
   * Implement uiomove(9) from physical memory using the direct map to
   * avoid the creation and destruction of ephemeral mappings.
   */
  int
  uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
  {
  	struct thread *td = curthread;
  	struct iovec *iov;
  	void *cp;
  	vm_offset_t page_offset;
  	size_t cnt;
  	int error = 0;
  	int save = 0;
  
  	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
  	    ("uiomove_fromphys: mode"));
  	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
  	    ("uiomove_fromphys proc"));
  	save = td->td_pflags & TDP_DEADLKTREAT;
  	td->td_pflags |= TDP_DEADLKTREAT;
  	while (n > 0 && uio->uio_resid) {
  		iov = uio->uio_iov;
  		cnt = iov->iov_len;
  		if (cnt == 0) {
  			uio->uio_iov++;
  			uio->uio_iovcnt--;
  			continue;
  		}
  		if (cnt > n)
  			cnt = n;
  		page_offset = offset & PAGE_MASK;
  		cnt = min(cnt, PAGE_SIZE - page_offset);
  		cp = (char *)PHYS_TO_DMAP(ma[offset >> PAGE_SHIFT]->phys_addr) +
  		    page_offset;
  		switch (uio->uio_segflg) {
  		case UIO_USERSPACE:
  			if (ticks - PCPU_GET(switchticks) >= hogticks)
  				uio_yield();
  			if (uio->uio_rw == UIO_READ)
  				error = copyout(cp, iov->iov_base, cnt);
  			else
  				error = copyin(iov->iov_base, cp, cnt);
  			if (error)
  				goto out;
  			break;
  		case UIO_SYSSPACE:
  			if (uio->uio_rw == UIO_READ)
  				bcopy(cp, iov->iov_base, cnt);
  			else
  				bcopy(iov->iov_base, cp, cnt);
  			break;
  		case UIO_NOCOPY:
  			break;
  		}
  		iov->iov_base = (char *)iov->iov_base + cnt;
  		iov->iov_len -= cnt;
  		uio->uio_resid -= cnt;
  		uio->uio_offset += cnt;
  		offset += cnt;
  		n -= cnt;
  	}
  out:
  	if (save == 0)
  		td->td_pflags &= ~TDP_DEADLKTREAT;
  	return (error);
  }
  