uio_machdep.c revision 267654
1169689Skan/*- 2169689Skan * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu> 3169689Skan * Copyright (c) 1982, 1986, 1991, 1993 4169689Skan * The Regents of the University of California. All rights reserved. 5169689Skan * (c) UNIX System Laboratories, Inc. 6169689Skan * All or some portions of this file are derived from material licensed 7169689Skan * to the University of California by American Telephone and Telegraph 8169689Skan * Co. or Unix System Laboratories, Inc. and are reproduced herein with 9169689Skan * the permission of UNIX System Laboratories, Inc. 10169689Skan * 11169689Skan * Redistribution and use in source and binary forms, with or without 12169689Skan * modification, are permitted provided that the following conditions 13169689Skan * are met: 14169689Skan * 1. Redistributions of source code must retain the above copyright 15169689Skan * notice, this list of conditions and the following disclaimer. 16169689Skan * 2. Redistributions in binary form must reproduce the above copyright 17169689Skan * notice, this list of conditions and the following disclaimer in the 18169689Skan * documentation and/or other materials provided with the distribution. 19169689Skan * 4. Neither the name of the University nor the names of its contributors 20169689Skan * may be used to endorse or promote products derived from this software 21169689Skan * without specific prior written permission. 22169689Skan * 23169689Skan * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24169689Skan * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25169689Skan * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26169689Skan * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27169689Skan * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28169689Skan * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29169689Skan * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30169689Skan * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31169689Skan * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32169689Skan * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33169689Skan * SUCH DAMAGE. 34169689Skan * 35169689Skan * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 36169689Skan */ 37169689Skan 38169689Skan#include <sys/cdefs.h> 39169689Skan__FBSDID("$FreeBSD: releng/9.3/sys/i386/i386/uio_machdep.c 218195 2011-02-02 16:35:10Z mdf $"); 40169689Skan 41169689Skan#include <sys/param.h> 42169689Skan#include <sys/kernel.h> 43169689Skan#include <sys/lock.h> 44169689Skan#include <sys/mutex.h> 45169689Skan#include <sys/proc.h> 46169689Skan#include <sys/sched.h> 47169689Skan#include <sys/sf_buf.h> 48169689Skan#include <sys/systm.h> 49169689Skan#include <sys/uio.h> 50169689Skan 51169689Skan#include <vm/vm.h> 52169689Skan#include <vm/vm_page.h> 53169689Skan 54169689Skan/* 55169689Skan * Implement uiomove(9) from physical memory using sf_bufs to reduce 56169689Skan * the creation and destruction of ephemeral mappings. 57169689Skan */ 58169689Skanint 59169689Skanuiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio) 60169689Skan{ 61169689Skan struct sf_buf *sf; 62169689Skan struct thread *td = curthread; 63169689Skan struct iovec *iov; 64169689Skan void *cp; 65169689Skan vm_offset_t page_offset; 66169689Skan size_t cnt; 67169689Skan int error = 0; 68169689Skan int save = 0; 69169689Skan 70169689Skan KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 71169689Skan ("uiomove_fromphys: mode")); 72169689Skan KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 73169689Skan ("uiomove_fromphys proc")); 74169689Skan save = td->td_pflags & TDP_DEADLKTREAT; 75169689Skan td->td_pflags |= TDP_DEADLKTREAT; 76169689Skan while (n > 0 && uio->uio_resid) { 77169689Skan iov = uio->uio_iov; 78169689Skan cnt = iov->iov_len; 79169689Skan if (cnt == 0) { 80169689Skan uio->uio_iov++; 81169689Skan uio->uio_iovcnt--; 82169689Skan continue; 83169689Skan } 84169689Skan if (cnt > n) 85169689Skan cnt = n; 86169689Skan page_offset = offset & PAGE_MASK; 87169689Skan cnt = min(cnt, PAGE_SIZE - page_offset); 88169689Skan sched_pin(); 89169689Skan sf = sf_buf_alloc(ma[offset >> PAGE_SHIFT], SFB_CPUPRIVATE); 90169689Skan cp = (char *)sf_buf_kva(sf) + page_offset; 91169689Skan switch (uio->uio_segflg) { 92169689Skan case UIO_USERSPACE: 93169689Skan maybe_yield(); 94169689Skan if (uio->uio_rw == UIO_READ) 95169689Skan error = copyout(cp, iov->iov_base, cnt); 96169689Skan else 97169689Skan error = copyin(iov->iov_base, cp, cnt); 98169689Skan if (error) { 99169689Skan sf_buf_free(sf); 100169689Skan sched_unpin(); 101169689Skan goto out; 102169689Skan } 103169689Skan break; 104169689Skan case UIO_SYSSPACE: 105169689Skan if (uio->uio_rw == UIO_READ) 106169689Skan bcopy(cp, iov->iov_base, cnt); 107169689Skan else 108169689Skan bcopy(iov->iov_base, cp, cnt); 109169689Skan break; 110169689Skan case UIO_NOCOPY: 111169689Skan break; 112169689Skan } 113169689Skan sf_buf_free(sf); 114169689Skan sched_unpin(); 115169689Skan iov->iov_base = (char *)iov->iov_base + cnt; 116169689Skan iov->iov_len -= cnt; 117169689Skan uio->uio_resid -= cnt; 118169689Skan uio->uio_offset += cnt; 119169689Skan offset += cnt; 120169689Skan n -= cnt; 121169689Skan } 122169689Skanout: 123169689Skan if (save == 0) 124169689Skan td->td_pflags &= ~TDP_DEADLKTREAT; 125169689Skan return (error); 126169689Skan} 127169689Skan