1 /*- 2 * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu> 3 * Copyright (c) 1982, 1986, 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * (c) UNIX System Laboratories, Inc. 6 * All or some portions of this file are derived from material licensed 7 * to the University of California by American Telephone and Telegraph 8 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 9 * the permission of UNIX System Laboratories, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 40 */ 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <sys/param.h> 46 #include <sys/kernel.h> 47 #include <sys/lock.h> 48 #include <sys/mutex.h> 49 #include <sys/proc.h> 50 #include <sys/systm.h> 51 #include <sys/uio.h> 52 #include <sys/sf_buf.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_page.h> 56 57 #include <machine/vmparam.h> 58 59 /* 60 * Implement uiomove(9) from physical memory using sf_bufs to 61 * avoid the creation and destruction of ephemeral mappings. 62 */ 63 int 64 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio) 65 { 66 struct thread *td = curthread; 67 struct iovec *iov; 68 void *cp; 69 vm_offset_t page_offset; 70 size_t cnt; 71 int error = 0; 72 int save = 0; 73 struct sf_buf *sf; 74 75 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 76 ("uiomove_fromphys: mode")); 77 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 78 ("uiomove_fromphys proc")); 79 save = td->td_pflags & TDP_DEADLKTREAT; 80 td->td_pflags |= TDP_DEADLKTREAT; 81 while (n > 0 && uio->uio_resid) { 82 iov = uio->uio_iov; 83 cnt = iov->iov_len; 84 if (cnt == 0) { 85 uio->uio_iov++; 86 uio->uio_iovcnt--; 87 continue; 88 } 89 if (cnt > n) 90 cnt = n; 91 page_offset = offset & PAGE_MASK; 92 cnt = min(cnt, PAGE_SIZE - page_offset); 93 sf = sf_buf_alloc(ma[offset >> PAGE_SHIFT], 0); 94 cp = (char*)sf_buf_kva(sf) + page_offset; 95 switch (uio->uio_segflg) { 96 case UIO_USERSPACE: 97 if (ticks - PCPU_GET(switchticks) >= hogticks) 98 uio_yield(); 99 if (uio->uio_rw == UIO_READ) 100 error = copyout(cp, iov->iov_base, cnt); 101 else 102 error = copyin(iov->iov_base, cp, cnt); 103 if (error) 104 goto out; 105 break; 106 case UIO_SYSSPACE: 107 if (uio->uio_rw == UIO_READ) 108 bcopy(cp, iov->iov_base, cnt); 109 else 110 bcopy(iov->iov_base, cp, cnt); 111 break; 112 case UIO_NOCOPY: 113 break; 114 } 115 sf_buf_free(sf); 116 iov->iov_base = (char *)iov->iov_base + cnt; 117 iov->iov_len -= cnt; 118 uio->uio_resid -= cnt; 119 uio->uio_offset += cnt; 120 offset += cnt; 121 n -= cnt; 122 } 123 out: 124 if (save == 0) 125 td->td_pflags &= ~TDP_DEADLKTREAT; 126 return (error); 127 } 128