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 53 #include <vm/vm.h> 54 #include <vm/vm_page.h> 55 56 #include <machine/vmparam.h> 57 58 /* 59 * Implement uiomove(9) from physical memory using the direct map to 60 * avoid the creation and destruction of emphemeral mappings. 61 */ 62 int 63 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio) 64 { 65 struct thread *td = curthread; 66 struct iovec *iov; 67 void *cp; 68 vm_offset_t page_offset; 69 size_t cnt; 70 int error = 0; 71 int save = 0; 72 73 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 74 ("uiomove_fromphys: mode")); 75 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 76 ("uiomove_fromphys proc")); 77 if (td != NULL) { 78 mtx_lock_spin(&sched_lock); 79 save = td->td_flags & TDF_DEADLKTREAT; 80 td->td_flags |= TDF_DEADLKTREAT; 81 mtx_unlock_spin(&sched_lock); 82 } 83 while (n > 0 && uio->uio_resid) { 84 iov = uio->uio_iov; 85 cnt = iov->iov_len; 86 if (cnt == 0) { 87 uio->uio_iov++; 88 uio->uio_iovcnt--; 89 continue; 90 } 91 if (cnt > n) 92 cnt = n; 93 page_offset = offset & PAGE_MASK; 94 cnt = min(cnt, PAGE_SIZE - page_offset); 95 cp = (char *)PHYS_TO_DMAP(ma[offset >> PAGE_SHIFT]->phys_addr) + 96 page_offset; 97 switch (uio->uio_segflg) { 98 case UIO_USERSPACE: 99 if (ticks - PCPU_GET(switchticks) >= hogticks) 100 uio_yield(); 101 if (uio->uio_rw == UIO_READ) 102 error = copyout(cp, iov->iov_base, cnt); 103 else 104 error = copyin(iov->iov_base, cp, cnt); 105 if (error) 106 goto out; 107 break; 108 case UIO_SYSSPACE: 109 if (uio->uio_rw == UIO_READ) 110 bcopy(cp, iov->iov_base, cnt); 111 else 112 bcopy(iov->iov_base, cp, cnt); 113 break; 114 case UIO_NOCOPY: 115 break; 116 } 117 iov->iov_base = (char *)iov->iov_base + cnt; 118 iov->iov_len -= cnt; 119 uio->uio_resid -= cnt; 120 uio->uio_offset += cnt; 121 offset += cnt; 122 n -= cnt; 123 } 124 out: 125 if (td != NULL && save == 0) { 126 mtx_lock_spin(&sched_lock); 127 td->td_flags &= ~TDF_DEADLKTREAT; 128 mtx_unlock_spin(&sched_lock); 129 } 130 return (error); 131 } 132