1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu> 5 * Copyright (c) 1982, 1986, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 38 */ 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include <sys/param.h> 44 #include <sys/kernel.h> 45 #include <sys/lock.h> 46 #include <sys/mutex.h> 47 #include <sys/proc.h> 48 #include <sys/systm.h> 49 #include <sys/uio.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_page.h> 53 54 #include <machine/vmparam.h> 55 56 /* 57 * Implement uiomove(9) from physical memory using the direct map to 58 * avoid the creation and destruction of ephemeral mappings. 59 */ 60 int 61 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio) 62 { 63 struct thread *td = curthread; 64 struct iovec *iov; 65 void *cp; 66 vm_offset_t page_offset, vaddr; 67 size_t cnt; 68 int error = 0; 69 int save = 0; 70 boolean_t mapped; 71 72 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 73 ("uiomove_fromphys: mode")); 74 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 75 ("uiomove_fromphys proc")); 76 save = td->td_pflags & TDP_DEADLKTREAT; 77 td->td_pflags |= TDP_DEADLKTREAT; 78 mapped = FALSE; 79 while (n > 0 && uio->uio_resid) { 80 iov = uio->uio_iov; 81 cnt = iov->iov_len; 82 if (cnt == 0) { 83 uio->uio_iov++; 84 uio->uio_iovcnt--; 85 continue; 86 } 87 if (cnt > n) 88 cnt = n; 89 page_offset = offset & PAGE_MASK; 90 cnt = min(cnt, PAGE_SIZE - page_offset); 91 if (uio->uio_segflg != UIO_NOCOPY) { 92 mapped = pmap_map_io_transient( 93 &ma[offset >> PAGE_SHIFT], &vaddr, 1, TRUE); 94 cp = (char *)vaddr + page_offset; 95 } 96 switch (uio->uio_segflg) { 97 case UIO_USERSPACE: 98 maybe_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 if (__predict_false(mapped)) { 116 pmap_unmap_io_transient(&ma[offset >> PAGE_SHIFT], 117 &vaddr, 1, TRUE); 118 mapped = FALSE; 119 } 120 iov->iov_base = (char *)iov->iov_base + cnt; 121 iov->iov_len -= cnt; 122 uio->uio_resid -= cnt; 123 uio->uio_offset += cnt; 124 offset += cnt; 125 n -= cnt; 126 } 127 out: 128 if (__predict_false(mapped)) 129 pmap_unmap_io_transient(&ma[offset >> PAGE_SHIFT], &vaddr, 1, 130 TRUE); 131 if (save == 0) 132 td->td_pflags &= ~TDP_DEADLKTREAT; 133 return (error); 134 } 135