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: releng/12.0/sys/powerpc/powerpc/uio_machdep.c 326023 2017-11-20 19:43:44Z pfg $");
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/proc.h>
49 #include <sys/uio.h>
50 #include <sys/sf_buf.h>
51
52 #include <vm/vm.h>
53 #include <vm/vm_page.h>
54
55 #include <machine/cpu.h>
56 #include <machine/vmparam.h>
57 #include <machine/md_var.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 vm_page_t m;
71 size_t cnt;
72 int error = 0;
73 int save = 0;
74 struct sf_buf *sf;
75
76 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
77 ("uiomove_fromphys: mode"));
78 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
79 ("uiomove_fromphys proc"));
80
81 save = td->td_pflags & TDP_DEADLKTREAT;
82 td->td_pflags |= TDP_DEADLKTREAT;
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
96 m = ma[offset >> PAGE_SHIFT];
97 sf = sf_buf_alloc(m, 0);
98 cp = (char*)sf_buf_kva(sf) + page_offset;
99
100 switch (uio->uio_segflg) {
101 case UIO_USERSPACE:
102 maybe_yield();
103 if (uio->uio_rw == UIO_READ)
104 error = copyout(cp, iov->iov_base, cnt);
105 else
106 error = copyin(iov->iov_base, cp, cnt);
107 if (error) {
108 sf_buf_free(sf);
109 goto out;
110 }
111 break;
112 case UIO_SYSSPACE:
113 if (uio->uio_rw == UIO_READ)
114 bcopy(cp, iov->iov_base, cnt);
115 else
116 bcopy(iov->iov_base, cp, cnt);
117 break;
118 case UIO_NOCOPY:
119 break;
120 }
121 sf_buf_free(sf);
122 iov->iov_base = (char *)iov->iov_base + cnt;
123 iov->iov_len -= cnt;
124 uio->uio_resid -= cnt;
125 uio->uio_offset += cnt;
126 offset += cnt;
127 n -= cnt;
128 }
129 out:
130 if (save == 0)
131 td->td_pflags &= ~TDP_DEADLKTREAT;
132 return (error);
133 }
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