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. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/param.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/proc.h>
41 #include <sys/systm.h>
42 #include <sys/uio.h>
43
44 #include <vm/vm.h>
45 #include <vm/vm_page.h>
46
47 #include <machine/vmparam.h>
48
49 /*
50 * Implement uiomove(9) from physical memory using the direct map to
51 * avoid the creation and destruction of ephemeral mappings.
52 */
53 int
uiomove_fromphys(vm_page_t ma[],vm_offset_t offset,int n,struct uio * uio)54 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
55 {
56 struct thread *td = curthread;
57 struct iovec *iov;
58 void *cp;
59 vm_offset_t page_offset, vaddr;
60 size_t cnt;
61 int error = 0;
62 int save = 0;
63 bool mapped;
64
65 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
66 ("uiomove_fromphys: mode"));
67 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
68 ("uiomove_fromphys proc"));
69 KASSERT(uio->uio_resid >= 0,
70 ("%s: uio %p resid underflow", __func__, uio));
71
72 save = td->td_pflags & TDP_DEADLKTREAT;
73 td->td_pflags |= TDP_DEADLKTREAT;
74 mapped = false;
75 while (n > 0 && uio->uio_resid) {
76 KASSERT(uio->uio_iovcnt > 0,
77 ("%s: uio %p iovcnt underflow", __func__, uio));
78
79 iov = uio->uio_iov;
80 cnt = iov->iov_len;
81 if (cnt == 0) {
82 uio->uio_iov++;
83 uio->uio_iovcnt--;
84 continue;
85 }
86 if (cnt > n)
87 cnt = n;
88 page_offset = offset & PAGE_MASK;
89 cnt = min(cnt, PAGE_SIZE - page_offset);
90 if (uio->uio_segflg != UIO_NOCOPY) {
91 mapped = pmap_map_io_transient(
92 &ma[offset >> PAGE_SHIFT], &vaddr, 1, true);
93 cp = (char *)vaddr + page_offset;
94 }
95 switch (uio->uio_segflg) {
96 case UIO_USERSPACE:
97 maybe_yield();
98 if (uio->uio_rw == UIO_READ)
99 error = copyout(cp, iov->iov_base, cnt);
100 else
101 error = copyin(iov->iov_base, cp, cnt);
102 if (error)
103 goto out;
104 break;
105 case UIO_SYSSPACE:
106 if (uio->uio_rw == UIO_READ)
107 bcopy(cp, iov->iov_base, cnt);
108 else
109 bcopy(iov->iov_base, cp, cnt);
110 break;
111 case UIO_NOCOPY:
112 break;
113 }
114 if (__predict_false(mapped)) {
115 pmap_unmap_io_transient(&ma[offset >> PAGE_SHIFT],
116 &vaddr, 1, true);
117 mapped = false;
118 }
119 iov->iov_base = (char *)iov->iov_base + cnt;
120 iov->iov_len -= cnt;
121 uio->uio_resid -= cnt;
122 uio->uio_offset += cnt;
123 offset += cnt;
124 n -= cnt;
125 }
126 out:
127 if (__predict_false(mapped)) {
128 panic("TODO 3");
129 pmap_unmap_io_transient(&ma[offset >> PAGE_SHIFT], &vaddr, 1,
130 true);
131 }
132 if (save == 0)
133 td->td_pflags &= ~TDP_DEADLKTREAT;
134 return (error);
135 }
136