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 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
36 */
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/proc.h>
47 #include <sys/sf_buf.h>
48 #include <sys/uio.h>
49
50 #include <vm/vm.h>
51 #include <vm/vm_page.h>
52 #include <vm/vm_param.h>
53
54 #include <machine/cache.h>
55
56 /*
57 * Implement uiomove(9) from physical memory using a combination
58 * of the direct mapping and sf_bufs to reduce the creation and
59 * destruction of ephemeral mappings.
60 */
61 int
uiomove_fromphys(vm_page_t ma[],vm_offset_t offset,int n,struct uio * uio)62 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
63 {
64 struct sf_buf *sf;
65 struct thread *td = curthread;
66 struct iovec *iov;
67 void *cp;
68 vm_offset_t page_offset;
69 vm_paddr_t pa;
70 vm_page_t m;
71 size_t cnt;
72 int error = 0;
73 int save = 0;
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 = ulmin(cnt, PAGE_SIZE - page_offset);
93 m = ma[offset >> PAGE_SHIFT];
94 pa = VM_PAGE_TO_PHYS(m);
95 if (MIPS_DIRECT_MAPPABLE(pa)) {
96 sf = NULL;
97 cp = (char *)MIPS_PHYS_TO_DIRECT(pa) + page_offset;
98 /*
99 * flush all mappings to this page, KSEG0 address first
100 * in order to get it overwritten by correct data
101 */
102 mips_dcache_wbinv_range((vm_offset_t)cp, cnt);
103 pmap_flush_pvcache(m);
104 } else {
105 sf = sf_buf_alloc(m, 0);
106 cp = (char *)sf_buf_kva(sf) + page_offset;
107 }
108 switch (uio->uio_segflg) {
109 case UIO_USERSPACE:
110 maybe_yield();
111 if (uio->uio_rw == UIO_READ)
112 error = copyout(cp, iov->iov_base, cnt);
113 else
114 error = copyin(iov->iov_base, cp, cnt);
115 if (error) {
116 if (sf != NULL)
117 sf_buf_free(sf);
118 goto out;
119 }
120 break;
121 case UIO_SYSSPACE:
122 if (uio->uio_rw == UIO_READ)
123 bcopy(cp, iov->iov_base, cnt);
124 else
125 bcopy(iov->iov_base, cp, cnt);
126 break;
127 case UIO_NOCOPY:
128 break;
129 }
130 if (sf != NULL)
131 sf_buf_free(sf);
132 else
133 mips_dcache_wbinv_range((vm_offset_t)cp, cnt);
134 iov->iov_base = (char *)iov->iov_base + cnt;
135 iov->iov_len -= cnt;
136 uio->uio_resid -= cnt;
137 uio->uio_offset += cnt;
138 offset += cnt;
139 n -= cnt;
140 }
141 out:
142 if (save == 0)
143 td->td_pflags &= ~TDP_DEADLKTREAT;
144 return (error);
145 }
146