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: stable/12/sys/mips/mips/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/sf_buf.h>
50 #include <sys/uio.h>
51
52 #include <vm/vm.h>
53 #include <vm/vm_page.h>
54 #include <vm/vm_param.h>
55
56 #include <machine/cache.h>
57
58 /*
59 * Implement uiomove(9) from physical memory using a combination
60 * of the direct mapping and sf_bufs to reduce the creation and
61 * destruction of ephemeral mappings.
62 */
63 int
uiomove_fromphys(vm_page_t ma[],vm_offset_t offset,int n,struct uio * uio)64 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
65 {
66 struct sf_buf *sf;
67 struct thread *td = curthread;
68 struct iovec *iov;
69 void *cp;
70 vm_offset_t page_offset;
71 vm_paddr_t pa;
72 vm_page_t m;
73 size_t cnt;
74 int error = 0;
75 int save = 0;
76
77 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
78 ("uiomove_fromphys: mode"));
79 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
80 ("uiomove_fromphys proc"));
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 = ulmin(cnt, PAGE_SIZE - page_offset);
95 m = ma[offset >> PAGE_SHIFT];
96 pa = VM_PAGE_TO_PHYS(m);
97 if (MIPS_DIRECT_MAPPABLE(pa)) {
98 sf = NULL;
99 cp = (char *)MIPS_PHYS_TO_DIRECT(pa) + page_offset;
100 /*
101 * flush all mappings to this page, KSEG0 address first
102 * in order to get it overwritten by correct data
103 */
104 mips_dcache_wbinv_range((vm_offset_t)cp, cnt);
105 pmap_flush_pvcache(m);
106 } else {
107 sf = sf_buf_alloc(m, 0);
108 cp = (char *)sf_buf_kva(sf) + page_offset;
109 }
110 switch (uio->uio_segflg) {
111 case UIO_USERSPACE:
112 maybe_yield();
113 if (uio->uio_rw == UIO_READ)
114 error = copyout(cp, iov->iov_base, cnt);
115 else
116 error = copyin(iov->iov_base, cp, cnt);
117 if (error) {
118 if (sf != NULL)
119 sf_buf_free(sf);
120 goto out;
121 }
122 break;
123 case UIO_SYSSPACE:
124 if (uio->uio_rw == UIO_READ)
125 bcopy(cp, iov->iov_base, cnt);
126 else
127 bcopy(iov->iov_base, cp, cnt);
128 break;
129 case UIO_NOCOPY:
130 break;
131 }
132 if (sf != NULL)
133 sf_buf_free(sf);
134 else
135 mips_dcache_wbinv_range((vm_offset_t)cp, cnt);
136 iov->iov_base = (char *)iov->iov_base + cnt;
137 iov->iov_len -= cnt;
138 uio->uio_resid -= cnt;
139 uio->uio_offset += cnt;
140 offset += cnt;
141 n -= cnt;
142 }
143 out:
144 if (save == 0)
145 td->td_pflags &= ~TDP_DEADLKTREAT;
146 return (error);
147 }
148