FreeBSD/Linux Kernel Cross Reference
sys/riscv/riscv/mem.c
1 /*-
2 * Copyright (c) 2014 Andrew Turner
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD: releng/12.0/sys/riscv/riscv/mem.c 295041 2016-01-29 15:12:31Z br $");
30
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/conf.h>
34 #include <sys/malloc.h>
35 #include <sys/memrange.h>
36 #include <sys/uio.h>
37
38 #include <machine/memdev.h>
39 #include <machine/vmparam.h>
40
41 #include <vm/vm.h>
42 #include <vm/pmap.h>
43 #include <vm/vm_extern.h>
44 #include <vm/vm_page.h>
45
46 struct mem_range_softc mem_range_softc;
47
48 int
49 memrw(struct cdev *dev, struct uio *uio, int flags)
50 {
51 ssize_t orig_resid;
52 vm_offset_t off, v;
53 struct iovec *iov;
54 struct vm_page m;
55 vm_page_t marr;
56 u_int cnt;
57 int error;
58
59 error = 0;
60 orig_resid = uio->uio_resid;
61 while (uio->uio_resid > 0 && error == 0) {
62 iov = uio->uio_iov;
63 if (iov->iov_len == 0) {
64 uio->uio_iov++;
65 uio->uio_iovcnt--;
66 if (uio->uio_iovcnt < 0)
67 panic("memrw");
68 continue;
69 }
70
71 v = uio->uio_offset;
72 off = v & PAGE_MASK;
73 cnt = ulmin(iov->iov_len, PAGE_SIZE - (u_int)off);
74 if (cnt == 0)
75 continue;
76
77 switch(dev2unit(dev)) {
78 case CDEV_MINOR_KMEM:
79 /* If the address is in the DMAP just copy it */
80 if (VIRT_IN_DMAP(v)) {
81 error = uiomove((void *)v, cnt, uio);
82 break;
83 }
84
85 if (!kernacc((void *)v, cnt, uio->uio_rw == UIO_READ ?
86 VM_PROT_READ : VM_PROT_WRITE)) {
87 error = EFAULT;
88 break;
89 }
90
91 /* Get the physical address to read */
92 v = pmap_extract(kernel_pmap, v);
93 if (v == 0) {
94 error = EFAULT;
95 break;
96 }
97
98 /* FALLTHROUGH */
99 case CDEV_MINOR_MEM:
100 /* If within the DMAP use this to copy from */
101 if (PHYS_IN_DMAP(v)) {
102 v = PHYS_TO_DMAP(v);
103 error = uiomove((void *)v, cnt, uio);
104 break;
105 }
106
107 /* Have uiomove_fromphys handle the data */
108 m.phys_addr = trunc_page(v);
109 marr = &m;
110 uiomove_fromphys(&marr, off, cnt, uio);
111 break;
112 }
113 }
114
115 /*
116 * Don't return error if any byte was written. Read and write
117 * can return error only if no i/o was performed.
118 */
119 if (uio->uio_resid != orig_resid)
120 error = 0;
121
122 return (error);
123 }
124
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