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("$FreeBSD$");
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
46struct mem_range_softc mem_range_softc;
47
48int
49memrw(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
125