mem.c revision 305135 
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: stable/11/sys/arm64/arm64/mem.c 305135 2016-08-31 17:30:21Z andrew $");
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	struct iovec *iov;
52	struct vm_page m;
53	vm_page_t marr;
54	vm_offset_t off, v;
55	u_int cnt;
56	int error;
57
58	error = 0;
59
60	while (uio->uio_resid > 0 && error == 0) {
61		iov = uio->uio_iov;
62		if (iov->iov_len == 0) {
63			uio->uio_iov++;
64			uio->uio_iovcnt--;
65			if (uio->uio_iovcnt < 0)
66				panic("memrw");
67			continue;
68		}
69
70		v = uio->uio_offset;
71		off = v & PAGE_MASK;
72		cnt = ulmin(iov->iov_len, PAGE_SIZE - (u_int)off);
73		if (cnt == 0)
74			continue;
75
76		switch(dev2unit(dev)) {
77		case CDEV_MINOR_KMEM:
78			/* If the address is in the DMAP just copy it */
79			if (VIRT_IN_DMAP(v)) {
80				error = uiomove((void *)v, cnt, uio);
81				break;
82			}
83
84			if (!kernacc((void *)v, cnt, uio->uio_rw == UIO_READ ?
85			    VM_PROT_READ : VM_PROT_WRITE)) {
86				error = EFAULT;
87				break;
88			}
89
90			/* Get the physical address to read */
91			v = pmap_extract(kernel_pmap, v);
92			if (v == 0) {
93				error = EFAULT;
94				break;
95			}
96
97			/* FALLTHROUGH */
98		case CDEV_MINOR_MEM:
99			/* If within the DMAP use this to copy from */
100			if (PHYS_IN_DMAP(v)) {
101				v = PHYS_TO_DMAP(v);
102				error = uiomove((void *)v, cnt, uio);
103				break;
104			}
105
106			/* Have uiomove_fromphys handle the data */
107			m.phys_addr = trunc_page(v);
108			marr = &m;
109			uiomove_fromphys(&marr, off, cnt, uio);
110			break;
111		}
112	}
113
114	return (error);
115}
116
117/*
118 * allow user processes to MMAP some memory sections
119 * instead of going through read/write
120 */
121/* ARGSUSED */
122int
123memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
124    int prot __unused, vm_memattr_t *memattr __unused)
125{
126	if (dev2unit(dev) == CDEV_MINOR_MEM)
127		*paddr = offset;
128	else if (dev2unit(dev) == CDEV_MINOR_KMEM)
129		*paddr = vtophys(offset);
130	/* else panic! */
131	return (0);
132}
133