1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Written by Pekka Paalanen, 2008-2009 <pq@iki.fi>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/io.h>
#include <linux/mmiotrace.h>
#include <linux/security.h>
static unsigned long mmio_address;
module_param_hw(mmio_address, ulong, iomem, 0);
MODULE_PARM_DESC(mmio_address, " Start address of the mapping of 16 kB "
"(or 8 MB if read_far is non-zero).");
static unsigned long read_far = 0x400100;
module_param(read_far, ulong, 0);
MODULE_PARM_DESC(read_far, " Offset of a 32-bit read within 8 MB "
"(default: 0x400100).");
static unsigned v16(unsigned i)
{
return i * 12 + 7;
}
static unsigned v32(unsigned i)
{
return i * 212371 + 13;
}
static void do_write_test(void __iomem *p)
{
unsigned int i;
pr_info("write test.\n");
mmiotrace_printk("Write test.\n");
for (i = 0; i < 256; i++)
iowrite8(i, p + i);
for (i = 1024; i < (5 * 1024); i += 2)
iowrite16(v16(i), p + i);
for (i = (5 * 1024); i < (16 * 1024); i += 4)
iowrite32(v32(i), p + i);
}
static void do_read_test(void __iomem *p)
{
unsigned int i;
unsigned errs[3] = { 0 };
pr_info("read test.\n");
mmiotrace_printk("Read test.\n");
for (i = 0; i < 256; i++)
if (ioread8(p + i) != i)
++errs[0];
for (i = 1024; i < (5 * 1024); i += 2)
if (ioread16(p + i) != v16(i))
++errs[1];
for (i = (5 * 1024); i < (16 * 1024); i += 4)
if (ioread32(p + i) != v32(i))
++errs[2];
mmiotrace_printk("Read errors: 8-bit %d, 16-bit %d, 32-bit %d.\n",
errs[0], errs[1], errs[2]);
}
static void do_read_far_test(void __iomem *p)
{
pr_info("read far test.\n");
mmiotrace_printk("Read far test.\n");
ioread32(p + read_far);
}
static void do_test(unsigned long size)
{
void __iomem *p = ioremap(mmio_address, size);
if (!p) {
pr_err("could not ioremap, aborting.\n");
return;
}
mmiotrace_printk("ioremap returned %p.\n", p);
do_write_test(p);
do_read_test(p);
if (read_far && read_far < size - 4)
do_read_far_test(p);
iounmap(p);
}
/*
* Tests how mmiotrace behaves in face of multiple ioremap / iounmaps in
* a short time. We had a bug in deferred freeing procedure which tried
* to free this region multiple times (ioremap can reuse the same address
* for many mappings).
*/
static void do_test_bulk_ioremapping(void)
{
void __iomem *p;
int i;
for (i = 0; i < 10; ++i) {
p = ioremap(mmio_address, PAGE_SIZE);
if (p)
iounmap(p);
}
/* Force freeing. If it will crash we will know why. */
synchronize_rcu();
}
static int __init init(void)
{
unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
int ret = security_locked_down(LOCKDOWN_MMIOTRACE);
if (ret)
return ret;
if (mmio_address == 0) {
pr_err("you have to use the module argument mmio_address.\n");
pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n");
return -ENXIO;
}
pr_warn("WARNING: mapping %lu kB @ 0x%08lx in PCI address space, "
"and writing 16 kB of rubbish in there.\n",
size >> 10, mmio_address);
do_test(size);
do_test_bulk_ioremapping();
pr_info("All done.\n");
return 0;
}
static void __exit cleanup(void)
{
pr_debug("unloaded.\n");
}
module_init(init);
module_exit(cleanup);
MODULE_LICENSE("GPL");
|
