1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Written by Pekka Paalanen, 2008-2009 <pq@iki.fi>
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/module.h>
9*4882a593Smuzhiyun #include <linux/io.h>
10*4882a593Smuzhiyun #include <linux/mmiotrace.h>
11*4882a593Smuzhiyun #include <linux/security.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun static unsigned long mmio_address;
14*4882a593Smuzhiyun module_param_hw(mmio_address, ulong, iomem, 0);
15*4882a593Smuzhiyun MODULE_PARM_DESC(mmio_address, " Start address of the mapping of 16 kB "
16*4882a593Smuzhiyun "(or 8 MB if read_far is non-zero).");
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun static unsigned long read_far = 0x400100;
19*4882a593Smuzhiyun module_param(read_far, ulong, 0);
20*4882a593Smuzhiyun MODULE_PARM_DESC(read_far, " Offset of a 32-bit read within 8 MB "
21*4882a593Smuzhiyun "(default: 0x400100).");
22*4882a593Smuzhiyun
v16(unsigned i)23*4882a593Smuzhiyun static unsigned v16(unsigned i)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun return i * 12 + 7;
26*4882a593Smuzhiyun }
27*4882a593Smuzhiyun
v32(unsigned i)28*4882a593Smuzhiyun static unsigned v32(unsigned i)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun return i * 212371 + 13;
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun
do_write_test(void __iomem * p)33*4882a593Smuzhiyun static void do_write_test(void __iomem *p)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun unsigned int i;
36*4882a593Smuzhiyun pr_info("write test.\n");
37*4882a593Smuzhiyun mmiotrace_printk("Write test.\n");
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun for (i = 0; i < 256; i++)
40*4882a593Smuzhiyun iowrite8(i, p + i);
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun for (i = 1024; i < (5 * 1024); i += 2)
43*4882a593Smuzhiyun iowrite16(v16(i), p + i);
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun for (i = (5 * 1024); i < (16 * 1024); i += 4)
46*4882a593Smuzhiyun iowrite32(v32(i), p + i);
47*4882a593Smuzhiyun }
48*4882a593Smuzhiyun
do_read_test(void __iomem * p)49*4882a593Smuzhiyun static void do_read_test(void __iomem *p)
50*4882a593Smuzhiyun {
51*4882a593Smuzhiyun unsigned int i;
52*4882a593Smuzhiyun unsigned errs[3] = { 0 };
53*4882a593Smuzhiyun pr_info("read test.\n");
54*4882a593Smuzhiyun mmiotrace_printk("Read test.\n");
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun for (i = 0; i < 256; i++)
57*4882a593Smuzhiyun if (ioread8(p + i) != i)
58*4882a593Smuzhiyun ++errs[0];
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun for (i = 1024; i < (5 * 1024); i += 2)
61*4882a593Smuzhiyun if (ioread16(p + i) != v16(i))
62*4882a593Smuzhiyun ++errs[1];
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun for (i = (5 * 1024); i < (16 * 1024); i += 4)
65*4882a593Smuzhiyun if (ioread32(p + i) != v32(i))
66*4882a593Smuzhiyun ++errs[2];
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun mmiotrace_printk("Read errors: 8-bit %d, 16-bit %d, 32-bit %d.\n",
69*4882a593Smuzhiyun errs[0], errs[1], errs[2]);
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun
do_read_far_test(void __iomem * p)72*4882a593Smuzhiyun static void do_read_far_test(void __iomem *p)
73*4882a593Smuzhiyun {
74*4882a593Smuzhiyun pr_info("read far test.\n");
75*4882a593Smuzhiyun mmiotrace_printk("Read far test.\n");
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun ioread32(p + read_far);
78*4882a593Smuzhiyun }
79*4882a593Smuzhiyun
do_test(unsigned long size)80*4882a593Smuzhiyun static void do_test(unsigned long size)
81*4882a593Smuzhiyun {
82*4882a593Smuzhiyun void __iomem *p = ioremap(mmio_address, size);
83*4882a593Smuzhiyun if (!p) {
84*4882a593Smuzhiyun pr_err("could not ioremap, aborting.\n");
85*4882a593Smuzhiyun return;
86*4882a593Smuzhiyun }
87*4882a593Smuzhiyun mmiotrace_printk("ioremap returned %p.\n", p);
88*4882a593Smuzhiyun do_write_test(p);
89*4882a593Smuzhiyun do_read_test(p);
90*4882a593Smuzhiyun if (read_far && read_far < size - 4)
91*4882a593Smuzhiyun do_read_far_test(p);
92*4882a593Smuzhiyun iounmap(p);
93*4882a593Smuzhiyun }
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun /*
96*4882a593Smuzhiyun * Tests how mmiotrace behaves in face of multiple ioremap / iounmaps in
97*4882a593Smuzhiyun * a short time. We had a bug in deferred freeing procedure which tried
98*4882a593Smuzhiyun * to free this region multiple times (ioremap can reuse the same address
99*4882a593Smuzhiyun * for many mappings).
100*4882a593Smuzhiyun */
do_test_bulk_ioremapping(void)101*4882a593Smuzhiyun static void do_test_bulk_ioremapping(void)
102*4882a593Smuzhiyun {
103*4882a593Smuzhiyun void __iomem *p;
104*4882a593Smuzhiyun int i;
105*4882a593Smuzhiyun
106*4882a593Smuzhiyun for (i = 0; i < 10; ++i) {
107*4882a593Smuzhiyun p = ioremap(mmio_address, PAGE_SIZE);
108*4882a593Smuzhiyun if (p)
109*4882a593Smuzhiyun iounmap(p);
110*4882a593Smuzhiyun }
111*4882a593Smuzhiyun
112*4882a593Smuzhiyun /* Force freeing. If it will crash we will know why. */
113*4882a593Smuzhiyun synchronize_rcu();
114*4882a593Smuzhiyun }
115*4882a593Smuzhiyun
init(void)116*4882a593Smuzhiyun static int __init init(void)
117*4882a593Smuzhiyun {
118*4882a593Smuzhiyun unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
119*4882a593Smuzhiyun int ret = security_locked_down(LOCKDOWN_MMIOTRACE);
120*4882a593Smuzhiyun
121*4882a593Smuzhiyun if (ret)
122*4882a593Smuzhiyun return ret;
123*4882a593Smuzhiyun
124*4882a593Smuzhiyun if (mmio_address == 0) {
125*4882a593Smuzhiyun pr_err("you have to use the module argument mmio_address.\n");
126*4882a593Smuzhiyun pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n");
127*4882a593Smuzhiyun return -ENXIO;
128*4882a593Smuzhiyun }
129*4882a593Smuzhiyun
130*4882a593Smuzhiyun pr_warn("WARNING: mapping %lu kB @ 0x%08lx in PCI address space, "
131*4882a593Smuzhiyun "and writing 16 kB of rubbish in there.\n",
132*4882a593Smuzhiyun size >> 10, mmio_address);
133*4882a593Smuzhiyun do_test(size);
134*4882a593Smuzhiyun do_test_bulk_ioremapping();
135*4882a593Smuzhiyun pr_info("All done.\n");
136*4882a593Smuzhiyun return 0;
137*4882a593Smuzhiyun }
138*4882a593Smuzhiyun
cleanup(void)139*4882a593Smuzhiyun static void __exit cleanup(void)
140*4882a593Smuzhiyun {
141*4882a593Smuzhiyun pr_debug("unloaded.\n");
142*4882a593Smuzhiyun }
143*4882a593Smuzhiyun
144*4882a593Smuzhiyun module_init(init);
145*4882a593Smuzhiyun module_exit(cleanup);
146*4882a593Smuzhiyun MODULE_LICENSE("GPL");
147