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v5.9
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Written by Pekka Paalanen, 2008-2009 <pq@iki.fi>
  4 */
  5
  6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  7
  8#include <linux/module.h>
  9#include <linux/io.h>
 10#include <linux/mmiotrace.h>
 11#include <linux/security.h>
 12
 13static unsigned long mmio_address;
 14module_param_hw(mmio_address, ulong, iomem, 0);
 15MODULE_PARM_DESC(mmio_address, " Start address of the mapping of 16 kB "
 16				"(or 8 MB if read_far is non-zero).");
 17
 18static unsigned long read_far = 0x400100;
 19module_param(read_far, ulong, 0);
 20MODULE_PARM_DESC(read_far, " Offset of a 32-bit read within 8 MB "
 21				"(default: 0x400100).");
 22
 23static unsigned v16(unsigned i)
 24{
 25	return i * 12 + 7;
 26}
 27
 28static unsigned v32(unsigned i)
 29{
 30	return i * 212371 + 13;
 31}
 32
 33static void do_write_test(void __iomem *p)
 34{
 35	unsigned int i;
 36	pr_info("write test.\n");
 37	mmiotrace_printk("Write test.\n");
 38
 39	for (i = 0; i < 256; i++)
 40		iowrite8(i, p + i);
 41
 42	for (i = 1024; i < (5 * 1024); i += 2)
 43		iowrite16(v16(i), p + i);
 44
 45	for (i = (5 * 1024); i < (16 * 1024); i += 4)
 46		iowrite32(v32(i), p + i);
 47}
 48
 49static void do_read_test(void __iomem *p)
 50{
 51	unsigned int i;
 52	unsigned errs[3] = { 0 };
 53	pr_info("read test.\n");
 54	mmiotrace_printk("Read test.\n");
 55
 56	for (i = 0; i < 256; i++)
 57		if (ioread8(p + i) != i)
 58			++errs[0];
 59
 60	for (i = 1024; i < (5 * 1024); i += 2)
 61		if (ioread16(p + i) != v16(i))
 62			++errs[1];
 63
 64	for (i = (5 * 1024); i < (16 * 1024); i += 4)
 65		if (ioread32(p + i) != v32(i))
 66			++errs[2];
 67
 68	mmiotrace_printk("Read errors: 8-bit %d, 16-bit %d, 32-bit %d.\n",
 69						errs[0], errs[1], errs[2]);
 70}
 71
 72static void do_read_far_test(void __iomem *p)
 73{
 74	pr_info("read far test.\n");
 75	mmiotrace_printk("Read far test.\n");
 76
 77	ioread32(p + read_far);
 78}
 79
 80static void do_test(unsigned long size)
 81{
 82	void __iomem *p = ioremap(mmio_address, size);
 83	if (!p) {
 84		pr_err("could not ioremap, aborting.\n");
 85		return;
 86	}
 87	mmiotrace_printk("ioremap returned %p.\n", p);
 88	do_write_test(p);
 89	do_read_test(p);
 90	if (read_far && read_far < size - 4)
 91		do_read_far_test(p);
 92	iounmap(p);
 93}
 94
 95/*
 96 * Tests how mmiotrace behaves in face of multiple ioremap / iounmaps in
 97 * a short time. We had a bug in deferred freeing procedure which tried
 98 * to free this region multiple times (ioremap can reuse the same address
 99 * for many mappings).
100 */
101static void do_test_bulk_ioremapping(void)
102{
103	void __iomem *p;
104	int i;
105
106	for (i = 0; i < 10; ++i) {
107		p = ioremap(mmio_address, PAGE_SIZE);
108		if (p)
109			iounmap(p);
110	}
111
112	/* Force freeing. If it will crash we will know why. */
113	synchronize_rcu();
114}
115
116static int __init init(void)
117{
118	unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
119	int ret = security_locked_down(LOCKDOWN_MMIOTRACE);
120
121	if (ret)
122		return ret;
123
124	if (mmio_address == 0) {
125		pr_err("you have to use the module argument mmio_address.\n");
126		pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n");
127		return -ENXIO;
128	}
129
130	pr_warn("WARNING: mapping %lu kB @ 0x%08lx in PCI address space, "
131		"and writing 16 kB of rubbish in there.\n",
132		size >> 10, mmio_address);
133	do_test(size);
134	do_test_bulk_ioremapping();
135	pr_info("All done.\n");
136	return 0;
137}
138
139static void __exit cleanup(void)
140{
141	pr_debug("unloaded.\n");
142}
143
144module_init(init);
145module_exit(cleanup);
146MODULE_LICENSE("GPL");
v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Written by Pekka Paalanen, 2008-2009 <pq@iki.fi>
  4 */
  5
  6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  7
  8#include <linux/module.h>
  9#include <linux/io.h>
 10#include <linux/mmiotrace.h>
 11#include <linux/security.h>
 12
 13static unsigned long mmio_address;
 14module_param_hw(mmio_address, ulong, iomem, 0);
 15MODULE_PARM_DESC(mmio_address, " Start address of the mapping of 16 kB "
 16				"(or 8 MB if read_far is non-zero).");
 17
 18static unsigned long read_far = 0x400100;
 19module_param(read_far, ulong, 0);
 20MODULE_PARM_DESC(read_far, " Offset of a 32-bit read within 8 MB "
 21				"(default: 0x400100).");
 22
 23static unsigned v16(unsigned i)
 24{
 25	return i * 12 + 7;
 26}
 27
 28static unsigned v32(unsigned i)
 29{
 30	return i * 212371 + 13;
 31}
 32
 33static void do_write_test(void __iomem *p)
 34{
 35	unsigned int i;
 36	pr_info("write test.\n");
 37	mmiotrace_printk("Write test.\n");
 38
 39	for (i = 0; i < 256; i++)
 40		iowrite8(i, p + i);
 41
 42	for (i = 1024; i < (5 * 1024); i += 2)
 43		iowrite16(v16(i), p + i);
 44
 45	for (i = (5 * 1024); i < (16 * 1024); i += 4)
 46		iowrite32(v32(i), p + i);
 47}
 48
 49static void do_read_test(void __iomem *p)
 50{
 51	unsigned int i;
 52	unsigned errs[3] = { 0 };
 53	pr_info("read test.\n");
 54	mmiotrace_printk("Read test.\n");
 55
 56	for (i = 0; i < 256; i++)
 57		if (ioread8(p + i) != i)
 58			++errs[0];
 59
 60	for (i = 1024; i < (5 * 1024); i += 2)
 61		if (ioread16(p + i) != v16(i))
 62			++errs[1];
 63
 64	for (i = (5 * 1024); i < (16 * 1024); i += 4)
 65		if (ioread32(p + i) != v32(i))
 66			++errs[2];
 67
 68	mmiotrace_printk("Read errors: 8-bit %d, 16-bit %d, 32-bit %d.\n",
 69						errs[0], errs[1], errs[2]);
 70}
 71
 72static void do_read_far_test(void __iomem *p)
 73{
 74	pr_info("read far test.\n");
 75	mmiotrace_printk("Read far test.\n");
 76
 77	ioread32(p + read_far);
 78}
 79
 80static void do_test(unsigned long size)
 81{
 82	void __iomem *p = ioremap(mmio_address, size);
 83	if (!p) {
 84		pr_err("could not ioremap, aborting.\n");
 85		return;
 86	}
 87	mmiotrace_printk("ioremap returned %p.\n", p);
 88	do_write_test(p);
 89	do_read_test(p);
 90	if (read_far && read_far < size - 4)
 91		do_read_far_test(p);
 92	iounmap(p);
 93}
 94
 95/*
 96 * Tests how mmiotrace behaves in face of multiple ioremap / iounmaps in
 97 * a short time. We had a bug in deferred freeing procedure which tried
 98 * to free this region multiple times (ioremap can reuse the same address
 99 * for many mappings).
100 */
101static void do_test_bulk_ioremapping(void)
102{
103	void __iomem *p;
104	int i;
105
106	for (i = 0; i < 10; ++i) {
107		p = ioremap(mmio_address, PAGE_SIZE);
108		if (p)
109			iounmap(p);
110	}
111
112	/* Force freeing. If it will crash we will know why. */
113	synchronize_rcu();
114}
115
116static int __init init(void)
117{
118	unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
119	int ret = security_locked_down(LOCKDOWN_MMIOTRACE);
120
121	if (ret)
122		return ret;
123
124	if (mmio_address == 0) {
125		pr_err("you have to use the module argument mmio_address.\n");
126		pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n");
127		return -ENXIO;
128	}
129
130	pr_warn("WARNING: mapping %lu kB @ 0x%08lx in PCI address space, "
131		"and writing 16 kB of rubbish in there.\n",
132		size >> 10, mmio_address);
133	do_test(size);
134	do_test_bulk_ioremapping();
135	pr_info("All done.\n");
136	return 0;
137}
138
139static void __exit cleanup(void)
140{
141	pr_debug("unloaded.\n");
142}
143
144module_init(init);
145module_exit(cleanup);
146MODULE_LICENSE("GPL");