1 // SPDX-License-Identifier: GPL-2.0
2 /**
3  * imr_selftest.c -- Intel Isolated Memory Region self-test driver
4  *
5  * Copyright(c) 2013 Intel Corporation.
6  * Copyright(c) 2015 Bryan O'Donoghue <pure.logic@nexus-software.ie>
7  *
8  * IMR self test. The purpose of this module is to run a set of tests on the
9  * IMR API to validate it's sanity. We check for overlapping, reserved
10  * addresses and setup/teardown sanity.
11  *
12  */
13 
14 #include <asm-generic/sections.h>
15 #include <asm/cpu_device_id.h>
16 #include <asm/imr.h>
17 #include <linux/init.h>
18 #include <linux/mm.h>
19 #include <linux/types.h>
20 
21 #define SELFTEST KBUILD_MODNAME ": "
22 /**
23  * imr_self_test_result - Print result string for self test.
24  *
25  * @res:	result code - true if test passed false otherwise.
26  * @fmt:	format string.
27  * ...		variadic argument list.
28  */
29 static __printf(2, 3)
30 void __init imr_self_test_result(int res, const char *fmt, ...)
31 {
32 	va_list vlist;
33 
34 	/* Print pass/fail. */
35 	if (res)
36 		pr_info(SELFTEST "pass ");
37 	else
38 		pr_info(SELFTEST "fail ");
39 
40 	/* Print variable string. */
41 	va_start(vlist, fmt);
42 	vprintk(fmt, vlist);
43 	va_end(vlist);
44 
45 	/* Optional warning. */
46 	WARN(res == 0, "test failed");
47 }
48 #undef SELFTEST
49 
50 /**
51  * imr_self_test
52  *
53  * Verify IMR self_test with some simple tests to verify overlap,
54  * zero sized allocations and 1 KiB sized areas.
55  *
56  */
57 static void __init imr_self_test(void)
58 {
59 	phys_addr_t base  = virt_to_phys(&_text);
60 	size_t size = virt_to_phys(&__end_rodata) - base;
61 	const char *fmt_over = "overlapped IMR @ (0x%08lx - 0x%08lx)\n";
62 	int ret;
63 
64 	/* Test zero zero. */
65 	ret = imr_add_range(0, 0, 0, 0);
66 	imr_self_test_result(ret < 0, "zero sized IMR\n");
67 
68 	/* Test exact overlap. */
69 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
70 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
71 
72 	/* Test overlap with base inside of existing. */
73 	base += size - IMR_ALIGN;
74 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
75 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
76 
77 	/* Test overlap with end inside of existing. */
78 	base -= size + IMR_ALIGN * 2;
79 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
80 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
81 
82 	/* Test that a 1 KiB IMR @ zero with read/write all will bomb out. */
83 	ret = imr_add_range(0, IMR_ALIGN, IMR_READ_ACCESS_ALL,
84 			    IMR_WRITE_ACCESS_ALL);
85 	imr_self_test_result(ret < 0, "1KiB IMR @ 0x00000000 - access-all\n");
86 
87 	/* Test that a 1 KiB IMR @ zero with CPU only will work. */
88 	ret = imr_add_range(0, IMR_ALIGN, IMR_CPU, IMR_CPU);
89 	imr_self_test_result(ret >= 0, "1KiB IMR @ 0x00000000 - cpu-access\n");
90 	if (ret >= 0) {
91 		ret = imr_remove_range(0, IMR_ALIGN);
92 		imr_self_test_result(ret == 0, "teardown - cpu-access\n");
93 	}
94 
95 	/* Test 2 KiB works. */
96 	size = IMR_ALIGN * 2;
97 	ret = imr_add_range(0, size, IMR_READ_ACCESS_ALL, IMR_WRITE_ACCESS_ALL);
98 	imr_self_test_result(ret >= 0, "2KiB IMR @ 0x00000000\n");
99 	if (ret >= 0) {
100 		ret = imr_remove_range(0, size);
101 		imr_self_test_result(ret == 0, "teardown 2KiB\n");
102 	}
103 }
104 
105 static const struct x86_cpu_id imr_ids[] __initconst = {
106 	{ X86_VENDOR_INTEL, 5, 9 },	/* Intel Quark SoC X1000. */
107 	{}
108 };
109 
110 /**
111  * imr_self_test_init - entry point for IMR driver.
112  *
113  * return: -ENODEV for no IMR support 0 if good to go.
114  */
115 static int __init imr_self_test_init(void)
116 {
117 	if (x86_match_cpu(imr_ids))
118 		imr_self_test();
119 	return 0;
120 }
121 
122 /**
123  * imr_self_test_exit - exit point for IMR code.
124  *
125  * return:
126  */
127 device_initcall(imr_self_test_init);
128