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