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 __printf(2, 3)
29 void __init imr_self_test_result(int res, const char *fmt, ...)
30 {
31 	va_list vlist;
32 
33 	/* Print pass/fail. */
34 	if (res)
35 		pr_info(SELFTEST "pass ");
36 	else
37 		pr_info(SELFTEST "fail ");
38 
39 	/* Print variable string. */
40 	va_start(vlist, fmt);
41 	vprintk(fmt, vlist);
42 	va_end(vlist);
43 
44 	/* Optional warning. */
45 	WARN(res == 0, "test failed");
46 }
47 #undef SELFTEST
48 
49 /**
50  * imr_self_test
51  *
52  * Verify IMR self_test with some simple tests to verify overlap,
53  * zero sized allocations and 1 KiB sized areas.
54  *
55  */
56 static void __init imr_self_test(void)
57 {
58 	phys_addr_t base  = virt_to_phys(&_text);
59 	size_t size = virt_to_phys(&__end_rodata) - base;
60 	const char *fmt_over = "overlapped IMR @ (0x%08lx - 0x%08lx)\n";
61 	int ret;
62 
63 	/* Test zero zero. */
64 	ret = imr_add_range(0, 0, 0, 0);
65 	imr_self_test_result(ret < 0, "zero sized IMR\n");
66 
67 	/* Test exact overlap. */
68 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
69 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
70 
71 	/* Test overlap with base inside of existing. */
72 	base += size - IMR_ALIGN;
73 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
74 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
75 
76 	/* Test overlap with end inside of existing. */
77 	base -= size + IMR_ALIGN * 2;
78 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
79 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
80 
81 	/* Test that a 1 KiB IMR @ zero with read/write all will bomb out. */
82 	ret = imr_add_range(0, IMR_ALIGN, IMR_READ_ACCESS_ALL,
83 			    IMR_WRITE_ACCESS_ALL);
84 	imr_self_test_result(ret < 0, "1KiB IMR @ 0x00000000 - access-all\n");
85 
86 	/* Test that a 1 KiB IMR @ zero with CPU only will work. */
87 	ret = imr_add_range(0, IMR_ALIGN, IMR_CPU, IMR_CPU);
88 	imr_self_test_result(ret >= 0, "1KiB IMR @ 0x00000000 - cpu-access\n");
89 	if (ret >= 0) {
90 		ret = imr_remove_range(0, IMR_ALIGN);
91 		imr_self_test_result(ret == 0, "teardown - cpu-access\n");
92 	}
93 
94 	/* Test 2 KiB works. */
95 	size = IMR_ALIGN * 2;
96 	ret = imr_add_range(0, size, IMR_READ_ACCESS_ALL, IMR_WRITE_ACCESS_ALL);
97 	imr_self_test_result(ret >= 0, "2KiB IMR @ 0x00000000\n");
98 	if (ret >= 0) {
99 		ret = imr_remove_range(0, size);
100 		imr_self_test_result(ret == 0, "teardown 2KiB\n");
101 	}
102 }
103 
104 static const struct x86_cpu_id imr_ids[] __initconst = {
105 	{ X86_VENDOR_INTEL, 5, 9 },	/* Intel Quark SoC X1000. */
106 	{}
107 };
108 
109 /**
110  * imr_self_test_init - entry point for IMR driver.
111  *
112  * return: -ENODEV for no IMR support 0 if good to go.
113  */
114 static int __init imr_self_test_init(void)
115 {
116 	if (x86_match_cpu(imr_ids))
117 		imr_self_test();
118 	return 0;
119 }
120 
121 /**
122  * imr_self_test_exit - exit point for IMR code.
123  *
124  * return:
125  */
126 device_initcall(imr_self_test_init);
127