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 <asm/io.h>
18 
19 #include <linux/init.h>
20 #include <linux/mm.h>
21 #include <linux/types.h>
22 
23 #define SELFTEST KBUILD_MODNAME ": "
24 /**
25  * imr_self_test_result - Print result string for self test.
26  *
27  * @res:	result code - true if test passed false otherwise.
28  * @fmt:	format string.
29  * ...		variadic argument list.
30  */
31 static __printf(2, 3)
imr_self_test_result(int res,const char * fmt,...)32 void __init imr_self_test_result(int res, const char *fmt, ...)
33 {
34 	va_list vlist;
35 
36 	/* Print pass/fail. */
37 	if (res)
38 		pr_info(SELFTEST "pass ");
39 	else
40 		pr_info(SELFTEST "fail ");
41 
42 	/* Print variable string. */
43 	va_start(vlist, fmt);
44 	vprintk(fmt, vlist);
45 	va_end(vlist);
46 
47 	/* Optional warning. */
48 	WARN(res == 0, "test failed");
49 }
50 #undef SELFTEST
51 
52 /**
53  * imr_self_test
54  *
55  * Verify IMR self_test with some simple tests to verify overlap,
56  * zero sized allocations and 1 KiB sized areas.
57  *
58  */
imr_self_test(void)59 static void __init imr_self_test(void)
60 {
61 	phys_addr_t base  = virt_to_phys(&_text);
62 	size_t size = virt_to_phys(&__end_rodata) - base;
63 	const char *fmt_over = "overlapped IMR @ (0x%08lx - 0x%08lx)\n";
64 	int ret;
65 
66 	/* Test zero zero. */
67 	ret = imr_add_range(0, 0, 0, 0);
68 	imr_self_test_result(ret < 0, "zero sized IMR\n");
69 
70 	/* Test exact overlap. */
71 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
72 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
73 
74 	/* Test overlap with base inside of existing. */
75 	base += size - IMR_ALIGN;
76 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
77 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
78 
79 	/* Test overlap with end inside of existing. */
80 	base -= size + IMR_ALIGN * 2;
81 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
82 	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
83 
84 	/* Test that a 1 KiB IMR @ zero with read/write all will bomb out. */
85 	ret = imr_add_range(0, IMR_ALIGN, IMR_READ_ACCESS_ALL,
86 			    IMR_WRITE_ACCESS_ALL);
87 	imr_self_test_result(ret < 0, "1KiB IMR @ 0x00000000 - access-all\n");
88 
89 	/* Test that a 1 KiB IMR @ zero with CPU only will work. */
90 	ret = imr_add_range(0, IMR_ALIGN, IMR_CPU, IMR_CPU);
91 	imr_self_test_result(ret >= 0, "1KiB IMR @ 0x00000000 - cpu-access\n");
92 	if (ret >= 0) {
93 		ret = imr_remove_range(0, IMR_ALIGN);
94 		imr_self_test_result(ret == 0, "teardown - cpu-access\n");
95 	}
96 
97 	/* Test 2 KiB works. */
98 	size = IMR_ALIGN * 2;
99 	ret = imr_add_range(0, size, IMR_READ_ACCESS_ALL, IMR_WRITE_ACCESS_ALL);
100 	imr_self_test_result(ret >= 0, "2KiB IMR @ 0x00000000\n");
101 	if (ret >= 0) {
102 		ret = imr_remove_range(0, size);
103 		imr_self_test_result(ret == 0, "teardown 2KiB\n");
104 	}
105 }
106 
107 static const struct x86_cpu_id imr_ids[] __initconst = {
108 	X86_MATCH_VENDOR_FAM_MODEL(INTEL, 5, INTEL_FAM5_QUARK_X1000, NULL),
109 	{}
110 };
111 
112 /**
113  * imr_self_test_init - entry point for IMR driver.
114  *
115  * return: -ENODEV for no IMR support 0 if good to go.
116  */
imr_self_test_init(void)117 static int __init imr_self_test_init(void)
118 {
119 	if (x86_match_cpu(imr_ids))
120 		imr_self_test();
121 	return 0;
122 }
123 
124 /**
125  * imr_self_test_exit - exit point for IMR code.
126  *
127  * return:
128  */
129 device_initcall(imr_self_test_init);
130