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 its 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