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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
10ca87fd | 2 | #include <errno.h> |
bacf7e5d JO |
3 | #include <unistd.h> |
4 | #include <stdlib.h> | |
5 | #include <signal.h> | |
6 | #include <sys/mman.h> | |
10ca87fd ACM |
7 | #include <sys/types.h> |
8 | #include <sys/wait.h> | |
d944c4ee | 9 | #include <linux/types.h> |
bacf7e5d JO |
10 | #include "perf.h" |
11 | #include "debug.h" | |
d8b167f9 | 12 | #include "tests/tests.h" |
57480d2c | 13 | #include "cloexec.h" |
10ca87fd | 14 | #include "util.h" |
d8b167f9 | 15 | #include "arch-tests.h" |
bacf7e5d | 16 | |
bacf7e5d JO |
17 | static u64 rdpmc(unsigned int counter) |
18 | { | |
19 | unsigned int low, high; | |
20 | ||
21 | asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter)); | |
22 | ||
23 | return low | ((u64)high) << 32; | |
24 | } | |
25 | ||
26 | static u64 rdtsc(void) | |
27 | { | |
28 | unsigned int low, high; | |
29 | ||
30 | asm volatile("rdtsc" : "=a" (low), "=d" (high)); | |
31 | ||
32 | return low | ((u64)high) << 32; | |
33 | } | |
34 | ||
35 | static u64 mmap_read_self(void *addr) | |
36 | { | |
37 | struct perf_event_mmap_page *pc = addr; | |
38 | u32 seq, idx, time_mult = 0, time_shift = 0; | |
39 | u64 count, cyc = 0, time_offset = 0, enabled, running, delta; | |
40 | ||
41 | do { | |
42 | seq = pc->lock; | |
43 | barrier(); | |
44 | ||
45 | enabled = pc->time_enabled; | |
46 | running = pc->time_running; | |
47 | ||
48 | if (enabled != running) { | |
49 | cyc = rdtsc(); | |
50 | time_mult = pc->time_mult; | |
51 | time_shift = pc->time_shift; | |
52 | time_offset = pc->time_offset; | |
53 | } | |
54 | ||
55 | idx = pc->index; | |
56 | count = pc->offset; | |
57 | if (idx) | |
58 | count += rdpmc(idx - 1); | |
59 | ||
60 | barrier(); | |
61 | } while (pc->lock != seq); | |
62 | ||
63 | if (enabled != running) { | |
64 | u64 quot, rem; | |
65 | ||
66 | quot = (cyc >> time_shift); | |
a23f96ee | 67 | rem = cyc & (((u64)1 << time_shift) - 1); |
bacf7e5d JO |
68 | delta = time_offset + quot * time_mult + |
69 | ((rem * time_mult) >> time_shift); | |
70 | ||
71 | enabled += delta; | |
72 | if (idx) | |
73 | running += delta; | |
74 | ||
75 | quot = count / running; | |
76 | rem = count % running; | |
77 | count = quot * enabled + (rem * enabled) / running; | |
78 | } | |
79 | ||
80 | return count; | |
81 | } | |
82 | ||
83 | /* | |
84 | * If the RDPMC instruction faults then signal this back to the test parent task: | |
85 | */ | |
86 | static void segfault_handler(int sig __maybe_unused, | |
87 | siginfo_t *info __maybe_unused, | |
88 | void *uc __maybe_unused) | |
89 | { | |
90 | exit(-1); | |
91 | } | |
92 | ||
93 | static int __test__rdpmc(void) | |
94 | { | |
95 | volatile int tmp = 0; | |
96 | u64 i, loops = 1000; | |
97 | int n; | |
98 | int fd; | |
99 | void *addr; | |
100 | struct perf_event_attr attr = { | |
101 | .type = PERF_TYPE_HARDWARE, | |
102 | .config = PERF_COUNT_HW_INSTRUCTIONS, | |
103 | .exclude_kernel = 1, | |
104 | }; | |
105 | u64 delta_sum = 0; | |
106 | struct sigaction sa; | |
ba3dfff8 | 107 | char sbuf[STRERR_BUFSIZE]; |
bacf7e5d JO |
108 | |
109 | sigfillset(&sa.sa_mask); | |
110 | sa.sa_sigaction = segfault_handler; | |
e17a0e16 | 111 | sa.sa_flags = 0; |
bacf7e5d JO |
112 | sigaction(SIGSEGV, &sa, NULL); |
113 | ||
57480d2c YD |
114 | fd = sys_perf_event_open(&attr, 0, -1, -1, |
115 | perf_event_open_cloexec_flag()); | |
bacf7e5d JO |
116 | if (fd < 0) { |
117 | pr_err("Error: sys_perf_event_open() syscall returned " | |
ba3dfff8 | 118 | "with %d (%s)\n", fd, |
c8b5f2c9 | 119 | str_error_r(errno, sbuf, sizeof(sbuf))); |
bacf7e5d JO |
120 | return -1; |
121 | } | |
122 | ||
123 | addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0); | |
124 | if (addr == (void *)(-1)) { | |
125 | pr_err("Error: mmap() syscall returned with (%s)\n", | |
c8b5f2c9 | 126 | str_error_r(errno, sbuf, sizeof(sbuf))); |
bacf7e5d JO |
127 | goto out_close; |
128 | } | |
129 | ||
130 | for (n = 0; n < 6; n++) { | |
131 | u64 stamp, now, delta; | |
132 | ||
133 | stamp = mmap_read_self(addr); | |
134 | ||
135 | for (i = 0; i < loops; i++) | |
136 | tmp++; | |
137 | ||
138 | now = mmap_read_self(addr); | |
139 | loops *= 10; | |
140 | ||
141 | delta = now - stamp; | |
142 | pr_debug("%14d: %14Lu\n", n, (long long)delta); | |
143 | ||
144 | delta_sum += delta; | |
145 | } | |
146 | ||
147 | munmap(addr, page_size); | |
148 | pr_debug(" "); | |
149 | out_close: | |
150 | close(fd); | |
151 | ||
152 | if (!delta_sum) | |
153 | return -1; | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
81f17c90 | 158 | int test__rdpmc(struct test *test __maybe_unused, int subtest __maybe_unused) |
bacf7e5d JO |
159 | { |
160 | int status = 0; | |
161 | int wret = 0; | |
162 | int ret; | |
163 | int pid; | |
164 | ||
165 | pid = fork(); | |
166 | if (pid < 0) | |
167 | return -1; | |
168 | ||
169 | if (!pid) { | |
170 | ret = __test__rdpmc(); | |
171 | ||
172 | exit(ret); | |
173 | } | |
174 | ||
175 | wret = waitpid(pid, &status, 0); | |
176 | if (wret < 0 || status) | |
177 | return -1; | |
178 | ||
179 | return 0; | |
180 | } |