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