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-rw-r--r--kernel/tools/perf/tests/rdpmc.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/kernel/tools/perf/tests/rdpmc.c b/kernel/tools/perf/tests/rdpmc.c
new file mode 100644
index 000000000..d31f2c4d9
--- /dev/null
+++ b/kernel/tools/perf/tests/rdpmc.c
@@ -0,0 +1,177 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/mman.h>
+#include <linux/types.h>
+#include "perf.h"
+#include "debug.h"
+#include "tests.h"
+#include "cloexec.h"
+
+#if defined(__x86_64__) || defined(__i386__)
+
+static u64 rdpmc(unsigned int counter)
+{
+ unsigned int low, high;
+
+ asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter));
+
+ return low | ((u64)high) << 32;
+}
+
+static u64 rdtsc(void)
+{
+ unsigned int low, high;
+
+ asm volatile("rdtsc" : "=a" (low), "=d" (high));
+
+ return low | ((u64)high) << 32;
+}
+
+static u64 mmap_read_self(void *addr)
+{
+ struct perf_event_mmap_page *pc = addr;
+ u32 seq, idx, time_mult = 0, time_shift = 0;
+ u64 count, cyc = 0, time_offset = 0, enabled, running, delta;
+
+ do {
+ seq = pc->lock;
+ barrier();
+
+ enabled = pc->time_enabled;
+ running = pc->time_running;
+
+ if (enabled != running) {
+ cyc = rdtsc();
+ time_mult = pc->time_mult;
+ time_shift = pc->time_shift;
+ time_offset = pc->time_offset;
+ }
+
+ idx = pc->index;
+ count = pc->offset;
+ if (idx)
+ count += rdpmc(idx - 1);
+
+ barrier();
+ } while (pc->lock != seq);
+
+ if (enabled != running) {
+ u64 quot, rem;
+
+ quot = (cyc >> time_shift);
+ rem = cyc & ((1 << time_shift) - 1);
+ delta = time_offset + quot * time_mult +
+ ((rem * time_mult) >> time_shift);
+
+ enabled += delta;
+ if (idx)
+ running += delta;
+
+ quot = count / running;
+ rem = count % running;
+ count = quot * enabled + (rem * enabled) / running;
+ }
+
+ return count;
+}
+
+/*
+ * If the RDPMC instruction faults then signal this back to the test parent task:
+ */
+static void segfault_handler(int sig __maybe_unused,
+ siginfo_t *info __maybe_unused,
+ void *uc __maybe_unused)
+{
+ exit(-1);
+}
+
+static int __test__rdpmc(void)
+{
+ volatile int tmp = 0;
+ u64 i, loops = 1000;
+ int n;
+ int fd;
+ void *addr;
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_HARDWARE,
+ .config = PERF_COUNT_HW_INSTRUCTIONS,
+ .exclude_kernel = 1,
+ };
+ u64 delta_sum = 0;
+ struct sigaction sa;
+ char sbuf[STRERR_BUFSIZE];
+
+ sigfillset(&sa.sa_mask);
+ sa.sa_sigaction = segfault_handler;
+ sigaction(SIGSEGV, &sa, NULL);
+
+ fd = sys_perf_event_open(&attr, 0, -1, -1,
+ perf_event_open_cloexec_flag());
+ if (fd < 0) {
+ pr_err("Error: sys_perf_event_open() syscall returned "
+ "with %d (%s)\n", fd,
+ strerror_r(errno, sbuf, sizeof(sbuf)));
+ return -1;
+ }
+
+ addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0);
+ if (addr == (void *)(-1)) {
+ pr_err("Error: mmap() syscall returned with (%s)\n",
+ strerror_r(errno, sbuf, sizeof(sbuf)));
+ goto out_close;
+ }
+
+ for (n = 0; n < 6; n++) {
+ u64 stamp, now, delta;
+
+ stamp = mmap_read_self(addr);
+
+ for (i = 0; i < loops; i++)
+ tmp++;
+
+ now = mmap_read_self(addr);
+ loops *= 10;
+
+ delta = now - stamp;
+ pr_debug("%14d: %14Lu\n", n, (long long)delta);
+
+ delta_sum += delta;
+ }
+
+ munmap(addr, page_size);
+ pr_debug(" ");
+out_close:
+ close(fd);
+
+ if (!delta_sum)
+ return -1;
+
+ return 0;
+}
+
+int test__rdpmc(void)
+{
+ int status = 0;
+ int wret = 0;
+ int ret;
+ int pid;
+
+ pid = fork();
+ if (pid < 0)
+ return -1;
+
+ if (!pid) {
+ ret = __test__rdpmc();
+
+ exit(ret);
+ }
+
+ wret = waitpid(pid, &status, 0);
+ if (wret < 0 || status)
+ return -1;
+
+ return 0;
+}
+
+#endif