timing_test: Add cpuid and iret_to_self modes
Signed-off-by: Andy Lutomirski <luto@kernel.org>
diff --git a/timing_test.cc b/timing_test.cc
index ff8062e..1ad1b43 100644
--- a/timing_test.cc
+++ b/timing_test.cc
@@ -52,6 +52,40 @@
return NULL;
}
+static void iret_to_self(void)
+{
+#ifndef __x86_64__
+ register void *__sp asm("esp");
+
+ asm volatile (
+ "pushl %%ss\n\t"
+ "pushl %%esp\n\t"
+ "addl $4, (%%esp)\n\t"
+ "pushfl\n\t"
+ "pushl %%cs\n\t"
+ "pushl $1f\n\t"
+ "iret\n\t"
+ "1:"
+ : "+r" (__sp) : : "cc");
+#else
+ register void *__sp asm("rsp");
+ unsigned long tmp;
+
+ asm volatile (
+ "movq %%ss, %0\n\t"
+ "pushq %0\n\t"
+ "pushq %%rsp\n\t"
+ "addq $8, (%%rsp)\n\t"
+ "pushfq\n\t"
+ "movq %%cs, %0\n\t"
+ "pushq %0\n\t"
+ "pushq $1f\n\t"
+ "iretq\n\t"
+ "1:"
+ : "=r" (tmp), "+r" (__sp) : : "cc");
+#endif
+}
+
int main(int argc, char **argv)
{
if (argc < 3) {
@@ -303,6 +337,14 @@
err(1, "pthread_create");
pthread_join(thread, NULL);
}
+ } else if (!strcmp(mode, "iret_to_self")) {
+ for (size_t i = 0; i < loops; ++i)
+ iret_to_self();
+ } else if (!strcmp(mode, "cpuid")) {
+ for (size_t i = 0; i < loops; ++i) {
+ unsigned int ax = 1, cx = 0;
+ asm volatile ("cpuid" : "+a" (ax), "+c" (cx) : : "ebx", "edx");
+ }
} else {
printf("Unknown mode %s\n", mode);
return 1;
