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Diffstat (limited to 'tools/testing/selftests/powerpc/dscr/dscr_default_test.c')
-rw-r--r--tools/testing/selftests/powerpc/dscr/dscr_default_test.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/dscr/dscr_default_test.c b/tools/testing/selftests/powerpc/dscr/dscr_default_test.c
new file mode 100644
index 000000000000..df17c3bab0a7
--- /dev/null
+++ b/tools/testing/selftests/powerpc/dscr/dscr_default_test.c
@@ -0,0 +1,127 @@
+/*
+ * POWER Data Stream Control Register (DSCR) default test
+ *
+ * This test modifies the system wide default DSCR through
+ * it's sysfs interface and then verifies that all threads
+ * see the correct changed DSCR value immediately.
+ *
+ * Copyright 2012, Anton Blanchard, IBM Corporation.
+ * Copyright 2015, Anshuman Khandual, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+#include "dscr.h"
+
+static unsigned long dscr; /* System DSCR default */
+static unsigned long sequence;
+static unsigned long result[THREADS];
+
+static void *do_test(void *in)
+{
+ unsigned long thread = (unsigned long)in;
+ unsigned long i;
+
+ for (i = 0; i < COUNT; i++) {
+ unsigned long d, cur_dscr, cur_dscr_usr;
+ unsigned long s1, s2;
+
+ s1 = ACCESS_ONCE(sequence);
+ if (s1 & 1)
+ continue;
+ rmb();
+
+ d = dscr;
+ cur_dscr = get_dscr();
+ cur_dscr_usr = get_dscr_usr();
+
+ rmb();
+ s2 = sequence;
+
+ if (s1 != s2)
+ continue;
+
+ if (cur_dscr != d) {
+ fprintf(stderr, "thread %ld kernel DSCR should be %ld "
+ "but is %ld\n", thread, d, cur_dscr);
+ result[thread] = 1;
+ pthread_exit(&result[thread]);
+ }
+
+ if (cur_dscr_usr != d) {
+ fprintf(stderr, "thread %ld user DSCR should be %ld "
+ "but is %ld\n", thread, d, cur_dscr_usr);
+ result[thread] = 1;
+ pthread_exit(&result[thread]);
+ }
+ }
+ result[thread] = 0;
+ pthread_exit(&result[thread]);
+}
+
+int dscr_default(void)
+{
+ pthread_t threads[THREADS];
+ unsigned long i, *status[THREADS];
+ unsigned long orig_dscr_default;
+
+ orig_dscr_default = get_default_dscr();
+
+ /* Initial DSCR default */
+ dscr = 1;
+ set_default_dscr(dscr);
+
+ /* Spawn all testing threads */
+ for (i = 0; i < THREADS; i++) {
+ if (pthread_create(&threads[i], NULL, do_test, (void *)i)) {
+ perror("pthread_create() failed");
+ goto fail;
+ }
+ }
+
+ srand(getpid());
+
+ /* Keep changing the DSCR default */
+ for (i = 0; i < COUNT; i++) {
+ double ret = uniform_deviate(rand());
+
+ if (ret < 0.0001) {
+ sequence++;
+ wmb();
+
+ dscr++;
+ if (dscr > DSCR_MAX)
+ dscr = 0;
+
+ set_default_dscr(dscr);
+
+ wmb();
+ sequence++;
+ }
+ }
+
+ /* Individual testing thread exit status */
+ for (i = 0; i < THREADS; i++) {
+ if (pthread_join(threads[i], (void **)&(status[i]))) {
+ perror("pthread_join() failed");
+ goto fail;
+ }
+
+ if (*status[i]) {
+ printf("%ldth thread failed to join with %ld status\n",
+ i, *status[i]);
+ goto fail;
+ }
+ }
+ set_default_dscr(orig_dscr_default);
+ return 0;
+fail:
+ set_default_dscr(orig_dscr_default);
+ return 1;
+}
+
+int main(int argc, char *argv[])
+{
+ return test_harness(dscr_default, "dscr_default_test");
+}