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Diffstat (limited to 'tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c')
-rw-r--r--tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c b/tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c
new file mode 100644
index 000000000000..ad9c3ec26048
--- /dev/null
+++ b/tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c
@@ -0,0 +1,71 @@
+/*
+ * POWER Data Stream Control Register (DSCR) explicit test
+ *
+ * This test modifies the DSCR value using mtspr instruction and
+ * verifies the change with mfspr instruction. It uses both the
+ * privilege state SPR and the problem state SPR for this purpose.
+ *
+ * When using the privilege state SPR, the instructions such as
+ * mfspr or mtspr are priviledged and the kernel emulates them
+ * for us. Instructions using problem state SPR can be exuecuted
+ * directly without any emulation if the HW supports them. Else
+ * they also get emulated by the kernel.
+ *
+ * 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"
+
+int dscr_explicit(void)
+{
+ unsigned long i, dscr = 0;
+
+ srand(getpid());
+ set_dscr(dscr);
+
+ for (i = 0; i < COUNT; i++) {
+ unsigned long cur_dscr, cur_dscr_usr;
+ double ret = uniform_deviate(rand());
+
+ if (ret < 0.001) {
+ dscr++;
+ if (dscr > DSCR_MAX)
+ dscr = 0;
+
+ set_dscr(dscr);
+ }
+
+ cur_dscr = get_dscr();
+ if (cur_dscr != dscr) {
+ fprintf(stderr, "Kernel DSCR should be %ld but "
+ "is %ld\n", dscr, cur_dscr);
+ return 1;
+ }
+
+ ret = uniform_deviate(rand());
+ if (ret < 0.001) {
+ dscr++;
+ if (dscr > DSCR_MAX)
+ dscr = 0;
+
+ set_dscr_usr(dscr);
+ }
+
+ cur_dscr_usr = get_dscr_usr();
+ if (cur_dscr_usr != dscr) {
+ fprintf(stderr, "User DSCR should be %ld but "
+ "is %ld\n", dscr, cur_dscr_usr);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ return test_harness(dscr_explicit, "dscr_explicit_test");
+}