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authorAnshuman Khandual <khandual@linux.vnet.ibm.com>2015-05-21 09:43:07 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2015-06-07 12:36:08 +0300
commit1554f21a9890301d1b6586474396e7c9de586204 (patch)
tree2610614525d086a565634cbd2c65c5eb0a3c7178 /tools/testing
parent4c6315f8f9387d638ccb1cc3a46a28a82a109928 (diff)
downloadlinux-1554f21a9890301d1b6586474396e7c9de586204.tar.xz
selftests/powerpc: Add test for explicitly changing DSCR value
This patch adds a test which modifies the DSCR using mtspr instruction and verifies the change using mfspr instruction. It uses both the privilege state SPR as well as the problem state SPR for the purpose. Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'tools/testing')
-rw-r--r--tools/testing/selftests/powerpc/dscr/Makefile2
-rw-r--r--tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c71
2 files changed, 72 insertions, 1 deletions
diff --git a/tools/testing/selftests/powerpc/dscr/Makefile b/tools/testing/selftests/powerpc/dscr/Makefile
index 8e975387023b..d72c3200f696 100644
--- a/tools/testing/selftests/powerpc/dscr/Makefile
+++ b/tools/testing/selftests/powerpc/dscr/Makefile
@@ -1,4 +1,4 @@
-TEST_PROGS := dscr_default_test
+TEST_PROGS := dscr_default_test dscr_explicit_test
dscr_default_test: LDLIBS += -lpthread
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");
+}