selftests/powerpc: Add test for DSCR SPR numbers

This patch adds a test which verifies that the DSCR privilege and
problem state SPR read & write accesses while making sure that the
results are always the same irrespective of which SPR number is being
used.

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>

diff --git a/tools/testing/selftests/powerpc/dscr/Makefile b/tools/testing/selftests/powerpc/dscr/Makefile
index d72c3200f696a0614ede31b8d0aa8f19c29dd4dd..3c3856be6bf9ed6fba84773284ef10bf5069eddd 100644 (file)
--- a/tools/testing/selftests/powerpc/dscr/Makefile
+++ b/tools/testing/selftests/powerpc/dscr/Makefile
@@ -1,4 +1,4 @@
-TEST_PROGS := dscr_default_test dscr_explicit_test
+TEST_PROGS := dscr_default_test dscr_explicit_test dscr_user_test
 
 dscr_default_test: LDLIBS += -lpthread
 

diff --git a/tools/testing/selftests/powerpc/dscr/dscr_user_test.c b/tools/testing/selftests/powerpc/dscr/dscr_user_test.c
new file mode 100644 (file)
index 0000000..77d16b5
--- /dev/null
+++ b/tools/testing/selftests/powerpc/dscr/dscr_user_test.c
@@ -0,0 +1,61 @@
+/*
+ * POWER Data Stream Control Register (DSCR) SPR test
+ *
+ * This test modifies the DSCR value through both the SPR number
+ * based mtspr instruction and then makes sure that the same is
+ * reflected through mfspr instruction using either of the SPR
+ * numbers.
+ *
+ * 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 2013, 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 int check_dscr(char *str)
+{
+       unsigned long cur_dscr, cur_dscr_usr;
+
+       cur_dscr = get_dscr();
+       cur_dscr_usr = get_dscr_usr();
+       if (cur_dscr != cur_dscr_usr) {
+               printf("%s set, kernel get %lx != user get %lx\n",
+                                       str, cur_dscr, cur_dscr_usr);
+               return 1;
+       }
+       return 0;
+}
+
+int dscr_user(void)
+{
+       int i;
+
+       check_dscr("");
+
+       for (i = 0; i < COUNT; i++) {
+               set_dscr(i);
+               if (check_dscr("kernel"))
+                       return 1;
+       }
+
+       for (i = 0; i < COUNT; i++) {
+               set_dscr_usr(i);
+               if (check_dscr("user"))
+                       return 1;
+       }
+       return 0;
+}
+
+int main(int argc, char *argv[])
+{
+       return test_harness(dscr_user, "dscr_user_test");
+}