From 1554f21a9890301d1b6586474396e7c9de586204 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 21 May 2015 12:13:07 +0530 Subject: [PATCH] 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 Signed-off-by: Anshuman Khandual Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman --- tools/testing/selftests/powerpc/dscr/Makefile | 2 +- .../powerpc/dscr/dscr_explicit_test.c | 71 +++++++++++++++++++ 2 files changed, 72 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c 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"); +} -- 2.30.2