From 4c6315f8f9387d638ccb1cc3a46a28a82a109928 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 21 May 2015 12:13:06 +0530 Subject: selftests/powerpc: Add test for system wide DSCR default This patch adds a test case for the system wide DSCR default value, which when changed through it's sysfs interface must be visible to all threads reading DSCR either through the privilege state SPR or the problem state SPR. The DSCR value change should be immediate as well. Acked-by: Shuah Khan Signed-off-by: Anshuman Khandual Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman --- .../selftests/powerpc/dscr/dscr_default_test.c | 127 +++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 tools/testing/selftests/powerpc/dscr/dscr_default_test.c (limited to 'tools/testing/selftests/powerpc/dscr/dscr_default_test.c') 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"); +} -- cgit v1.2.3-59-g8ed1b