diff options
| -rw-r--r-- | tools/testing/selftests/powerpc/dscr/Makefile | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c | 95 |
2 files changed, 97 insertions, 1 deletions
diff --git a/tools/testing/selftests/powerpc/dscr/Makefile b/tools/testing/selftests/powerpc/dscr/Makefile index 3c3856be6bf9..764fadc36cbb 100644 --- a/tools/testing/selftests/powerpc/dscr/Makefile +++ b/tools/testing/selftests/powerpc/dscr/Makefile @@ -1,4 +1,5 @@ -TEST_PROGS := dscr_default_test dscr_explicit_test dscr_user_test +TEST_PROGS := dscr_default_test dscr_explicit_test dscr_user_test \ + dscr_inherit_test dscr_default_test: LDLIBS += -lpthread diff --git a/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c b/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c new file mode 100644 index 000000000000..4e414caf7f40 --- /dev/null +++ b/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c @@ -0,0 +1,95 @@ +/* + * POWER Data Stream Control Register (DSCR) fork test + * + * This testcase modifies the DSCR using mtspr, forks and then + * verifies that the child process has the correct changed DSCR + * value using mfspr. + * + * 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_inherit(void) +{ + unsigned long i, dscr = 0; + pid_t pid; + + srand(getpid()); + set_dscr(dscr); + + for (i = 0; i < COUNT; i++) { + unsigned long cur_dscr, cur_dscr_usr; + + dscr++; + if (dscr > DSCR_MAX) + dscr = 0; + + if (i % 2 == 0) + set_dscr_usr(dscr); + else + set_dscr(dscr); + + /* + * XXX: Force a context switch out so that DSCR + * current value is copied into the thread struct + * which is required for the child to inherit the + * changed value. + */ + sleep(1); + + pid = fork(); + if (pid == -1) { + perror("fork() failed"); + exit(1); + } else if (pid) { + int status; + + if (waitpid(pid, &status, 0) == -1) { + perror("waitpid() failed"); + exit(1); + } + + if (!WIFEXITED(status)) { + fprintf(stderr, "Child didn't exit cleanly\n"); + exit(1); + } + + if (WEXITSTATUS(status) != 0) { + fprintf(stderr, "Child didn't exit cleanly\n"); + return 1; + } + } else { + cur_dscr = get_dscr(); + if (cur_dscr != dscr) { + fprintf(stderr, "Kernel DSCR should be %ld " + "but is %ld\n", dscr, cur_dscr); + exit(1); + } + + 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); + exit(1); + } + exit(0); + } + } + return 0; +} + +int main(int argc, char *argv[]) +{ + return test_harness(dscr_inherit, "dscr_inherit_test"); +} |