export CFLAGS
-SUB_DIRS = pmu copyloops mm tm primitives stringloops vphn switch_endian
+SUB_DIRS = pmu copyloops mm tm primitives stringloops vphn switch_endian dscr
endif
--- /dev/null
+TEST_PROGS := dscr_default_test
+
+dscr_default_test: LDLIBS += -lpthread
+
+all: $(TEST_PROGS)
+
+$(TEST_PROGS): ../harness.c
+
+include ../../lib.mk
+
+clean:
+ rm -f $(TEST_PROGS) *.o
--- /dev/null
+/*
+ * POWER Data Stream Control Register (DSCR)
+ *
+ * This header file contains helper functions and macros
+ * required for all the DSCR related test cases.
+ *
+ * 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.
+ */
+#ifndef _SELFTESTS_POWERPC_DSCR_DSCR_H
+#define _SELFTESTS_POWERPC_DSCR_DSCR_H
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <pthread.h>
+#include <sched.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+#include "utils.h"
+
+#define SPRN_DSCR 0x11 /* Privilege state SPR */
+#define SPRN_DSCR_USR 0x03 /* Problem state SPR */
+#define THREADS 100 /* Max threads */
+#define COUNT 100 /* Max iterations */
+#define DSCR_MAX 16 /* Max DSCR value */
+#define LEN_MAX 100 /* Max name length */
+
+#define DSCR_DEFAULT "/sys/devices/system/cpu/dscr_default"
+#define CPU_PATH "/sys/devices/system/cpu/"
+
+#define rmb() asm volatile("lwsync":::"memory")
+#define wmb() asm volatile("lwsync":::"memory")
+
+#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
+
+/* Prilvilege state DSCR access */
+inline unsigned long get_dscr(void)
+{
+ unsigned long ret;
+
+ asm volatile("mfspr %0,%1" : "=r" (ret): "i" (SPRN_DSCR));
+
+ return ret;
+}
+
+inline void set_dscr(unsigned long val)
+{
+ asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
+}
+
+/* Problem state DSCR access */
+inline unsigned long get_dscr_usr(void)
+{
+ unsigned long ret;
+
+ asm volatile("mfspr %0,%1" : "=r" (ret): "i" (SPRN_DSCR_USR));
+
+ return ret;
+}
+
+inline void set_dscr_usr(unsigned long val)
+{
+ asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR_USR));
+}
+
+/* Default DSCR access */
+unsigned long get_default_dscr(void)
+{
+ int fd = -1, ret;
+ char buf[16];
+ unsigned long val;
+
+ if (fd == -1) {
+ fd = open(DSCR_DEFAULT, O_RDONLY);
+ if (fd == -1) {
+ perror("open() failed");
+ exit(1);
+ }
+ }
+ memset(buf, 0, sizeof(buf));
+ lseek(fd, 0, SEEK_SET);
+ ret = read(fd, buf, sizeof(buf));
+ if (ret == -1) {
+ perror("read() failed");
+ exit(1);
+ }
+ sscanf(buf, "%lx", &val);
+ close(fd);
+ return val;
+}
+
+void set_default_dscr(unsigned long val)
+{
+ int fd = -1, ret;
+ char buf[16];
+
+ if (fd == -1) {
+ fd = open(DSCR_DEFAULT, O_RDWR);
+ if (fd == -1) {
+ perror("open() failed");
+ exit(1);
+ }
+ }
+ sprintf(buf, "%lx\n", val);
+ ret = write(fd, buf, strlen(buf));
+ if (ret == -1) {
+ perror("write() failed");
+ exit(1);
+ }
+ close(fd);
+}
+
+double uniform_deviate(int seed)
+{
+ return seed * (1.0 / (RAND_MAX + 1.0));
+}
+#endif /* _SELFTESTS_POWERPC_DSCR_DSCR_H */
--- /dev/null
+/*
+ * 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");
+}
projects / cascardo / linux.git / commitdiff