summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/powerpc/utils.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /tools/testing/selftests/powerpc/utils.c
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'tools/testing/selftests/powerpc/utils.c')
-rw-r--r--tools/testing/selftests/powerpc/utils.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c
new file mode 100644
index 000000000..dcf74184b
--- /dev/null
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2013-2015, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#define _GNU_SOURCE /* For CPU_ZERO etc. */
+
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <link.h>
+#include <sched.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "utils.h"
+
+static char auxv[4096];
+
+void *get_auxv_entry(int type)
+{
+ ElfW(auxv_t) *p;
+ void *result;
+ ssize_t num;
+ int fd;
+
+ fd = open("/proc/self/auxv", O_RDONLY);
+ if (fd == -1) {
+ perror("open");
+ return NULL;
+ }
+
+ result = NULL;
+
+ num = read(fd, auxv, sizeof(auxv));
+ if (num < 0) {
+ perror("read");
+ goto out;
+ }
+
+ if (num > sizeof(auxv)) {
+ printf("Overflowed auxv buffer\n");
+ goto out;
+ }
+
+ p = (ElfW(auxv_t) *)auxv;
+
+ while (p->a_type != AT_NULL) {
+ if (p->a_type == type) {
+ result = (void *)p->a_un.a_val;
+ break;
+ }
+
+ p++;
+ }
+out:
+ close(fd);
+ return result;
+}
+
+int pick_online_cpu(void)
+{
+ cpu_set_t mask;
+ int cpu;
+
+ CPU_ZERO(&mask);
+
+ if (sched_getaffinity(0, sizeof(mask), &mask)) {
+ perror("sched_getaffinity");
+ return -1;
+ }
+
+ /* We prefer a primary thread, but skip 0 */
+ for (cpu = 8; cpu < CPU_SETSIZE; cpu += 8)
+ if (CPU_ISSET(cpu, &mask))
+ return cpu;
+
+ /* Search for anything, but in reverse */
+ for (cpu = CPU_SETSIZE - 1; cpu >= 0; cpu--)
+ if (CPU_ISSET(cpu, &mask))
+ return cpu;
+
+ printf("No cpus in affinity mask?!\n");
+ return -1;
+}