cpupower: If root, try to load msr driver on x86 if /dev/cpu/0/msr is not available

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/tools/power/cpupower/utils/cpupower.c b/tools/power/cpupower/utils/cpupower.c
index 7efc570ffbaa..7cdcf88659c7 100644
--- a/tools/power/cpupower/utils/cpupower.c
+++ b/tools/power/cpupower/utils/cpupower.c
@@ -12,6 +12,9 @@
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/utsname.h>
 
 #include "builtin.h"
 #include "helpers/helpers.h"
@@ -169,6 +172,8 @@ int main(int argc, const char *argv[])
 {
         const char *cmd;
         unsigned int i, ret;
+        struct stat statbuf;
+        struct utsname uts;
 
         cpus_chosen = bitmask_alloc(sysconf(_SC_NPROCESSORS_CONF));
 
@@ -195,6 +200,15 @@ int main(int argc, const char *argv[])
 
         get_cpu_info(0, &cpupower_cpu_info);
         run_as_root = !getuid();
+        if (run_as_root) {
+                ret = uname(&uts);
+                if (!ret && !strcmp(uts.machine, "x86_64") &&
+                    stat("/dev/cpu/0/msr", &statbuf) != 0) {
+                        if (system("modprobe msr") == -1)
+        fprintf(stderr, _("MSR access not available.\n"));
+                }
+        }
+                
 
         for (i = 0; i < ARRAY_SIZE(commands); i++) {
                 struct cmd_struct *p = commands + i;