tools/power turbostat: Add run-time MSR driver probe

Rather than starting down the conditional-compile road...

Probe the location of the MSR files at run-time.

Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 8154d110dd07d81001bbd444490d9b39e1877fba..e85bdb00f24a567b3b7d720948c652a1d63e380b 100644 (file)
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -142,6 +142,7 @@ struct msr_counter {
 #define        FLAGS_SHOW      (1 << 1)
 #define        SYSFS_PERCPU    (1 << 1)
 };
+static int use_android_msr_path;
 
 struct msr_counter bic[] = {
        { 0x0, "usec", NULL, 0, 0, 0, NULL, 0 },
@@ -2413,20 +2414,11 @@ int get_msr_fd(int cpu)
 
        if (fd)
                return fd;
-#if defined(ANDROID)
-       sprintf(pathname, "/dev/msr%d", cpu);
-#else
-       sprintf(pathname, "/dev/cpu/%d/msr", cpu);
-#endif
+       sprintf(pathname, use_android_msr_path ? "/dev/msr%d" : "/dev/cpu/%d/msr", cpu);
        fd = open(pathname, O_RDONLY);
        if (fd < 0)
-#if defined(ANDROID)
-               err(-1, "%s open failed, try chown or chmod +r /dev/msr*, "
-                   "or run with --no-msr, or run as root", pathname);
-#else
-               err(-1, "%s open failed, try chown or chmod +r /dev/cpu/*/msr, "
-                   "or run with --no-msr, or run as root", pathname);
-#endif
+               err(-1, "%s open failed, try chown or chmod +r %s, "
+                   "or run with --no-msr, or run as root", pathname, use_android_msr_path ? "/dev/msr*" : "/dev/cpu/*/msr");
        fd_percpu[cpu] = fd;
 
        return fd;
@@ -6777,21 +6769,43 @@ restart:
        }
 }
 
-void check_dev_msr()
+int probe_dev_msr(void)
+{
+       struct stat sb;
+       char pathname[32];
+
+        sprintf(pathname, "/dev/msr%d", base_cpu);
+        return !stat(pathname, &sb);
+}
+
+int probe_dev_cpu_msr(void)
 {
        struct stat sb;
        char pathname[32];
 
-       if (no_msr)
-               return;
-#if defined(ANDROID)
-       sprintf(pathname, "/dev/msr%d", base_cpu);
-#else
        sprintf(pathname, "/dev/cpu/%d/msr", base_cpu);
-#endif
-       if (stat(pathname, &sb))
-               if (system("/sbin/modprobe msr > /dev/null 2>&1"))
-                       no_msr = 1;
+       return !stat(pathname, &sb);
+}
+
+int probe_msr_driver(void)
+{
+       if (probe_dev_msr()) {
+               use_android_msr_path = 1;
+               return 1;
+       }
+       return probe_dev_cpu_msr();
+}
+
+void check_msr_driver(void)
+{
+       if (probe_msr_driver())
+               return;
+
+       if (system("/sbin/modprobe msr > /dev/null 2>&1"))
+               no_msr = 1;
+
+       if (!probe_msr_driver())
+               no_msr = 1;
 }
 
 /*
@@ -6846,11 +6860,7 @@ void check_msr_permission(void)
        failed += check_for_cap_sys_rawio();
 
        /* test file permissions */
-#if defined(ANDROID)
-       sprintf(pathname, "/dev/msr%d", base_cpu);
-#else
-       sprintf(pathname, "/dev/cpu/%d/msr", base_cpu);
-#endif
+       sprintf(pathname, use_android_msr_path ? "/dev/msr%d" : "/dev/cpu/%d/msr", base_cpu);
        if (euidaccess(pathname, R_OK)) {
                failed++;
        }
@@ -9476,7 +9486,7 @@ bool has_added_counters(void)
 
 void check_msr_access(void)
 {
-       check_dev_msr();
+       check_msr_driver();
        check_msr_permission();
 
        if (no_msr)
@@ -10147,7 +10157,7 @@ int get_and_dump_counters(void)
 
 void print_version()
 {
-       fprintf(outf, "turbostat version 2025.10.24 - Len Brown <lenb@kernel.org>\n");
+       fprintf(outf, "turbostat version 2025.11.29 - Len Brown <lenb@kernel.org>\n");
 }
 
 #define COMMAND_LINE_SIZE 2048