x86, bts: add selftest for BTS

Perform a selftest of branch trace store when a cpu is initialized.

WARN and disable branch trace store support if the selftest fails.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090313104507.A30125@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 21 insertions, 0 deletions

diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index 6e5ec679a0cd..51c936c1a390 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -29,6 +29,7 @@
 #include <linux/mm.h>
 #include <linux/kernel.h>
 
+#include "ds_selftest.h"
 
 /*
  * The configuration for a particular DS hardware implementation.
@@ -940,6 +941,26 @@ ds_configure(const struct ds_configuration *cfg,
                 printk(KERN_INFO "[ds] pebs not available\n");
         }
 
+        if (ds_cfg.sizeof_rec[ds_bts]) {
+                int error;
+
+                error = ds_selftest_bts();
+                if (error) {
+                        WARN(1, "[ds] selftest failed. disabling bts.\n");
+                        ds_cfg.sizeof_rec[ds_bts] = 0;
+                }
+        }
+
+        if (ds_cfg.sizeof_rec[ds_pebs]) {
+                int error;
+
+                error = ds_selftest_pebs();
+                if (error) {
+                        WARN(1, "[ds] selftest failed. disabling pebs.\n");
+                        ds_cfg.sizeof_rec[ds_pebs] = 0;
+                }
+        }
+
         printk(KERN_INFO "[ds] sizes: address: %u bit, ",
                8 * ds_cfg.sizeof_ptr_field);
         printk("bts/pebs record: %u/%u bytes\n",