tpm_tis: Introduce durations sysfs entry

Display the TPM's command timeouts in a 'durations' sysfs entry. Display
the entries as having been adjusted when they were scaled due to their values
being reported in milliseconds rather than microseconds.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Guillaume Chazarain <guichaz@gmail.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>

3 files changed, 21 insertions, 1 deletions

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 277cf22609ca..27abfd93714d 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -597,6 +597,7 @@ duration:
                 chip->vendor.duration[TPM_SHORT] = HZ;
                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
                 chip->vendor.duration[TPM_LONG] *= 1000;
+                chip->vendor.duration_adjusted = true;
                 dev_info(chip->dev, "Adjusting TPM timeout parameters.");
         }
 }
@@ -944,6 +945,20 @@ ssize_t tpm_show_caps_1_2(struct device * dev,
 }
 EXPORT_SYMBOL_GPL(tpm_show_caps_1_2);
 
+ssize_t tpm_show_durations(struct device *dev, struct device_attribute *attr,
+                          char *buf)
+{
+        struct tpm_chip *chip = dev_get_drvdata(dev);
+
+        return sprintf(buf, "%d %d %d [%s]\n",
+                       jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
+                       jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
+                       jiffies_to_usecs(chip->vendor.duration[TPM_LONG]),
+                       chip->vendor.duration_adjusted
+                       ? "adjusted" : "original");
+}
+EXPORT_SYMBOL_GPL(tpm_show_durations);
+
 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
                         const char *buf, size_t count)
 {
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 72ddb031b69a..6fc797611ccb 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -56,6 +56,8 @@ extern ssize_t tpm_show_owned(struct device *, struct device_attribute *attr,
                                 char *);
 extern ssize_t tpm_show_temp_deactivated(struct device *,
                                          struct device_attribute *attr, char *);
+extern ssize_t tpm_show_durations(struct device *,
+                                  struct device_attribute *attr, char *);
 
 struct tpm_chip;
 
@@ -82,6 +84,7 @@ struct tpm_vendor_specific {
         int locality;
         unsigned long timeout_a, timeout_b, timeout_c, timeout_d; /* jiffies */
         unsigned long duration[3]; /* jiffies */
+        bool duration_adjusted;
 
         wait_queue_head_t read_queue;
         wait_queue_head_t int_queue;
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index dd21df55689d..e15b30d49543 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -376,6 +376,7 @@ static DEVICE_ATTR(temp_deactivated, S_IRUGO, tpm_show_temp_deactivated,
                    NULL);
 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps_1_2, NULL);
 static DEVICE_ATTR(cancel, S_IWUSR | S_IWGRP, NULL, tpm_store_cancel);
+static DEVICE_ATTR(durations, S_IRUGO, tpm_show_durations, NULL);
 
 static struct attribute *tis_attrs[] = {
         &dev_attr_pubek.attr,
@@ -385,7 +386,8 @@ static struct attribute *tis_attrs[] = {
         &dev_attr_owned.attr,
         &dev_attr_temp_deactivated.attr,
         &dev_attr_caps.attr,
-        &dev_attr_cancel.attr, NULL,
+        &dev_attr_cancel.attr,
+        &dev_attr_durations.attr, NULL,
 };
 
 static struct attribute_group tis_attr_grp = {