tpm: Introduce function to poll for result of self test
This patch introduces a function that runs the TPM_ContinueSelfTest()
function and then polls the TPM to check whether it finished the selftest
and can receive new commands.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 9bd4668..2e12b3f 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -627,7 +627,7 @@
* Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
* a TPM error code.
*/
-int tpm_continue_selftest(struct tpm_chip *chip)
+static int tpm_continue_selftest(struct tpm_chip *chip)
{
int rc;
struct tpm_cmd_t cmd;
@@ -637,7 +637,6 @@
"continue selftest");
return rc;
}
-EXPORT_SYMBOL_GPL(tpm_continue_selftest);
ssize_t tpm_show_enabled(struct device * dev, struct device_attribute * attr,
char *buf)
@@ -732,7 +731,7 @@
.ordinal = TPM_ORDINAL_PCRREAD
};
-int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
+static int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
{
int rc;
struct tpm_cmd_t cmd;
@@ -812,6 +811,45 @@
}
EXPORT_SYMBOL_GPL(tpm_pcr_extend);
+/**
+ * tpm_do_selftest - have the TPM continue its selftest and wait until it
+ * can receive further commands
+ * @chip: TPM chip to use
+ *
+ * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
+ * a TPM error code.
+ */
+int tpm_do_selftest(struct tpm_chip *chip)
+{
+ int rc;
+ u8 digest[TPM_DIGEST_SIZE];
+ unsigned int loops;
+ unsigned int delay_msec = 1000;
+ unsigned long duration;
+
+ duration = tpm_calc_ordinal_duration(chip,
+ TPM_ORD_CONTINUE_SELFTEST);
+
+ loops = jiffies_to_msecs(duration) / delay_msec;
+
+ rc = tpm_continue_selftest(chip);
+ /* This may fail if there was no TPM driver during a suspend/resume
+ * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
+ */
+ if (rc)
+ return rc;
+
+ do {
+ rc = __tpm_pcr_read(chip, 0, digest);
+ if (rc != TPM_WARN_DOING_SELFTEST)
+ return rc;
+ msleep(delay_msec);
+ } while (--loops > 0);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_do_selftest);
+
int tpm_send(u32 chip_num, void *cmd, size_t buflen)
{
struct tpm_chip *chip;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 5d2be8a..e264de1 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -38,6 +38,8 @@
TPM_ADDR = 0x4E,
};
+#define TPM_WARN_DOING_SELFTEST 0x802
+
extern ssize_t tpm_show_pubek(struct device *, struct device_attribute *attr,
char *);
extern ssize_t tpm_show_pcrs(struct device *, struct device_attribute *attr,
@@ -281,7 +283,7 @@
extern int tpm_get_timeouts(struct tpm_chip *);
extern void tpm_gen_interrupt(struct tpm_chip *);
-extern int tpm_continue_selftest(struct tpm_chip *);
+extern int tpm_do_selftest(struct tpm_chip *);
extern unsigned long tpm_calc_ordinal_duration(struct tpm_chip *, u32);
extern struct tpm_chip* tpm_register_hardware(struct device *,
const struct tpm_vendor_specific *);
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 3f4051a..d30d5c3 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -616,6 +616,12 @@
/* get the timeouts before testing for irqs */
tpm_get_timeouts(chip);
+ if (tpm_do_selftest(chip)) {
+ dev_err(dev, "TPM self test failed\n");
+ rc = -ENODEV;
+ goto out_err;
+ }
+
/* INTERRUPT Setup */
init_waitqueue_head(&chip->vendor.read_queue);
init_waitqueue_head(&chip->vendor.int_queue);
@@ -722,7 +728,6 @@
list_add(&chip->vendor.list, &tis_chips);
spin_unlock(&tis_lock);
- tpm_continue_selftest(chip);
return 0;
out_err:
@@ -790,7 +795,7 @@
ret = tpm_pm_resume(&dev->dev);
if (!ret)
- tpm_continue_selftest(chip);
+ tpm_do_selftest(chip);
return ret;
}