tpm: take TPM chip power gating out of tpm_transmit()

Call tpm_chip_start() and tpm_chip_stop() in

* tpm_chip_register()
* tpm_class_shutdown()
* tpm_del_char_device()
* tpm_pm_suspend()
* tpm_try_get_ops() and tpm_put_ops()
* tpm2_del_space()

And remove these calls from tpm_transmit(). The core reason for this
change is that in tpm_vtpm_proxy a locality change requires a virtual
TPM command (a command made up just for that driver).

The consequence of this is that this commit removes the remaining nested
calls.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>

6 files changed, 40 insertions, 37 deletions

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index ed673c7216a0..1dbc7f45e2b4 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -41,9 +41,6 @@ static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
 {
 	int rc;
 
-	if (flags & TPM_TRANSMIT_NESTED)
-		return 0;
-
 	if (!chip->ops->request_locality)
 		return 0;
 
@@ -59,9 +56,6 @@ static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
 {
 	int rc;
 
-	if (flags & TPM_TRANSMIT_NESTED)
-		return;
-
 	if (!chip->ops->relinquish_locality)
 		return;
 
@@ -74,9 +68,6 @@ static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
 
 static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
 {
-	if (flags & TPM_TRANSMIT_NESTED)
-		return 0;
-
 	if (!chip->ops->cmd_ready)
 		return 0;
 
@@ -85,9 +76,6 @@ static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
 
 static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
 {
-	if (flags & TPM_TRANSMIT_NESTED)
-		return 0;
-
 	if (!chip->ops->go_idle)
 		return 0;
 
@@ -167,11 +155,17 @@ int tpm_try_get_ops(struct tpm_chip *chip)
 
 	down_read(&chip->ops_sem);
 	if (!chip->ops)
-		goto out_lock;
+		goto out_ops;
 
 	mutex_lock(&chip->tpm_mutex);
+	rc = tpm_chip_start(chip, 0);
+	if (rc)
+		goto out_lock;
+
 	return 0;
 out_lock:
+	mutex_unlock(&chip->tpm_mutex);
+out_ops:
 	up_read(&chip->ops_sem);
 	put_device(&chip->dev);
 	return rc;
@@ -187,6 +181,7 @@ EXPORT_SYMBOL_GPL(tpm_try_get_ops);
  */
 void tpm_put_ops(struct tpm_chip *chip)
 {
+	tpm_chip_stop(chip, 0);
 	mutex_unlock(&chip->tpm_mutex);
 	up_read(&chip->ops_sem);
 	put_device(&chip->dev);
@@ -302,7 +297,10 @@ static int tpm_class_shutdown(struct device *dev)
 
 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 		down_write(&chip->ops_sem);
-		tpm2_shutdown(chip, TPM2_SU_CLEAR);
+		if (!tpm_chip_start(chip, 0)) {
+			tpm2_shutdown(chip, TPM2_SU_CLEAR);
+			tpm_chip_stop(chip, 0);
+		}
 		chip->ops = NULL;
 		up_write(&chip->ops_sem);
 	}
@@ -481,8 +479,12 @@ static void tpm_del_char_device(struct tpm_chip *chip)
 
 	/* Make the driver uncallable. */
 	down_write(&chip->ops_sem);
-	if (chip->flags & TPM_CHIP_FLAG_TPM2)
-		tpm2_shutdown(chip, TPM2_SU_CLEAR);
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		if (!tpm_chip_start(chip, 0)) {
+			tpm2_shutdown(chip, TPM2_SU_CLEAR);
+			tpm_chip_stop(chip, 0);
+		}
+	}
 	chip->ops = NULL;
 	up_write(&chip->ops_sem);
 }
@@ -564,7 +566,11 @@ int tpm_chip_register(struct tpm_chip *chip)
 {
 	int rc;
 
+	rc = tpm_chip_start(chip, 0);
+	if (rc)
+		return rc;
 	rc = tpm_auto_startup(chip);
+	tpm_chip_stop(chip, 0);
 	if (rc)
 		return rc;
 
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 038a4767d9d6..744f1b96128e 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -177,13 +177,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
 	memcpy(save, buf, save_size);
 
 	for (;;) {
-		ret = tpm_chip_start(chip, flags);
-		if (ret)
-			return ret;
-
 		ret = tpm_try_transmit(chip, buf, bufsiz, flags);
-
-		tpm_chip_stop(chip, flags);
 		if (ret < 0)
 			break;
 		rc = be32_to_cpu(header->return_code);
@@ -420,10 +414,16 @@ int tpm_pm_suspend(struct device *dev)
 	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
 		return 0;
 
-	if (chip->flags & TPM_CHIP_FLAG_TPM2)
-		tpm2_shutdown(chip, TPM2_SU_STATE);
-	else
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		mutex_lock(&chip->tpm_mutex);
+		if (!tpm_chip_start(chip, 0)) {
+			tpm2_shutdown(chip, TPM2_SU_STATE);
+			tpm_chip_stop(chip, 0);
+		}
+		mutex_unlock(&chip->tpm_mutex);
+	} else {
 		rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
+	}
 
 	return rc;
 }
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 2d6d934f1c8b..53e4208759ee 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -485,15 +485,6 @@ extern const struct file_operations tpm_fops;
 extern const struct file_operations tpmrm_fops;
 extern struct idr dev_nums_idr;
 
-/**
- * enum tpm_transmit_flags - flags for tpm_transmit()
- *
- * %TPM_TRANSMIT_NESTED:	discard setup steps (power management, locality)
- */
-enum tpm_transmit_flags {
-	TPM_TRANSMIT_NESTED      = BIT(0),
-};
-
 ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
 		     unsigned int flags);
 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 8a8754a0f964..6cc7bb442162 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -60,7 +60,10 @@ int tpm2_init_space(struct tpm_space *space)
 void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space)
 {
 	mutex_lock(&chip->tpm_mutex);
-	tpm2_flush_sessions(chip, space);
+	if (!tpm_chip_start(chip, 0)) {
+		tpm2_flush_sessions(chip, space);
+		tpm_chip_stop(chip, 0);
+	}
 	mutex_unlock(&chip->tpm_mutex);
 	kfree(space->context_buf);
 	kfree(space->session_buf);
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index c6b0c6d541a5..e33a10491f07 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -916,7 +916,11 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
 
+	rc = tpm_chip_start(chip, 0);
+	if (rc)
+		goto out_err;
 	rc = tpm2_probe(chip);
+	tpm_chip_stop(chip, 0);
 	if (rc)
 		goto out_err;
 
diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 8678c4bba38a..9aa6a3baa491 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -416,8 +416,7 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality)
 
 	proxy_dev->state |= STATE_DRIVER_COMMAND;
 
-	rc = tpm_transmit_cmd(chip, &buf, 0, TPM_TRANSMIT_NESTED,
-			      "attempting to set locality");
+	rc = tpm_transmit_cmd(chip, &buf, 0, 0, "attempting to set locality");
 
 	proxy_dev->state &= ~STATE_DRIVER_COMMAND;