[PATCH v7 16/17] tpm: take TPM chip power gating out of tpm_transmit()

From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: linux-integrity@vger.kernel.org
Cc: linux-security-module@vger.kernel.org,
	James Bottomley <James.Bottomley@HansenPartnership.com>,
	Tomas Winkler <tomas.winkler@intel.com>,
	Tadeusz Struk <tadeusz.struk@intel.com>,
	Stefan Berger <stefanb@linux.vnet.ibm.com>,
	Nayna Jain <nayna@linux.ibm.com>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	Peter Huewe <peterhuewe@gmx.de>, Jason Gunthorpe <jgg@ziepe.ca>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v7 16/17] tpm: take TPM chip power gating out of tpm_transmit()
Date: Tue, 13 Nov 2018 20:36:15 +0200	[thread overview]
Message-ID: <20181113183620.27447-17-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20181113183620.27447-1-jarkko.sakkinen@linux.intel.com>

Call tpm_chip_start() and tpm_chip_stop() in

* tpm_try_get_ops() and tpm_put_ops()
* tpm_chip_register()
* 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>
---
 drivers/char/tpm/tpm-chip.c       | 19 ++++++-------------
 drivers/char/tpm/tpm-interface.c  |  4 ----
 drivers/char/tpm/tpm.h            |  9 ---------
 drivers/char/tpm/tpm2-space.c     |  5 ++++-
 drivers/char/tpm/tpm_vtpm_proxy.c |  3 +--
 5 files changed, 11 insertions(+), 29 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 65f1561eba81..87570182f75e 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;
 
@@ -169,7 +157,7 @@ int tpm_try_get_ops(struct tpm_chip *chip)
 		goto out_lock;
 
 	mutex_lock(&chip->tpm_mutex);
-	return 0;
+	return tpm_chip_start(chip, 0);
 out_lock:
 	up_read(&chip->ops_sem);
 	put_device(&chip->dev);
@@ -186,6 +174,7 @@ 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);
@@ -563,7 +552,11 @@ 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 888c9923fca1..5c04c0d9aaba 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -168,11 +168,7 @@ 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);
 
 		rc = be32_to_cpu(header->return_code);
 		if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index c42a75710b70..f9d56dfd0d20 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 ced1dc91ba6f..d913715d30aa 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_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index e8a1da2810a9..a4bb60e163cc 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -417,8 +417,7 @@ 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;
 
-- 
2.19.1

