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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 v9 16/17] tpm: take TPM chip power gating out of tpm_transmit()
Date:   Sun, 18 Nov 2018 14:47:49 +0200
Message-Id: <20181118124753.18613-17-jarkko.sakkinen@linux.intel.com>
In-Reply-To: <20181118124753.18613-1-jarkko.sakkinen@linux.intel.com>
References: <20181118124753.18613-1-jarkko.sakkinen@linux.intel.com>
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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       | 25 ++++++++++++-------------
 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, 17 insertions(+), 29 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 65f1561eba81..7ad4d9045e4c 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;
 
@@ -166,11 +154,17 @@ 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;
@@ -186,6 +180,7 @@ 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 +558,11 @@ 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 2c79284ffd4e..21ac8da94d90 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);
 		if (ret < 0)
 			break;
 		rc = be32_to_cpu(header->return_code);
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