Re: [PATCH v11 15/16] tpm: take TPM chip power gating out of tpm_transmit()

On 2/5/19 5:47 PM, Jarkko Sakkinen wrote:

quoted

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 <redacted>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <redacted>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
---
 drivers/char/tpm/tpm-chip.c       | 25 ++++++++++++-------------
 drivers/char/tpm/tpm-interface.c  |  6 ------
 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(+), 31 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 f7b7e4e75fcf..f20c78055731 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c

@@ -168,13 +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 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 9c9ccf2c0681..6c6ad2d4d31b 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;

This patch seems to be missing a hunk along these lines here

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index e74c5b7b64bf..52afe20cc8a1 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c

@@ -799,7 +799,9 @@ int tpm2_probe(struct tpm_chip *chip)

    tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
    tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
    tpm_buf_append_u32(&buf, 1);
+    tpm_chip_start(chip, 0);
    rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
+    tpm_chip_stop(chip, 0);
    /* We ignore TPM return codes on purpose. */
    if (rc >=  0) {
        out = (struct tpm_header *)buf.data;


Of course you need to check the error from tpm_chip_start().