We cannot use go_idle cmd_ready commands via runtime_pm handles
as with the introduction of localities this is no longer an optional
feature, while runtime pm can be not enabled.
Though cmd_ready/go_idle provides a power saving, it's also a part of
TPM2 protocol and should be called explicitly.
This patch exposes cmd_read/go_idle via tpm class ops and removes
runtime pm support as it is not used by any driver.

A new tpm transmit flag is added TPM_TRANSMIT_NESTED, which implies
TPM_TRANSMIT_UNLOCKED and TPM_TRANSMIT_RAW. Both are needed to resolve
tpm spaces and locality request recursive calls to tpm_transmit().

New wrappers are added tpm_cmd_ready() and tpm_go_idle() to
streamline tpm_try_transmit code.

tpm_crb no longer needs own power saving functions and can drop using
tpm_pm_suspend/resume.

This patch cannot be really separated from the locality fix.
Fixes: 888d867df441 (tpm: cmd_ready command can be issued only after granting locality)


Cc: stable at vger.kernel.org
Fixes: 888d867df441 (tpm: cmd_ready command can be issued only after granting locality)
Signed-off-by: Tomas Winkler <redacted>
---
V2-3:resent
V4: 1. Use tpm_pm_suspend/resume in tpm_crb
    2. Drop cmd_ready/go_idle around tpm_chip_register, as there is no
       usage counter like in runtime_pm.
V5: 1. add tpm_cmd_ready and tpm_go_idle wrappers.
    2. Abuse TPM_TRANSMIT_UNLOCKED flag to resolve tpm space
       recursion.
V6: 1. Add new flags TPM_TRANSMIT_NESTED which implies
       TPM_TRANSMIT_UNLOCKED and TPM_TRANSMIT_RAW, as not all
       unlocked flows are recursive i.e. tpm2_unseal_trusted.

 drivers/char/tpm/tpm-interface.c  |  51 +++++++++++++++----
 drivers/char/tpm/tpm.h            |  13 ++++-
 drivers/char/tpm/tpm2-space.c     |  12 ++---
 drivers/char/tpm/tpm_crb.c        | 101 ++++++++++----------------------------
 drivers/char/tpm/tpm_vtpm_proxy.c |   2 +-
 include/linux/tpm.h               |   2 +
 6 files changed, 88 insertions(+), 93 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index e32f6e85dc6d..1abd8261651b 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c

@@ -29,7 +29,6 @@
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/freezer.h>
-#include <linux/pm_runtime.h>
 #include <linux/tpm_eventlog.h>
 
 #include "tpm.h"

@@ -369,10 +368,13 @@ static int tpm_validate_command(struct tpm_chip *chip,
 	return -EINVAL;
 }
 
-static int tpm_request_locality(struct tpm_chip *chip)
+static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
 {
 	int rc;
 
+	if (flags & __TPM_TRANSMIT_RAW)
+		return 0;
+
 	if (!chip->ops->request_locality)
 		return 0;
 

@@ -385,10 +387,13 @@ static int tpm_request_locality(struct tpm_chip *chip)
 	return 0;
 }
 
-static void tpm_relinquish_locality(struct tpm_chip *chip)
+static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
 {
 	int rc;
 
+	if (flags & __TPM_TRANSMIT_RAW)
+		return;
+
 	if (!chip->ops->relinquish_locality)
 		return;
 

@@ -399,6 +404,28 @@ static void tpm_relinquish_locality(struct tpm_chip *chip)
 	chip->locality = -1;
 }
 
+static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
+{
+	if (flags & __TPM_TRANSMIT_RAW)
+		return 0;
+
+	if (!chip->ops->cmd_ready)
+		return 0;
+
+	return chip->ops->cmd_ready(chip);
+}
+
+static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
+{
+	if (flags & __TPM_TRANSMIT_RAW)
+		return 0;
+
+	if (!chip->ops->go_idle)
+		return 0;
+
+	return chip->ops->go_idle(chip);
+}
+
 static ssize_t tpm_try_transmit(struct tpm_chip *chip,
 				struct tpm_space *space,
 				u8 *buf, size_t bufsiz,

@@ -449,14 +476,15 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
 	/* Store the decision as chip->locality will be changed. */
 	need_locality = chip->locality == -1;
 
-	if (!(flags & TPM_TRANSMIT_RAW) && need_locality) {
-		rc = tpm_request_locality(chip);
+	if (need_locality) {
+		rc = tpm_request_locality(chip, flags);
 		if (rc < 0)
 			goto out_no_locality;
 	}
 
-	if (chip->dev.parent)
-		pm_runtime_get_sync(chip->dev.parent);
+	rc = tpm_cmd_ready(chip, flags);
+	if (rc)
+		goto out;
 
 	rc = tpm2_prepare_space(chip, space, ordinal, buf);
 	if (rc)

@@ -516,13 +544,16 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
 	}
 
 	rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
+	if (rc)
+		dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc);
 
 out:
-	if (chip->dev.parent)
-		pm_runtime_put_sync(chip->dev.parent);
+	rc = tpm_go_idle(chip, flags);
+	if (rc)
+		goto out;
 
 	if (need_locality)
-		tpm_relinquish_locality(chip);
+		tpm_relinquish_locality(chip, flags);
 
 out_no_locality:
 	if (chip->ops->clk_enable != NULL)

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 4426649e431c..beb0a763016c 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h

@@ -511,9 +511,18 @@ extern const struct file_operations tpm_fops;
 extern const struct file_operations tpmrm_fops;
 extern struct idr dev_nums_idr;
 
+/**
+ * enum tpm_transmit_flags
+ *
+ * @TPM_TRANSMIT_UNLOCKED: used to lock sequence of tpm_transmit calls.
+ * @__TPM_TRANSMIT_RAW: prevent recursive calls into setup steps
+ *                    (go idle, locality,..). Don't use directly.
+ * @TPM_TRANSMIT_NESTED: Use from nested tpm_transmit calls
+ */
 enum tpm_transmit_flags {
-	TPM_TRANSMIT_UNLOCKED	= BIT(0),
-	TPM_TRANSMIT_RAW	= BIT(1),
+	TPM_TRANSMIT_UNLOCKED   = BIT(0),
+	__TPM_TRANSMIT_RAW      = BIT(1),