tpm: separate cmd_ready/go_idle from runtime_pm

Fix tpm ptt initialization error:
tpm tpm0: A TPM error (378) occurred get tpm pcr allocation.

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.

When calling from nested context always use both flags:
TPM_TRANSMIT_UNLOCKED and TPM_TRANSMIT_RAW. Both are needed to resolve
tpm spaces and locality request recursive calls to tpm_transmit().
TPM_TRANSMIT_RAW should never be used standalone as it will fail
on double locking. While TPM_TRANSMIT_UNLOCKED standalone should be
called from non-recursive locked contexts.

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@vger.kernel.org
Fixes: 888d867df441 (tpm: cmd_ready command can be issued only after granting locality)
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

1 files changed, 41 insertions, 10 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index e32f6e85dc6d..31b86e027f9d 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 @@ err_len:
 	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 @@ out_recv:
 	}
 
 	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)