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, 10 insertions, 2 deletions

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 9824cccb2c76..17833ef63f6c 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -512,9 +512,17 @@ 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,..). Always use with UNLOCKED
+ *                    as it will fail on double locking.
+ */
 enum tpm_transmit_flags {
-	TPM_TRANSMIT_UNLOCKED	= BIT(0),
-	TPM_TRANSMIT_RAW	= BIT(1),
+	TPM_TRANSMIT_UNLOCKED = BIT(0),
+	TPM_TRANSMIT_RAW      = BIT(1),
 };
 
 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,