tpm: move TPM space code out of tpm_transmit()

Prepare and commit TPM space before and after calling tpm_transmit()
instead of doing that inside tpm_transmit(). After this change we can
remove TPM_TRANSMIT_NESTED flag from tpm2_prepare_space() and
tpm2_commit_space() and replace it with TPM_TRANSMIT_UNLOCKED.

Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>

drivers/char/tpm/tpm-dev-common.c

@@ -30,13 +30,35 @@ static DEFINE_MUTEX(tpm_dev_wq_lock);
 static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space,
 				u8 *buf, size_t bufsiz)
 {
-	ssize_t ret;
+	struct tpm_header *header = (void *)buf;
+	ssize_t ret, len;
 
 	mutex_lock(&chip->tpm_mutex);
-	ret = tpm_transmit(chip, space, buf, bufsiz, TPM_TRANSMIT_UNLOCKED);
+	ret = tpm2_prepare_space(chip, space, buf, bufsiz);
+	/* If the command is not implemented by the TPM, synthesize a
+	 * response with a TPM2_RC_COMMAND_CODE return for user-space.
+	 */
+	if (ret == -EOPNOTSUPP) {
+		header->length = cpu_to_be32(sizeof(*header));
+		header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
+		header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
+						  TSS2_RESMGR_TPM_RC_LAYER);
+		ret = sizeof(*header);
+	}
+	if (ret)
+		goto out_lock;
+
+	len = tpm_transmit(chip, space, buf, bufsiz, TPM_TRANSMIT_UNLOCKED);
+	if (len < 0)
+		ret = len;
+
+	if (!ret)
+		ret = tpm2_commit_space(chip, space, buf, &len);
+
+out_lock:
 	mutex_unlock(&chip->tpm_mutex);
 
-	return ret;
+	return ret ? ret : len;
 }
 
 static void tpm_dev_async_work(struct work_struct *work)

drivers/char/tpm/tpm-interface.c

@@ -145,27 +145,12 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
 		return -E2BIG;
 	}
 
-	rc = tpm2_prepare_space(chip, space, buf, bufsiz);
-	/*
-	 * If the command is not implemented by the TPM, synthesize a
-	 * response with a TPM2_RC_COMMAND_CODE return for user-space.
-	 */
-	if (rc == -EOPNOTSUPP) {
-		header->length = cpu_to_be32(sizeof(*header));
-		header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
-		header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
-						  TSS2_RESMGR_TPM_RC_LAYER);
-		return sizeof(*header);
-	}
-	if (rc)
-		return rc;
-
 	rc = chip->ops->send(chip, buf, count);
 	if (rc < 0) {
 		if (rc != -EPIPE)
 			dev_err(&chip->dev,
 				"%s: send(): error %d\n", __func__, rc);
-		goto out_rc;
+		return rc;
 	}
 
 	/* A sanity check. send() should just return zero on success e.g.
@@ -189,8 +174,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
 
 		if (chip->ops->req_canceled(chip, status)) {
 			dev_err(&chip->dev, "Operation Canceled\n");
-			rc = -ECANCELED;
-			goto out_rc;
+			return -ECANCELED;
 		}
 
 		tpm_msleep(TPM_TIMEOUT_POLL);
@@ -199,8 +183,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
 
 	chip->ops->cancel(chip);
 	dev_err(&chip->dev, "Operation Timed out\n");
-	rc = -ETIME;
-	goto out_rc;
+	return -ETIME;
 
 out_recv:
 	len = chip->ops->recv(chip, buf, bufsiz);
@@ -210,10 +193,6 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
 	} else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
 		rc = -EFAULT;
 
-out_rc:
-	if (!rc)
-		rc = tpm2_commit_space(chip, space, buf, &len);
-
 	return rc ? rc : len;
 }
 

drivers/char/tpm/tpm2-space.c

@@ -39,7 +39,7 @@ static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space)
 	for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++) {
 		if (space->session_tbl[i])
 			tpm2_flush_context_cmd(chip, space->session_tbl[i],
-					       TPM_TRANSMIT_NESTED);
+					       TPM_TRANSMIT_UNLOCKED);
 	}
 }
 
@@ -84,7 +84,7 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
 	tpm_buf_append(&tbuf, &buf[*offset], body_size);
 
 	rc = tpm_transmit_cmd(chip, NULL, &tbuf, 4,
-			      TPM_TRANSMIT_NESTED, NULL);
+			      TPM_TRANSMIT_UNLOCKED, NULL);
 	if (rc < 0) {
 		dev_warn(&chip->dev, "%s: failed with a system error %d\n",
 			 __func__, rc);
@@ -133,7 +133,7 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
 	tpm_buf_append_u32(&tbuf, handle);
 
 	rc = tpm_transmit_cmd(chip, NULL, &tbuf, 0,
-			      TPM_TRANSMIT_NESTED, NULL);
+			      TPM_TRANSMIT_UNLOCKED, NULL);
 	if (rc < 0) {
 		dev_warn(&chip->dev, "%s: failed with a system error %d\n",
 			 __func__, rc);
@@ -170,7 +170,7 @@ void tpm2_flush_space(struct tpm_chip *chip)
 	for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
 		if (space->context_tbl[i] && ~space->context_tbl[i])
 			tpm2_flush_context_cmd(chip, space->context_tbl[i],
-					       TPM_TRANSMIT_NESTED);
+					       TPM_TRANSMIT_UNLOCKED);
 
 	tpm2_flush_sessions(chip, space);
 }
@@ -418,7 +418,7 @@ static int tpm2_map_response_header(struct tpm_chip *chip, u32 cc, u8 *rsp,
 
 	return 0;
 out_no_slots:
-	tpm2_flush_context_cmd(chip, phandle, TPM_TRANSMIT_NESTED);
+	tpm2_flush_context_cmd(chip, phandle, TPM_TRANSMIT_UNLOCKED);
 	dev_warn(&chip->dev, "%s: out of slots for 0x%08X\n", __func__,
 		 phandle);
 	return -ENOMEM;
@@ -506,7 +506,7 @@ static int tpm2_save_space(struct tpm_chip *chip)
 			return rc;
 
 		tpm2_flush_context_cmd(chip, space->context_tbl[i],
-				       TPM_TRANSMIT_NESTED);
+				       TPM_TRANSMIT_UNLOCKED);
 		space->context_tbl[i] = ~0;
 	}