tpm: move tpm_validate_commmand() to tpm2-space.c

Move tpm_validate_command() to tpm2-space.c and make it part of the
tpm2_prepare_space() flow. Make cc resolution as part of the TPM space
functionality in order to detach it from rest of the tpm_transmit()
flow.

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>

3 files changed, 66 insertions, 64 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index ce06e66b4400..88ed6109984e 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -62,45 +62,6 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
 }
 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 
-static int tpm_validate_command(struct tpm_chip *chip, struct tpm_space *space,
-				const void *cmd, size_t len)
-{
-	const struct tpm_header *header = cmd;
-	int i;
-	u32 cc;
-	u32 attrs;
-	unsigned int nr_handles;
-
-	if (len < TPM_HEADER_SIZE)
-		return -EINVAL;
-
-	if (!space)
-		return 0;
-
-	if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
-		cc = be32_to_cpu(header->ordinal);
-
-		i = tpm2_find_cc(chip, cc);
-		if (i < 0) {
-			dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
-				cc);
-			return -EOPNOTSUPP;
-		}
-
-		attrs = chip->cc_attrs_tbl[i];
-		nr_handles =
-			4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
-		if (len < TPM_HEADER_SIZE + 4 * nr_handles)
-			goto err_len;
-	}
-
-	return 0;
-err_len:
-	dev_dbg(&chip->dev,
-		"%s: insufficient command length %zu", __func__, len);
-	return -EINVAL;
-}
-
 static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
 {
 	int rc;
@@ -168,20 +129,8 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
 	u32 count, ordinal;
 	unsigned long stop;
 
-	rc = tpm_validate_command(chip, space, buf, bufsiz);
-	if (rc == -EINVAL)
-		return rc;
-	/*
-	 * 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 (bufsiz < TPM_HEADER_SIZE)
+		return -EINVAL;
 
 	if (bufsiz > TPM_BUFSIZE)
 		bufsiz = TPM_BUFSIZE;
@@ -196,7 +145,18 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
 		return -E2BIG;
 	}
 
-	rc = tpm2_prepare_space(chip, space, ordinal, buf);
+	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;
 
@@ -252,7 +212,7 @@ out_recv:
 
 out_rc:
 	if (!rc)
-		rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
+		rc = tpm2_commit_space(chip, space, buf, &len);
 
 	return rc ? rc : len;
 }
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 6eb67ccad2a3..e84333259e28 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -264,6 +264,7 @@ struct tpm_chip {
 #endif /* CONFIG_ACPI */
 
 	struct tpm_space work_space;
+	u32 last_cc;
 	u32 nr_commands;
 	u32 *cc_attrs_tbl;
 
@@ -577,10 +578,10 @@ int tpm2_find_cc(struct tpm_chip *chip, u32 cc);
 int tpm2_init_space(struct tpm_space *space);
 void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space);
 void tpm2_flush_space(struct tpm_chip *chip);
-int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
-		       u8 *cmd);
-int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
-		      u32 cc, void *buf, size_t *bufsiz);
+int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd,
+		       size_t cmdsiz);
+int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, void *buf,
+		      size_t *bufsiz);
 
 int tpm_bios_log_setup(struct tpm_chip *chip);
 void tpm_bios_log_teardown(struct tpm_chip *chip);
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 5d6487575074..92aea758d9c6 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -264,14 +264,54 @@ static int tpm2_map_command(struct tpm_chip *chip, u32 cc, u8 *cmd)
 	return 0;
 }
 
-int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
-		       u8 *cmd)
+static int tpm_find_and_validate_cc(struct tpm_chip *chip,
+				    struct tpm_space *space,
+				    const void *cmd, size_t len)
+{
+	const struct tpm_header *header = (const void *)cmd;
+	int i;
+	u32 cc;
+	u32 attrs;
+	unsigned int nr_handles;
+
+	if (len < TPM_HEADER_SIZE || !chip->nr_commands)
+		return -EINVAL;
+
+	cc = be32_to_cpu(header->ordinal);
+
+	i = tpm2_find_cc(chip, cc);
+	if (i < 0) {
+		dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
+			cc);
+		return -EOPNOTSUPP;
+	}
+
+	attrs = chip->cc_attrs_tbl[i];
+	nr_handles =
+		4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
+	if (len < TPM_HEADER_SIZE + 4 * nr_handles)
+		goto err_len;
+
+	return cc;
+err_len:
+	dev_dbg(&chip->dev, "%s: insufficient command length %zu", __func__,
+		len);
+	return -EINVAL;
+}
+
+int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd,
+		       size_t cmdsiz)
 {
 	int rc;
+	int cc;
 
 	if (!space)
 		return 0;
 
+	cc = tpm_find_and_validate_cc(chip, space, cmd, cmdsiz);
+	if (cc < 0)
+		return cc;
+
 	memcpy(&chip->work_space.context_tbl, &space->context_tbl,
 	       sizeof(space->context_tbl));
 	memcpy(&chip->work_space.session_tbl, &space->session_tbl,
@@ -291,6 +331,7 @@ int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc,
 		return rc;
 	}
 
+	chip->last_cc = cc;
 	return 0;
 }
 
@@ -490,7 +531,7 @@ static int tpm2_save_space(struct tpm_chip *chip)
 }
 
 int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
-		      u32 cc, void *buf, size_t *bufsiz)
+		      void *buf, size_t *bufsiz)
 {
 	struct tpm_header *header = buf;
 	int rc;
@@ -498,13 +539,13 @@ int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
 	if (!space)
 		return 0;
 
-	rc = tpm2_map_response_header(chip, cc, buf, *bufsiz);
+	rc = tpm2_map_response_header(chip, chip->last_cc, buf, *bufsiz);
 	if (rc) {
 		tpm2_flush_space(chip);
 		goto out;
 	}
 
-	rc = tpm2_map_response_body(chip, cc, buf, *bufsiz);
+	rc = tpm2_map_response_body(chip, chip->last_cc, buf, *bufsiz);
 	if (rc) {
 		tpm2_flush_space(chip);
 		goto out;