tpm: rename and export tpm2_digest and tpm2_algorithms

Rename tpm2_* to tpm_* and move the definitions to include/linux/tpm.h so
that these can be used by other kernel subsystems (e.g. IMA).

Also, set the length of the digest array in tpm_digest to a new constant
named TPM_MAX_DIGEST_SIZE, equal to SHA512_DIGEST_SIZE.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 13563b8..9fe8c98 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -22,12 +22,31 @@
 #ifndef __LINUX_TPM_H__
 #define __LINUX_TPM_H__
 
+#include <crypto/hash_info.h>
+
 #define TPM_DIGEST_SIZE 20	/* Max TPM v1.2 PCR size */
+#define TPM_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE
 
 struct tpm_chip;
 struct trusted_key_payload;
 struct trusted_key_options;
 
+enum tpm_algorithms {
+	TPM_ALG_ERROR		= 0x0000,
+	TPM_ALG_SHA1		= 0x0004,
+	TPM_ALG_KEYEDHASH	= 0x0008,
+	TPM_ALG_SHA256		= 0x000B,
+	TPM_ALG_SHA384		= 0x000C,
+	TPM_ALG_SHA512		= 0x000D,
+	TPM_ALG_NULL		= 0x0010,
+	TPM_ALG_SM3_256		= 0x0012,
+};
+
+struct tpm_digest {
+	u16 alg_id;
+	u8 digest[TPM_MAX_DIGEST_SIZE];
+} __packed;
+
 enum TPM_OPS_FLAGS {
 	TPM_OPS_AUTO_STARTUP = BIT(0),
 };