tpm: add sysfs exports for all banks of PCR registers

Create sysfs per hash groups with 24 PCR files in them one group,
named pcr-<hash>, for each agile hash of the TPM.  The files are
plugged in to a PCR read function which is TPM version agnostic, so
this works also for TPM 1.2 but the hash is only sha1 in that case.

Note: the macros used to create the hashes emit spurious checkpatch
warnings.  Do not try to "fix" them as checkpatch recommends, otherwise
they'll break.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 8f4ff39f51e7..ae2482510f8c 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -31,6 +31,7 @@ struct tpm_chip;
 struct trusted_key_payload;
 struct trusted_key_options;
 
+/* if you add a new hash to this, increment TPM_MAX_HASHES below */
 enum tpm_algorithms {
 	TPM_ALG_ERROR		= 0x0000,
 	TPM_ALG_SHA1		= 0x0004,
@@ -42,6 +43,12 @@ enum tpm_algorithms {
 	TPM_ALG_SM3_256		= 0x0012,
 };
 
+/*
+ * maximum number of hashing algorithms a TPM can have.  This is
+ * basically a count of every hash in tpm_algorithms above
+ */
+#define TPM_MAX_HASHES	5
+
 struct tpm_digest {
 	u16 alg_id;
 	u8 digest[TPM_MAX_DIGEST_SIZE];
@@ -146,7 +153,7 @@ struct tpm_chip {
 
 	struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
 
-	const struct attribute_group *groups[3];
+	const struct attribute_group *groups[3 + TPM_MAX_HASHES];
 	unsigned int groups_cnt;
 
 	u32 nr_allocated_banks;