Re: [PATCH 4/4] tpm: Move TPM common base definitions to the command header

[Jarkko Sakkinen]

On Thu, Mar 26, 2026 at 07:54:36PM +0000, Alec Brown wrote:
> On Mon, Mar 23, 2026 at 1:42 AM, Jarkko Sakkinen <jarkko@xxxxxxxxxx> wrote:
> > On Tue, Mar 17, 2026 at 04:03:35PM +0000, Alec Brown wrote:
> > > From: Ross Philipson <ross.philipson@xxxxxxxxxx>
> > >
> > > From: Ross Philipson <ross.philipson@xxxxxxxxxx>
> > >
> > > These are top level definitions shared by both TPM 1 and 2 family
> > > chips. This includes core definitions like TPM localities, common
> > > crypto algorithm IDs, and the base TPM command header.
> > >
> > > Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
> > > Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx>
> > > Signed-off-by: Alec Brown <alec.r.brown@xxxxxxxxxx>
> > > ---
> > >  include/linux/tpm.h         | 50 +--------------------
> > >  include/linux/tpm_command.h | 89
> > > +++++++++++++++++++++++++++++++++++++
> > >  2 files changed, 90 insertions(+), 49 deletions(-)
> > >
> > > diff --git a/include/linux/tpm.h b/include/linux/tpm.h index
> > > 92957452f7a7..a282b7045a24 100644
> > > --- a/include/linux/tpm.h
> > > +++ b/include/linux/tpm.h
> > > @@ -27,49 +27,12 @@
> > >
> > >  #include "tpm_command.h"
> > >
> > > -#define TPM_DIGEST_SIZE 20	/* Max TPM v1.2 PCR size */
> > > -
> > > -#define TPM2_MAX_DIGEST_SIZE	SHA512_DIGEST_SIZE
> > > -#define TPM2_MAX_PCR_BANKS	8
> > > -
> > >  struct tpm_chip;
> > >  struct trusted_key_payload;
> > >  struct trusted_key_options;
> > >  /* opaque structure, holds auth session parameters like the session
> > > key */  struct tpm2_auth;
> > >
> > > -/* if you add a new hash to this, increment TPM_MAX_HASHES below */
> > > -enum tpm_algorithms {
> > > -	TPM_ALG_ERROR		= 0x0000,
> > > -	TPM_ALG_SHA1		= 0x0004,
> > > -	TPM_ALG_AES		= 0x0006,
> > > -	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,
> > > -	TPM_ALG_ECC		= 0x0023,
> > > -	TPM_ALG_CFB		= 0x0043,
> > > -};
> > > -
> > > -/*
> > > - * 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[TPM2_MAX_DIGEST_SIZE];
> > > -} __packed;
> > > -
> > > -struct tpm_bank_info {
> > > -	u16 alg_id;
> > > -	u16 digest_size;
> > > -	u16 crypto_id;
> > > -};
> > > -
> > >  enum TPM_OPS_FLAGS {
> > >  	TPM_OPS_AUTO_STARTUP = BIT(0),
> > >  };
> > > @@ -127,7 +90,7 @@ struct tpm_chip_seqops {
> > >  	const struct seq_operations *seqops;  };
> > >
> > > -/* fixed define for the curve we use which is NIST_P256 */
> > > +/* Fixed define for the curve we use which is NIST_P256 */
> > >  #define EC_PT_SZ	32
> > >
> > >  /*
> > > @@ -209,8 +172,6 @@ struct tpm_chip {
> > >  #endif
> > >  };
> > >
> > > -#define TPM_HEADER_SIZE		10
> > > -
> > >  static inline enum tpm2_mso_type tpm2_handle_mso(u32 handle)  {
> > >  	return handle >> 24;
> > > @@ -239,15 +200,6 @@ enum tpm_chip_flags {
> > >
> > >  #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
> > >
> > > -struct tpm_header {
> > > -	__be16 tag;
> > > -	__be32 length;
> > > -	union {
> > > -		__be32 ordinal;
> > > -		__be32 return_code;
> > > -	};
> > > -} __packed;
> > > -
> > >  enum tpm_buf_flags {
> > >  	/* the capacity exceeded: */
> > >  	TPM_BUF_OVERFLOW	= BIT(0),
> > > diff --git a/include/linux/tpm_command.h b/include/linux/tpm_command.h
> > > index ee76fcd5ecef..25a247254140 100644
> > > --- a/include/linux/tpm_command.h
> > > +++ b/include/linux/tpm_command.h
> > > @@ -431,4 +431,93 @@ struct tpm2_context {
> > >  	__be16 blob_size;
> > >  } __packed;
> > >
> > > +/************************************************/
> > > +/* TPM Common Defs                              */
> > > +/************************************************/


One nit I just noticed here: let's use kernel standard block comments.

E.g.

/*
 * Common definitions for TPM.
 */


> > > +
> > > +#define TPM_DIGEST_SIZE		20	/* Max TPM v1.2 PCR size */
> > > +#define TPM_BUFSIZE		4096
> > > +
> > > +/*
> > > + * SHA-512 is, as of today, the largest digest in the TCG algorithm repository.
> > > + */
> > > +#define TPM2_MAX_DIGEST_SIZE	SHA512_DIGEST_SIZE
> > > +
> > > +/*
> > > + * A TPM name digest i.e., TPMT_HA, is a concatenation of TPM_ALG_ID
> > > +of the
> > > + * name algorithm and hash of TPMT_PUBLIC.
> > > + */
> > > +#define TPM2_MAX_NAME_SIZE	(TPM2_MAX_DIGEST_SIZE + 2)
> > > +
> > > +/*
> > > + * Fixed define for the size of a name.  This is actually HASHALG
> > > +size
> > > + * plus 2, so 32 for SHA256
> > > + */
> > > +#define TPM2_NULL_NAME_SIZE	34
> > > +
> > > +/*
> > > + * The maximum number of PCR banks.
> > > + */
> > > +#define TPM2_MAX_PCR_BANKS	8
> > > +
> > > +/* If you add a new hash to this, increment TPM_MAX_HASHES below */
> > > +enum tpm_algorithms {
> > > +	TPM_ALG_ERROR		= 0x0000,
> > > +	TPM_ALG_SHA1		= 0x0004,
> > > +	TPM_ALG_AES		= 0x0006,
> > > +	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,
> > > +	TPM_ALG_ECC		= 0x0023,
> > > +	TPM_ALG_CFB		= 0x0043,
> > > +};
> > > +
> > > +/*
> > > + * The locality (0 - 4) for a TPM, as defined in section 3.2 of the
> > > + * Client Platform Profile Specification.
> > > + */
> > > +enum tpm_localities {
> > > +	TPM_LOCALITY_0		= 0, /* Static RTM */
> > > +	TPM_LOCALITY_1		= 1, /* Dynamic OS */
> > > +	TPM_LOCALITY_2		= 2, /* DRTM Environment */
> > > +	TPM_LOCALITY_3		= 3, /* Aux Components */
> > > +	TPM_LOCALITY_4		= 4, /* CPU DRTM Establishment */
> > > +	TPM_MAX_LOCALITY	= TPM_LOCALITY_4
> > > +};
> > > +
> > > +/*
> > > + * Structure to represent active PCR algorithm banks usable by the
> > > + * TPM chip.
> > > + */
> > > +struct tpm_bank_info {
> > > +	u16 alg_id;
> > > +	u16 digest_size;
> > > +	u16 crypto_id;
> > > +};
> > > +
> > > +/*
> > > + * 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[TPM2_MAX_DIGEST_SIZE];
> > > +} __packed;
> > > +
> > > +#define TPM_HEADER_SIZE		10
> > > +
> > > +struct tpm_header {
> > > +	__be16 tag;
> > > +	__be32 length;
> > > +	union {
> > > +		__be32 ordinal;
> > > +		__be32 return_code;
> > > +	};
> > > +} __packed;
> > > +
> > >  #endif
> > > --
> > > 2.47.3
> > >
> > 
> > Yep, all looks great and clean to me but exactly for that reason
> > this needs to the truth serum :-)
> > 
> > BR, Jarkko
> 
> Thanks for taking a look! Glad to hear the patches are looking good!
> 
> Alec Brown 

BR, Jarkko