[PATCH v3 1/4] tpm: add buf_size parameter in the .send callback

Stefano Garzarella sgarzare at redhat.com
Tue May 6 22:56:54 AEST 2025


On Wed, Apr 30, 2025 at 06:39:58PM +0300, Jarkko Sakkinen wrote:
>On Mon, Apr 14, 2025 at 04:56:50PM +0200, Stefano Garzarella wrote:
>> From: Stefano Garzarella <sgarzare at redhat.com>
>>
>> In preparation for the next commit, add a new `buf_size` parameter to
>> the `.send` callback in `tpm_class_ops` which contains the entire buffer
>> size. In this patch it is pretty much ignored by all drivers, but it will
>> be used in the next patch.
>
>So instead "in preparation for the next commit" just plain say why it
>will be needed. "next commit" is a fuzzy reference :-)
>
>Same goes for "next patch". Neither can be used to query any possible
>information. That sort of makes the whole paragraph useless, once it
>is in the commit log.

Got it! What about somethig like this:

    Add a new `buf_size` parameter to the `.send` callback in
    `tpm_class_ops`. This parameter will allow drivers to differentiate
    between the actual command length to send and the total buffer
    size. Currently `buf_now` is not used, but it will be used to
    support devices with synchronous `.send` callback to send the
    command and receive the response on the same buffer.

Thanks,
Stefano


>
>>
>> Also rename the previous parameter `len` to `cmd_len` in the
>> declaration to make it clear that it contains the length in bytes of the
>> command stored in the buffer. The semantics don't change and it can be
>> used as before by drivers. This is an optimization since the drivers
>> could get it from the header, but let's avoid duplicating code.
>>
>> While we are here, resolve a checkpatch warning:
>>   WARNING: Unnecessary space before function pointer arguments
>>   #66: FILE: include/linux/tpm.h:90:
>>   +	int (*send) (struct tpm_chip *chip, u8 *buf, size_t cmd_len,
>>
>> Suggested-by: Jarkko Sakkinen <jarkko at kernel.org>
>> Signed-off-by: Stefano Garzarella <sgarzare at redhat.com>
>> ---
>>  include/linux/tpm.h                  | 3 ++-
>>  drivers/char/tpm/st33zp24/st33zp24.c | 2 +-
>>  drivers/char/tpm/tpm-interface.c     | 2 +-
>>  drivers/char/tpm/tpm_atmel.c         | 3 ++-
>>  drivers/char/tpm/tpm_crb.c           | 2 +-
>>  drivers/char/tpm/tpm_ftpm_tee.c      | 4 +++-
>>  drivers/char/tpm/tpm_i2c_atmel.c     | 3 ++-
>>  drivers/char/tpm/tpm_i2c_infineon.c  | 3 ++-
>>  drivers/char/tpm/tpm_i2c_nuvoton.c   | 3 ++-
>>  drivers/char/tpm/tpm_ibmvtpm.c       | 6 ++++--
>>  drivers/char/tpm/tpm_infineon.c      | 3 ++-
>>  drivers/char/tpm/tpm_nsc.c           | 3 ++-
>>  drivers/char/tpm/tpm_svsm.c          | 3 ++-
>>  drivers/char/tpm/tpm_tis_core.c      | 3 ++-
>>  drivers/char/tpm/tpm_tis_i2c_cr50.c  | 6 ++++--
>>  drivers/char/tpm/tpm_vtpm_proxy.c    | 4 +++-
>>  drivers/char/tpm/xen-tpmfront.c      | 3 ++-
>>  17 files changed, 37 insertions(+), 19 deletions(-)
>>
>> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
>> index 6c3125300c00..2e38edd5838c 100644
>> --- a/include/linux/tpm.h
>> +++ b/include/linux/tpm.h
>> @@ -87,7 +87,8 @@ struct tpm_class_ops {
>>  	const u8 req_complete_val;
>>  	bool (*req_canceled)(struct tpm_chip *chip, u8 status);
>>  	int (*recv) (struct tpm_chip *chip, u8 *buf, size_t len);
>> -	int (*send) (struct tpm_chip *chip, u8 *buf, size_t len);
>> +	int (*send)(struct tpm_chip *chip, u8 *buf, size_t cmd_len,
>> +		    size_t buf_size);
>>  	void (*cancel) (struct tpm_chip *chip);
>>  	u8 (*status) (struct tpm_chip *chip);
>>  	void (*update_timeouts)(struct tpm_chip *chip,
>> diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c
>> index c0771980bc2f..3de68bca1740 100644
>> --- a/drivers/char/tpm/st33zp24/st33zp24.c
>> +++ b/drivers/char/tpm/st33zp24/st33zp24.c
>> @@ -300,7 +300,7 @@ static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
>>   * send TPM commands through the I2C bus.
>>   */
>>  static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
>> -			 size_t len)
>> +			 size_t len, size_t buf_size)
>>  {
>>  	struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
>>  	u32 status, i, size, ordinal;
>> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
>> index 8d7e4da6ed53..3b6ddcdb4051 100644
>> --- a/drivers/char/tpm/tpm-interface.c
>> +++ b/drivers/char/tpm/tpm-interface.c
>> @@ -106,7 +106,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
>>  		return -E2BIG;
>>  	}
>>
>> -	rc = chip->ops->send(chip, buf, count);
>> +	rc = chip->ops->send(chip, buf, count, bufsiz);
>>  	if (rc < 0) {
>>  		if (rc != -EPIPE)
>>  			dev_err(&chip->dev,
>> diff --git a/drivers/char/tpm/tpm_atmel.c b/drivers/char/tpm/tpm_atmel.c
>> index 54a0360a3c95..5733168bfc26 100644
>> --- a/drivers/char/tpm/tpm_atmel.c
>> +++ b/drivers/char/tpm/tpm_atmel.c
>> @@ -148,7 +148,8 @@ static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>>  	return size;
>>  }
>>
>> -static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
>> +static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count,
>> +			 size_t buf_size)
>>  {
>>  	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
>>  	int i;
>> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
>> index 876edf2705ab..38f765a44a97 100644
>> --- a/drivers/char/tpm/tpm_crb.c
>> +++ b/drivers/char/tpm/tpm_crb.c
>> @@ -426,7 +426,7 @@ static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
>>  }
>>  #endif
>>
>> -static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
>> +static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len, size_t buf_size)
>>  {
>>  	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
>>  	int rc = 0;
>> diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
>> index 53ba28ccd5d3..637cc8b6599e 100644
>> --- a/drivers/char/tpm/tpm_ftpm_tee.c
>> +++ b/drivers/char/tpm/tpm_ftpm_tee.c
>> @@ -64,12 +64,14 @@ static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>>   * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h
>>   * @buf:	the buffer to send.
>>   * @len:	the number of bytes to send.
>> + * @buf_size:	the size of the buffer.
>>   *
>>   * Return:
>>   *	In case of success, returns 0.
>>   *	On failure, -errno
>>   */
>> -static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len)
>> +static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len,
>> +				size_t buf_size)
>>  {
>>  	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
>>  	size_t resp_len;
>> diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
>> index d1d27fdfe523..572f97cb9e89 100644
>> --- a/drivers/char/tpm/tpm_i2c_atmel.c
>> +++ b/drivers/char/tpm/tpm_i2c_atmel.c
>> @@ -37,7 +37,8 @@ struct priv_data {
>>  	u8 buffer[sizeof(struct tpm_header) + 25];
>>  };
>>
>> -static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
>> +static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len,
>> +			  size_t buf_size)
>>  {
>>  	struct priv_data *priv = dev_get_drvdata(&chip->dev);
>>  	struct i2c_client *client = to_i2c_client(chip->dev.parent);
>> diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
>> index 81d8a78dc655..25d6ae3a4cc1 100644
>> --- a/drivers/char/tpm/tpm_i2c_infineon.c
>> +++ b/drivers/char/tpm/tpm_i2c_infineon.c
>> @@ -514,7 +514,8 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>>  	return size;
>>  }
>>
>> -static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
>> +static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len,
>> +			    size_t buf_size)
>>  {
>>  	int rc, status;
>>  	ssize_t burstcnt;
>> diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
>> index 3c3ee5f551db..169078ce6ac4 100644
>> --- a/drivers/char/tpm/tpm_i2c_nuvoton.c
>> +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
>> @@ -350,7 +350,8 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>>   * tpm.c can skip polling for the data to be available as the interrupt is
>>   * waited for here
>>   */
>> -static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
>> +static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len,
>> +			    size_t buf_size)
>>  {
>>  	struct priv_data *priv = dev_get_drvdata(&chip->dev);
>>  	struct device *dev = chip->dev.parent;
>> diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
>> index 76d048f63d55..660a7f9da1d8 100644
>> --- a/drivers/char/tpm/tpm_ibmvtpm.c
>> +++ b/drivers/char/tpm/tpm_ibmvtpm.c
>> @@ -191,13 +191,15 @@ static int tpm_ibmvtpm_resume(struct device *dev)
>>   * tpm_ibmvtpm_send() - Send a TPM command
>>   * @chip:	tpm chip struct
>>   * @buf:	buffer contains data to send
>> - * @count:	size of buffer
>> + * @count:	length of the command
>> + * @buf_size:   size of the buffer
>>   *
>>   * Return:
>>   *   0 on success,
>>   *   -errno on error
>>   */
>> -static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
>> +static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count,
>> +			    size_t buf_size)
>>  {
>>  	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
>>  	bool retry = true;
>> diff --git a/drivers/char/tpm/tpm_infineon.c b/drivers/char/tpm/tpm_infineon.c
>> index 2d2ae37153ba..7896fdacd156 100644
>> --- a/drivers/char/tpm/tpm_infineon.c
>> +++ b/drivers/char/tpm/tpm_infineon.c
>> @@ -312,7 +312,8 @@ static int tpm_inf_recv(struct tpm_chip *chip, u8 * buf, size_t count)
>>  	return -EIO;
>>  }
>>
>> -static int tpm_inf_send(struct tpm_chip *chip, u8 * buf, size_t count)
>> +static int tpm_inf_send(struct tpm_chip *chip, u8 *buf, size_t count,
>> +			size_t buf_size)
>>  {
>>  	int i;
>>  	int ret;
>> diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
>> index 0f62bbc940da..12aedef3c50e 100644
>> --- a/drivers/char/tpm/tpm_nsc.c
>> +++ b/drivers/char/tpm/tpm_nsc.c
>> @@ -178,7 +178,8 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
>>  	return size;
>>  }
>>
>> -static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
>> +static int tpm_nsc_send(struct tpm_chip *chip, u8 *buf, size_t count,
>> +			size_t buf_size)
>>  {
>>  	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
>>  	u8 data;
>> diff --git a/drivers/char/tpm/tpm_svsm.c b/drivers/char/tpm/tpm_svsm.c
>> index 4280edf427d6..d3ca5615b6f7 100644
>> --- a/drivers/char/tpm/tpm_svsm.c
>> +++ b/drivers/char/tpm/tpm_svsm.c
>> @@ -25,7 +25,8 @@ struct tpm_svsm_priv {
>>  	void *buffer;
>>  };
>>
>> -static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t len)
>> +static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t len,
>> +			 size_t buf_size)
>>  {
>>  	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
>>  	int ret;
>> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
>> index ed0d3d8449b3..5641a73ce280 100644
>> --- a/drivers/char/tpm/tpm_tis_core.c
>> +++ b/drivers/char/tpm/tpm_tis_core.c
>> @@ -580,7 +580,8 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
>>  	return rc;
>>  }
>>
>> -static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
>> +static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len,
>> +			size_t buf_size)
>>  {
>>  	int rc, irq;
>>  	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
>> diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c
>> index 3b55a7b05c46..1914b368472d 100644
>> --- a/drivers/char/tpm/tpm_tis_i2c_cr50.c
>> +++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c
>> @@ -546,13 +546,15 @@ static int tpm_cr50_i2c_tis_recv(struct tpm_chip *chip, u8 *buf, size_t buf_len)
>>   * tpm_cr50_i2c_tis_send() - TPM transmission callback.
>>   * @chip:	A TPM chip.
>>   * @buf:	Buffer to send.
>> - * @len:	Buffer length.
>> + * @len:	Command length.
>> + * @buf_size:	Buffer size.
>>   *
>>   * Return:
>>   * - 0:		Success.
>>   * - -errno:	A POSIX error code.
>>   */
>> -static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
>> +static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t len,
>> +				 size_t buf_size)
>>  {
>>  	size_t burstcnt, limit, sent = 0;
>>  	u8 tpm_go[4] = { TPM_STS_GO };
>> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
>> index 8fe4a01eea12..beaa84428b49 100644
>> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
>> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
>> @@ -322,11 +322,13 @@ static int vtpm_proxy_is_driver_command(struct tpm_chip *chip,
>>   * @chip: tpm chip to use
>>   * @buf: send buffer
>>   * @count: bytes to send
>> + * @buf_size: size of the buffer
>>   *
>>   * Return:
>>   *      0 in case of success, negative error value otherwise.
>>   */
>> -static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count)
>> +static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count,
>> +				  size_t buf_size)
>>  {
>>  	struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev);
>>
>> diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c
>> index 80cca3b83b22..66a4dbb4a4d8 100644
>> --- a/drivers/char/tpm/xen-tpmfront.c
>> +++ b/drivers/char/tpm/xen-tpmfront.c
>> @@ -131,7 +131,8 @@ static size_t shr_data_offset(struct vtpm_shared_page *shr)
>>  	return struct_size(shr, extra_pages, shr->nr_extra_pages);
>>  }
>>
>> -static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
>> +static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t count,
>> +		     size_t buf_size)
>>  {
>>  	struct tpm_private *priv = dev_get_drvdata(&chip->dev);
>>  	struct vtpm_shared_page *shr = priv->shr;
>> --
>> 2.49.0
>>
>>
>
>BR, Jarkko
>



More information about the Linuxppc-dev mailing list