Re: [PATCH v3 3/6] tpm_crb: Add start_cmd parameter to tpm_crb_start wrapper

[Jarkko Sakkinen <jarkko@kernel.org>]

On Mon, May 18, 2026 at 08:47:21PM +0530, Arun Menon wrote:
> From: Arun Menon <armenon@redhat.com>
> 
> The current implementation of tpm_crb_start() is limited to triggering
> the CRB_START_INVOKE bit. To support command and response chunking, the
> driver must be able to send other control bits, like
> CRB_START_NEXT_CHUNK, using the same platform-specific paths.
> 
> This commit adds the start_cmd parameter to tpm_crb_start() so the
> caller can specify which command to send.
> 
> Signed-off-by: Arun Menon <armenon@redhat.com>
> ---
>  drivers/char/tpm/tpm_crb.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 9a2f512b4ae3..31f530744e90 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -446,7 +446,7 @@ static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
>  }
>  #endif
>  
> -static int tpm_crb_start(struct tpm_chip *chip)
> +static int tpm_crb_start(struct tpm_chip *chip, u32 start_cmd)
>  {
>  	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
>  	int rc = 0;
> @@ -457,16 +457,16 @@ static int tpm_crb_start(struct tpm_chip *chip)
>  	if (priv->sm == ACPI_TPM2_COMMAND_BUFFER ||
>  	    priv->sm == ACPI_TPM2_MEMORY_MAPPED ||
>  	    !strcmp(priv->hid, "MSFT0101"))
> -		iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
> +		iowrite32(start_cmd, &priv->regs_t->ctrl_start);
>  	if (priv->sm == ACPI_TPM2_START_METHOD ||
>  	    priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
>  		rc = crb_do_acpi_start(chip);
>  	if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
> -		iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
> +		iowrite32(start_cmd, &priv->regs_t->ctrl_start);
>  		rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
>  	}
>  	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
> -		iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
> +		iowrite32(start_cmd, &priv->regs_t->ctrl_start);
>  		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, chip->locality);
>  	}
>  	return rc;
> @@ -497,7 +497,7 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz, size_t len)
>  	/* Make sure that cmd is populated before issuing start. */
>  	wmb();
>  
> -	rc = tpm_crb_start(chip);
> +	rc = tpm_crb_start(chip, CRB_START_INVOKE);
>  	if (rc)
>  		return rc;
>  
> -- 
> 2.54.0
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko