Re: [PATCH v2] tpm_tis: convert to using locality callbacks

[Jarkko Sakkinen]

On Mon, Mar 27, 2017 at 08:46:04AM -0700, Jerry Snitselaar wrote:
> This patch converts tpm_tis to use of the new tpm class ops
> request_locality, and relinquish_locality.
> 
> With the move to using the callbacks, release_locality is changed so
> that we now release the locality even if there is no request pending.
> 
> This required some changes to the tpm_tis_core_init code path to
> make sure locality is requested when needed:
> 
>   - tpm2_probe code path will end up calling request/release through
>     callbacks, so request_locality prior to tpm2_probe not needed.
> 
>   - probe_itpm makes calls to tpm_tis_send_data which no longer calls
>     request_locality, so add request_locality prior to tpm_tis_send_data
>     calls. Also drop release_locality call in middleof probe_itpm, and
>     keep locality until release_locality called at end of probe_itpm.
> 
> Cc: Peter Huewe <peterhuewe@xxxxxx>
> Cc: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> Cc: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
> Cc: Marcel Selhorst <tpmdd@xxxxxxxxxxxx>
> Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>

I'll give Reviewed-by for this and it's already in my master branch but
not yet in next because I haven't been able to test it yet. Tested-by's
are very welcome and testing should be easy to do as the change is
already pushed.

Thank you for doing this.

/Jarkko

> ---
> v2: drop release_locality call in tpm_tis_remove
> 
> drivers/char/tpm/tpm_tis_core.c | 34 ++++++++--------------------------
>  1 file changed, 8 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index f31fc831c8f9..b617b2eeb080 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -75,21 +75,11 @@ static bool check_locality(struct tpm_chip *chip, int l)
>  	return false;
>  }
>  
> -static void release_locality(struct tpm_chip *chip, int l, int force)
> +static void release_locality(struct tpm_chip *chip, int l)
>  {
>  	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> -	int rc;
> -	u8 access;
> -
> -	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
> -	if (rc < 0)
> -		return;
> -
> -	if (force || (access &
> -		      (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
> -	    (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID))
> -		tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
>  
> +	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
>  }
>  
>  static int request_locality(struct tpm_chip *chip, int l)
> @@ -254,7 +244,6 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>  
>  out:
>  	tpm_tis_ready(chip);
> -	release_locality(chip, priv->locality, 0);
>  	return size;
>  }
>  
> @@ -270,9 +259,6 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
>  	size_t count = 0;
>  	bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;
>  
> -	if (request_locality(chip, 0) < 0)
> -		return -EBUSY;
> -
>  	status = tpm_tis_status(chip);
>  	if ((status & TPM_STS_COMMAND_READY) == 0) {
>  		tpm_tis_ready(chip);
> @@ -331,7 +317,6 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
>  
>  out_err:
>  	tpm_tis_ready(chip);
> -	release_locality(chip, priv->locality, 0);
>  	return rc;
>  }
>  
> @@ -392,7 +377,6 @@ static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len)
>  	return len;
>  out_err:
>  	tpm_tis_ready(chip);
> -	release_locality(chip, priv->locality, 0);
>  	return rc;
>  }
>  
> @@ -479,12 +463,14 @@ static int probe_itpm(struct tpm_chip *chip)
>  	if (vendor != TPM_VID_INTEL)
>  		return 0;
>  
> +	if (request_locality(chip, 0) != 0)
> +		return -EBUSY;
> +
>  	rc = tpm_tis_send_data(chip, cmd_getticks, len);
>  	if (rc == 0)
>  		goto out;
>  
>  	tpm_tis_ready(chip);
> -	release_locality(chip, priv->locality, 0);
>  
>  	priv->flags |= TPM_TIS_ITPM_WORKAROUND;
>  
> @@ -498,7 +484,7 @@ static int probe_itpm(struct tpm_chip *chip)
>  
>  out:
>  	tpm_tis_ready(chip);
> -	release_locality(chip, priv->locality, 0);
> +	release_locality(chip, priv->locality);
>  
>  	return rc;
>  }
> @@ -672,7 +658,6 @@ void tpm_tis_remove(struct tpm_chip *chip)
>  		interrupt = 0;
>  
>  	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
> -	release_locality(chip, priv->locality, 1);
>  }
>  EXPORT_SYMBOL_GPL(tpm_tis_remove);
>  
> @@ -686,6 +671,8 @@ static const struct tpm_class_ops tpm_tis = {
>  	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
>  	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
>  	.req_canceled = tpm_tis_req_canceled,
> +	.request_locality = request_locality,
> +	.relinquish_locality = release_locality,
>  };
>  
>  int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> @@ -728,11 +715,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>  	intmask &= ~TPM_GLOBAL_INT_ENABLE;
>  	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
>  
> -	if (request_locality(chip, 0) != 0) {
> -		rc = -ENODEV;
> -		goto out_err;
> -	}
> -
>  	rc = tpm2_probe(chip);
>  	if (rc)
>  		goto out_err;
> -- 
> 2.11.0.258.ge05806da9
>