Re: [PATCH 2/2] tpm, tpm_tis: reuse code in disable_interrupts()

Péter Ujfalusi
2023-05-23T07:08:20Z

On 22/05/2023 17:31, Lino Sanfilippo wrote:
> From: Lino Sanfilippo <l.sanfilippo@kunbus.com>
>
> Avoid code redundancy by shifting part of the code in disable_interrupts()
> into a subfunction and reusing this function in tpm_tis_handle_irq_storm().
> Make sure that in the subfunction the INT_ENABLE register is written with a
> claimed locality even if the caller did not claim it before.
>
> In the shifted code get rid of the variable "rc" by initializing the
> interrupt mask to zero at variable declaration.

Reviewed-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>

> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
> ---
> drivers/char/tpm/tpm_tis_core.c | 36 ++++++++++++++++-----------------
> 1 file changed, 17 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 458ebf8c2f16..8f4f2cb5520f 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -468,25 +468,32 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
> return rc;
> }
>
> +static void __tpm_tis_disable_interrupts(struct tpm_chip *chip)
> +{
> + struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> + u32 intmask = 0;
> +
> + tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
> + intmask &= ~TPM_GLOBAL_INT_ENABLE;
> +
> + tpm_tis_request_locality(chip, 0);
> + tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
> + tpm_tis_relinquish_locality(chip, 0);
> +
> + chip->flags &= ~TPM_CHIP_FLAG_IRQ;
> +}
> +
> static void disable_interrupts(struct tpm_chip *chip)
> {
> struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> - u32 intmask;
> - int rc;
>
> if (priv->irq == 0)
> return;
>
> - rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
> - if (rc < 0)
> - intmask = 0;
> -
> - intmask &= ~TPM_GLOBAL_INT_ENABLE;
> - rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
> + __tpm_tis_disable_interrupts(chip);
>
> devm_free_irq(chip->dev.parent, priv->irq, chip);
> priv->irq = 0;
> - chip->flags &= ~TPM_CHIP_FLAG_IRQ;
> }
>
> /*
> @@ -755,20 +762,11 @@ static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
> static void tpm_tis_handle_irq_storm(struct tpm_chip *chip)
> {
> struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> - int intmask = 0;
>
> dev_err(&chip->dev, HW_ERR
> "TPM interrupt storm detected, polling instead\n");
>
> - tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
> -
> - intmask &= ~TPM_GLOBAL_INT_ENABLE;
> -
> - tpm_tis_request_locality(chip, 0);
> - tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
> - tpm_tis_relinquish_locality(chip, 0);
> -
> - chip->flags &= ~TPM_CHIP_FLAG_IRQ;
> + __tpm_tis_disable_interrupts(chip);
>
> /*
> * We must not call devm_free_irq() from within the interrupt handler,

--
Péter