Re: [PATCH v10 05/14] tpm, tpm_tis: Claim locality before writing interrupt registers

Jarkko Sakkinen
2022-11-24T00:55:36Z

On Sun, Nov 20, 2022 at 02:31:25PM +0100, Lino Sanfilippo wrote:
> From: Lino Sanfilippo <l.sanfilippo@kunbus.com>
>
> In tpm_tis_probe_single_irq() interrupt registers TPM_INT_VECTOR,
> TPM_INT_STATUS and TPM_INT_ENABLE are modified to setup the interrupts.
> Currently these modifications are done without holding a locality thus they
> have no effect. Fix this by claiming the (default) locality before the
> registers are written.
>
> Since now tpm_tis_gen_interrupt() is called with the locality already
> claimed remove locality request and release from this function.
>
> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
> ---
> drivers/char/tpm/tpm_tis_core.c | 21 +++++++++++----------
> 1 file changed, 11 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 1eac1279594d..58a53ec534aa 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -734,18 +734,11 @@ static void tpm_tis_gen_interrupt(struct tpm_chip *chip)
> const char *desc = "attempting to generate an interrupt";
> u32 cap2;
> cap_t cap;
> - int ret;
> -
> - ret = request_locality(chip, 0);
> - if (ret < 0)
> - return;
>
> if (chip->flags & TPM_CHIP_FLAG_TPM2)
> tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
> else
> tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc, 0);
> -
> - release_locality(chip, 0);
> }
>
> /* Register the IRQ and issue a command that will cause an interrupt. If an
> @@ -768,10 +761,16 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
> }
> priv->irq = irq;
>
> + rc = request_locality(chip, 0);
> + if (rc < 0)
> + return rc;
> +
> rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
> &original_int_vec);
> - if (rc < 0)
> + if (rc < 0) {
> + release_locality(chip, priv->locality);
> return rc;
> + }
>
> rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
> if (rc < 0)
> @@ -805,10 +804,12 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
> if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
> tpm_tis_write8(priv, original_int_vec,
> TPM_INT_VECTOR(priv->locality));
> - return -1;
> + rc = -1;
> }
>
> - return 0;
> + release_locality(chip, priv->locality);
> +
> + return rc;
> }
>
> /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
> --
> 2.36.1
>

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

BR, Jarkko