On Wed, Jun 08, 2016 at 04:00:17PM -0700, Ed Swierk wrote:
> Some TPM chips report bogus command durations in their capabilities,
> just as others report incorrect timeouts. Rework tpm_get_timeouts()
> to allow chip drivers to override either via a single callback.
> Also clean up handling of TPMs that report milliseconds instead of
> microseconds.
> 
> Signed-off-by: Ed Swierk <eswi...@skyportsystems.com>
> ---
>  drivers/char/tpm/tpm-interface.c | 177 
> +++++++++++++++++++++------------------
>  drivers/char/tpm/tpm_tis.c       |  35 ++------
>  include/linux/tpm.h              |   3 +-
>  3 files changed, 106 insertions(+), 109 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-interface.c 
> b/drivers/char/tpm/tpm-interface.c
> index cc1e5bc..b8a08bb 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -502,123 +502,138 @@ static int tpm_startup(struct tpm_chip *chip, __be16 
> startup_type)
>                               "attempting to start the TPM");
>  }
>  
> -int tpm_get_timeouts(struct tpm_chip *chip)
> +static int tpm_get_cap_prop(struct tpm_chip *chip, __be32 type, int size,
> +                         cap_t *cap, char *desc)
>  {
>       struct tpm_cmd_t tpm_cmd;
> -     unsigned long new_timeout[4];
> -     unsigned long old_timeout[4];
> -     struct duration_t *duration_cap;
>       ssize_t rc;
>  
>       tpm_cmd.header.in = tpm_getcap_header;
>       tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
>       tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> -     tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> +     tpm_cmd.params.getcap_in.subcap = type;
>       rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
>  
>       if (rc == TPM_ERR_INVALID_POSTINIT) {
>               /* The TPM is not started, we are the first to talk to it.
>                  Execute a startup command. */
> -             dev_info(chip->pdev, "Issuing TPM_STARTUP");
> +             dev_info(chip->pdev, "Issuing TPM_STARTUP\n");
>               if (tpm_startup(chip, TPM_ST_CLEAR))
>                       return rc;
>  
>               tpm_cmd.header.in = tpm_getcap_header;
>               tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
>               tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> -             tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> +             tpm_cmd.params.getcap_in.subcap = type;
>               rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
>                                 NULL);
>       }
> +
>       if (rc) {
>               dev_err(chip->pdev,
> -                     "A TPM error (%zd) occurred attempting to determine the 
> timeouts\n",
> -                     rc);
> -             goto duration;
> +                     "Error %zd reading %s\n", rc, desc);
> +             return -EINVAL;
>       }
>  
>       if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
>           be32_to_cpu(tpm_cmd.header.out.length)
> -         != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
> +         != sizeof(tpm_cmd.header.out) + sizeof(u32) + size * sizeof(u32)) {
> +             dev_err(chip->pdev,
> +                     "Bad return code or length reading %s\n", desc);
>               return -EINVAL;
> -
> -     old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
> -     old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
> -     old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
> -     old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
> -     memcpy(new_timeout, old_timeout, sizeof(new_timeout));
> -
> -     /*
> -      * Provide ability for vendor overrides of timeout values in case
> -      * of misreporting.
> -      */
> -     if (chip->ops->update_timeouts != NULL)
> -             chip->vendor.timeout_adjusted =
> -                     chip->ops->update_timeouts(chip, new_timeout);
> -
> -     if (!chip->vendor.timeout_adjusted) {
> -             /* Don't overwrite default if value is 0 */
> -             if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
> -                     int i;
> -
> -                     /* timeouts in msec rather usec */
> -                     for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
> -                             new_timeout[i] *= 1000;
> -                     chip->vendor.timeout_adjusted = true;
> -             }
>       }
>  
> -     /* Report adjusted timeouts */
> -     if (chip->vendor.timeout_adjusted) {
> -             dev_info(chip->pdev,
> -                      HW_ERR "Adjusting reported timeouts: A %lu->%luus B 
> %lu->%luus C %lu->%luus D %lu->%luus\n",
> -                      old_timeout[0], new_timeout[0],
> -                      old_timeout[1], new_timeout[1],
> -                      old_timeout[2], new_timeout[2],
> -                      old_timeout[3], new_timeout[3]);
> -     }
> +     memcpy(cap, &tpm_cmd.params.getcap_out.cap, sizeof(cap_t));
>  
> -     chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
> -     chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
> -     chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
> -     chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
> +     return 0;
> +}
>  
> -duration:
> -     tpm_cmd.header.in = tpm_getcap_header;
> -     tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
> -     tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> -     tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
> +int tpm_get_timeouts(struct tpm_chip *chip)
> +{
> +     cap_t cap1, cap2;
> +     int rc1, rc2;
> +     struct tpm_vendor_specific orig_vendor;
> +
> +     rc1 = tpm_get_cap_prop(chip, TPM_CAP_PROP_TIS_TIMEOUT, 4, &cap1,
> +                            "timeouts");
> +     if (rc1 == 0) {
> +             be32_to_cpus(&cap1.timeout.a);
> +             be32_to_cpus(&cap1.timeout.b);
> +             be32_to_cpus(&cap1.timeout.c);
> +             be32_to_cpus(&cap1.timeout.d);
> +             chip->vendor.timeout_a = usecs_to_jiffies(cap1.timeout.a);
> +             chip->vendor.timeout_b = usecs_to_jiffies(cap1.timeout.b);
> +             chip->vendor.timeout_c = usecs_to_jiffies(cap1.timeout.c);
> +             chip->vendor.timeout_d = usecs_to_jiffies(cap1.timeout.d);
> +     }
> +     rc2 = tpm_get_cap_prop(chip, TPM_CAP_PROP_TIS_DURATION, 3, &cap2,
> +                            "durations");
> +     if (rc2 == 0) {
> +             be32_to_cpus(&cap2.duration.tpm_short);
> +             be32_to_cpus(&cap2.duration.tpm_medium);
> +             be32_to_cpus(&cap2.duration.tpm_long);
> +             chip->vendor.duration[TPM_SHORT] =
> +                     usecs_to_jiffies(cap2.duration.tpm_short);
> +             chip->vendor.duration[TPM_MEDIUM] =
> +                     usecs_to_jiffies(cap2.duration.tpm_medium);
> +             chip->vendor.duration[TPM_LONG] =
> +                     usecs_to_jiffies(cap2.duration.tpm_long);
> +     }

This is major change to the semantics. Before -EINVAL would have been
return on error condition.

PS If you want to encapsulate tpm_get_cap_prop(), that step should be
a separate commit (prepend this one).

/Jarkko

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