Re: [PATCH v3 2/4] tpm: Implement tpm_chip_find() for other subsystems to find a TPM chip

[Stefan Berger]

On 06/22/2018 04:43 PM, Jason Gunthorpe wrote:
> On Fri, Jun 22, 2018 at 12:46:11PM -0400, Stefan Berger wrote:
> > Implement tpm_chip_find() for other subsystems to find a TPM chip and
> > get a reference to that chip.
> >
> > Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
> >   drivers/char/tpm/tpm-chip.c | 27 +++++++++++++++++++++++++++
> >   include/linux/tpm.h         |  5 +++++
> >   2 files changed, 32 insertions(+)
> >
> > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> > index 4e83695af068..2520555b1e17 100644
> > +++ b/drivers/char/tpm/tpm-chip.c
> > @@ -81,6 +81,33 @@ void tpm_put_ops(struct tpm_chip *chip)
> >   EXPORT_SYMBOL_GPL(tpm_put_ops);
> >   
> >   /**
> > + * tpm_chip_find() - find a TPM chip and get a reference to it
> > + */
> > +struct tpm_chip *tpm_chip_find(void)
> I feel like this should be called 'tpm_default_chip()'
>
> > +{
> > +	struct tpm_chip *chip, *res = NULL;
> > +	int chip_num = 0;
> > +	int chip_prev;
> > +
> > +	mutex_lock(&idr_lock);
> > +
> > +	do {
> > +		chip_prev = chip_num;
> > +		chip = idr_get_next(&dev_nums_idr, &chip_num);
> > +		if (chip) {
> > +			get_device(&chip->dev);
> > +			res = chip;
> > +			break;
> > +		}
> > +	} while (chip_prev != chip_num);
> > +
> > +	mutex_unlock(&idr_lock);
> And what was tpm_chip_find_get should just call this function..
And then after that each time tpm_get_ops() ?
> Jason