Re: [PATCH RFC v3 1/2] mmc: core: Add vendor hook to control reprogram keys to Crypto Engine

[Seshu Madhavi Puppala]

On 10/8/2024 7:30 PM, Ulf Hansson wrote:
> On Sun, 6 Oct 2024 at 15:55, Seshu Madhavi Puppala
> <quic_spuppala@xxxxxxxxxxx> wrote:
> > Add mmc_host_ops hook avoid_reprogram_allkeys to control
> > reprogramming keys to Inline Crypto Engine by vendor as some
> > vendors might not require this feature.
> >
> > Signed-off-by: Seshu Madhavi Puppala <quic_spuppala@xxxxxxxxxxx>
> > Co-developed-by: Ram Prakash Gupta <quic_rampraka@xxxxxxxxxxx>
> > Signed-off-by: Ram Prakash Gupta <quic_rampraka@xxxxxxxxxxx>
> > ---
> >   drivers/mmc/core/crypto.c | 8 +++++---
> >   drivers/mmc/host/sdhci.c  | 6 ++++++
> >   include/linux/mmc/host.h  | 7 +++++++
> >   3 files changed, 18 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/mmc/core/crypto.c b/drivers/mmc/core/crypto.c
> > index fec4fbf16a5b..4168f7d135ff 100644
> > --- a/drivers/mmc/core/crypto.c
> > +++ b/drivers/mmc/core/crypto.c
> > @@ -14,9 +14,11 @@
> >
> >   void mmc_crypto_set_initial_state(struct mmc_host *host)
> >   {
> > -       /* Reset might clear all keys, so reprogram all the keys. */
> > -       if (host->caps2 & MMC_CAP2_CRYPTO)
> > -               blk_crypto_reprogram_all_keys(&host->crypto_profile);
> > +       if (host->ops->avoid_reprogram_allkeys && !host->ops->avoid_reprogram_allkeys()) {
> > +               /* Reset might clear all keys, so reprogram all the keys. */
> > +               if (host->caps2 & MMC_CAP2_CRYPTO)
> > +                       blk_crypto_reprogram_all_keys(&host->crypto_profile);
>
> Don't you even need to call this once, during the first initialization
> of the card?

The first card initialization is done during the boot up for qcom socs 
and the kernel keyring contains no keys immediately after bootup.After 
the initialization of the card, the block i/o operations to encrypted 
folders will automatically trigger the corresponding program key calls 
to the crypto engine since the kernel keyring does not contain the 
required encryption key. So, it is not necessary to explicitly reprogram 
all keys for qcom socs.
> > +       }
> >   }
>
> [...]
>
> Kind regards
> Uffe