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

[Seshu Madhavi Puppala]

On 10/24/2024 2:58 AM, Eric Biggers wrote:
> On Sun, Oct 06, 2024 at 07:25:29PM +0530, Seshu Madhavi Puppala 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);
> > +	}
>
> This should be a simple flag, not an indirect function call which is
> inefficient.
>
> It could be a bit in mmc_host_ops, though based on the existing code maybe a new
> bit in MMC_CAP2_* would be more appropriate.

I will update this in v2 patchset by adding the flag as part of host->caps2

Thanks,
Seshu
> - Eric