[PATCH 2/3] crypto/fsl: Introduce SPL_FSL_CAAM_RNG

[Tim Harvey]

On Fri, Apr 26, 2024 at 7:45 AM Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 26.04.24 06:03, Marek Vasut wrote:
> > On 4/26/24 2:16 AM, Tim Harvey wrote:
> >
> >>> diff --git a/drivers/crypto/fsl/Makefile b/drivers/crypto/fsl/Makefile
> >>> index 7a2543e16cc..4fbce519a0b 100644
> >>> --- a/drivers/crypto/fsl/Makefile
> >>> +++ b/drivers/crypto/fsl/Makefile
> >>> @@ -6,6 +6,6 @@ obj-y += sec.o
> >>>   obj-$(CONFIG_FSL_CAAM) += jr.o fsl_hash.o jobdesc.o error.o
> >>>   obj-$(CONFIG_CMD_BLOB)$(CONFIG_IMX_CAAM_DEK_ENCAP) += fsl_blob.o
> >>>   obj-$(CONFIG_RSA_FREESCALE_EXP) += fsl_rsa.o
> >>> -obj-$(CONFIG_FSL_CAAM_RNG) += rng.o
> >>> +obj-$(CONFIG_$(SPL_TPL_)FSL_CAAM_RNG) += rng.o
> >>>   obj-$(CONFIG_FSL_DCP_RNG) += dcp_rng.o
> >>>   obj-$(CONFIG_FSL_MFGPROT) += fsl_mfgprot.o
> >>> --
> >>> 2.43.0
> >>>
> >>
> >> Marek,
> >
> > Hi,
> >
> >> Thanks - this series does solve the issue I am seeing in the SPL when
> >> enabling DM_RNG. Is this going to cause an issue for people who expect
> >> it to be currently enabled and now have to manually enable it?
> >
> > That's a good question. If I do '$ git grep FSL_CAAM_RNG' , there seem
> > to be no users, so I don't think we need to worry here, right ?
> >
> > With SPL_DM_RNG i.e. 1/3 I am a bit more concerned. But, looking at the
> > users that enable DM_RNG, I am not seeing any obvious ones that would
> > require SPL_DM_RNG too. What do you think ?
>
> Grepping for UCLASS_RNG should find usages.
>
> The only possible SPL usage seems to be in net/net_rand.h. Here a
> fallback to the mac address as seed exists.
>
> Best regards
>
> Heinrich
>

Hi Heinrich,

looks like its also used in lib/uuid.c by CONFIG_RANDOM_UUID and the
few configs have CONFIG_RANDOM_UUID=y do not have DM_RNG=y so not an
issue.

srand_mac is used in:
net/bootp.c which is CONFIG_CMD_BOOTP so not SPL
net/dhcpv6.c which is CONIFG_CMD_DHCP6 so not in SPL
net/net.c which is used by CONFIG_SPL_DM_ETH and the fallback you
refer to but 'git grep DM_RNG=y configs/ | cut -d: -f1 | xargs grep
SPL_DM_ETH' shows no results so I think this is ok right?

but I also see lib/efi_loader/efi_rng.c where UCLASS_RNG used by
efi_rng_protocol - I don't know anything about efi... is this going to
be used by SPL?

Best Regards,

Tim