Messages in this thread | | | From | Horia Geanta <> | Subject | Re: [PATCH v6 0/7] enable CAAM's HWRNG as default | Date | Wed, 22 Jan 2020 15:11:51 +0000 |
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On 1/8/2020 5:41 PM, Andrey Smirnov wrote: > Everyone: > > This series is a continuation of original [discussion]. I don't know > if what's in the series is enough to use CAAMs HWRNG system wide, but > I am hoping that with enough iterations and feedback it will be. > Testing on DPAA2-based Layerscape platforms, for e.g. LS1088A: [...] [ 12.379136] caam_jr 8010000.jr: 20000256: CCB: desc idx 2: RNG: Prediction resistance [ 12.387036] hwrng: no data available [...]
caamrng driver fails, because RNG initialization is skipped in ctrl.c - caam_probe(): [...] np = of_find_compatible_node(NULL, NULL, "fsl,qoriq-mc"); ctrlpriv->mc_en = !!np; [...] /* * If SEC has RNG version >= 4 and RNG state handle has not been * already instantiated, do RNG instantiation * In case of SoCs with Management Complex, RNG is managed by MC f/w. */ if (!ctrlpriv->mc_en && rng_vid >= 4) { [...]
NXP is working at adding RNG Prediction Resistance support in MC f/w (will be available in v10.20.1).
However, there's a backwards-compatibility requirement: kernel should work with older MC f/w versions. To fix this, my suggestion is to force RNG (re)initialization in case MC f/w is present and its version is < 10.20.1, i.e.: if ((!ctrlpriv->mc_en || (fsl_mc_get_version() < "10.20.1")) && rng_vid >= 4) { [...]
fsl_mc_get_version() - I've made this up, it currently doesn't exist, it should be added in fsl-mc bus driver (drivers/bus/fsl-mc). We will provide this shortly, the plan being to integrate this change as part of this series.
Thanks, Horia
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