diff options
| author | Aymen Sghaier <aymen.sghaier@nxp.com> | 2018-09-13 18:19:13 +0200 |
|---|---|---|
| committer | Aymen Sghaier <aymen.sghaier@nxp.com> | 2018-09-14 08:58:50 +0200 |
| commit | 2aff5ffb2c4bb19106f3faa76415b51591cbc2b2 (patch) | |
| tree | c73231b17c1334b1950645128818abcf964e00f1 | |
| parent | bada3388a1c60b99abe73c22c53cd32d95294005 (diff) | |
MLK-19053: crypto: caam: RNG4 TRNG errata
The TRNG as used in RNG4, used in CAAM has a documentation issue. The
effect is that it is possible that the entropy used to instantiate the
DRBG may be old entropy, rather than newly generated entropy. There is
proper programming guidance, but it is not in the documentation.
Signed-off-by: Aymen Sghaier <aymen.sghaier@nxp.com>
| -rw-r--r-- | drivers/crypto/fsl_caam.c | 11 | ||||
| -rw-r--r-- | drivers/crypto/fsl_caam_internal.h | 1 |
2 files changed, 9 insertions, 3 deletions
diff --git a/drivers/crypto/fsl_caam.c b/drivers/crypto/fsl_caam.c index 52c8797c2b..8ff1b3a28c 100644 --- a/drivers/crypto/fsl_caam.c +++ b/drivers/crypto/fsl_caam.c @@ -339,7 +339,12 @@ static void kick_trng(u32 ent_delay) u32 val; /* Put RNG in program mode */ - setbits_le32(CAAM_RTMCTL, RTMCTL_PGM); + /* Setting both RTMCTL:PRGM and RTMCTL:TRNG_ACC causes TRNG to + * properly invalidate the entropy in the entropy register and + * force re-generation. + */ + setbits_le32(CAAM_RTMCTL, RTMCTL_PGM | RTMCTL_ACC); + /* Configure the RNG Entropy Delay * Performance-wise, it does not make sense to * set the delay to a value that is lower @@ -353,7 +358,7 @@ static void kick_trng(u32 ent_delay) val >>= BS_TRNG_ENT_DLY; if (ent_delay < val) { /* Put RNG4 into run mode */ - clrbits_le32(CAAM_RTMCTL, RTMCTL_PGM); + clrbits_le32(CAAM_RTMCTL, RTMCTL_PGM | RTMCTL_ACC); return; } @@ -385,7 +390,7 @@ static void kick_trng(u32 ent_delay) val &= ~BM_TRNG_SAMP_MODE; val |= TRNG_SAMP_MODE_RAW_ES_SC; /* Put RNG4 into run mode */ - val &= ~RTMCTL_PGM; + val &= ~(RTMCTL_PGM | RTMCTL_ACC); /*test with sample mode only */ __raw_writel(val, CAAM_RTMCTL); diff --git a/drivers/crypto/fsl_caam_internal.h b/drivers/crypto/fsl_caam_internal.h index dca8ba7169..a58e215d85 100644 --- a/drivers/crypto/fsl_caam_internal.h +++ b/drivers/crypto/fsl_caam_internal.h @@ -147,6 +147,7 @@ #define RTMCTL_PGM BIT(16) #define RTMCTL_ERR BIT(12) #define RTMCTL_RST BIT(6) +#define RTMCTL_ACC BIT(5) #define RDSTA_IF0 (1) #define RDSTA_IF1 (2) #define RDSTA_SKVN BIT(30) |