Instantiate CAAM RNG with prediction resistance enabled to improve its quality (with PR on DRNG is forced to reseed from TRNG every time random data is generated). Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx> Cc: Chris Healy <cphealy@xxxxxxxxx> Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> Cc: Horia Geantă <horia.geanta@xxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Iuliana Prodan <iuliana.prodan@xxxxxxx> Cc: linux-crypto@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-imx@xxxxxxx --- drivers/crypto/caam/caamrng.c | 3 ++- drivers/crypto/caam/ctrl.c | 41 +++++++++++++++++++++++++++-------- drivers/crypto/caam/desc.h | 2 ++ drivers/crypto/caam/regs.h | 4 +++- 4 files changed, 39 insertions(+), 11 deletions(-) diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c index 790624ae83c6..62f3a69ae837 100644 --- a/drivers/crypto/caam/caamrng.c +++ b/drivers/crypto/caam/caamrng.c @@ -77,7 +77,8 @@ static u32 *caam_init_desc(u32 *desc, dma_addr_t dst_dma, int len) { init_job_desc(desc, 0); /* + 1 cmd_sz */ /* Generate random bytes: + 1 cmd_sz */ - append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG); + append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG | + OP_ALG_PR_ON); /* Store bytes */ append_fifo_store(desc, dst_dma, len, FIFOST_TYPE_RNGSTORE); diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c index bcbc832b208e..ad3f6aa921d3 100644 --- a/drivers/crypto/caam/ctrl.c +++ b/drivers/crypto/caam/ctrl.c @@ -36,7 +36,8 @@ static void build_instantiation_desc(u32 *desc, int handle, int do_sk) init_job_desc(desc, 0); op_flags = OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG | - (handle << OP_ALG_AAI_SHIFT) | OP_ALG_AS_INIT; + (handle << OP_ALG_AAI_SHIFT) | OP_ALG_AS_INIT | + OP_ALG_PR_ON; /* INIT RNG in non-test mode */ append_operation(desc, op_flags); @@ -276,12 +277,25 @@ static int instantiate_rng(struct device *ctrldev, int state_handle_mask, return -ENOMEM; for (sh_idx = 0; sh_idx < RNG4_MAX_HANDLES; sh_idx++) { + const u32 rdsta_if = RDSTA_IF0 << sh_idx; + const u32 rdsta_pr = RDSTA_PR0 << sh_idx; + const u32 rdsta_mask = rdsta_if | rdsta_pr; /* * If the corresponding bit is set, this state handle * was initialized by somebody else, so it's left alone. */ - if ((1 << sh_idx) & state_handle_mask) - continue; + if (rdsta_if & state_handle_mask) { + if (rdsta_pr & state_handle_mask) + continue; + + dev_info(ctrldev, + "RNG4 SH%d was previously instantiated without prediction resistance. Tearing it down\n", + sh_idx); + + ret = deinstantiate_rng(ctrldev, rdsta_if); + if (ret) + break; + } /* Create the descriptor for instantiating RNG State Handle */ build_instantiation_desc(desc, sh_idx, gen_sk); @@ -301,9 +315,9 @@ static int instantiate_rng(struct device *ctrldev, int state_handle_mask, if (ret) break; - rdsta_val = rd_reg32(&ctrl->r4tst[0].rdsta) & RDSTA_IFMASK; + rdsta_val = rd_reg32(&ctrl->r4tst[0].rdsta) & RDSTA_MASK; if ((status && status != JRSTA_SSRC_JUMP_HALT_CC) || - !(rdsta_val & (1 << sh_idx))) { + (rdsta_val & rdsta_mask) != rdsta_mask) { ret = -EAGAIN; break; } @@ -563,6 +577,15 @@ static void caam_remove_debugfs(void *root) } #endif +static bool caam_mc_skip_hwrng_init(struct caam_drv_private *ctrlpriv) +{ + return ctrlpriv->mc_en; + /* + * FIXME: Add check for MC firmware version that need + * reinitialization due to PR bit + */ +} + /* Probe routine for CAAM top (controller) level */ static int caam_probe(struct platform_device *pdev) { @@ -783,7 +806,7 @@ static int caam_probe(struct platform_device *pdev) * 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) { + if (!caam_mc_skip_hwrng_init(ctrlpriv) && rng_vid >= 4) { ctrlpriv->rng4_sh_init = rd_reg32(&ctrl->r4tst[0].rdsta); /* @@ -793,11 +816,11 @@ static int caam_probe(struct platform_device *pdev) * to regenerate these keys before the next POR. */ gen_sk = ctrlpriv->rng4_sh_init & RDSTA_SKVN ? 0 : 1; - ctrlpriv->rng4_sh_init &= RDSTA_IFMASK; + ctrlpriv->rng4_sh_init &= RDSTA_MASK; do { int inst_handles = rd_reg32(&ctrl->r4tst[0].rdsta) & - RDSTA_IFMASK; + RDSTA_MASK; /* * If either SH were instantiated by somebody else * (e.g. u-boot) then it is assumed that the entropy @@ -837,7 +860,7 @@ static int caam_probe(struct platform_device *pdev) * Set handles init'ed by this module as the complement of the * already initialized ones */ - ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_IFMASK; + ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_MASK; /* Enable RDB bit so that RNG works faster */ clrsetbits_32(&ctrl->scfgr, 0, SCFGR_RDBENABLE); diff --git a/drivers/crypto/caam/desc.h b/drivers/crypto/caam/desc.h index 4b6854bf896a..e796d3cb9be8 100644 --- a/drivers/crypto/caam/desc.h +++ b/drivers/crypto/caam/desc.h @@ -1254,6 +1254,8 @@ #define OP_ALG_ICV_OFF (0 << OP_ALG_ICV_SHIFT) #define OP_ALG_ICV_ON (1 << OP_ALG_ICV_SHIFT) +#define OP_ALG_PR_ON BIT(1) + #define OP_ALG_DIR_SHIFT 0 #define OP_ALG_DIR_MASK 1 #define OP_ALG_DECRYPT 0 diff --git a/drivers/crypto/caam/regs.h b/drivers/crypto/caam/regs.h index c191e8fd0fa7..0f810bc13b2b 100644 --- a/drivers/crypto/caam/regs.h +++ b/drivers/crypto/caam/regs.h @@ -524,9 +524,11 @@ struct rng4tst { u32 rsvd1[40]; #define RDSTA_SKVT 0x80000000 #define RDSTA_SKVN 0x40000000 +#define RDSTA_PR0 BIT(4) +#define RDSTA_PR1 BIT(5) #define RDSTA_IF0 0x00000001 #define RDSTA_IF1 0x00000002 -#define RDSTA_IFMASK (RDSTA_IF1 | RDSTA_IF0) +#define RDSTA_MASK (RDSTA_PR1 | RDSTA_PR0 | RDSTA_IF1 | RDSTA_IF0) u32 rdsta; u32 rsvd2[15]; }; -- 2.21.0