The rockchip IP has a TRNG which could be used as a hwrng. Since TRNG is only failling rngtests on rk3328 and does not work on rk3288, the TRNG is enabled only on rk3399 via a variant. But this is not a surprise since when vendor tried to add support for TRNG upstream, rk3288 was not handled, and rk3328 was added "disabled", so I conclude this is a known problem. Anyway the quality of rk3399 TRNG is low, so a dedicated kconfig option is done to not enabled it by default. Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx> --- Hello All rk3288 compatible crypto IP have a TRNG and supporting it was awaited for some time (https://bugzilla.kernel.org/show_bug.cgi?id=216502) I has some problem with this one, it was the first time I hit so many 100% failure on rngtest. I finally bisected a RNG_SAMPLE value (1200) which lead to "only" 50-70% failure. The calcul of fail rate is done with (FIPS 140-2 successes/FIPS 140-2 failures) of rngtest. Since it is the first time I hit that case, does setting rng_quality to 300 is what to do (using the worst succes rate of 30%) ? But I am really puzzled why vendor default is to use RNG_SAMPLE=100 which is total failure (according to rngtest). Unfortunatly all my try to have more answer from them seems to have been forwarded to /dev/null. Thanks Regards drivers/crypto/Kconfig | 8 ++ drivers/crypto/rockchip/Makefile | 1 + drivers/crypto/rockchip/rk3288_crypto.c | 18 +++- drivers/crypto/rockchip/rk3288_crypto.h | 18 ++++ drivers/crypto/rockchip/rk3288_crypto_ahash.c | 2 + .../crypto/rockchip/rk3288_crypto_skcipher.c | 2 + drivers/crypto/rockchip/rk3288_crypto_trng.c | 92 +++++++++++++++++++ 7 files changed, 140 insertions(+), 1 deletion(-) create mode 100644 drivers/crypto/rockchip/rk3288_crypto_trng.c diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig index 44e44b8d9ce6..7226d441686c 100644 --- a/drivers/crypto/Kconfig +++ b/drivers/crypto/Kconfig @@ -650,6 +650,14 @@ config CRYPTO_DEV_ROCKCHIP This driver interfaces with the hardware crypto accelerator. Supporting cbc/ecb chainmode, and aes/des/des3_ede cipher mode. +config CRYPTO_DEV_ROCKCHIP_TRNG + bool "Support for Rockchip TRNG" + depends on CRYPTO_DEV_ROCKCHIP + select HW_RANDOM + help + Select this option if you want to provide kernel-side support for + the True Random Number Generator found in the Crypto IP. + config CRYPTO_DEV_ROCKCHIP_DEBUG bool "Enable Rockchip crypto stats" depends on CRYPTO_DEV_ROCKCHIP diff --git a/drivers/crypto/rockchip/Makefile b/drivers/crypto/rockchip/Makefile index 785277aca71e..11910f0e6a62 100644 --- a/drivers/crypto/rockchip/Makefile +++ b/drivers/crypto/rockchip/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_CRYPTO_DEV_ROCKCHIP) += rk_crypto.o rk_crypto-objs := rk3288_crypto.o \ rk3288_crypto_skcipher.o \ rk3288_crypto_ahash.o +rk_crypto-$(CONFIG_CRYPTO_DEV_ROCKCHIP_TRNG) += rk3288_crypto_trng.o diff --git a/drivers/crypto/rockchip/rk3288_crypto.c b/drivers/crypto/rockchip/rk3288_crypto.c index 9f6ba770a90a..880e4db812a2 100644 --- a/drivers/crypto/rockchip/rk3288_crypto.c +++ b/drivers/crypto/rockchip/rk3288_crypto.c @@ -40,15 +40,18 @@ static const struct rk_variant rk3288_variant = { .num_clks = 4, .rkclks = { { "sclk", 150000000}, - } + }, + .trng = false, }; static const struct rk_variant rk3328_variant = { .num_clks = 3, + .trng = false, }; static const struct rk_variant rk3399_variant = { .num_clks = 3, + .trng = true, }; static int rk_crypto_get_clks(struct rk_crypto_info *dev) @@ -195,6 +198,10 @@ static int rk_crypto_debugfs_show(struct seq_file *seq, void *v) seq_printf(seq, "%s %s requests: %lu\n", dev_driver_string(dd->dev), dev_name(dd->dev), dd->nreq); +#ifdef CONFIG_CRYPTO_DEV_ROCKCHIP_TRNG + seq_printf(seq, "HWRNG: %lu %lu\n", + dd->hwrng_stat_req, dd->hwrng_stat_bytes); +#endif } spin_unlock(&rocklist.lock); @@ -381,6 +388,10 @@ static int rk_crypto_probe(struct platform_device *pdev) dev_err(dev, "Fail to register crypto algorithms"); goto err_register_alg; } +#ifdef CONFIG_CRYPTO_DEV_ROCKCHIP_TRNG + if (crypto_info->variant->trng) + rk3288_hwrng_register(crypto_info); +#endif register_debugfs(crypto_info); } @@ -411,6 +422,11 @@ static int rk_crypto_remove(struct platform_device *pdev) #ifdef CONFIG_CRYPTO_DEV_ROCKCHIP_DEBUG debugfs_remove_recursive(rocklist.dbgfs_dir); #endif +#ifdef CONFIG_CRYPTO_DEV_ROCKCHIP_TRNG + if (crypto_tmp->variant->trng) + rk3288_hwrng_unregister(crypto_tmp); +#endif + rk_crypto_unregister(); } rk_crypto_pm_exit(crypto_tmp); diff --git a/drivers/crypto/rockchip/rk3288_crypto.h b/drivers/crypto/rockchip/rk3288_crypto.h index b2695258cade..016c3b72c19c 100644 --- a/drivers/crypto/rockchip/rk3288_crypto.h +++ b/drivers/crypto/rockchip/rk3288_crypto.h @@ -9,6 +9,7 @@ #include <linux/interrupt.h> #include <linux/debugfs.h> #include <linux/delay.h> +#include <linux/hw_random.h> #include <linux/pm_runtime.h> #include <linux/scatterlist.h> #include <crypto/engine.h> @@ -183,6 +184,16 @@ #define RK_CRYPTO_HASH_DOUT_6 0x01a4 #define RK_CRYPTO_HASH_DOUT_7 0x01a8 +#define RK_CRYPTO_TRNG_CTRL 0x0200 +#define RK_CRYPTO_OSC_ENABLE BIT(16) +#define RK_CRYPTO_TRNG_DOUT_0 0x0204 +/* sample < 1000 lead to 100% failure on rngtest, + * using more than 1200 does not increase success. + */ +#define RK_CRYPTO_RNG_SAMPLE 1200 + +#define RK_CRYPTO_MAX_TRNG_BYTE 32 + #define CRYPTO_READ(dev, offset) \ readl_relaxed(((dev)->reg + (offset))) #define CRYPTO_WRITE(dev, offset, val) \ @@ -212,6 +223,7 @@ struct rk_clks { struct rk_variant { int num_clks; struct rk_clks rkclks[RK_MAX_CLKS]; + bool trng; }; struct rk_crypto_info { @@ -222,11 +234,15 @@ struct rk_crypto_info { struct reset_control *rst; void __iomem *reg; int irq; + struct mutex lock; + struct hwrng hwrng; const struct rk_variant *variant; unsigned long nreq; struct crypto_engine *engine; struct completion complete; int status; + unsigned long hwrng_stat_req; + unsigned long hwrng_stat_bytes; }; /* the private variable of hash */ @@ -288,3 +304,5 @@ extern struct rk_crypto_tmp rk_ahash_md5; struct rk_crypto_info *get_rk_crypto(void); #endif +int rk3288_hwrng_register(struct rk_crypto_info *rk); +void rk3288_hwrng_unregister(struct rk_crypto_info *rk); diff --git a/drivers/crypto/rockchip/rk3288_crypto_ahash.c b/drivers/crypto/rockchip/rk3288_crypto_ahash.c index a78ff3dcd0b1..67ed3a54bc7b 100644 --- a/drivers/crypto/rockchip/rk3288_crypto_ahash.c +++ b/drivers/crypto/rockchip/rk3288_crypto_ahash.c @@ -287,6 +287,7 @@ static int rk_hash_run(struct crypto_engine *engine, void *breq) goto theend; } + mutex_lock(&rkc->lock); rk_ahash_reg_init(areq, rkc); while (sg) { @@ -321,6 +322,7 @@ static int rk_hash_run(struct crypto_engine *engine, void *breq) } theend: + mutex_unlock(&rkc->lock); pm_runtime_put_autosuspend(rkc->dev); local_bh_disable(); diff --git a/drivers/crypto/rockchip/rk3288_crypto_skcipher.c b/drivers/crypto/rockchip/rk3288_crypto_skcipher.c index 59069457582b..304c2c44fea0 100644 --- a/drivers/crypto/rockchip/rk3288_crypto_skcipher.c +++ b/drivers/crypto/rockchip/rk3288_crypto_skcipher.c @@ -357,6 +357,7 @@ static int rk_cipher_run(struct crypto_engine *engine, void *async_req) } } err = 0; + mutex_unlock(&rkc->lock); rk_cipher_hw_init(rkc, areq); if (ivsize) { if (ivsize == DES_BLOCK_SIZE) @@ -372,6 +373,7 @@ static int rk_cipher_run(struct crypto_engine *engine, void *async_req) crypto_dma_start(rkc, sgs, sgd, todo / 4); wait_for_completion_interruptible_timeout(&rkc->complete, msecs_to_jiffies(2000)); + mutex_unlock(&rkc->lock); if (!rkc->status) { dev_err(rkc->dev, "DMA timeout\n"); err = -EFAULT; diff --git a/drivers/crypto/rockchip/rk3288_crypto_trng.c b/drivers/crypto/rockchip/rk3288_crypto_trng.c new file mode 100644 index 000000000000..7a0e1300d0e8 --- /dev/null +++ b/drivers/crypto/rockchip/rk3288_crypto_trng.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * rk3288_crypto_trng.c - hardware cryptographic offloader for rockchip + * + * Copyright (C) 2022-2023 Corentin Labbe <clabbe@xxxxxxxxxxxx> + * + * This file handle the TRNG + */ +#include "rk3288_crypto.h" +#include <linux/hw_random.h> +#include <linux/iopoll.h> +#include <linux/pm_runtime.h> + +static int rk3288_trng_read(struct hwrng *hwrng, void *data, size_t max, bool wait) +{ + struct rk_crypto_info *rk; + unsigned int todo; + int err = 0; + int i; + u32 v; + + rk = container_of(hwrng, struct rk_crypto_info, hwrng); + + todo = min_t(size_t, max, RK_CRYPTO_MAX_TRNG_BYTE); + +#ifdef CONFIG_CRYPTO_DEV_ROCKCHIP_DEBUG + rk->hwrng_stat_req++; + rk->hwrng_stat_bytes += todo; +#endif + + err = pm_runtime_resume_and_get(rk->dev); + if (err < 0) + goto err_pm; + + mutex_lock(&rk->lock); + +#define HIWORD_UPDATE(val, mask, shift) \ + ((val) << (shift) | (mask) << ((shift) + 16)) + v = RK_CRYPTO_OSC_ENABLE | RK_CRYPTO_RNG_SAMPLE; + CRYPTO_WRITE(rk, RK_CRYPTO_TRNG_CTRL, v); + + v = HIWORD_UPDATE(RK_CRYPTO_TRNG_START, RK_CRYPTO_TRNG_START, 0); + CRYPTO_WRITE(rk, RK_CRYPTO_CTRL, v); + wmb(); + + err = readl_poll_timeout(rk->reg + RK_CRYPTO_CTRL, v, + !(v & RK_CRYPTO_TRNG_START), + 100, 2000); + if (err) { + dev_err(rk->dev, "HWRNG read timeout"); + goto readfail; + } + + for (i = 0; i < todo / 4; i++) { + v = readl(rk->reg + RK_CRYPTO_TRNG_DOUT_0 + i * 4); + put_unaligned_le32(v, data + i * 4); + } + + err = todo; + + v = HIWORD_UPDATE(0, RK_CRYPTO_TRNG_START, 0); + CRYPTO_WRITE(rk, RK_CRYPTO_CTRL, v); + +readfail: + mutex_unlock(&rk->lock); + + pm_runtime_put(rk->dev); + +err_pm: + return err; +} + +int rk3288_hwrng_register(struct rk_crypto_info *rk) +{ + int ret; + + dev_info(rk->dev, "Register TRNG with sample=%d\n", RK_CRYPTO_RNG_SAMPLE); + + rk->hwrng.name = "Rockchip rk3288 TRNG"; + rk->hwrng.read = rk3288_trng_read; + rk->hwrng.quality = 300; + + ret = hwrng_register(&rk->hwrng); + if (ret) + dev_err(rk->dev, "Fail to register the TRNG\n"); + return ret; +} + +void rk3288_hwrng_unregister(struct rk_crypto_info *rk) +{ + hwrng_unregister(&rk->hwrng); +} -- 2.39.3