[PATCH 8/9] crypto: sun8i-ce: Add support for the PRNG

From: Corentin Labbe
Date: Mon Apr 13 2020 - 06:05:26 EST

This patch had support for the PRNG present in the CE.
The output was tested with rngtest without any failure.

Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx>
---
drivers/crypto/allwinner/Kconfig | 8 +
drivers/crypto/allwinner/sun8i-ce/Makefile | 1 +
.../crypto/allwinner/sun8i-ce/sun8i-ce-core.c | 58 +++++-
.../crypto/allwinner/sun8i-ce/sun8i-ce-prng.c | 191 ++++++++++++++++++
drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h | 31 +++
5 files changed, 288 insertions(+), 1 deletion(-)
create mode 100644 drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c

diff --git a/drivers/crypto/allwinner/Kconfig b/drivers/crypto/allwinner/Kconfig
index 93cc67adb1ed..223a5823867c 100644
--- a/drivers/crypto/allwinner/Kconfig
+++ b/drivers/crypto/allwinner/Kconfig
@@ -79,6 +79,14 @@ config CRYPTO_DEV_SUN8I_CE_HASH
help
Say y to enable support for hash algorithms.

+config CRYPTO_DEV_SUN8I_CE_PRNG
+ bool "Support for Allwinner Crypto Engine PRNG"
+ depends on CRYPTO_DEV_SUN8I_CE
+ select CRYPTO_RNG
+ help
+ Select this option if you want to provide kernel-side support for
+ the Pseudo-Random Number Generator found in the Crypto Engine.
+
config CRYPTO_DEV_SUN8I_SS
tristate "Support for Allwinner Security System cryptographic offloader"
select CRYPTO_SKCIPHER
diff --git a/drivers/crypto/allwinner/sun8i-ce/Makefile b/drivers/crypto/allwinner/sun8i-ce/Makefile
index d1b1f0e86c79..c0ea81da2c7d 100644
--- a/drivers/crypto/allwinner/sun8i-ce/Makefile
+++ b/drivers/crypto/allwinner/sun8i-ce/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_CRYPTO_DEV_SUN8I_CE) += sun8i-ce.o
sun8i-ce-y += sun8i-ce-core.o sun8i-ce-cipher.o
sun8i-ce-$(CONFIG_CRYPTO_DEV_SUN8I_CE_HASH) += sun8i-ce-hash.o
+sun8i-ce-$(CONFIG_CRYPTO_DEV_SUN8I_CE_PRNG) += sun8i-ce-prng.o
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
index d65e73afbd47..54dfd7b9463e 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
@@ -22,6 +22,7 @@
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
+#include <crypto/internal/rng.h>
#include <crypto/internal/skcipher.h>

#include "sun8i-ce.h"
@@ -45,6 +46,7 @@ static const struct ce_variant ce_h3_variant = {
{ "mod", 50000000, 0 },
},
.esr = ESR_H3,
+ .prng = CE_ALG_PRNG,
};

static const struct ce_variant ce_h5_variant = {
@@ -60,6 +62,7 @@ static const struct ce_variant ce_h5_variant = {
{ "mod", 300000000, 0 },
},
.esr = ESR_H5,
+ .prng = CE_ALG_PRNG,
};

static const struct ce_variant ce_h6_variant = {
@@ -72,12 +75,14 @@ static const struct ce_variant ce_h6_variant = {
},
.cipher_t_dlen_in_bytes = true,
.hash_t_dlen_in_bits = true,
+ .prng_t_dlen_in_bytes = true,
.ce_clks = {
{ "bus", 0, 200000000 },
{ "mod", 300000000, 0 },
{ "ram", 0, 400000000 },
},
.esr = ESR_H6,
+ .prng = CE_ALG_PRNG_V2,
};

static const struct ce_variant ce_a64_variant = {
@@ -93,6 +98,7 @@ static const struct ce_variant ce_a64_variant = {
{ "mod", 300000000, 0 },
},
.esr = ESR_A64,
+ .prng = CE_ALG_PRNG,
};

static const struct ce_variant ce_r40_variant = {
@@ -108,15 +114,17 @@ static const struct ce_variant ce_r40_variant = {
{ "mod", 300000000, 0 },
},
.esr = ESR_R40,
+ .prng = CE_ALG_PRNG,
};

/*
* sun8i_ce_get_engine_number() get the next channel slot
* This is a simple round-robin way of getting the next channel
+ * The flow 3 is reserve for xRNG operations
*/
int sun8i_ce_get_engine_number(struct sun8i_ce_dev *ce)
{
- return atomic_inc_return(&ce->flow) % MAXFLOW;
+ return atomic_inc_return(&ce->flow) % (MAXFLOW - 1);
}

int sun8i_ce_run_task(struct sun8i_ce_dev *ce, int flow, const char *name)
@@ -130,6 +138,7 @@ int sun8i_ce_run_task(struct sun8i_ce_dev *ce, int flow, const char *name)
#endif

mutex_lock(&ce->mlock);
+ mutex_init(&ce->rnglock);

v = readl(ce->base + CE_ICR);
v |= 1 << flow;
@@ -516,6 +525,25 @@ static struct sun8i_ce_alg_template ce_algs[] = {
}
},
#endif
+#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_PRNG
+{
+ .type = CRYPTO_ALG_TYPE_RNG,
+ .alg.rng = {
+ .base = {
+ .cra_name = "stdrng",
+ .cra_driver_name = "sun8i-ce-prng",
+ .cra_priority = 300,
+ .cra_ctxsize = sizeof(struct sun8i_ce_rng_tfm_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_init = sun8i_ce_prng_init,
+ .cra_exit = sun8i_ce_prng_exit,
+ },
+ .generate = sun8i_ce_prng_generate,
+ .seed = sun8i_ce_prng_seed,
+ .seedsize = PRNG_SEED_SIZE,
+ }
+},
+#endif
};

#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG
@@ -543,6 +571,12 @@ static int sun8i_ce_dbgfs_read(struct seq_file *seq, void *v)
ce_algs[i].alg.hash.halg.base.cra_name,
ce_algs[i].stat_req, ce_algs[i].stat_fb);
break;
+ case CRYPTO_ALG_TYPE_RNG:
+ seq_printf(seq, "%s %s %lu %lu\n",
+ ce_algs[i].alg.rng.base.cra_driver_name,
+ ce_algs[i].alg.rng.base.cra_name,
+ ce_algs[i].stat_req, ce_algs[i].stat_bytes);
+ break;
}
}
return 0;
@@ -777,6 +811,23 @@ static int sun8i_ce_register_algs(struct sun8i_ce_dev *ce)
return err;
}
break;
+ case CRYPTO_ALG_TYPE_RNG:
+ if (ce->variant->prng == CE_ID_NOTSUPP) {
+ dev_info(ce->dev,
+ "DEBUG: Algo of %s not supported\n",
+ ce_algs[i].alg.rng.base.cra_name);
+ ce_algs[i].ce = NULL;
+ break;
+ }
+ dev_info(ce->dev, "Register %s\n",
+ ce_algs[i].alg.rng.base.cra_name);
+ err = crypto_register_rng(&ce_algs[i].alg.rng);
+ if (err) {
+ dev_err(ce->dev, "Fail to register %s\n",
+ ce_algs[i].alg.rng.base.cra_name);
+ ce_algs[i].ce = NULL;
+ }
+ break;
default:
ce_algs[i].ce = NULL;
dev_err(ce->dev, "ERROR: tried to register an unknown algo\n");
@@ -803,6 +854,11 @@ static void sun8i_ce_unregister_algs(struct sun8i_ce_dev *ce)
ce_algs[i].alg.hash.halg.base.cra_name);
crypto_unregister_ahash(&ce_algs[i].alg.hash);
break;
+ case CRYPTO_ALG_TYPE_RNG:
+ dev_info(ce->dev, "Unregister %d %s\n", i,
+ ce_algs[i].alg.rng.base.cra_name);
+ crypto_unregister_rng(&ce_algs[i].alg.rng);
+ break;
}
}
}
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
new file mode 100644
index 000000000000..4d201b1d522d
--- /dev/null
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sun8i-ce-prng.c - hardware cryptographic offloader for
+ * Allwinner H3/A64/H5/H2+/H6/R40 SoC
+ *
+ * Copyright (C) 2015-2020 Corentin Labbe <clabbe@xxxxxxxxxxxx>
+ *
+ * This file handle the PRNG
+ *
+ * You could find a link for the datasheet in Documentation/arm/sunxi/README
+ */
+#include "sun8i-ce.h"
+#include <linux/pm_runtime.h>
+#include <crypto/internal/rng.h>
+
+int sun8i_ce_prng_init(struct crypto_tfm *tfm)
+{
+ struct crypto_rng *rngtfm = __crypto_rng_cast(tfm);
+ struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(rngtfm);
+
+ memset(ctx, 0, sizeof(struct sun8i_ce_rng_tfm_ctx));
+ return 0;
+}
+
+void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
+{
+ struct crypto_rng *rngtfm = __crypto_rng_cast(tfm);
+ struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(rngtfm);
+
+ kfree(ctx->seed);
+ ctx->seed = NULL;
+ ctx->slen = 0;
+}
+
+int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,
+ unsigned int slen)
+{
+ struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
+
+ if (ctx->seed && ctx->slen != slen) {
+ ctx->slen = 0;
+ kfree(ctx->seed);
+ ctx->seed = NULL;
+ }
+ if (!ctx->seed)
+ ctx->seed = kmalloc(slen, GFP_KERNEL | GFP_DMA);
+ if (!ctx->seed)
+ return -ENOMEM;
+
+ memcpy(ctx->seed, seed, slen);
+ ctx->slen = slen;
+
+ return 0;
+}
+
+int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
+ unsigned int slen, u8 *dst, unsigned int dlen)
+{
+ struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
+ struct rng_alg *alg = crypto_rng_alg(tfm);
+ struct sun8i_ce_alg_template *algt;
+ struct sun8i_ce_dev *ce;
+ dma_addr_t dma_iv, dma_dst;
+ int err = 0;
+ int flow = 3;
+ unsigned int todo;
+ struct sun8i_ce_flow *chan;
+ struct ce_task *cet;
+ u32 common, sym;
+ dma_addr_t dma_next, dma_key;
+ void *next, *key;
+ void *d;
+
+ algt = container_of(alg, struct sun8i_ce_alg_template, alg.rng);
+ ce = algt->ce;
+
+ if (ctx->slen == 0) {
+ dev_err(ce->dev, "not seeded\n");
+ return -EINVAL;
+ }
+
+ next = kzalloc(256, GFP_KERNEL | GFP_DMA);
+ if (!next)
+ return -ENOMEM;
+
+ key = kzalloc(256, GFP_KERNEL | GFP_DMA);
+ if (!key)
+ return -ENOMEM;
+
+ /* we want dlen + seedsize rounded up to a multiple of PRNG_DATA_SIZE */
+ todo = dlen + ctx->slen + PRNG_DATA_SIZE * 2;
+ todo -= todo % PRNG_DATA_SIZE;
+
+ d = kzalloc(todo + 20, GFP_KERNEL | GFP_DMA);
+ if (!d)
+ return -ENOMEM;
+
+ dev_dbg(ce->dev, "%s PRNG slen=%u dlen=%u todo=%u multi=%u\n", __func__,
+ slen, dlen, todo, todo / PRNG_DATA_SIZE);
+
+ if (ctx->slen == 0) {
+ dev_err(ce->dev, "not seeded\n");
+ return -EINVAL;
+ }
+
+#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG
+ algt->stat_req++;
+ algt->stat_bytes += todo;
+#endif
+
+ dma_iv = dma_map_single(ce->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);
+ if (dma_mapping_error(ce->dev, dma_iv)) {
+ dev_err(ce->dev, "Cannot DMA MAP IV\n");
+ return -EFAULT;
+ }
+
+ dma_dst = dma_map_single(ce->dev, d, todo, DMA_FROM_DEVICE);
+ if (dma_mapping_error(ce->dev, dma_dst)) {
+ dev_err(ce->dev, "Cannot DMA MAP DST\n");
+ err = -EFAULT;
+ goto err_iv;
+ }
+
+ dma_next = dma_map_single(ce->dev, next, 256, DMA_FROM_DEVICE);
+ if (dma_mapping_error(ce->dev, dma_next)) {
+ dev_err(ce->dev, "Cannot DMA MAP NEXT\n");
+ err = -EFAULT;
+ goto err_iv;
+ }
+
+ dma_key = dma_map_single(ce->dev, key, 256, DMA_FROM_DEVICE);
+ if (dma_mapping_error(ce->dev, dma_key)) {
+ dev_err(ce->dev, "Cannot DMA MAP NEXT\n");
+ err = -EFAULT;
+ goto err_iv;
+ }
+
+ err = pm_runtime_get_sync(ce->dev);
+ if (err < 0)
+ goto err_pm;
+
+ mutex_lock(&ce->rnglock);
+ chan = &ce->chanlist[flow];
+
+ cet = &chan->tl[0];
+ memset(cet, 0, sizeof(struct ce_task));
+
+ cet->t_id = cpu_to_le32(flow);
+ common = ce->variant->prng | CE_COMM_INT;
+ cet->t_common_ctl = cpu_to_le32(common);
+
+ /* recent CE (H6) need length in bytes, in word otherwise */
+ if (ce->variant->prng_t_dlen_in_bytes)
+ cet->t_dlen = cpu_to_le32(todo);
+ else
+ cet->t_dlen = cpu_to_le32(todo / 4);
+
+ sym = PRNG_LD;
+ cet->t_sym_ctl = cpu_to_le32(sym);
+ cet->t_asym_ctl = 0;
+
+ cet->t_key = cpu_to_le32(dma_key);
+ cet->t_key = cpu_to_le32(dma_iv);
+ cet->t_iv = cpu_to_le32(dma_iv);
+ cet->t_ctr = cpu_to_le32(dma_next);
+
+ cet->t_dst[0].addr = cpu_to_le32(dma_dst);
+ cet->t_dst[0].len = cpu_to_le32(todo / 4);
+ ce->chanlist[flow].timeout = 2000;
+
+ err = sun8i_ce_run_task(ce, 3, "PRNG");
+ mutex_unlock(&ce->rnglock);
+
+ pm_runtime_put(ce->dev);
+
+ dma_unmap_single(ce->dev, dma_key, 256, DMA_FROM_DEVICE);
+ dma_unmap_single(ce->dev, dma_next, 256, DMA_FROM_DEVICE);
+err_pm:
+ dma_unmap_single(ce->dev, dma_dst, todo, DMA_FROM_DEVICE);
+err_iv:
+ dma_unmap_single(ce->dev, dma_iv, ctx->slen, DMA_TO_DEVICE);
+
+ if (!err) {
+ memcpy(dst, d, dlen);
+ memcpy(ctx->seed, d + dlen, ctx->slen);
+ }
+ kfree(next);
+ kfree(key);
+ kfree(d);
+ return err;
+}
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h
index ef2f1e5aa23a..2ef0c3814367 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h
@@ -14,6 +14,7 @@
#include <linux/crypto.h>
#include <crypto/internal/hash.h>
#include <crypto/md5.h>
+#include <crypto/rng.h>
#include <crypto/sha.h>

/* CE Registers */
@@ -54,6 +55,8 @@
#define CE_ALG_SHA256 19
#define CE_ALG_SHA384 20
#define CE_ALG_SHA512 21
+#define CE_ALG_PRNG 49
+#define CE_ALG_PRNG_V2 0x1d

/* Used in ce_variant */
#define CE_ID_NOTSUPP 0xFF
@@ -88,6 +91,10 @@
#define ESR_H5 3
#define ESR_H6 4

+#define PRNG_DATA_SIZE (160 / 8)
+#define PRNG_SEED_SIZE DIV_ROUND_UP(175, 8)
+#define PRNG_LD BIT(17)
+
#define CE_DIE_ID_SHIFT 16
#define CE_DIE_ID_MASK 0x07

@@ -120,8 +127,11 @@ struct ce_clock {
* bytes or words
* @hash_t_dlen_in_bytes: Does the request size for hash is in
* bits or words
+ * @prng_t_dlen_in_bytes: Does the request size for PRNG is in
+ * bytes or words
* @ce_clks: list of clocks needed by this variant
* @esr: The type of error register
+ * @prng: The CE_ALG_XXX value for the PRNG
*/
struct ce_variant {
char alg_cipher[CE_ID_CIPHER_MAX];
@@ -129,8 +139,10 @@ struct ce_variant {
u32 op_mode[CE_ID_OP_MAX];
bool cipher_t_dlen_in_bytes;
bool hash_t_dlen_in_bits;
+ bool prng_t_dlen_in_bytes;
struct ce_clock ce_clks[CE_MAX_CLOCKS];
int esr;
+ char prng;
};

struct sginfo {
@@ -185,6 +197,7 @@ struct sun8i_ce_flow {
* @reset: pointer to reset controller
* @dev: the platform device
* @mlock: Control access to device registers
+ * @rnglock: Control access to the RNG (dedicated channel 3)
* @chanlist: array of all flow
* @flow: flow to use in next request
* @variant: pointer to variant specific data
@@ -197,6 +210,7 @@ struct sun8i_ce_dev {
struct reset_control *reset;
struct device *dev;
struct mutex mlock;
+ struct mutex rnglock;
struct sun8i_ce_flow *chanlist;
atomic_t flow;
const struct ce_variant *variant;
@@ -264,6 +278,16 @@ struct sun8i_ce_hash_reqctx {
int flow;
};

+/*
+ * struct sun8i_ce_prng_ctx - context for PRNG TFM
+ * @seed: The seed to use
+ * @slen: The size of the seed
+ */
+struct sun8i_ce_rng_tfm_ctx {
+ void *seed;
+ unsigned int slen;
+};
+
/*
* struct sun8i_ce_alg_template - crypto_alg template
* @type: the CRYPTO_ALG_TYPE for this template
@@ -284,6 +308,7 @@ struct sun8i_ce_alg_template {
union {
struct skcipher_alg skcipher;
struct ahash_alg hash;
+ struct rng_alg rng;
} alg;
#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG
unsigned long stat_req;
@@ -318,3 +343,9 @@ int sun8i_ce_hash_update(struct ahash_request *areq);
int sun8i_ce_hash_finup(struct ahash_request *areq);
int sun8i_ce_hash_digest(struct ahash_request *areq);
int sun8i_ce_hash_run(struct crypto_engine *engine, void *breq);
+
+int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
+ unsigned int slen, u8 *dst, unsigned int dlen);
+int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed, unsigned int slen);
+void sun8i_ce_prng_exit(struct crypto_tfm *tfm);
+int sun8i_ce_prng_init(struct crypto_tfm *tfm);
--
2.24.1