sunxi: backport support for Allwinner Security System PRNG

Signed-off-by: Lucian Cristian <[email protected]>

target/linux/sunxi/cortexa7/config-default

@@ -1,4 +1,5 @@
 CONFIG_DWMAC_SUN8I=y
+CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG=y
 # CONFIG_MACH_SUN4I is not set
 # CONFIG_MACH_SUN5I is not set
 # CONFIG_PINCTRL_GR8 is not set

target/linux/sunxi/cortexa8/config-default

@@ -1,6 +1,7 @@
 # CONFIG_ARCH_PHYS_ADDR_T_64BIT is not set
 # CONFIG_ARM_ERRATA_643719 is not set
 # CONFIG_ARM_LPAE is not set
+CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG=y
 # CONFIG_MACH_SUN6I is not set
 # CONFIG_MACH_SUN7I is not set
 # CONFIG_MACH_SUN8I is not set

target/linux/sunxi/patches-4.9/0054-crypto-sun4i-ss_support_the_Security_System_PRNG.patch

@@ -0,0 +1,206 @@
+From b8ae5c7387ad075ee61e8c8774ce2bca46bc9236 Mon Sep 17 00:00:00 2001
+From: Corentin LABBE <[email protected]>
+Date: Mon, 3 Jul 2017 20:48:48 +0200
+Subject: crypto: sun4i-ss - support the Security System PRNG
+
+The Security System has a PRNG, this patch adds support for it via
+crypto_rng.
+
+Signed-off-by: Corentin Labbe <[email protected]>
+Signed-off-by: Herbert Xu <[email protected]>
+---
+ drivers/crypto/Kconfig                  |  8 +++++
+ drivers/crypto/sunxi-ss/Makefile        |  1 +
+ drivers/crypto/sunxi-ss/sun4i-ss-core.c | 30 ++++++++++++++++++
+ drivers/crypto/sunxi-ss/sun4i-ss-prng.c | 56 +++++++++++++++++++++++++++++++++
+ drivers/crypto/sunxi-ss/sun4i-ss.h      | 11 +++++++
+ 5 files changed, 106 insertions(+)
+ create mode 100644 drivers/crypto/sunxi-ss/sun4i-ss-prng.c
+
+--- a/drivers/crypto/Kconfig
++++ b/drivers/crypto/Kconfig
+@@ -538,6 +538,14 @@ config CRYPTO_DEV_SUN4I_SS
+ 	  To compile this driver as a module, choose M here: the module
+ 	  will be called sun4i-ss.
+ 
++config CRYPTO_DEV_SUN4I_SS_PRNG
++	bool "Support for Allwinner Security System PRNG"
++	depends on CRYPTO_DEV_SUN4I_SS
++	select CRYPTO_RNG
++	help
++	  Select this option if you want to provide kernel-side support for
++	  the Pseudo-Random Number Generator found in the Security System.
++
+ config CRYPTO_DEV_ROCKCHIP
+ 	tristate "Rockchip's Cryptographic Engine driver"
+ 	depends on OF && ARCH_ROCKCHIP
+--- a/drivers/crypto/sunxi-ss/Makefile
++++ b/drivers/crypto/sunxi-ss/Makefile
+@@ -1,2 +1,3 @@
+ obj-$(CONFIG_CRYPTO_DEV_SUN4I_SS) += sun4i-ss.o
+ sun4i-ss-y += sun4i-ss-core.o sun4i-ss-hash.o sun4i-ss-cipher.o
++sun4i-ss-$(CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG) += sun4i-ss-prng.o
+--- a/drivers/crypto/sunxi-ss/sun4i-ss-core.c
++++ b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
+@@ -214,6 +214,23 @@ static struct sun4i_ss_alg_template ss_a
+ 		}
+ 	}
+ },
++#ifdef CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG
++{
++	.type = CRYPTO_ALG_TYPE_RNG,
++	.alg.rng = {
++		.base = {
++			.cra_name		= "stdrng",
++			.cra_driver_name	= "sun4i_ss_rng",
++			.cra_priority		= 300,
++			.cra_ctxsize		= 0,
++			.cra_module		= THIS_MODULE,
++		},
++		.generate               = sun4i_ss_prng_generate,
++		.seed                   = sun4i_ss_prng_seed,
++		.seedsize               = SS_SEED_LEN / BITS_PER_BYTE,
++	}
++},
++#endif
+ };
+ 
+ static int sun4i_ss_probe(struct platform_device *pdev)
+@@ -356,6 +373,13 @@ static int sun4i_ss_probe(struct platfor
+ 				goto error_alg;
+ 			}
+ 			break;
++		case CRYPTO_ALG_TYPE_RNG:
++			err = crypto_register_rng(&ss_algs[i].alg.rng);
++			if (err) {
++				dev_err(ss->dev, "Fail to register %s\n",
++					ss_algs[i].alg.rng.base.cra_name);
++			}
++			break;
+ 		}
+ 	}
+ 	platform_set_drvdata(pdev, ss);
+@@ -370,6 +394,9 @@ error_alg:
+ 		case CRYPTO_ALG_TYPE_AHASH:
+ 			crypto_unregister_ahash(&ss_algs[i].alg.hash);
+ 			break;
++		case CRYPTO_ALG_TYPE_RNG:
++			crypto_unregister_rng(&ss_algs[i].alg.rng);
++			break;
+ 		}
+ 	}
+ 	if (ss->reset)
+@@ -394,6 +421,9 @@ static int sun4i_ss_remove(struct platfo
+ 		case CRYPTO_ALG_TYPE_AHASH:
+ 			crypto_unregister_ahash(&ss_algs[i].alg.hash);
+ 			break;
++		case CRYPTO_ALG_TYPE_RNG:
++			crypto_unregister_rng(&ss_algs[i].alg.rng);
++			break;
+ 		}
+ 	}
+ 
+--- /dev/null
++++ b/drivers/crypto/sunxi-ss/sun4i-ss-prng.c
+@@ -0,0 +1,56 @@
++#include "sun4i-ss.h"
++
++int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed,
++		       unsigned int slen)
++{
++	struct sun4i_ss_alg_template *algt;
++	struct rng_alg *alg = crypto_rng_alg(tfm);
++
++	algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
++	memcpy(algt->ss->seed, seed, slen);
++
++	return 0;
++}
++
++int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
++			   unsigned int slen, u8 *dst, unsigned int dlen)
++{
++	struct sun4i_ss_alg_template *algt;
++	struct rng_alg *alg = crypto_rng_alg(tfm);
++	int i;
++	u32 v;
++	u32 *data = (u32 *)dst;
++	const u32 mode = SS_OP_PRNG | SS_PRNG_CONTINUE | SS_ENABLED;
++	size_t len;
++	struct sun4i_ss_ctx *ss;
++	unsigned int todo = (dlen / 4) * 4;
++
++	algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
++	ss = algt->ss;
++
++	spin_lock(&ss->slock);
++
++	writel(mode, ss->base + SS_CTL);
++
++	while (todo > 0) {
++		/* write the seed */
++		for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++)
++			writel(ss->seed[i], ss->base + SS_KEY0 + i * 4);
++
++		/* Read the random data */
++		len = min_t(size_t, SS_DATA_LEN / BITS_PER_BYTE, todo);
++		readsl(ss->base + SS_TXFIFO, data, len / 4);
++		data += len / 4;
++		todo -= len;
++
++		/* Update the seed */
++		for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++) {
++			v = readl(ss->base + SS_KEY0 + i * 4);
++			ss->seed[i] = v;
++		}
++	}
++
++	writel(0, ss->base + SS_CTL);
++	spin_unlock(&ss->slock);
++	return dlen;
++}
+--- a/drivers/crypto/sunxi-ss/sun4i-ss.h
++++ b/drivers/crypto/sunxi-ss/sun4i-ss.h
+@@ -30,6 +30,7 @@
+ #include <crypto/aes.h>
+ #include <crypto/des.h>
+ #include <crypto/internal/rng.h>
++#include <crypto/rng.h>
+ 
+ #define SS_CTL            0x00
+ #define SS_KEY0           0x04
+@@ -125,6 +126,9 @@
+ #define SS_RXFIFO_EMP_INT_ENABLE	(1 << 2)
+ #define SS_TXFIFO_AVA_INT_ENABLE	(1 << 0)
+ 
++#define SS_SEED_LEN 192
++#define SS_DATA_LEN 160
++
+ struct sun4i_ss_ctx {
+ 	void __iomem *base;
+ 	int irq;
+@@ -134,6 +138,9 @@ struct sun4i_ss_ctx {
+ 	struct device *dev;
+ 	struct resource *res;
+ 	spinlock_t slock; /* control the use of the device */
++#ifdef CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG
++	u32 seed[SS_SEED_LEN / BITS_PER_LONG];
++#endif
+ };
+ 
+ struct sun4i_ss_alg_template {
+@@ -142,6 +149,7 @@ struct sun4i_ss_alg_template {
+ 	union {
+ 		struct crypto_alg crypto;
+ 		struct ahash_alg hash;
++		struct rng_alg rng;
+ 	} alg;
+ 	struct sun4i_ss_ctx *ss;
+ };
+@@ -199,3 +207,6 @@ int sun4i_ss_des_setkey(struct crypto_ab
+ 			unsigned int keylen);
+ int sun4i_ss_des3_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+ 			 unsigned int keylen);
++int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
++			   unsigned int slen, u8 *dst, unsigned int dlen);
++int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed, unsigned int slen);