[1/3] crypto: hw_random - Add new Exynos RNG driver

Message ID	20170324142446.31129-2-krzk@kernel.org (mailing list archive)
State	Not Applicable
Headers	show Return-Path: <linux-samsung-soc-owner@kernel.org> From: Krzysztof Kozlowski <krzk@kernel.org> To: Kukjin Kim <kgene@kernel.org>, Javier Martinez Canillas <javier@osg.samsung.com>, Matt Mackall <mpm@selenic.com>, Herbert Xu <herbert@gondor.apana.org.au>, "David S. Miller" <davem@davemloft.net>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-crypto@vger.kernel.org Cc: Arnd Bergmann <arnd@arndb.de>, Olof Johansson <olof@lixom.net>, Krzysztof Kozlowski <krzk@kernel.org> Subject: [PATCH 1/3] crypto: hw_random - Add new Exynos RNG driver Date: Fri, 24 Mar 2017 17:24:44 +0300 Message-Id: <20170324142446.31129-2-krzk@kernel.org> In-Reply-To: <20170324142446.31129-1-krzk@kernel.org> References: <20170324142446.31129-1-krzk@kernel.org> Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk

diff --git a/MAINTAINERS b/MAINTAINERS index affecc6d59f4..371fda859d43 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10977,6 +10977,14 @@ L: alsa-devel@alsa-project.org (moderated for non-subscribers) S: Supported F: sound/soc/samsung/ +SAMSUNG EXYNOS PSEUDO RANDOM NUMBER GENERATOR (RNG) DRIVER +M: Krzysztof Kozlowski <krzk@kernel.org> +L: linux-crypto@vger.kernel.org +L: linux-samsung-soc@vger.kernel.org +S: Maintained +F: drivers/crypto/exynos-rng.c +F: Documentation/devicetree/bindings/rng/samsung,exynos-rng4.txt + SAMSUNG FRAMEBUFFER DRIVER M: Jingoo Han <jingoohan1@gmail.com> L: linux-fbdev@vger.kernel.org diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 0cafe08919c9..bdae802e7154 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -294,20 +294,6 @@ config HW_RANDOM_POWERNV If unsure, say Y. -config HW_RANDOM_EXYNOS - tristate "EXYNOS HW random number generator support" - depends on ARCH_EXYNOS || COMPILE_TEST - depends on HAS_IOMEM - default HW_RANDOM - ---help--- - This driver provides kernel-side support for the Random Number - Generator hardware found on EXYNOS SOCs. - - To compile this driver as a module, choose M here: the - module will be called exynos-rng. - - If unsure, say Y. - config HW_RANDOM_TPM tristate "TPM HW Random Number Generator support" depends on TCG_TPM diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 5f52b1e4e7be..6f1eecc2045c 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -24,7 +24,6 @@ obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o -obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o obj-$(CONFIG_HW_RANDOM_HISI) += hisi-rng.o obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c deleted file mode 100644 index 23d358553b21..000000000000 --- a/drivers/char/hw_random/exynos-rng.c +++ /dev/null @@ -1,231 +0,0 @@ -/* - * exynos-rng.c - Random Number Generator driver for the exynos - * - * Copyright (C) 2012 Samsung Electronics - * Jonghwa Lee <jonghwa3.lee@samsung.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * - */ - -#include <linux/hw_random.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/io.h> -#include <linux/platform_device.h> -#include <linux/clk.h> -#include <linux/pm_runtime.h> -#include <linux/err.h> - -#define EXYNOS_PRNG_STATUS_OFFSET 0x10 -#define EXYNOS_PRNG_SEED_OFFSET 0x140 -#define EXYNOS_PRNG_OUT1_OFFSET 0x160 -#define SEED_SETTING_DONE BIT(1) -#define PRNG_START 0x18 -#define PRNG_DONE BIT(5) -#define EXYNOS_AUTOSUSPEND_DELAY 100 - -struct exynos_rng { - struct device *dev; - struct hwrng rng; - void __iomem *mem; - struct clk *clk; -}; - -static u32 exynos_rng_readl(struct exynos_rng *rng, u32 offset) -{ - return readl_relaxed(rng->mem + offset); -} - -static void exynos_rng_writel(struct exynos_rng *rng, u32 val, u32 offset) -{ - writel_relaxed(val, rng->mem + offset); -} - -static int exynos_rng_configure(struct exynos_rng *exynos_rng) -{ - int i; - int ret = 0; - - for (i = 0 ; i < 5 ; i++) - exynos_rng_writel(exynos_rng, jiffies, - EXYNOS_PRNG_SEED_OFFSET + 4*i); - - if (!(exynos_rng_readl(exynos_rng, EXYNOS_PRNG_STATUS_OFFSET) - & SEED_SETTING_DONE)) - ret = -EIO; - - return ret; -} - -static int exynos_init(struct hwrng *rng) -{ - struct exynos_rng *exynos_rng = container_of(rng, - struct exynos_rng, rng); - int ret = 0; - - pm_runtime_get_sync(exynos_rng->dev); - ret = exynos_rng_configure(exynos_rng); - pm_runtime_mark_last_busy(exynos_rng->dev); - pm_runtime_put_autosuspend(exynos_rng->dev); - - return ret; -} - -static int exynos_read(struct hwrng *rng, void *buf, - size_t max, bool wait) -{ - struct exynos_rng *exynos_rng = container_of(rng, - struct exynos_rng, rng); - u32 *data = buf; - int retry = 100; - int ret = 4; - - pm_runtime_get_sync(exynos_rng->dev); - - exynos_rng_writel(exynos_rng, PRNG_START, 0); - - while (!(exynos_rng_readl(exynos_rng, - EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE) && --retry) - cpu_relax(); - if (!retry) { - ret = -ETIMEDOUT; - goto out; - } - - exynos_rng_writel(exynos_rng, PRNG_DONE, EXYNOS_PRNG_STATUS_OFFSET); - - *data = exynos_rng_readl(exynos_rng, EXYNOS_PRNG_OUT1_OFFSET); - -out: - pm_runtime_mark_last_busy(exynos_rng->dev); - pm_runtime_put_sync_autosuspend(exynos_rng->dev); - - return ret; -} - -static int exynos_rng_probe(struct platform_device *pdev) -{ - struct exynos_rng *exynos_rng; - struct resource *res; - int ret; - - exynos_rng = devm_kzalloc(&pdev->dev, sizeof(struct exynos_rng), - GFP_KERNEL); - if (!exynos_rng) - return -ENOMEM; - - exynos_rng->dev = &pdev->dev; - exynos_rng->rng.name = "exynos"; - exynos_rng->rng.init = exynos_init; - exynos_rng->rng.read = exynos_read; - exynos_rng->clk = devm_clk_get(&pdev->dev, "secss"); - if (IS_ERR(exynos_rng->clk)) { - dev_err(&pdev->dev, "Couldn't get clock.\n"); - return -ENOENT; - } - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - exynos_rng->mem = devm_ioremap_resource(&pdev->dev, res); - if (IS_ERR(exynos_rng->mem)) - return PTR_ERR(exynos_rng->mem); - - platform_set_drvdata(pdev, exynos_rng); - - pm_runtime_set_autosuspend_delay(&pdev->dev, EXYNOS_AUTOSUSPEND_DELAY); - pm_runtime_use_autosuspend(&pdev->dev); - pm_runtime_enable(&pdev->dev); - - ret = devm_hwrng_register(&pdev->dev, &exynos_rng->rng); - if (ret) { - pm_runtime_dont_use_autosuspend(&pdev->dev); - pm_runtime_disable(&pdev->dev); - } - - return ret; -} - -static int exynos_rng_remove(struct platform_device *pdev) -{ - pm_runtime_dont_use_autosuspend(&pdev->dev); - pm_runtime_disable(&pdev->dev); - - return 0; -} - -static int __maybe_unused exynos_rng_runtime_suspend(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct exynos_rng *exynos_rng = platform_get_drvdata(pdev); - - clk_disable_unprepare(exynos_rng->clk); - - return 0; -} - -static int __maybe_unused exynos_rng_runtime_resume(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct exynos_rng *exynos_rng = platform_get_drvdata(pdev); - - return clk_prepare_enable(exynos_rng->clk); -} - -static int __maybe_unused exynos_rng_suspend(struct device *dev) -{ - return pm_runtime_force_suspend(dev); -} - -static int __maybe_unused exynos_rng_resume(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct exynos_rng *exynos_rng = platform_get_drvdata(pdev); - int ret; - - ret = pm_runtime_force_resume(dev); - if (ret) - return ret; - - return exynos_rng_configure(exynos_rng); -} - -static const struct dev_pm_ops exynos_rng_pm_ops = { - SET_SYSTEM_SLEEP_PM_OPS(exynos_rng_suspend, exynos_rng_resume) - SET_RUNTIME_PM_OPS(exynos_rng_runtime_suspend, - exynos_rng_runtime_resume, NULL) -}; - -static const struct of_device_id exynos_rng_dt_match[] = { - { - .compatible = "samsung,exynos4-rng", - }, - { }, -}; -MODULE_DEVICE_TABLE(of, exynos_rng_dt_match); - -static struct platform_driver exynos_rng_driver = { - .driver = { - .name = "exynos-rng", - .pm = &exynos_rng_pm_ops, - .of_match_table = exynos_rng_dt_match, - }, - .probe = exynos_rng_probe, - .remove = exynos_rng_remove, -}; - -module_platform_driver(exynos_rng_driver); - -MODULE_DESCRIPTION("EXYNOS 4 H/W Random Number Generator driver"); -MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>"); -MODULE_LICENSE("GPL"); diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig index 1a60626937e4..7d1fdf6a751c 100644 --- a/drivers/crypto/Kconfig +++ b/drivers/crypto/Kconfig @@ -388,6 +388,21 @@ config CRYPTO_DEV_MXC_SCC This option enables support for the Security Controller (SCC) found in Freescale i.MX25 chips. +config CRYPTO_DEV_EXYNOS_RNG + tristate "EXYNOS HW pseudo random number generator support" + depends on ARCH_EXYNOS || COMPILE_TEST + depends on HAS_IOMEM + select CRYPTO_RNG + ---help--- + This driver provides kernel-side support through the + cryptographic API for the pseudo random number generator hardware + found on Exynos SoCs. + + To compile this driver as a module, choose M here: the + module will be called exynos-rng. + + If unsure, say Y. + config CRYPTO_DEV_S5P tristate "Support for Samsung S5PV210/Exynos crypto accelerator" depends on ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile index 41ca339e89d3..9603f1862b30 100644 --- a/drivers/crypto/Makefile +++ b/drivers/crypto/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_CRYPTO_DEV_CAVIUM_ZIP) += cavium/ obj-$(CONFIG_CRYPTO_DEV_CCP) += ccp/ obj-$(CONFIG_CRYPTO_DEV_CHELSIO) += chelsio/ obj-$(CONFIG_CRYPTO_DEV_CPT) += cavium/cpt/ +obj-$(CONFIG_CRYPTO_DEV_EXYNOS_RNG) += exynos-rng.o obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM) += caam/ obj-$(CONFIG_CRYPTO_DEV_GEODE) += geode-aes.o obj-$(CONFIG_CRYPTO_DEV_HIFN_795X) += hifn_795x.o diff --git a/drivers/crypto/exynos-rng.c b/drivers/crypto/exynos-rng.c new file mode 100644 index 000000000000..9993f0eb3425 --- /dev/null +++ b/drivers/crypto/exynos-rng.c @@ -0,0 +1,306 @@ +/* + * exynos-rng.c - Random Number Generator driver for the Exynos + * + * Copyright (c) 2017 Krzysztof Kozlowski <krzk@kernel.org> + * + * Loosely based on old driver from drivers/char/hw_random/exynos-rng.c: + * Copyright (C) 2012 Samsung Electronics + * Jonghwa Lee <jonghwa3.lee@samsung.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk.h> +#include <linux/crypto.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include <crypto/internal/rng.h> + +#define EXYNOS_RNG_CONTROL 0x0 +#define EXYNOS_RNG_STATUS 0x10 +#define EXYNOS_RNG_SEED_BASE 0x140 +#define EXYNOS_RNG_SEED(n) (EXYNOS_RNG_SEED_BASE + (n * 0x4)) +#define EXYNOS_RNG_OUT_BASE 0x160 +#define EXYNOS_RNG_OUT(n) (EXYNOS_RNG_OUT_BASE + (n * 0x4)) + +/* EXYNOS_RNG_CONTROL bit fields */ +#define EXYNOS_RNG_CONTROL_START 0x18 +/* EXYNOS_RNG_STATUS bit fields */ +#define EXYNOS_RNG_STATUS_SEED_SETTING_DONE BIT(1) +#define EXYNOS_RNG_STATUS_RNG_DONE BIT(5) + +/* Five seed and output registers, each 4 bytes */ +#define EXYNOS_RNG_SEED_REGS 5 +#define EXYNOS_RNG_SEED_SIZE (EXYNOS_RNG_SEED_REGS * 4) + +/* Context for crypto */ +struct exynos_rng_ctx { + struct exynos_rng_dev *rng; +}; + +/* Device associated memory */ +struct exynos_rng_dev { + struct device *dev; + struct exynos_rng_ctx *ctx; + void __iomem *mem; + struct clk *clk; + u8 seed_save[EXYNOS_RNG_SEED_SIZE]; +}; + +static struct exynos_rng_dev *exynos_rng_dev; + +static u32 exynos_rng_readl(struct exynos_rng_dev *rng, u32 offset) +{ + return readl_relaxed(rng->mem + offset); +} + +static void exynos_rng_writel(struct exynos_rng_dev *rng, u32 val, u32 offset) +{ + writel_relaxed(val, rng->mem + offset); +} + +static unsigned int exynos_rng_copy_random(struct exynos_rng_dev *rng, + u8 *dst, unsigned int dlen) +{ + unsigned int cnt = 0; + int i, j; + u32 val; + + for (j = 0; j < EXYNOS_RNG_SEED_REGS; j++) { + val = exynos_rng_readl(rng, EXYNOS_RNG_OUT(j)); + + for (i = 0; i < 4; i++) { + dst[cnt] = val & 0xff; + val >>= 8; + if (++cnt >= dlen) + return cnt; + } + } + + return cnt; +} + +static int exynos_rng_get_random(struct exynos_rng_dev *rng, + u8 *dst, unsigned int dlen, + unsigned int *read) +{ + int retry = 100; + + exynos_rng_writel(rng, EXYNOS_RNG_CONTROL_START, + EXYNOS_RNG_CONTROL); + + while (!(exynos_rng_readl(rng, + EXYNOS_RNG_STATUS) & EXYNOS_RNG_STATUS_RNG_DONE) && --retry) + cpu_relax(); + + if (!retry) + return -ETIMEDOUT; + + /* Clear status bit */ + exynos_rng_writel(rng, EXYNOS_RNG_STATUS_RNG_DONE, + EXYNOS_RNG_STATUS); + + *read = exynos_rng_copy_random(rng, dst, dlen); + + return 0; +} + +static int exynos_rng_generate(struct crypto_rng *tfm, + const u8 *src, unsigned int slen, + u8 *dst, unsigned int dlen) +{ + struct exynos_rng_ctx *ctx = crypto_rng_ctx(tfm); + struct exynos_rng_dev *rng = ctx->rng; + unsigned int read = 0; + int ret; + + ret = clk_prepare_enable(rng->clk); + if (ret) + return ret; + + do { + ret = exynos_rng_get_random(rng, dst, dlen, &read); + if (ret) + break; + + dlen -= read; + dst += read; + } while (dlen > 0); + + clk_disable_unprepare(rng->clk); + + return ret; +} + +static int exynos_rng_set_seed(struct exynos_rng_dev *rng, + const u8 *seed, unsigned int slen) +{ + int ret, i; + u32 val; + + dev_dbg(rng->dev, "Seeding with %u bytes\n", slen); + + ret = clk_prepare_enable(rng->clk); + if (ret) + return ret; + + if (slen < EXYNOS_RNG_SEED_SIZE) { + dev_warn(rng->dev, "Seed too short (only %u bytes)\n", slen); + ret = -EINVAL; + goto out; + } + + for (i = 0 ; i < EXYNOS_RNG_SEED_REGS ; i++) { + val = seed[i * 4] << 24; + val |= seed[i * 4 + 1] << 16; + val |= seed[i * 4 + 2] << 8; + val |= seed[i * 4 + 3] << 0; + + exynos_rng_writel(rng, val, EXYNOS_RNG_SEED(i)); + } + + val = exynos_rng_readl(rng, EXYNOS_RNG_STATUS); + if (!(val & EXYNOS_RNG_STATUS_SEED_SETTING_DONE)) { + dev_warn(rng->dev, "Seed setting not finished\n"); + ret = -EIO; + goto out; + } + + ret = 0; + /* Save seed for suspend */ + memcpy(rng->seed_save, seed, slen); + +out: + clk_disable_unprepare(rng->clk); + + return ret; +} + +static int exynos_rng_seed(struct crypto_rng *tfm, const u8 *seed, + unsigned int slen) +{ + struct exynos_rng_ctx *ctx = crypto_rng_ctx(tfm); + + return exynos_rng_set_seed(ctx->rng, seed, slen); +} + +static int exynos_rng_kcapi_init(struct crypto_tfm *tfm) +{ + struct exynos_rng_ctx *ctx = crypto_tfm_ctx(tfm); + + ctx->rng = exynos_rng_dev; + + return 0; +} + +static struct rng_alg exynos_rng_alg = { + .generate = exynos_rng_generate, + .seed = exynos_rng_seed, + .seedsize = EXYNOS_RNG_SEED_SIZE, + .base = { + .cra_name = "exynos_rng", + .cra_driver_name = "exynos_rng", + .cra_priority = 100, + .cra_ctxsize = sizeof(struct exynos_rng_ctx), + .cra_module = THIS_MODULE, + .cra_init = exynos_rng_kcapi_init, + } +}; + +static int exynos_rng_probe(struct platform_device *pdev) +{ + struct exynos_rng_dev *rng; + struct resource *res; + int ret; + + if (exynos_rng_dev) + return -EEXIST; + + rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); + if (!rng) + return -ENOMEM; + + rng->dev = &pdev->dev; + rng->clk = devm_clk_get(&pdev->dev, "secss"); + if (IS_ERR(rng->clk)) { + dev_err(&pdev->dev, "Couldn't get clock.\n"); + return PTR_ERR(rng->clk); + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + rng->mem = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(rng->mem)) + return PTR_ERR(rng->mem); + + platform_set_drvdata(pdev, rng); + + exynos_rng_dev = rng; + + ret = crypto_register_rng(&exynos_rng_alg); + if (ret) { + dev_err(&pdev->dev, + "Couldn't register rng crypto alg: %d\n", ret); + exynos_rng_dev = NULL; + } + + return ret; +} + +static int exynos_rng_remove(struct platform_device *pdev) +{ + crypto_unregister_rng(&exynos_rng_alg); + + exynos_rng_dev = NULL; + + return 0; +} + +static int __maybe_unused exynos_rng_suspend(struct device *dev) +{ + return 0; +} + +static int __maybe_unused exynos_rng_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct exynos_rng_dev *rng = platform_get_drvdata(pdev); + + return exynos_rng_set_seed(rng, rng->seed_save, sizeof(rng->seed_save)); +} + +static SIMPLE_DEV_PM_OPS(exynos_rng_pm_ops, exynos_rng_suspend, + exynos_rng_resume); + +static const struct of_device_id exynos_rng_dt_match[] = { + { + .compatible = "samsung,exynos4-rng", + }, + { }, +}; +MODULE_DEVICE_TABLE(of, exynos_rng_dt_match); + +static struct platform_driver exynos_rng_driver = { + .driver = { + .name = "exynos-rng", + .pm = &exynos_rng_pm_ops, + .of_match_table = exynos_rng_dt_match, + }, + .probe = exynos_rng_probe, + .remove = exynos_rng_remove, +}; + +module_platform_driver(exynos_rng_driver); + +MODULE_DESCRIPTION("Exynos H/W Random Number Generator driver"); +MODULE_AUTHOR("Krzysztof Kozlowski <krzk@kernel.org>"); +MODULE_LICENSE("GPL");

[1/3] crypto: hw_random - Add new Exynos RNG driver

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