From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 13 Mar 2024 11:57:37 +0100 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1rkMIj-004HUd-05 for lore@lore.pengutronix.de; Wed, 13 Mar 2024 11:57:37 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rkMIh-0001Lv-Nl for lore@pengutronix.de; Wed, 13 Mar 2024 11:57:36 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=WtqAT1bEXeWc7xivf90RlhBrkpIGu7XgAlu+tlsw49c=; b=KxuR8syWEpqE/GrN9JwRMufzK+ QFYW2MXjA+lJD4mRvzsZiIaJ5X7pLAdZUGGBtiqLcSEiuTlrpbqdoLUTduB9L7IQz4AD56B8H0VQ2 ykP4pkfJMJF1FBYUm1H3BqlmkvAzuqzIiocHfMxP6yBVzH+wQokc+TO/KSy/iGXaQ+ykzS3hkhs3b vUgclakNqi+sM5DCyMCU3UsW+dESLh6qLGU8JcbLyGnYm6ah8dRNlf0Ay7UaUHfE2DOi6AbFNe9Xu 4sjkUa+bNZ4FosNuTMTIlskN/qqZmEr+m0T73B5Nfy1jeoDbCPA0EY1KXHdeGXfW3M8mAcLOIi3H2 ZjmMCfCA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rkMIA-00000009kZl-3HDa; Wed, 13 Mar 2024 10:57:02 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rkMHi-00000009kKq-1meU for barebox@lists.infradead.org; Wed, 13 Mar 2024 10:56:39 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rkMHh-0008Pk-6B; Wed, 13 Mar 2024 11:56:33 +0100 Received: from [2a0a:edc0:0:1101:1d::54] (helo=dude05.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1rkMHg-00661O-OX; Wed, 13 Mar 2024 11:56:32 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1rkMHg-004FrF-0W; Wed, 13 Mar 2024 11:56:32 +0100 From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Ahmad Fatoum Date: Wed, 13 Mar 2024 11:56:27 +0100 Message-Id: <20240313105631.686778-9-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240313105631.686778-1-a.fatoum@pengutronix.de> References: <20240313105631.686778-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240313_035634_753332_E0E8A68B X-CRM114-Status: GOOD ( 24.95 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.6 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH 08/12] hw_random: add BCM2835 RNG driver X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) To enable proper hardening with stack protector, add support for the BCM2835 RNG. This has been tested on a Raspberry Pi 3B. Signed-off-by: Ahmad Fatoum --- drivers/hw_random/Kconfig | 7 ++ drivers/hw_random/Makefile | 1 + drivers/hw_random/bcm2835-rng.c | 199 ++++++++++++++++++++++++++++++++ include/linux/hw_random.h | 5 + 4 files changed, 212 insertions(+) create mode 100644 drivers/hw_random/bcm2835-rng.c diff --git a/drivers/hw_random/Kconfig b/drivers/hw_random/Kconfig index 873e2bf1e4f4..e38bf42a67cd 100644 --- a/drivers/hw_random/Kconfig +++ b/drivers/hw_random/Kconfig @@ -66,4 +66,11 @@ config HW_RANDOM_ATMEL This driver provides barebox support for the Random Number Generator hardware found on Atmel AT91 devices. +config HW_RANDOM_BCM2835 + tristate "Broadcom BCM2835/BCM63xx Random Number Generator support" + depends on ARCH_BCM283X || COMPILE_TEST + help + This driver provides barebox support for the Random Number + Generator hardware found on the Broadcom BCM2835 SoCs. + endif diff --git a/drivers/hw_random/Makefile b/drivers/hw_random/Makefile index b0710e4ce977..ed0a4efeedf4 100644 --- a/drivers/hw_random/Makefile +++ b/drivers/hw_random/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_HW_RANDOM_STARFIVE) += starfive-vic-rng.o obj-$(CONFIG_HW_RANDOM_EFI) += efi-rng.o obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o obj-$(CONFIG_HW_RANDOM_ATMEL) += atmel-rng.o +obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o diff --git a/drivers/hw_random/bcm2835-rng.c b/drivers/hw_random/bcm2835-rng.c new file mode 100644 index 000000000000..d82331c950d2 --- /dev/null +++ b/drivers/hw_random/bcm2835-rng.c @@ -0,0 +1,199 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2010-2012 Broadcom. All rights reserved. + * Copyright (c) 2013 Lubomir Rintel + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define RNG_CTRL 0x0 +#define RNG_STATUS 0x4 +#define RNG_DATA 0x8 +#define RNG_INT_MASK 0x10 + +/* enable rng */ +#define RNG_RBGEN 0x1 + +/* the initial numbers generated are "less random" so will be discarded */ +#define RNG_WARMUP_COUNT 0x40000 + +#define RNG_INT_OFF 0x1 + +struct bcm2835_rng_priv { + struct hwrng rng; + void __iomem *base; + bool mask_interrupts; + struct clk *clk; + struct reset_control *reset; +}; + +static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng) +{ + return container_of(rng, struct bcm2835_rng_priv, rng); +} + +static inline u32 rng_readl(struct bcm2835_rng_priv *priv, u32 offset) +{ + /* MIPS chips strapped for BE will automagically configure the + * peripheral registers for CPU-native byte order. + */ + if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) + return __raw_readl(priv->base + offset); + else + return readl(priv->base + offset); +} + +static inline void rng_writel(struct bcm2835_rng_priv *priv, u32 val, + u32 offset) +{ + if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) + __raw_writel(val, priv->base + offset); + else + writel(val, priv->base + offset); +} + +static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, + bool wait) +{ + struct bcm2835_rng_priv *priv = to_rng_priv(rng); + u32 max_words = max / sizeof(u32); + u32 num_words, count; + + while ((rng_readl(priv, RNG_STATUS) >> 24) == 0) { + if (!wait) + return 0; + hwrng_yield(rng); + } + + num_words = rng_readl(priv, RNG_STATUS) >> 24; + if (num_words > max_words) + num_words = max_words; + + for (count = 0; count < num_words; count++) + ((u32 *)buf)[count] = rng_readl(priv, RNG_DATA); + + return num_words * sizeof(u32); +} + +static int bcm2835_rng_init(struct hwrng *rng) +{ + struct bcm2835_rng_priv *priv = to_rng_priv(rng); + int ret = 0; + u32 val; + + ret = clk_prepare_enable(priv->clk); + if (ret) + return ret; + + ret = reset_control_reset(priv->reset); + if (ret) + return ret; + + if (priv->mask_interrupts) { + /* mask the interrupt */ + val = rng_readl(priv, RNG_INT_MASK); + val |= RNG_INT_OFF; + rng_writel(priv, val, RNG_INT_MASK); + } + + /* set warm-up count & enable */ + rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS); + rng_writel(priv, RNG_RBGEN, RNG_CTRL); + + return ret; +} + +static void bcm2835_rng_cleanup(struct bcm2835_rng_priv *priv) +{ + /* disable rng hardware */ + rng_writel(priv, 0, RNG_CTRL); + + clk_disable_unprepare(priv->clk); +} + +struct bcm2835_rng_of_data { + bool mask_interrupts; +}; + +static const struct bcm2835_rng_of_data nsp_rng_of_data = { + .mask_interrupts = true, +}; + +static const struct of_device_id bcm2835_rng_of_match[] = { + { .compatible = "brcm,bcm2835-rng"}, + { .compatible = "brcm,bcm-nsp-rng", .data = &nsp_rng_of_data }, + { .compatible = "brcm,bcm5301x-rng", .data = &nsp_rng_of_data }, + { .compatible = "brcm,bcm6368-rng"}, + {}, +}; + +static int bcm2835_rng_probe(struct device *dev) +{ + const struct bcm2835_rng_of_data *of_data; + struct bcm2835_rng_priv *priv; + int err; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + /* map peripheral */ + priv->base = dev_platform_ioremap_resource(dev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + /* Clock is optional on most platforms */ + priv->clk = clk_get_optional(dev, NULL); + if (IS_ERR(priv->clk)) + return PTR_ERR(priv->clk); + + priv->reset = reset_control_get_optional(dev, NULL); + if (IS_ERR(priv->reset)) + return PTR_ERR(priv->reset); + + priv->rng.name = dev_name(dev); + priv->rng.init = bcm2835_rng_init; + priv->rng.read = bcm2835_rng_read; + + of_data = device_get_match_data(dev); + if (of_data) + priv->mask_interrupts = of_data->mask_interrupts; + + /* register driver */ + err = hwrng_register(dev, &priv->rng); + if (err) + dev_err(dev, "hwrng registration failed\n"); + else + dev_info(dev, "hwrng registered\n"); + + dev->priv = priv; + + return err; +} + +static void bcm2835_rng_remove(struct device *dev) +{ + bcm2835_rng_cleanup(dev->priv); +} + +MODULE_DEVICE_TABLE(of, bcm2835_rng_of_match); + +static struct driver bcm2835_rng_driver = { + .name = "bcm2835-rng", + .of_match_table = bcm2835_rng_of_match, + .probe = bcm2835_rng_probe, + .remove = bcm2835_rng_remove, +}; +device_platform_driver(bcm2835_rng_driver); + +MODULE_AUTHOR("Lubomir Rintel "); +MODULE_DESCRIPTION("BCM2835 Random Number Generator (RNG) driver"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/hw_random.h b/include/linux/hw_random.h index 4479428bc743..ff6d3bb58285 100644 --- a/include/linux/hw_random.h +++ b/include/linux/hw_random.h @@ -52,4 +52,9 @@ static inline int hwrng_get_data(struct hwrng *rng, void *buffer, size_t size, i void hwrng_unregister(struct hwrng *rng); +static inline long hwrng_yield(struct hwrng *rng) +{ + return 0; +} + #endif /* LINUX_HWRANDOM_H_ */ -- 2.39.2