From patchwork Wed Nov 27 14:22:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Neal Liu X-Patchwork-Id: 11264183 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C14941390 for ; Wed, 27 Nov 2019 14:23:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 98EF920674 for ; Wed, 27 Nov 2019 14:23:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="BAVmAcet" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727197AbfK0OXV (ORCPT ); Wed, 27 Nov 2019 09:23:21 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:15498 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727118AbfK0OXT (ORCPT ); Wed, 27 Nov 2019 09:23:19 -0500 X-UUID: f8ae20a4f1ad42c1ba79108682bc28a7-20191127 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=WFphvlMRaDKdtjVxAem+AWZT/bf0cnW1dQzo9Dpt9Co=; b=BAVmAcettnKIN1LE0bkG5QTvcqrXyT6Lq4JIDlH38hYhfJ8FTOlxN3QoH1xjhx1wWhwxunCIiuk/H10ksaFLNX9EmECaOLGB0dOp2Gq5OUwYBI76/NEVoOh6EpOkq9vVtUI/U3c8mH5lnHnhQTvLPen0WfOhLgbefYONPOT/2Dw=; X-UUID: f8ae20a4f1ad42c1ba79108682bc28a7-20191127 Received: from mtkexhb01.mediatek.inc [(172.21.101.102)] by mailgw02.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 433868931; Wed, 27 Nov 2019 22:23:10 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 27 Nov 2019 22:23:05 +0800 Received: from mtkswgap22.mediatek.inc (172.21.77.33) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Wed, 27 Nov 2019 22:23:03 +0800 From: Neal Liu To: Matt Mackall , Herbert Xu , Rob Herring , Mark Rutland , Matthias Brugger , Sean Wang CC: Neal Liu , Crystal Guo , , , , , , Subject: [PATCH v5 3/3] hwrng: add mtk-sec-rng driver Date: Wed, 27 Nov 2019 22:22:58 +0800 Message-ID: <1574864578-467-4-git-send-email-neal.liu@mediatek.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1574864578-467-1-git-send-email-neal.liu@mediatek.com> References: <1574864578-467-1-git-send-email-neal.liu@mediatek.com> MIME-Version: 1.0 X-MTK: N Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org For MediaTek SoCs on ARMv8 with TrustZone enabled, peripherals like entropy sources is not accessible from normal world (linux) and rather accessible from secure world (ATF/TEE) only. This driver aims to provide a generic interface to ATF rng service. Signed-off-by: Neal Liu --- drivers/char/hw_random/Kconfig | 16 ++++++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/mtk-sec-rng.c | 103 ++++++++++++++++++++++++++++++++++ 3 files changed, 120 insertions(+) create mode 100644 drivers/char/hw_random/mtk-sec-rng.c diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 25a7d8f..f08c852 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -398,6 +398,22 @@ config HW_RANDOM_MTK If unsure, say Y. +config HW_RANDOM_MTK_SEC + tristate "MediaTek Security Random Number Generator support" + depends on HW_RANDOM + depends on ARCH_MEDIATEK || COMPILE_TEST + default HW_RANDOM + help + This driver provides kernel-side support for the Random Number + Generator hardware found on MediaTek SoCs. The difference with + mtk-rng is the Random Number Generator hardware is secure + access only. + + To compile this driver as a module, choose M here. the + module will be called mtk-sec-rng. + + If unsure, say Y. + config HW_RANDOM_S390 tristate "S390 True Random Number Generator support" depends on S390 diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 7c9ef4a..bee5412 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_HW_RANDOM_PIC32) += pic32-rng.o obj-$(CONFIG_HW_RANDOM_MESON) += meson-rng.o obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o +obj-$(CONFIG_HW_RANDOM_MTK_SEC) += mtk-sec-rng.o obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o diff --git a/drivers/char/hw_random/mtk-sec-rng.c b/drivers/char/hw_random/mtk-sec-rng.c new file mode 100644 index 0000000..69ddeca --- /dev/null +++ b/drivers/char/hw_random/mtk-sec-rng.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 MediaTek Inc. + */ + +#include +#include +#include +#include +#include +#include + +#define MTK_SEC_RNG_MAGIC 0x74726e67 +#define SMC_RET_NUM 4 +#define MTK_SEC_RND_SIZE (sizeof(u32) * SMC_RET_NUM) + +static void mtk_sec_get_rnd(uint32_t *val) +{ + struct arm_smccc_res res; + + arm_smccc_smc(MTK_SIP_KERNEL_GET_RND, + MTK_SEC_RNG_MAGIC, 0, 0, 0, 0, 0, 0, &res); + + val[0] = res.a0; + val[1] = res.a1; + val[2] = res.a2; + val[3] = res.a3; +} + +static int mtk_sec_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + u32 val[4] = {0}; + int retval = 0; + int i; + + while (max >= MTK_SEC_RND_SIZE) { + mtk_sec_get_rnd(val); + + for (i = 0; i < SMC_RET_NUM; i++) { + *(u32 *)buf = val[i]; + buf += sizeof(u32); + } + + retval += MTK_SEC_RND_SIZE; + max -= MTK_SEC_RND_SIZE; + } + + return retval; +} + +static struct hwrng mtk_sec_rng = { + .name = "mtk_sec_rng", + .read = mtk_sec_rng_read, + .quality = 900, +}; + +static int mtk_sec_rng_probe(void) +{ + int ret; + + ret = hwrng_register(&mtk_sec_rng); + if (ret) { + pr_err("Failed to register rng device: %d\n", ret); + return ret; + } + + return 0; +} + +static int __init mtk_sec_rng_driver_init(void) +{ + struct device_node *fw_np; + struct device_node *np; + const char *method; + + fw_np = of_find_node_by_name(NULL, "firmware"); + if (!fw_np) + return -ENODEV; + + np = of_find_compatible_node(fw_np, NULL, "mediatek,mtk-sec-rng"); + if (!np) + return -ENODEV; + + if (of_property_read_string(np, "method", &method)) + return -ENXIO; + + if (strncmp("smc", method, strlen("smc"))) + return -EINVAL; + + return mtk_sec_rng_probe(); +} + +static void __exit mtk_sec_rng_driver_exit(void) +{ + hwrng_unregister(&mtk_sec_rng); +} + +module_init(mtk_sec_rng_driver_init); +module_exit(mtk_sec_rng_driver_exit); + +MODULE_DESCRIPTION("MediaTek Security Random Number Generator Driver"); +MODULE_AUTHOR("Neal Liu "); +MODULE_LICENSE("GPL");