From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BB3DC4361B for ; Fri, 11 Dec 2020 17:14:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E96F23E1B for ; Fri, 11 Dec 2020 17:14:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406696AbgLKQBr (ORCPT ); Fri, 11 Dec 2020 11:01:47 -0500 Received: from foss.arm.com ([217.140.110.172]:37254 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406690AbgLKQBE (ORCPT ); Fri, 11 Dec 2020 11:01:04 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 242BE1424; Fri, 11 Dec 2020 08:00:19 -0800 (PST) Received: from donnerap.arm.com (donnerap.cambridge.arm.com [10.1.195.35]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3BD953F66B; Fri, 11 Dec 2020 08:00:17 -0800 (PST) From: Andre Przywara To: Will Deacon , Catalin Marinas , Ard Biesheuvel , Russell King , Marc Zyngier Cc: Theodore Ts'o , Sudeep Holla , Mark Rutland , Mark Brown , Lorenzo Pieralisi , Linus Walleij , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Subject: [PATCH v4 3/5] ARM: implement support for SMCCC TRNG entropy source Date: Fri, 11 Dec 2020 16:00:03 +0000 Message-Id: <20201211160005.187336-4-andre.przywara@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201211160005.187336-1-andre.przywara@arm.com> References: <20201211160005.187336-1-andre.przywara@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel Implement arch_get_random_seed_*() for ARM based on the firmware or hypervisor provided entropy source described in ARM DEN0098. This will make the kernel's random number generator consume entropy provided by this interface, at early boot, and periodically at runtime when reseeding. Cc: Linus Walleij Cc: Russell King Signed-off-by: Ard Biesheuvel [Andre: rework to be initialised by the SMCCC firmware driver] Signed-off-by: Andre Przywara Reviewed-by: Linus Walleij --- arch/arm/Kconfig | 4 ++ arch/arm/include/asm/archrandom.h | 64 +++++++++++++++++++++++++++++++ 2 files changed, 68 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index fe2f17eb2b50..a6d2d66f4110 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1667,6 +1667,10 @@ config STACKPROTECTOR_PER_TASK Enable this option to switch to a different method that uses a different canary value for each task. +config ARCH_RANDOM + def_bool y + depends on HAVE_ARM_SMCCC_DISCOVERY + endmenu menu "Boot options" diff --git a/arch/arm/include/asm/archrandom.h b/arch/arm/include/asm/archrandom.h index a8e84ca5c2ee..f3e96a5b65f8 100644 --- a/arch/arm/include/asm/archrandom.h +++ b/arch/arm/include/asm/archrandom.h @@ -2,9 +2,73 @@ #ifndef _ASM_ARCHRANDOM_H #define _ASM_ARCHRANDOM_H +#ifdef CONFIG_ARCH_RANDOM + +#include +#include + +#define ARM_SMCCC_TRNG_MIN_VERSION 0x10000UL + +extern bool smccc_trng_available; + +static inline bool __init smccc_probe_trng(void) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_VERSION, &res); + if ((s32)res.a0 < 0) + return false; + if (res.a0 >= ARM_SMCCC_TRNG_MIN_VERSION) { + /* double check that the 32-bit flavor is available */ + arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_FEATURES, + ARM_SMCCC_TRNG_RND32, + &res); + if ((s32)res.a0 >= 0) + return true; + } + + return false; +} + +static inline bool __must_check arch_get_random_long(unsigned long *v) +{ + return false; +} + +static inline bool __must_check arch_get_random_int(unsigned int *v) +{ + return false; +} + +static inline bool __must_check arch_get_random_seed_long(unsigned long *v) +{ + struct arm_smccc_res res; + + if (smccc_trng_available) { + arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_RND32, 8 * sizeof(*v), &res); + + if (res.a0 != 0) + return false; + + *v = res.a3; + return true; + } + + return false; +} + +static inline bool __must_check arch_get_random_seed_int(unsigned int *v) +{ + return arch_get_random_seed_long((unsigned long *)v); +} + + +#else /* !CONFIG_ARCH_RANDOM */ + static inline bool __init smccc_probe_trng(void) { return false; } +#endif /* CONFIG_ARCH_RANDOM */ #endif /* _ASM_ARCHRANDOM_H */ -- 2.17.1