From patchwork Wed Jun 28 13:14:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Samuel Ortiz X-Patchwork-Id: 113867 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp8925693vqr; Wed, 28 Jun 2023 06:27:49 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ52hER6+h0W1+GsHxvVJD7EH49wAq14Z7Jn1jlBkdVC6S3eLgacyPJvhNI78pnNWSm6twqP X-Received: by 2002:a17:907:701:b0:974:6026:a316 with SMTP id xb1-20020a170907070100b009746026a316mr33335347ejb.19.1687958869456; Wed, 28 Jun 2023 06:27:49 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1687958869; cv=none; d=google.com; s=arc-20160816; b=yk0NRZEwM2c7kBde328p0ukpsj2/ttJNw1y8qBI/vfDrwGKkiwyIXLfWduD2Y9ImEQ INXEk3udyIgYDO9b6HsKtqNjrmsa0xExa0HzLKTbDfXmCRtykICcQHUdM/qivEDVEOCi P/cT4+4UdYu21Idb9IrJg0NspW7VOKj1cKFuxqiYWQgp/4bZZ8Om5dYq7eJ2SXHupOkC pJMhpQY5JKUJJV1G1CyY9CKSeIQdH0PhqVMdJo2wpQSaPhlLpUqYWdi7/DDe0g7B246y 6h1WIkZ0RfuoSok6IUCJiX1ZhFxgfXF8UsJvNP3FjP+Sm0MCEbdi7ExD5BsHd7g/+CBy nNtg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=UEDUaqobIEXKBJUJL2QuyVEVDAnOAPT+PycLhsHH0e4=; fh=+KY35iURJH+A+xMI+PExjIVC2hBjVOkkyp1+1Nnq7Zo=; b=MeMv9/FBAvhMxdZBV5dzIRWggYPNLWtzQ4MP00fusFfyzU8BhFmvJBPjfqxsjX58db bl7DbIe5k6A0IzCyPZFYHI+WJ+XOhwEH6BVjQYadPq6zhgzaMuEsf14oLHuc7WW5VR5E qnIBByx7dZZMnqyDe0dVpDDJDY6R+JFr6j2jno9pEgxgBnuRzg1YpOIDF+I7RQebijqQ BxYD/nwqPl8UpPk4AxfADvT4hrldgIFDZTi3pjcAtowE099OuFINUTTSgp6zDQ8mFr9U E3cXbQDY+mfLswr7S1i0D9kfDVR/IjDZXhkia9Ksu39BtujwIjTdQeHXtiVYTFLYthP5 ZLgQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@rivosinc-com.20221208.gappssmtp.com header.s=20221208 header.b=PzpxfbdG; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id re21-20020a170906d8d500b00988f4b9113bsi5770904ejb.690.2023.06.28.06.27.25; Wed, 28 Jun 2023 06:27:49 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@rivosinc-com.20221208.gappssmtp.com header.s=20221208 header.b=PzpxfbdG; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231543AbjF1NPO (ORCPT + 99 others); Wed, 28 Jun 2023 09:15:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231182AbjF1NPJ (ORCPT ); Wed, 28 Jun 2023 09:15:09 -0400 Received: from mail-wr1-x42d.google.com (mail-wr1-x42d.google.com [IPv6:2a00:1450:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CAD82119 for ; Wed, 28 Jun 2023 06:15:08 -0700 (PDT) Received: by mail-wr1-x42d.google.com with SMTP id ffacd0b85a97d-313e12db357so6180926f8f.0 for ; Wed, 28 Jun 2023 06:15:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1687958107; x=1690550107; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=UEDUaqobIEXKBJUJL2QuyVEVDAnOAPT+PycLhsHH0e4=; b=PzpxfbdG1hP8JaT6dGu5MFaJuWjRSgEZs4u66K6iR/KAiam4nJBUjYSvQ8TGXoy+4q v3msqKsXNd1yS7SRhQcy7ZL8ICOg8OxVsNenTnJDmuHHE8o0XnzV17PUmR1OaqTFJUHb l80kTHBXJUsESLmsFFexDiSxsOPxOGvvD/4t7V9fnRf0eAA+AtbX/IyAKiXIbpophLiG 0Lu6napv/3ofoE5nfu0y1S7R6XrhGd53UBqqOr+9cYm+QU9rQa7eNEfhv3Vp08SLGuil o/frg8rQgA65BNf+0YiOOOUxHToVQf0mEehTnG/XL4E8vslfJFMrz5UYOTH2oNXNmBS+ ODIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687958107; x=1690550107; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=UEDUaqobIEXKBJUJL2QuyVEVDAnOAPT+PycLhsHH0e4=; b=ejnmrpF/QIVYEFUO0g1qRV61u82mivXJTsMcFAdkSNFv2EHk9kJvMVOmlbgivGvFcg RgXsqnNwpZ7nrmzo5mWuzYk71FWm8kl8xn/HQDsr7ildGd133V1mgJmBoxClv34cTD3a gFfNG3uxGluMz8JN+5VyqxP1rJrunFubv0ehO48rA0sE6V8Azcr61aDjEIRNZ9fYaCtC Ll7qmrgkL1AMgOnMqwxHEmGRfSIq2fJ0myKui4JO03LfbDk0fQdsXrJWCDT6t0GPhOxb WEQq0MErmjHp02kiBNQpwpsv5si97+TpasMSiUyfvNzaZdDn2ra5LZcDgygzTRfh/hWa pwBw== X-Gm-Message-State: ABy/qLabNaqBeJB8HBSLlWteRftMa3hUQjWgb7GeSCJgYOjX6vPW7xdj yzIlaOPxK9tLe7m985Wf3cJAvg== X-Received: by 2002:adf:eb11:0:b0:314:122a:9fe0 with SMTP id s17-20020adfeb11000000b00314122a9fe0mr35636wrn.8.1687958107035; Wed, 28 Jun 2023 06:15:07 -0700 (PDT) Received: from vermeer.tail79c99.ts.net ([2a01:cb1d:81a9:dd00:b570:b34c:ffd4:c805]) by smtp.gmail.com with ESMTPSA id a11-20020a056000050b00b003110dc7f408sm13456946wrf.41.2023.06.28.06.15.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Jun 2023 06:15:06 -0700 (PDT) From: Samuel Ortiz To: Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv@lists.infradead.org Cc: Samuel Ortiz , linux@rivosinc.com, Conor Dooley , Andrew Jones , Heiko Stuebner , Anup Patel , linux-kernel@vger.kernel.org, "Hongren (Zenithal) Zheng" , Guo Ren , Atish Patra , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Evan Green Subject: [PATCH v2 3/3] RISC-V: Implement archrandom when Zkr is available Date: Wed, 28 Jun 2023 15:14:35 +0200 Message-ID: <20230628131442.3022772-4-sameo@rivosinc.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230628131442.3022772-1-sameo@rivosinc.com> References: <20230628131442.3022772-1-sameo@rivosinc.com> MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1769953159176044810?= X-GMAIL-MSGID: =?utf-8?q?1769953159176044810?= The Zkr extension is ratified and provides 16 bits of entropy seed when reading the SEED CSR. We can implement arch_get_random_seed_longs() by doing multiple csrrw to that CSR and filling an unsigned long with valid entropy bits. Signed-off-by: Samuel Ortiz Acked-by: Conor Dooley Reviewed-by: Guo Ren --- arch/riscv/include/asm/archrandom.h | 70 +++++++++++++++++++++++++++++ arch/riscv/include/asm/csr.h | 9 ++++ 2 files changed, 79 insertions(+) create mode 100644 arch/riscv/include/asm/archrandom.h diff --git a/arch/riscv/include/asm/archrandom.h b/arch/riscv/include/asm/archrandom.h new file mode 100644 index 000000000000..8987cd0b891d --- /dev/null +++ b/arch/riscv/include/asm/archrandom.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Kernel interface for the RISCV arch_random_* functions + * + * Copyright (c) 2023 by Rivos Inc. + * + */ + +#ifndef ASM_RISCV_ARCHRANDOM_H +#define ASM_RISCV_ARCHRANDOM_H + +#include + +#define SEED_RETRY_LOOPS 10 + +static inline bool __must_check csr_seed_long(unsigned long *v) +{ + unsigned int retry = SEED_RETRY_LOOPS, valid_seeds = 0; + const int needed_seeds = sizeof(long) / sizeof(u16); + u16 *entropy = (u16 *)v; + + do { + /* + * The SEED CSR (0x015) must be accessed with a read-write + * instruction. + */ + unsigned long csr_seed = csr_swap(CSR_SEED, 0); + + switch (csr_seed & SEED_OPST_MASK) { + case SEED_OPST_ES16: + entropy[valid_seeds++] = csr_seed & SEED_ENTROPY_MASK; + if (valid_seeds == needed_seeds) + return true; + break; + + case SEED_OPST_DEAD: + pr_err_once("archrandom: Unrecoverable error\n"); + return false; + + case SEED_OPST_BIST: + case SEED_OPST_WAIT: + default: + continue; + } + } while (--retry); + + return false; +} + +static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs) +{ + return 0; +} + +static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs) +{ + if (!max_longs) + return 0; + + /* + * If Zkr is supported and csr_seed_long succeeds, we return one long + * worth of entropy. + */ + if (riscv_has_extension_likely(RISCV_ISA_EXT_ZKR) && csr_seed_long(v)) + return 1; + + return 0; +} + +#endif /* ASM_RISCV_ARCHRANDOM_H */ diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h index b98b3b6c9da2..7d0ca9082c66 100644 --- a/arch/riscv/include/asm/csr.h +++ b/arch/riscv/include/asm/csr.h @@ -389,6 +389,15 @@ #define CSR_VTYPE 0xc21 #define CSR_VLENB 0xc22 +/* Scalar Crypto Extension - Entropy */ +#define CSR_SEED 0x015 +#define SEED_OPST_MASK _AC(0xC0000000, UL) +#define SEED_OPST_BIST _AC(0x00000000, UL) +#define SEED_OPST_WAIT _AC(0x40000000, UL) +#define SEED_OPST_ES16 _AC(0x80000000, UL) +#define SEED_OPST_DEAD _AC(0xC0000000, UL) +#define SEED_ENTROPY_MASK _AC(0xFFFF, UL) + #ifdef CONFIG_RISCV_M_MODE # define CSR_STATUS CSR_MSTATUS # define CSR_IE CSR_MIE