From patchwork Mon Jul 24 12:45:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13324605 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFCA6C04A94 for ; Mon, 24 Jul 2023 12:48:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231169AbjGXMsN (ORCPT ); Mon, 24 Jul 2023 08:48:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231193AbjGXMsB (ORCPT ); Mon, 24 Jul 2023 08:48:01 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BCB6E7E; Mon, 24 Jul 2023 05:47:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BE0A46113D; Mon, 24 Jul 2023 12:47:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FE53C433D9; Mon, 24 Jul 2023 12:47:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690202857; bh=sadX6jRs7DdBAThhpdGK2D3phr2V3dLQCMXle4b8GlY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=K16sTq9Hn6ycqMora+BBwAk/ozE8SGLAK3z2N3zL60iYgOalkFMztrWQrhEAry0Vj CcVkx2kwQQKjL3HdmJxoAgQpF5yWOmRYxsW+QLgOxd4sWN90UptH+kGz92hZjGt+yN o3Ofa4xS4uCZEZbtOT06PBqw4pFNHzegdgSRDJiKaqOgWuxrjkVArJ4A9CCKPF/UOj xskgy53bAd4PRdXm+neB4s3/4qRwEEfWAq8/GHBgRLVTUw960S6FCEbMd8A+p78ZeJ 7XCeOVFGchbvinttLBXT4aeKvf1mUDuB8SDH1Tcqrv164NBYaUfyXwzmwIMjNzvLhi iVFf9d+YH0Ytw== From: Mark Brown Date: Mon, 24 Jul 2023 13:45:53 +0100 Subject: [PATCH v2 06/35] arm64/gcs: Add manual encodings of GCS instructions MIME-Version: 1.0 Message-Id: <20230724-arm64-gcs-v2-6-dc2c1d44c2eb@kernel.org> References: <20230724-arm64-gcs-v2-0-dc2c1d44c2eb@kernel.org> In-Reply-To: <20230724-arm64-gcs-v2-0-dc2c1d44c2eb@kernel.org> To: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Brown X-Mailer: b4 0.13-dev-099c9 X-Developer-Signature: v=1; a=openpgp-sha256; l=2577; i=broonie@kernel.org; h=from:subject:message-id; bh=sadX6jRs7DdBAThhpdGK2D3phr2V3dLQCMXle4b8GlY=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBkvnKKVmClDR5NeGhf5MemevHD0L0bH31Lfo0oBRNY y9EJtxuJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZL5yigAKCRAk1otyXVSH0HXhB/ 9jWPX3plb44CCP1lSbqRmoTanjOWee0vnZnhI5zu4xXhD9o3fE+5JeyJ0M1zlScNRpISjVxUCw6TZ4 6LotQ99ybyOyzqYR54lPtBV5caae/chJyKMDP+KJ1/vN6CcDTUU07qK8YWvcsr8n/7gEs4muWfCM0e zc01Ds4rOkjBzAVpDQ/wq/NNU+y4lRc5qDm50G0XEnk9CLpasxFGDptY3SJOl5NM7bORjUWH0LdxRL 5Y/1Lc1NnSJIDs/22LBT/PrUJAO4wQABjy4Nyudxnm5Bn4VySTpk+puEtJJEdmwLLH2+Mmv4pTlWJ/ gQD7KMDC7CuxzbVR1B9pG9aDwmfU91 X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Define C callable functions for GCS instructions used by the kernel. In order to avoid ambitious toolchain requirements for GCS support these are manually encoded, this means we have fixed register numbers which will be a bit limiting for the compiler but none of these should be used in sufficiently fast paths for this to be a problem. Note that GCSSTTR is used to store to EL0. Signed-off-by: Mark Brown --- arch/arm64/include/asm/gcs.h | 51 ++++++++++++++++++++++++++++++++++++++++ arch/arm64/include/asm/uaccess.h | 22 +++++++++++++++++ 2 files changed, 73 insertions(+) diff --git a/arch/arm64/include/asm/gcs.h b/arch/arm64/include/asm/gcs.h new file mode 100644 index 000000000000..7c5e95218db6 --- /dev/null +++ b/arch/arm64/include/asm/gcs.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2023 ARM Ltd. + */ +#ifndef __ASM_GCS_H +#define __ASM_GCS_H + +#include +#include + +static inline void gcsb_dsync(void) +{ + asm volatile(".inst 0xd503227f" : : : "memory"); +} + +static inline void gcsstr(u64 *addr, u64 val) +{ + register u64 *_addr __asm__ ("x0") = addr; + register long _val __asm__ ("x1") = val; + + /* GCSSTTR x1, x0 */ + asm volatile( + ".inst 0xd91f1c01\n" + : + : "rZ" (_val), "r" (_addr) + : "memory"); +} + +static inline void gcsss1(u64 Xt) +{ + asm volatile ( + "sys #3, C7, C7, #2, %0\n" + : + : "rZ" (Xt) + : "memory"); +} + +static inline u64 gcsss2(void) +{ + u64 Xt; + + asm volatile( + "SYSL %0, #3, C7, C7, #3\n" + : "=r" (Xt) + : + : "memory"); + + return Xt; +} + +#endif diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 14be5000c5a0..22e10e79f56a 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -425,4 +425,26 @@ static inline size_t probe_subpage_writeable(const char __user *uaddr, #endif /* CONFIG_ARCH_HAS_SUBPAGE_FAULTS */ +#ifdef CONFIG_ARM64_GCS + +static inline int gcssttr(unsigned long __user *addr, unsigned long val) +{ + register unsigned long __user *_addr __asm__ ("x0") = addr; + register unsigned long _val __asm__ ("x1") = val; + int err = 0; + + /* GCSSTTR x1, x0 */ + asm volatile( + "1: .inst 0xd91f1c01\n" + "2: \n" + _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %w0) + : "+r" (err) + : "rZ" (_val), "r" (_addr) + : "memory"); + + return err; +} + +#endif /* CONFIG_ARM64_GCS */ + #endif /* __ASM_UACCESS_H */