From patchwork Tue Aug 22 13:56:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13360830 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 D1E09EE49B1 for ; Tue, 22 Aug 2023 14:04:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236311AbjHVOEK (ORCPT ); Tue, 22 Aug 2023 10:04:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236316AbjHVOEI (ORCPT ); Tue, 22 Aug 2023 10:04:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A02FC10C9; Tue, 22 Aug 2023 07:03:47 -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 1CA4E65775; Tue, 22 Aug 2023 14:03:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 960CDC433CB; Tue, 22 Aug 2023 14:03:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692713026; bh=sadX6jRs7DdBAThhpdGK2D3phr2V3dLQCMXle4b8GlY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=KKzlO3Qq+PRK+tbHucKMd0ag4RDplna76NIOOKLqQ3Y6/CZZN72W14ML8g+RKfDOe qBX9bKAGlIhs2TZphzMa/zy7XFNwG1XUEv0xeqYLbDKjjUXNjZtfaUWSXEV83TJacK pZLKyLzKmfCLNNe4GYOJTZ1ZWfMQw1rY9Vdn6WzDIvsHAZyc6wamZ0twqeAmdfSQZz 7dsGLPM/jQRlY/w55J307Fr8CQHDRMwFhB9J1ca5QJVdMRHfYkZylBu6aDMfAdNekG 9kTGLiaf/rDXpqE2mt7bznqV/Joz6xLj5wHbQPgWgtyr0DSYx8sAZv328FvOuNFhGN +6LFrr1ySqcxg== From: Mark Brown Date: Tue, 22 Aug 2023 14:56:40 +0100 Subject: [PATCH v5 07/37] arm64/gcs: Add manual encodings of GCS instructions MIME-Version: 1.0 Message-Id: <20230822-arm64-gcs-v5-7-9ef181dd6324@kernel.org> References: <20230822-arm64-gcs-v5-0-9ef181dd6324@kernel.org> In-Reply-To: <20230822-arm64-gcs-v5-0-9ef181dd6324@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-034f2 X-Developer-Signature: v=1; a=openpgp-sha256; l=2577; i=broonie@kernel.org; h=from:subject:message-id; bh=sadX6jRs7DdBAThhpdGK2D3phr2V3dLQCMXle4b8GlY=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBk5L/1IzIK9b4CT61C11bXtYUumI20KBT+NviAf5QW KmkUc7CJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZOS/9QAKCRAk1otyXVSH0EadB/ 4pbEQ68xNEsXlzqT+FKSx4l2VDqcaSxDznurZmF3wiwHsUGqukXt4UPUqfjBdqJi6Oym5H3SsAnkPw goVhDlUrA1e9Ismj4oLhvp6filQQGx+V21HAV0F//QE8/vChISGpHJoYB3Bn+wHHjjf03fiAMCbVI6 bzOzlliwqLz0/itkNVmJ3by1VWsVogv/zJPz/owBZFe0T7q7q6P1bbeT8dAzSy6P7USzLBAsGsPl56 IuKF/2r9i/kopR0473dAcyso/W1OEYo9/K54E52GCXR5fWqThIcllYOYye86S7wqt/kB4IqhS0rny5 H5YWc3aMj80CfrlzlUdxQlWDKP6+Mn 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 */