From patchwork Mon Aug 7 22:00:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13345078 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 C8716C3DA40 for ; Mon, 7 Aug 2023 22:03:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230237AbjHGWDD (ORCPT ); Mon, 7 Aug 2023 18:03:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230405AbjHGWCk (ORCPT ); Mon, 7 Aug 2023 18:02:40 -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 107561FF9; Mon, 7 Aug 2023 15:02:09 -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 27A136229A; Mon, 7 Aug 2023 22:02:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3CFBC433C7; Mon, 7 Aug 2023 22:02:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691445728; bh=sadX6jRs7DdBAThhpdGK2D3phr2V3dLQCMXle4b8GlY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=QgRlN10k2BIzrEOhrn820jRtBTe+fdrBpMGuZxD/seyQ+pfycy1plO6GunO+YjM9T Imxo0U4YrMKhO3pM9TOiH1OsrcNBEzDNkq7sWsKjbuncXLC0IWK+hYLAIeA0UYbdWk 2J4Iivp40QsQkV9YiCt6It7TTmVxrr0kO4KV0AWCZ/z94uEi9EdtD7RDlHF27OkODA ALTuUeamaOoBl5Ucy1dzPpmmhTGCr3NgAIF0omW9GZ/buRCGh1cvjoN3coBiTqiDaf 7OYA7UQokad+VnlK1U1BN0N52ZqJdItBSCNdiLweUCMB1A4LCPHbqxW14S392t51qw PxjYi14eCeQ6g== From: Mark Brown Date: Mon, 07 Aug 2023 23:00:11 +0100 Subject: [PATCH v4 06/36] arm64/gcs: Add manual encodings of GCS instructions MIME-Version: 1.0 Message-Id: <20230807-arm64-gcs-v4-6-68cfa37f9069@kernel.org> References: <20230807-arm64-gcs-v4-0-68cfa37f9069@kernel.org> In-Reply-To: <20230807-arm64-gcs-v4-0-68cfa37f9069@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/pANAwAKASTWi3JdVIfQAcsmYgBk0Wmcf298yHaLe0/pQ+i80LO4Bv3pqAUzPuw6Cszl XMBwrJWJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZNFpnAAKCRAk1otyXVSH0DeHCA CBYigOoCQiC/afrEIqP7eij9j6h3yuzLkjzLJGHLMd2q+XK6KyAgnqoLcONFXVgzpQsR4r2WnoVo6x vsvqKlN9EoWl+KDVsz5kIWyQPqqk3G13mfnkVtQV37cfWcGtZ/smrnGlw4D+iAeK0ffl+CRwd3hZ5/ 3KLmhA2lNgm72VcXSA/ypXzPiXEW+XeGwk4iHYG9TnbIePSGsMxYtuT4Ak6yLYsNlQFAr61t4f0iet tChEloC3EnKkArOX8qkVzpA4Fcvyrv6rl9+IKhv9VWBSGmyQJvsfZLrXcv4CPimPFNechgNpN0zo2+ ordyWKedjaIbaaV7MSZtf3tbO6TfoJ X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@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 */