From patchwork Tue Nov 26 15:39:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 13886115 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 10A07D3B9A4 for ; Tue, 26 Nov 2024 15:43:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=h9V5pLmdM13IHLHW7OGnEjCTF5lVJXXAc6EX0Yk61pk=; b=hCYPYTA+UOHj2zlKxhBr0bdmKk ImpS6SvwRzViTpnESg9AbN+rnEp+e5mVew4HEP28sBQ5Q/SFdoccYQo2eEFXoGdSuf/OMeK615pry Tn9TI5GZXqHUeKjiq+gd3YcqgI5UfpLCcnwVgFHvZYfASBYT1CUks7XWPVcdDI2pxetCD9N4h7G/d poLqNJX6HSoKEjpIXrgJ+znhvntq6IphcIdClk9tvJ68/VnvEUukXs25IxwiTU4h+efrXm8lWFbs9 QVM1aXlqtKtrp+xOO98s9OvvTRpVeXiB/yTSWKONe76MQ1aIupjVTaagPxWZcI5Sv2ppV3eDGuYv4 AHUsawJQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tFxiO-0000000B2cf-2ML9; Tue, 26 Nov 2024 15:43:00 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tFxfe-0000000B285-27FH for linux-arm-kernel@lists.infradead.org; Tue, 26 Nov 2024 15:40:11 +0000 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 BAFFF153B; Tue, 26 Nov 2024 07:40:38 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1AFA53F5A1; Tue, 26 Nov 2024 07:40:07 -0800 (PST) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: broonie@kernel.org, mark.rutland@arm.com Subject: [BOOT-WRAPPER PATCH 2/3] aarch64: Enable use of FPMR for EL2 and below Date: Tue, 26 Nov 2024 15:39:54 +0000 Message-Id: <20241126153955.477569-3-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20241126153955.477569-1-mark.rutland@arm.com> References: <20241126153955.477569-1-mark.rutland@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241126_074010_582751_5296503E X-CRM114-Status: GOOD ( 12.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org FEAT_FPMR adds the FPMR register. Acceses to FPMR (whether direct or indirect) trap to EL3 unless SCR_EL3.EnFPM is set, and so boot-wrapper support is necessary. Support for FEAT_FPMR was added to Linux in v6.8 without any boot-wrapper support. Consequently when FPMR is enabled in a model, the kernel will hang when attempting to write to the FPMR (e.g. when entering userspace for the first time). Add boot-wrapper support for FEAT_FPMR. As FPMR is not described in the latest ARM ARM (ARM DDI 0487K.a), the relevant definitions are taken from the 2024-09 release of the "Arm Architecture Registers" document, ARM DDI 0601 (ID092424), which can be found at: https://developer.arm.com/documentation/ddi0601/2024-09/?lang=en The ID_AA64PFR2_EL1 ID register has existed as reserved RES0 space since ARMv8.0 but only recently gained a name, and so older assemblers may not be able to encode ID_AA64PFR2_EL1 directly. Thus we need an explicit definition of the sysreg encoding to support these assemblers. Signed-off-by: Mark Rutland Cc: Mark Brown Reviewed-by: Mark Brown --- arch/aarch64/include/asm/cpu.h | 4 ++++ arch/aarch64/init.c | 3 +++ 2 files changed, 7 insertions(+) diff --git a/arch/aarch64/include/asm/cpu.h b/arch/aarch64/include/asm/cpu.h index 6fa11da..3ef58f3 100644 --- a/arch/aarch64/include/asm/cpu.h +++ b/arch/aarch64/include/asm/cpu.h @@ -68,6 +68,7 @@ #define SCR_EL3_SCTLR2En BIT(44) #define SCR_EL3_PIEN BIT(45) #define SCR_EL3_D128En BIT(47) +#define SCR_EL3_EnFPM BIT(50) #define VTCR_EL2_MSA BIT(31) @@ -116,6 +117,9 @@ #define ID_AA64PFR1_EL1_CSV2_frac BITS(35, 32) #define ID_AA64PFR1_EL1_THE BITS(51, 48) +#define ID_AA64PFR2_EL1 s3_0_c0_c4_2 +#define ID_AA64PFR2_EL1_FPMR BITS(35, 32) + #define ID_AA64SMFR0_EL1 s3_0_c0_c4_5 #define ID_AA64SMFR0_EL1_FA64 BIT(63) diff --git a/arch/aarch64/init.c b/arch/aarch64/init.c index da036bb..1f38516 100644 --- a/arch/aarch64/init.c +++ b/arch/aarch64/init.c @@ -124,6 +124,9 @@ static void cpu_init_el3(void) if (mrs_field(ID_AA64PFR1_EL1, THE)) scr |= SCR_EL3_RCWMASKEn; + if (mrs_field(ID_AA64PFR2_EL1, FPMR)) + scr |= SCR_EL3_EnFPM; + msr(SCR_EL3, scr); msr(CPTR_EL3, cptr);