From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14925C43603 for ; Tue, 17 Dec 2019 18:34:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C97E124687 for ; Tue, 17 Dec 2019 18:34:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728281AbfLQSeY (ORCPT ); Tue, 17 Dec 2019 13:34:24 -0500 Received: from foss.arm.com ([217.140.110.172]:44770 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728181AbfLQSeU (ORCPT ); Tue, 17 Dec 2019 13:34:20 -0500 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 F384330E; Tue, 17 Dec 2019 10:34:19 -0800 (PST) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 8A6283F67D; Tue, 17 Dec 2019 10:34:18 -0800 (PST) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, will@kernel.org, maz@kernel.org, mark.rutland@arm.com, dave.martin@arm.com, catalin.marinas@arm.com, ard.biesheuvel@linaro.org, christoffer.dall@arm.com, Suzuki K Poulose , Will Deacon Subject: [PATCH v2 2/7] arm64: fpsimd: Make sure SVE setup is complete before SIMD is used Date: Tue, 17 Dec 2019 18:33:57 +0000 Message-Id: <20191217183402.2259904-3-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191217183402.2259904-1-suzuki.poulose@arm.com> References: <20191217183402.2259904-1-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In-kernel users of NEON rely on may_use_simd() to check if the SIMD can be used. However, we must initialize the SVE before SIMD can be used. Add a sanity check to make sure that we have completed the SVE setup before anyone uses the SIMD. Cc: Ard Biesheuvel Cc: Mark Rutland Cc: Will Deacon Cc: Catalin Marinas Signed-off-by: Suzuki K Poulose --- Discussion here : https://lkml.kernel.org/r/20191014145204.GS27757@arm.com --- arch/arm64/include/asm/simd.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/simd.h b/arch/arm64/include/asm/simd.h index 7434844036d3..afce6409be51 100644 --- a/arch/arm64/include/asm/simd.h +++ b/arch/arm64/include/asm/simd.h @@ -26,6 +26,8 @@ DECLARE_PER_CPU(bool, fpsimd_context_busy); static __must_check inline bool may_use_simd(void) { /* + * We must make sure that the SVE has been initialized properly + * before using the SIMD in kernel. * fpsimd_context_busy is only set while preemption is disabled, * and is clear whenever preemption is enabled. Since * this_cpu_read() is atomic w.r.t. preemption, fpsimd_context_busy @@ -33,8 +35,10 @@ static __must_check inline bool may_use_simd(void) * migrated, and if it's clear we cannot be migrated to a CPU * where it is set. */ - return !in_irq() && !irqs_disabled() && !in_nmi() && - !this_cpu_read(fpsimd_context_busy); + return system_capabilities_finalized() && + system_supports_fpsimd() && + !in_irq() && !irqs_disabled() && !in_nmi() && + !this_cpu_read(fpsimd_context_busy); } #else /* ! CONFIG_KERNEL_MODE_NEON */ -- 2.23.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77ADDC43603 for ; Tue, 17 Dec 2019 18:34:55 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 3B03B2072D for ; Tue, 17 Dec 2019 18:34:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="c9we6k0h" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B03B2072D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5OT+KNEScvvP8MsZ4Rz4upSavBfxFHQM38kD+iZoeoM=; b=c9we6k0hIPP+bU xdu1fxOxW4nRnz8S164oRpAaK1Nvt9kVy3J0KCz15dJa9QihkFPKNdY7dt+roXCvnsv4NxNw3iFvG MJcb0VtthEX5hpSrxzy2kFArH7JhUDyzuOOu3gQapMZR307rhMwu1Wf3V3akutTgLaBToEje3mHGG m/h5K8wcsyLd/xxyeRHr2QLgENrwCw+EgbA8+8uBmlNiK3DHvC3zymBO02UV+wWzTxf4je/jXLx/k eMQvLLSLvaxiDhy99SCy4NwQ2SPyDuqSJ03z7X73sMV8RVpFoqTg50HkFxp7zIbP1pd9r3TWLoZ4m 33AkHNDV7doSPASvhgNQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ihHgL-00085B-As; Tue, 17 Dec 2019 18:34:53 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ihHfo-0007cw-VQ for linux-arm-kernel@lists.infradead.org; Tue, 17 Dec 2019 18:34:22 +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 F384330E; Tue, 17 Dec 2019 10:34:19 -0800 (PST) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 8A6283F67D; Tue, 17 Dec 2019 10:34:18 -0800 (PST) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 2/7] arm64: fpsimd: Make sure SVE setup is complete before SIMD is used Date: Tue, 17 Dec 2019 18:33:57 +0000 Message-Id: <20191217183402.2259904-3-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191217183402.2259904-1-suzuki.poulose@arm.com> References: <20191217183402.2259904-1-suzuki.poulose@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191217_103421_065870_150A08EA X-CRM114-Status: GOOD ( 12.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, ard.biesheuvel@linaro.org, maz@kernel.org, Suzuki K Poulose , Will Deacon , linux-kernel@vger.kernel.org, christoffer.dall@arm.com, catalin.marinas@arm.com, will@kernel.org, dave.martin@arm.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org In-kernel users of NEON rely on may_use_simd() to check if the SIMD can be used. However, we must initialize the SVE before SIMD can be used. Add a sanity check to make sure that we have completed the SVE setup before anyone uses the SIMD. Cc: Ard Biesheuvel Cc: Mark Rutland Cc: Will Deacon Cc: Catalin Marinas Signed-off-by: Suzuki K Poulose --- Discussion here : https://lkml.kernel.org/r/20191014145204.GS27757@arm.com --- arch/arm64/include/asm/simd.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/simd.h b/arch/arm64/include/asm/simd.h index 7434844036d3..afce6409be51 100644 --- a/arch/arm64/include/asm/simd.h +++ b/arch/arm64/include/asm/simd.h @@ -26,6 +26,8 @@ DECLARE_PER_CPU(bool, fpsimd_context_busy); static __must_check inline bool may_use_simd(void) { /* + * We must make sure that the SVE has been initialized properly + * before using the SIMD in kernel. * fpsimd_context_busy is only set while preemption is disabled, * and is clear whenever preemption is enabled. Since * this_cpu_read() is atomic w.r.t. preemption, fpsimd_context_busy @@ -33,8 +35,10 @@ static __must_check inline bool may_use_simd(void) * migrated, and if it's clear we cannot be migrated to a CPU * where it is set. */ - return !in_irq() && !irqs_disabled() && !in_nmi() && - !this_cpu_read(fpsimd_context_busy); + return system_capabilities_finalized() && + system_supports_fpsimd() && + !in_irq() && !irqs_disabled() && !in_nmi() && + !this_cpu_read(fpsimd_context_busy); } #else /* ! CONFIG_KERNEL_MODE_NEON */ -- 2.23.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel