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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 2291CC10DC1 for ; Fri, 8 Dec 2023 05:55:57 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=sifive.com header.i=@sifive.com header.a=rsa-sha256 header.s=google header.b=Tttrp8cy; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4SmgNq3xb3z3dJm for ; Fri, 8 Dec 2023 16:55:55 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=sifive.com header.i=@sifive.com header.a=rsa-sha256 header.s=google header.b=Tttrp8cy; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=sifive.com (client-ip=2607:f8b0:4864:20::52a; helo=mail-pg1-x52a.google.com; envelope-from=samuel.holland@sifive.com; receiver=lists.ozlabs.org) Received: from mail-pg1-x52a.google.com (mail-pg1-x52a.google.com [IPv6:2607:f8b0:4864:20::52a]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4SmgMv3KqTz3cCS for ; Fri, 8 Dec 2023 16:55:06 +1100 (AEDT) Received: by mail-pg1-x52a.google.com with SMTP id 41be03b00d2f7-5c66418decaso1226874a12.3 for ; Thu, 07 Dec 2023 21:55:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; t=1702014904; x=1702619704; darn=lists.ozlabs.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=cT/f+zG+eBk9GDNM3PRDRS7FWs4vWVwDUJpda1v2enk=; b=Tttrp8cyBNmtdpxKzAto9XSNXCMFM20ryU8cUAY9FTt70Hy4TsYgxZ0BxhxagYx4DQ kY8JztOFQrsQ4DKcA5UoSmoPEoqKPwYhkSV96D0pJ129FPg6Ubj41qTNTwOHx2q4Rd1U ipzlLpxRHJ4lb6gufX5gfpr17Po8teJO/S4ow8MZQMgIJCfREHGdgqmKIUKhpPOqWdJE 5NgXPAsdupNlHr/FYYJ+Vl1/5o2ZRpAAvUmFUoEySp9R3W1J/Ph58rXikFcSZ0cOrw7E 7PFtptB/3H+lNOHZA9X3kBFPAb0utdCk4CQjARsIr/XKhSZR6mPZZ7DeKYbM8rd9ijtZ D40A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702014904; x=1702619704; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=cT/f+zG+eBk9GDNM3PRDRS7FWs4vWVwDUJpda1v2enk=; b=Su930RDBYW1pLOb5loHpWu7EniR9ewghqSmM7T+zveeMukuLpmMlg2jpvGbJ3GAPTG qlXjJ3Ign42frGh/N91J4znxgWL0srXb5hCiFm9qEywUACIC/x0v0LCbWcOx/BYa02eh Y2zWMJhxFZsggFNEa2g/1uVkTXJ0XkczGC4hsztp/QtHv2XVws9N8tq2Wvfe2vqYFbI1 88IZhjI2GTeVEBKMV9EMBTa/HxG3nYExDSlOP3G5o+Uu+0Tbt+9jfJ5ZNGOgid3d1BAe QriVHgVL/FbZZ7m7RYwmKGDuoUN4GZKHTVCv56cTDdXfcIMTJtssQGclA6TtdQBTUMOI K/7g== X-Gm-Message-State: AOJu0YzumdwoggsiBwcpq96EfCbQ34Q+XOlmQuW/vibziiC6wb+Q4hn3 xaVUtuiJQ0hvuvUheaCLJxH27g== X-Google-Smtp-Source: AGHT+IHjHZOPQupU2gBIY1LJy6ZLE2Spe4muScdMLjHj9er/qEsoCLB+Of3eLXhwYzBMH5NUihe96w== X-Received: by 2002:a05:6a20:160a:b0:190:14d9:4797 with SMTP id l10-20020a056a20160a00b0019014d94797mr1355279pzj.4.1702014904099; Thu, 07 Dec 2023 21:55:04 -0800 (PST) Received: from sw06.internal.sifive.com ([4.53.31.132]) by smtp.gmail.com with ESMTPSA id s22-20020a170902989600b001ce5b859a59sm786250plp.305.2023.12.07.21.55.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Dec 2023 21:55:03 -0800 (PST) From: Samuel Holland To: linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-riscv@lists.infradead.org, Christoph Hellwig Subject: [RFC PATCH 01/12] arch: Add ARCH_HAS_KERNEL_FPU_SUPPORT Date: Thu, 7 Dec 2023 21:54:31 -0800 Message-ID: <20231208055501.2916202-2-samuel.holland@sifive.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231208055501.2916202-1-samuel.holland@sifive.com> References: <20231208055501.2916202-1-samuel.holland@sifive.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, Samuel Holland Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Several architectures provide an API to enable the FPU and run floating-point SIMD code in kernel space. However, the function names, header locations, and semantics are inconsistent across architectures, and FPU support may be gated behind other Kconfig options. Provide a standard way for architectures to declare that kernel space FPU support is available. Architectures selecting this option must implement what is currently the most common API (kernel_fpu_begin() and kernel_fpu_end(), plus a new function kernel_fpu_available()) and provide the appropriate CFLAGS for compiling floating-point C code. Suggested-by: Christoph Hellwig Signed-off-by: Samuel Holland --- Makefile | 4 ++++ arch/Kconfig | 9 +++++++++ 2 files changed, 13 insertions(+) diff --git a/Makefile b/Makefile index 511b5616aa41..e65c186cf2c9 100644 --- a/Makefile +++ b/Makefile @@ -969,6 +969,10 @@ KBUILD_CFLAGS += $(CC_FLAGS_CFI) export CC_FLAGS_CFI endif +# Architectures can define flags to add/remove for floating-point support +export CC_FLAGS_FPU +export CC_FLAGS_NO_FPU + ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0) KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT) endif diff --git a/arch/Kconfig b/arch/Kconfig index f4b210ab0612..6df834e18e9c 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1478,6 +1478,15 @@ config ARCH_HAS_NONLEAF_PMD_YOUNG address translations. Page table walkers that clear the accessed bit may use this capability to reduce their search space. +config ARCH_HAS_KERNEL_FPU_SUPPORT + bool + help + An architecture should select this option if it supports running + floating-point code in kernel space. It must export the functions + kernel_fpu_available(), kernel_fpu_begin(), and kernel_fpu_end() from + , and define CC_FLAGS_FPU and/or CC_FLAGS_NO_FPU as + necessary in its Makefile. + source "kernel/gcov/Kconfig" source "scripts/gcc-plugins/Kconfig" -- 2.42.0