From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b="QhHAruhH" Received: from mail-qv1-xf31.google.com (mail-qv1-xf31.google.com [IPv6:2607:f8b0:4864:20::f31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23D89199 for ; Mon, 11 Dec 2023 08:16:16 -0800 (PST) Received: by mail-qv1-xf31.google.com with SMTP id 6a1803df08f44-67ab5e015aaso30775646d6.0 for ; Mon, 11 Dec 2023 08:16:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; t=1702311375; x=1702916175; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=9O17D9j4YT4XtoaSYd3/nhs4s1HCIt9uZx1EA+AxCks=; b=QhHAruhHDJwS1YqCWWOQjZe6vFaNZl9vgrCfr2rLk9334kqkidfz2I6xFi2MqCplRK HsRzepNc+fum+8+RIuauotY7cHATmK/eMKsnfV8ms2fP6nSNVCqcFUC7zmC/Nkm9ZwWW f0ZiLblbVR982iaPGxCRzOj8zDxoJ4o+hU+HdQ5znBuUlKgjWrSAaeO+z8su6MlRihKc keIHTLn2X4M+dJx5N5IkONalQ9m0AUtZJWKh8W8zBfA9PSke2nihsWQl1/fH2SRMuHg1 P4W4zt4SWofkbaBfwPZsvWksGts4NRS9buQk1JL+imD4BcQ33oW2Cj5/lepwoN1nia0g ZABQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702311375; x=1702916175; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=9O17D9j4YT4XtoaSYd3/nhs4s1HCIt9uZx1EA+AxCks=; b=TIyKHFZFpqgknc6VLHrWOAegO8r2ue5EYBnXE4/EPCJ6qqb3+U1FI7imJzbFHe14Rp RWQlHgL5SyPdeWTt6k8G4u0CVgd7jn00x9/LdFjfKpghXq54J8l78dDPnEmpn5/YJKD7 VKqaYLX4St5Ws1j6jmCKUjzCbNQartWQ/wgqfrhs59LpOeBnEl/etNTI2uFr4uovNdLV ceYfOByuZgphtz+Be2pYbNuDG0yaflu13oJf7Df/KsI7yfmMVz8cGFfV5wxMSXQP24mQ yHYHfBCT+suLA6Il8LovcZucegaRAb83aIF+Y6+1GOt4++7nBLFUMcV1rzZgeKIeIZgA vZ3A== X-Gm-Message-State: AOJu0YyAE8b//l9qvIBCB4d4uSGIYKy4k4cMoURGiN+JVL5UcILycJyb fSY4KBA6Yh8FqNPXgdllOBl3Vw== X-Google-Smtp-Source: AGHT+IHy4FKXKcoa5vr1zWRR7h8ldItNotN+bq27os2Gmy1WmTZV3fGNzyOi2gfObdJOXzxcGBLOzA== X-Received: by 2002:a05:6214:1fd9:b0:67e:b878:8e48 with SMTP id jh25-20020a0562141fd900b0067eb8788e48mr4904522qvb.39.1702311375258; Mon, 11 Dec 2023 08:16:15 -0800 (PST) Received: from ?IPV6:2600:1700:2000:b002:f8a3:26ec:ac85:392e? ([2600:1700:2000:b002:f8a3:26ec:ac85:392e]) by smtp.gmail.com with ESMTPSA id d17-20020a0cf6d1000000b0067a18167533sm3380983qvo.83.2023.12.11.08.16.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 11 Dec 2023 08:16:15 -0800 (PST) Message-ID: <3f28c1f7-f29c-461f-a90e-58d8e0996cc0@sifive.com> Date: Mon, 11 Dec 2023 10:16:14 -0600 Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 09/12] riscv: Add support for kernel-mode FPU Content-Language: en-US To: Christoph Hellwig Cc: linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-arch@vger.kernel.org References: <20231208055501.2916202-1-samuel.holland@sifive.com> <20231208055501.2916202-10-samuel.holland@sifive.com> From: Samuel Holland In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2023-12-11 10:11 AM, Christoph Hellwig wrote: >> +#ifdef __riscv_f >> + >> +#define kernel_fpu_begin() \ >> + static_assert(false, "floating-point code must use a separate translation unit") >> +#define kernel_fpu_end() kernel_fpu_begin() >> + >> +#else >> + >> +void kernel_fpu_begin(void); >> +void kernel_fpu_end(void); >> + >> +#endif > > I'll assume this is related to trick that places code in a separate > translation unit, but I fail to understand it. Can you add a comment > explaining it? Yes, I can add a comment. Here, __riscv_f refers to RISC-V's F extension for single-precision floating point, which is enabled by CC_FLAGS_FPU.