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.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 2FD25C5475B for ; Fri, 8 Mar 2024 07:18:48 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.690117.1075835 (Exim 4.92) (envelope-from ) id 1riUUx-0005XE-Ex; Fri, 08 Mar 2024 07:18:31 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 690117.1075835; Fri, 08 Mar 2024 07:18:31 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1riUUx-0005X7-Ax; Fri, 08 Mar 2024 07:18:31 +0000 Received: by outflank-mailman (input) for mailman id 690117; Fri, 08 Mar 2024 07:18:30 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1riUUw-0005X1-AA for xen-devel@lists.xenproject.org; Fri, 08 Mar 2024 07:18:30 +0000 Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [2a00:1450:4864:20::52f]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 0eab2fbe-dd1c-11ee-a1ee-f123f15fe8a2; Fri, 08 Mar 2024 08:18:27 +0100 (CET) Received: by mail-ed1-x52f.google.com with SMTP id 4fb4d7f45d1cf-564372fb762so627079a12.0 for ; Thu, 07 Mar 2024 23:18:27 -0800 (PST) Received: from [10.156.60.236] (ip-037-024-206-209.um08.pools.vodafone-ip.de. [37.24.206.209]) by smtp.gmail.com with ESMTPSA id l13-20020aa7d94d000000b0056828004c75sm579845eds.51.2024.03.07.23.18.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 07 Mar 2024 23:18:26 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 0eab2fbe-dd1c-11ee-a1ee-f123f15fe8a2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1709882306; x=1710487106; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:from:references:cc :to:content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=QfZcAyokEhcr3g+gmO7LAD2eQKRA9xZssWV+SW3Ru+c=; b=DL+qEZEUKfvCYBmb8uzbsIt2EVreekv8i90weqlOHRufoV0n0gcb9SK76mtlydT25r KKRMZr8wVqRGGMoZZ4tCJusu98GwSaxEFTOWVq8VZELAy2PKBi0/xT60sLzzoD3w3avM 8ymBNgW+wqxkQmlUQOvlursRid+1GlMr9EIbDmFsdldrs7p7/3/XdqT5ZwfTMUbRWcMF /rJRjXMIdHvl6a5oxG7zEfC/YkLXPyT6N0FpJ3OLAWH4FK3/kkWWQhmVvjOeUYtZsQoU SKvlio1x4JoYYRo3iegu6wR+TmIQuT5AYumXc+5HJ4ZHjnKMHh14RGscNiNYdUejvAMH b1vA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709882306; x=1710487106; h=content-transfer-encoding:in-reply-to:autocrypt: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=QfZcAyokEhcr3g+gmO7LAD2eQKRA9xZssWV+SW3Ru+c=; b=CUVHOnOk4sw10AGu9azeQubPw186Wt0PuVm1RLeDFjZTbnsT1zz5I0hGiEeeMVap8j Yl0qtBiJV4PFlYi7v/1NsRTCk2B928OVmJsoW1hy4brGg+BA/5Eqwj4E6GxSlE25T0Vc ZOKY3ljq7OhsXNofdyh2bm12sSod94ODSX0r9Iv8ogSGCwTWxlh/PJ+w21yu8dgshngy v26a0VlEglBI2himFqXocUhLuFVIcqaXD7JC5fymgnhFAVyzJb4gQcGa5w91ZpVMUyL3 YAcAmnFs/d47jHJeAbsAahUiOx3iTNZeRHHi+h6R3+Rds5p7Vt0JSsS//ZB2LgG7e4nB 043Q== X-Forwarded-Encrypted: i=1; AJvYcCVCtxX++RcS6RGyR1s8OfO+/SeSTLDBWSmvSlnX55BR1CVSl2bLHrePzCGz12aJiyoIrxSvFovoLlZUOKdcn+s612PBXTD1evMdaxpc4qM= X-Gm-Message-State: AOJu0Yx2Ng5s2kFnmXhf0UiBsmPvn7OPj635FrMDniZVuryBH5qD2E9x IWVLucJik2P5sr/a/XlZaZypeauUmm1jpAkrnmMyt35m8zmUZGr2s6oOP7w+ZQ== X-Google-Smtp-Source: AGHT+IGJy7zMTfl2hzXYs/0qb354ygpOPOx5PjLGAyXyLhohemM1LAVzVE3VNFv9jSyeWT3SkX6L7A== X-Received: by 2002:a05:6402:2311:b0:568:1599:b854 with SMTP id l17-20020a056402231100b005681599b854mr1146266eda.42.1709882306603; Thu, 07 Mar 2024 23:18:26 -0800 (PST) Message-ID: Date: Fri, 8 Mar 2024 08:18:25 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 12/23] xen/riscv: introduce io.h Content-Language: en-US To: Oleksii Cc: Alistair Francis , Bob Eshleman , Connor Davis , Andrew Cooper , George Dunlap , Julien Grall , Stefano Stabellini , Wei Liu , xen-devel@lists.xenproject.org References: <807c31d5-0c5a-4646-ba90-2f284289069f@suse.com> <2a3e49bf94332c17b50e4f0f745e4b28b16dceb1.camel@gmail.com> <2a05c233-b3c5-417c-bd6b-8b1c21f03c3d@suse.com> <9ec718f3bba178d437035add3c7467011fc3ffc0.camel@gmail.com> From: Jan Beulich Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: <9ec718f3bba178d437035add3c7467011fc3ffc0.camel@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 07.03.2024 21:49, Oleksii wrote: > On Thu, 2024-03-07 at 18:14 +0100, Jan Beulich wrote: >> For plain writes it should at least be "=Qo" then, yes. > Constraints Q is a machine specific constraint, and I am not sure that > it makes sense to use "=o" only and probably it is a reason why it is > enough only "r". Does it make sense? Especially the 'only "r"' part doesn't, no. I also don't see why "=o" would make no sense - that's fundamentally no different than "=m". Unless the immediates used in the ultimate insns are large enough to cover the full range of possible values, my take is that "o" is never appropriate to use. With one exception in a case like we have here: If the operand isn't used in the actual instruction(s), then that's fine, as the specific value of the adjusted immediate wouldn't matter at all. As to "Q" - that's an Arm constraint anyway, not a RISC-V one? If so, I'm not sure why we're discussing it here. In any event, I'd be curious to understand in how far the combination "Qo" makes sense. >> To me making those >> input operands on Arm can't have been quite right. > I don't understand why they both are input, logically it looks like an > address should be an output. How would an address be an output, when that's needed to be calculated for the memory access to take place? It would be an output (and presumably a dummy/fake one) only if the address calculation was done in the asm() itself (and there I don't mean the operands, but the actual assembly instruction(s)). Jan