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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 29E36C761A6 for ; Thu, 30 Mar 2023 10:40:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 89B2910E18B; Thu, 30 Mar 2023 10:40:40 +0000 (UTC) Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2AF1610E18B for ; Thu, 30 Mar 2023 10:40:38 +0000 (UTC) Received: by mail-ed1-x534.google.com with SMTP id r11so74632525edd.5 for ; Thu, 30 Mar 2023 03:40:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680172836; 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=9sPHrSGxR0K3twHFs+FItgUvHLx41QmLql9ppIFsJ3w=; b=O4LWYl9H9jOc5asNz9wyWPmI8DP9yeha25Tm031IXhqGjgDXXH4vZGFn/nLs+ODBfy cx4NhHCcAHfZFxv6YAzTWl4V7jWyjFzQnVhH1i2K3YeAFHBivGlSQXeHjcoa9VyBKSTF nTnmBTgTDHZ078GwGvrVoYg2cM7nWOLN8K3dcnnnNUn24lgqvaPhKwGb64YUX2/fS9AJ AbhJFj7Ms4CW9v+qO9gpSsJYi38wEtLd3Dhons2lhT4fVk8qyY3NtS4vbkqFLsZx7kdh QbzI+nEG0YsITw+zqLZGB/spXPMPxl7zcUNEB8OLssUTu/9ljG+Z9uyD28/0Pgsw0Ogr kyag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680172836; 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=9sPHrSGxR0K3twHFs+FItgUvHLx41QmLql9ppIFsJ3w=; b=0rfBj2sGVBZNQcMIbdLzlVDyusSI4nC051XYSUt6U8DotRMh5ASeaNfIgW/zCohB9U Z0czxzhbtvldYijsb7guRZE9yxy8e1IyUKblqbO89ZPyBUB+Xof+itpMOSniKkUm2LYb 3nGsViuBwtBjfmZ+KzALat6H9eaTTGM4aXMuXSFNSjT1U9MwCQ6MjBxF5OQRpRKL9PnU Nr4d2HuZrbK1NPLHF/dqImy20jyW73dlWZG0D8futYTDshebXUlZYJvCjthVPvx0LKGy AfdIzAdsLk5f3b5EX53hUmJjDs9McSKi8c/AF7iq6sHdGQH+x7lNJ0Sk0ZQOPzwbwJv3 5gjA== X-Gm-Message-State: AAQBX9eUO6Fd2JUF/5TcKltSXR6r2w0fkwwiz5VtK24XlnCAizfzISkQ nxFXujzEYckFFmPVcyrS6vU= X-Google-Smtp-Source: AKy350bhDKTluknkvAcIyEnOYJbJmwQALBz/rINKEtjGaS110bc+lx06VsaI+FdpnSPo4B+E8qzazw== X-Received: by 2002:a05:6402:c4:b0:502:4875:721 with SMTP id i4-20020a05640200c400b0050248750721mr10810750edu.15.1680172836323; Thu, 30 Mar 2023 03:40:36 -0700 (PDT) Received: from [192.168.178.21] (p4fc2092b.dip0.t-ipconnect.de. [79.194.9.43]) by smtp.gmail.com with ESMTPSA id u25-20020a50c2d9000000b004faf34064c8sm17810527edf.62.2023.03.30.03.40.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Mar 2023 03:40:35 -0700 (PDT) Message-ID: <3c76552d-e6cf-cc89-1e57-e5ee789e79a6@gmail.com> Date: Thu, 30 Mar 2023 12:40:34 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH v3 1/9] drm/amdgpu: UAPI for user queue management Content-Language: en-US To: Shashank Sharma , Pierre-Eric Pelloux-Prayer , amd-gfx@lists.freedesktop.org References: <20230329160445.1300-1-shashank.sharma@amd.com> <20230329160445.1300-2-shashank.sharma@amd.com> <71fc098c-c0cb-3097-4e11-c2d9bd9b4783@damsy.net> <48c60002-7f75-b0d0-fb7d-44b87d9cdedd@amd.com> From: =?UTF-8?Q?Christian_K=c3=b6nig?= In-Reply-To: <48c60002-7f75-b0d0-fb7d-44b87d9cdedd@amd.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alex Deucher , Felix Kuehling , Christian Koenig Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" Am 30.03.23 um 10:15 schrieb Shashank Sharma: > Hello Pierre-Eric, > [SNIP] >> I'm also wondering why the doorbell needs a handle+offset but >> other buffers are passed in as virtual addresses? >> > As you know, doorbell offset here will be an relative offset in this > doorbell page, but the MQD needs the absolute offset on the doorbell > PCI BAR. > > So kernel needs both the object as well as relative offset to > calculate absolute offset. > > something like: absolute offset = base offset of this doorbell page + > relative offset of this doorbell. Another much more obvious reason is that the doorbell doesn't have a virtual address. At least for GFX the doorbell is used to signal to the hw that new commands are available. So as long as we don't want a shader to kick of other work we don't need to map the doorbell into the GPUVM address space. Christian.