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 F3533CE7B10 for ; Thu, 28 Sep 2023 09:28:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C63D110E5FC; Thu, 28 Sep 2023 09:28:41 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 02B9810E5FC for ; Thu, 28 Sep 2023 09:28:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695893321; x=1727429321; h=from:to:subject:date:message-id:mime-version: content-transfer-encoding; bh=ZA2bJhXQ2FTHXg4Gx20naUMLR30YgNle42QdTmHmuq4=; b=OKTzeGEXqy7a/09c3k2gXUgW76Ss+DMWu/cKnuimbEejAt64PZFuU2+m xbFSu1rd0uxQ3XjVm0r93M0kzjlo83O8D3lEvfIapeuR6WM2S9YFF6SdF j6xJNY+2bxqQiWzFQ/3Nuo1+sUd/IwTaEmZX2DE7nO+rGNisuWioUX7B/ hm/dnf7YXVFKJE3Xo1iXue8EY4gmCyW+FM9tuENSFwXCtLEIcWqJG1bNl 0oo6lAvJrXeciGlymifgYEnLkffmByB5+X0y8xeOnrMA/inxelLmCgm8j Fqbf5M7JLhDJ/CQru7T0PxQRwxI+FGpLjQiyZLbEhQ6p+ic42HwdO9Hf9 w==; X-IronPort-AV: E=McAfee;i="6600,9927,10846"; a="448509981" X-IronPort-AV: E=Sophos;i="6.03,183,1694761200"; d="scan'208";a="448509981" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2023 02:28:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10846"; a="752900875" X-IronPort-AV: E=Sophos;i="6.03,183,1694761200"; d="scan'208";a="752900875" Received: from nlesniak-mobl.ger.corp.intel.com (HELO mwauld-desk1.intel.com) ([10.252.28.108]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2023 02:28:33 -0700 From: Matthew Auld To: intel-xe@lists.freedesktop.org Date: Thu, 28 Sep 2023 10:28:17 +0100 Message-ID: <20230928092816.375130-7-matthew.auld@intel.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-xe] [PATCH v5 0/5] PAT and cache coherency support X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Branch available here: https://gitlab.freedesktop.org/mwa/kernel/-/tree/xe-pat-index?ref_type=heads Goal here is to allow userspace to directly control the pat_index when mapping memory via the ppGTT, in addtion to the CPU caching mode. This is very much needed on newer igpu platforms which allow incoherent GT access, where the choice over the cache level and expected coherency is best left to userspace depending on their usecase. In the future there may also be other stuff encoded in the pat_index, so giving userspace direct control will also be needed there. To support this we added new gem_create uAPI for selecting the CPU cache mode to use for system memory, including the expected GPU coherency mode. There are various restrictions here for the selected coherency mode and compatible CPU cache modes. With that in place the actual pat_index can now be provided as part of vm_bind. The only restriction is that the coherency mode of the pat_index must be at least as coherent as the gem_create coherency mode. There are also some special cases like with userptr and dma-buf. v2: - Loads of improvements/tweaks. Main changes are to now allow gem_create.coh_mode <= coh_mode(pat_index), rather than it needing to match exactly. This simplifies the dma-buf policy from userspace pov. Also we now only consider COH_NONE and COH_AT_LEAST_1WAY. v3: - Rebase. Split the pte_encode() refactoring, plus various smaller tweaks and fixes. v4: - Rebase on Lucas' new series. - Drop UC cache mode. - s/smem_cpu_caching/cpu_caching/. Idea is to make VRAM WC explicit in the uapi, plus make it more future proof. v5: - Rebase, plus some small tweaks and fixes. -- 2.41.0