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 E217CC433F5 for ; Wed, 8 Dec 2021 16:11:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1F72B73887; Wed, 8 Dec 2021 16:11:39 +0000 (UTC) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id A1C397387E; Wed, 8 Dec 2021 16:11:36 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10192"; a="301243522" X-IronPort-AV: E=Sophos;i="5.88,189,1635231600"; d="scan'208";a="301243522" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2021 08:11:31 -0800 X-IronPort-AV: E=Sophos;i="5.88,189,1635231600"; d="scan'208";a="515813300" Received: from faerberc-mobl2.ger.corp.intel.com (HELO intel.com) ([10.251.209.148]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2021 08:11:28 -0800 Date: Wed, 8 Dec 2021 18:11:25 +0200 From: Andi Shyti To: Ramalingam C Message-ID: References: <20211208141613.7251-1-ramalingam.c@intel.com> <20211208141613.7251-4-ramalingam.c@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211208141613.7251-4-ramalingam.c@intel.com> Subject: Re: [Intel-gfx] [PATCH 3/4] drm/i915/gtt/xehpsdv: move scratch page to system memory X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Hellstrom , intel-gfx , Hellstrom Thomas , Matthew Auld , dri-devel Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Hi Ram and Matt, > On some platforms the hw has dropped support for 4K GTT pages when > dealing with LMEM, and due to the design of 64K GTT pages in the hw, we > can only mark the *entire* page-table as operating in 64K GTT mode, > since the enable bit is still on the pde, and not the pte. And since we > we still need to allow 4K GTT pages for SMEM objects, we can't have a > "normal" 4K page-table with scratch pointing to LMEM, since that's > undefined from the hw pov. The simplest solution is to just move the 64K > scratch page to SMEM on such platforms and call it a day, since that > should work for all configurations. > > Signed-off-by: Matthew Auld > Signed-off-by: Ramalingam C > Reviewed-by: Thomas Hellstrom Reviewed-by: Andi Shyti Andi