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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 55007C79F89 for ; Mon, 7 Sep 2026 14:00:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=EgLK3o+julTVE6C/8v3utQVcxVTdU7XWXdzws8YaC20=; b=TmINlSW2OiYwyW99ztLZX0fmY/ a0AngVULjlKFUSXuqmLfeCdGO7JGnL8W8IinyrvxtvQAjI/bNzWVLuRp2iigP9/1ZfsVcoO6WU0vJ mppPhzJWlIoAprx/ogdK+rMMUDPPC7WXJqbcmhTRDkq/Uhbs8I7uMWpKiYMlKDBJ5vZu3QJbw5H2r rRlaWoSfEJtES3RNLKQw44yL+V9Grj8qDLzjRStrTvpUWK5cK9GTdR12LMgP2G23Kxeo88QSATBNh OV353ArEVJ6VWrSQJ8eKLW5QJcovV1D8QqpcuzWf9DvtNntHaAsbDeBJjfaXgxLCLrX9qVRgzON92 PbO++I9Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3ZtY-00000006zxA-3UQw; Mon, 07 Sep 2026 14:00:24 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3ZtW-00000006zwm-47Ql for linux-arm-kernel@lists.infradead.org; Mon, 07 Sep 2026 14:00:23 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 476184086C; Mon, 7 Sep 2026 14:00:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 985261F00A3D; Mon, 7 Sep 2026 14:00:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788789622; bh=EgLK3o+julTVE6C/8v3utQVcxVTdU7XWXdzws8YaC20=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=gtOe0lI4tICmFeXO0VXaSZWun1zD97NtGKzB00Fxz4Ka/Zpm56GHzGCFmpkzXvwya IjgdW5ASTJB+qKa5sg3xhHy+2z3Tif4EUzgG6v2G0AqXAMe/0BNO4ao6/A+PGKiEDt LiunuR042Q+3iJ1jf+LikMpBoAosls+iqBo1ld1uAEuNgD3FyixqBGd1NK8XwlELz8 0aXr47TpsMtDRS4WsQVvIrdjIekWTZVzwY14LA7ppw9cLIVA/gJznyINUg586mqoJr i4bMWj2QqqCUzgdxYWZPl2+vXlMSa8ApBf/xkklnj7o+nTfBb5pP16MUu53RogA7JW PhrukphYxcyLg== Date: Mon, 7 Sep 2026 16:00:19 +0200 From: Thierry Reding To: Vincent Donnefort Cc: Rob Herring , catalin.marinas@arm.com, will@kernel.org, rppt@kernel.org, akpm@linux-foundation.org, sudeep.holla@kernel.org, jenswi@kernel.org, mark.rutland@arm.com, sumit.garg@kernel.org, ardb@kernel.org, david@kernel.org, danielmentz@google.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, op-tee@lists.trustedfirmware.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v9 02/10] of: reserved_mem: Introduce "ll-map" property Message-ID: References: <20260902104712.2399797-1-vdonnefort@google.com> <20260902104712.2399797-3-vdonnefort@google.com> <20260902172436.GB1440252-robh@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="3ihzba4bzldpza5m" Content-Disposition: inline In-Reply-To: X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --3ihzba4bzldpza5m Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH v9 02/10] of: reserved_mem: Introduce "ll-map" property MIME-Version: 1.0 On Thu, Sep 03, 2026 at 11:03:12AM +0100, Vincent Donnefort wrote: > On Wed, Sep 02, 2026 at 12:24:36PM -0500, Rob Herring wrote: > > On Wed, Sep 02, 2026 at 11:47:04AM +0100, Vincent Donnefort wrote: > > > Keeping last-level mappings is interesting on some architectures as it > > > allows mapping/unmapping pages from the kernel direct map without the > > > risk of splitting blocks which, under the break-before-make rule, may > > > trigger page-faults the kernel can't handle. > > >=20 > > > Add an "ll-map" property for reserved-memory regions. When set, it > > > splits the underlying memblock and sets the MEMBLOCK_LLMAP flag. > >=20 > > Where is this documented? Any DT property must have a schema. >=20 > Ack. >=20 > >=20 > > Though I'm not thrilled about more flag properties. Handling all the=20 > > combinations of properties has proven to be painful. Can this be implie= d=20 > > from the compatible string instead? > >=20 > > Rob >=20 > We need this before the kernel direct map has been created (paging_init()= ). >=20 > I would have moved that directly into the driver lend_pool.c, but then it= is > probed too late (unflatten_device_tree()). Any of the node_*() callbacks from struct reserved_mem_ops get called prior to paging_init(), so these could be used to manually set the memblock flags in the corresponding drivers. 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