From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 950E24A92F4; Wed, 2 Sep 2026 17:24:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788369878; cv=none; b=XYuN5A83YvWtPSvgNCjHj01x780TuXgFM8dmmn5UEiMmn2Y8mCPZd4Vb0Moel6NUTqE3BxRiQGI0zfVzZ1hAuJUt7c54/rrXmzCBEYBYYNAo6F95bxXjNkV6Zt3+1uKBRx+crcil9llq9gFDy8kpYDQapxnUUzVUE4yBs0Z4o04= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788369878; c=relaxed/simple; bh=O2HTZ8oMi/55GiW97GxYG2jCA376NJNvFoe5bFDZISQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BcuUqqKb4Mj7gna6S4oTud9OEU2tTol83Q0SjMT9D7/G2WDsGlt93K1KklkWvfcgKP/ktkQnrDWKnNDstGQLelXWEVNL2GciLq9UqthCLBDOaWorvPkg6K4Dit8LRa3eVMblbRmQo3wLFMnn6I6LMeY6HlcQTvRuh5f6Pho/4mM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DXiOsd0I; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DXiOsd0I" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1164D1F000E9; Wed, 2 Sep 2026 17:24:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788369877; bh=l3/1naZ1RhLgUWY856SAbE6LeQ8PQwzS4dxBvl1l3nM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=DXiOsd0IOwaWcqNMcESpWf4hFCXAp8Wnr0mmhtnowdnpJUppd8Az9ulZWwyJ2Uu4R wkSOKrsgXyrCbsZ4Ej8dCHAUO3I/4HPgFL476eGN0P/8NbBkNtGVWoaVvzxq629JSE MNyjdmuBfdWD9tp2ye9BdSsE7IZfLQ6ow1ntz6mprCCXuVX0AkCxGb50BYmQW7oBbd MPaDcJNFaSVqAkwRbQfma7hfoYES0jZcC+6XyiyrsPbnOzs3CpqliBh6dejcYwxVGB pQAl1sebDUlr62/dzSyXwzrWVKPVJmhKguUHvxr/r+W7Qs+BOd/D226mZ36jtpIbUb BuzrSWHmpSLjQ== Date: Wed, 2 Sep 2026 12:24:36 -0500 From: Rob Herring To: Vincent Donnefort Cc: 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, thierry.reding@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: <20260902172436.GB1440252-robh@kernel.org> References: <20260902104712.2399797-1-vdonnefort@google.com> <20260902104712.2399797-3-vdonnefort@google.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260902104712.2399797-3-vdonnefort@google.com> 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. > > Add an "ll-map" property for reserved-memory regions. When set, it > splits the underlying memblock and sets the MEMBLOCK_LLMAP flag. Where is this documented? Any DT property must have a schema. Though I'm not thrilled about more flag properties. Handling all the combinations of properties has proven to be painful. Can this be implied from the compatible string instead? Rob 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.trustedfirmware.org (lists.trustedfirmware.org [18.214.241.189]) (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 BA767C61DD6 for ; Wed, 2 Sep 2026 17:24:45 +0000 (UTC) Received: from lists.trustedfirmware.org (localhost [127.0.0.1]) by lists.trustedfirmware.org (Postfix) with ESMTP id EB7384532C for ; Wed, 2 Sep 2026 17:24:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lists.trustedfirmware.org; s=2024; t=1788369885; bh=O2HTZ8oMi/55GiW97GxYG2jCA376NJNvFoe5bFDZISQ=; h=Date:To:Subject:References:In-Reply-To:CC:List-Id:List-Archive: List-Help:List-Owner:List-Post:List-Subscribe:List-Unsubscribe: From:Reply-To:From; b=gaypfuewf03JGJyrCCYUV8J4TPzsW5MbqtT3t27EI9PZ2zwoJxAXuVajzBAfvWN6W WzYjJKbgPiLybnprqZPFHOrftprdGsk+WT2ChLR+yJuB5CdBrb0cGqLA4JTCh014ib xYNcm0xkvMcSI+Lx8zrm1wQSKF0Al/eacpgAqSZ9US9dpBfRKsXr69CJswpLtrJmYX AnyQ9Lo28wCw84hN72r1vJz/CbEzDHcVmAeINZ13sLA8SkdEIsPMYw4vJG/CpwGRel Vd4PCbTeVXkCSwynRDhExYuXb7RZhkoEBfmJCNd6MvZgr1+ChlmW+azjTkD28UA6YN ZfjCgBs2dhvGw== Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by lists.trustedfirmware.org (Postfix) with ESMTPS id 0610D44FD4 for ; Wed, 2 Sep 2026 17:24:38 +0000 (UTC) Authentication-Results: lists.trustedfirmware.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=DXiOsd0I; dkim-atps=neutral Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 4BF7E40273; Wed, 2 Sep 2026 17:24:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1164D1F000E9; Wed, 2 Sep 2026 17:24:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788369877; bh=l3/1naZ1RhLgUWY856SAbE6LeQ8PQwzS4dxBvl1l3nM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=DXiOsd0IOwaWcqNMcESpWf4hFCXAp8Wnr0mmhtnowdnpJUppd8Az9ulZWwyJ2Uu4R wkSOKrsgXyrCbsZ4Ej8dCHAUO3I/4HPgFL476eGN0P/8NbBkNtGVWoaVvzxq629JSE MNyjdmuBfdWD9tp2ye9BdSsE7IZfLQ6ow1ntz6mprCCXuVX0AkCxGb50BYmQW7oBbd MPaDcJNFaSVqAkwRbQfma7hfoYES0jZcC+6XyiyrsPbnOzs3CpqliBh6dejcYwxVGB pQAl1sebDUlr62/dzSyXwzrWVKPVJmhKguUHvxr/r+W7Qs+BOd/D226mZ36jtpIbUb BuzrSWHmpSLjQ== Date: Wed, 2 Sep 2026 12:24:36 -0500 To: Vincent Donnefort Subject: Re: [PATCH v9 02/10] of: reserved_mem: Introduce "ll-map" property Message-ID: <20260902172436.GB1440252-robh@kernel.org> References: <20260902104712.2399797-1-vdonnefort@google.com> <20260902104712.2399797-3-vdonnefort@google.com> MIME-Version: 1.0 Content-Type: text/plain; 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no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-op-tee.lists.trustedfirmware.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: 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, thierry.reding@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 X-Mailman-Version: 3.3.5 Precedence: list List-Id: Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: Rob Herring via OP-TEE Reply-To: Rob Herring 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. > > Add an "ll-map" property for reserved-memory regions. When set, it > splits the underlying memblock and sets the MEMBLOCK_LLMAP flag. Where is this documented? Any DT property must have a schema. Though I'm not thrilled about more flag properties. Handling all the combinations of properties has proven to be painful. Can this be implied from the compatible string instead? Rob