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 92CF5C3ABC3 for ; Tue, 13 May 2025 12:15:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C118410E1A4; Tue, 13 May 2025 12:15:33 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="PnypvhNr"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id BFD9810E0C4; Tue, 13 May 2025 12:15:25 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 636C54A0F2; Tue, 13 May 2025 12:15:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B342C4CEE4; Tue, 13 May 2025 12:15:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747138524; bh=idUfsrQz4c6EAsJ61Lq5mzmfS9aeS/MECofu2KJDb1o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PnypvhNrpMfQY13NqEm+v3dGZQaDT9RrOzjNpzu5ZexvD5a8i4aaQHNy6qaBtW6Re zQJ5P0+GEZ7DJbuOe0oihM/SKmSBnu/Efjqfqf9lChGf+MK1LM/auFwEPaDRGDEL7W m1D8Gc/7vi+5fwa7a9Y2tQkGaWo85VP0i8n44iFm6SfsuDZ1D6mQ3aYuHqtmUt64OA m0byRgs/EMIDOfL7J8fsUfaImyXULMSbZjQLrJdduuhDIgNgz4i+J5zPxwKlNa0GIM 6eHvmwDA+xVHk1vpRGCYup/VuuHzWAt4k+S7hBcHR2TwbGCPF1IEzeax5opSqIi4MY xlqB8rYz23uqQ== Date: Tue, 13 May 2025 14:15:16 +0200 From: Danilo Krummrich To: Alexandre Courbot Cc: Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Jonathan Corbet , John Hubbard , Ben Skeggs , Joel Fernandes , Timur Tabi , Alistair Popple , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH v3 01/19] rust: dma: expose the count and size of CoherentAllocation Message-ID: References: <20250507-nova-frts-v3-0-fcb02749754d@nvidia.com> <20250507-nova-frts-v3-1-fcb02749754d@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250507-nova-frts-v3-1-fcb02749754d@nvidia.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, May 07, 2025 at 10:52:28PM +0900, Alexandre Courbot wrote: > These properties are very useful to have and should be accessible. > > Signed-off-by: Alexandre Courbot > --- > rust/kernel/dma.rs | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs > index 605e01e35715667f93297fd9ec49d8e7032e0910..18602d771054fceb80c29278b1945254312ed7c6 100644 > --- a/rust/kernel/dma.rs > +++ b/rust/kernel/dma.rs > @@ -201,6 +201,20 @@ pub fn alloc_coherent( > CoherentAllocation::alloc_attrs(dev, count, gfp_flags, Attrs(0)) > } > > + /// Returns the number of elements `T` in this allocation. > + /// > + /// Note that this is not the size of the allocation in bytes, which is provided by > + /// [`Self::size`]. > + pub fn count(&self) -> usize { > + self.count > + } > + > + /// Returns the size in bytes of this allocation. > + pub fn size(&self) -> usize { > + // This is guaranteed not to overflow as the same operation has been done in `alloc_attrs`. Please make this an invariant of CoherentAllocation and refer to that instead. > + self.count * core::mem::size_of::() > + } > + > /// Returns the base address to the allocated region in the CPU's virtual address space. > pub fn start_ptr(&self) -> *const T { > self.cpu_addr > > -- > 2.49.0 >