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 A0334FF886D for ; Tue, 28 Apr 2026 19:06:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F0CD910EBBE; Tue, 28 Apr 2026 19:06:47 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="DwurtYVT"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8067310EBBE for ; Tue, 28 Apr 2026 19:06:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1777403205; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vTM6EzhoLmh2e5QFtxFH3AEoU2mZqpj3SZtrKYCsVYE=; b=DwurtYVTmOzUrqurYbZWWVM+REou2pAYVn6aTmBAgWe4nne8gu3IvbX+EuES2EdSjvm46k +YcJYZMQBUYxo3N4ntIscU0wvWqT1AAEYANHDZfJXIhut+UKiJTMa4eo2OwZcWv98L1Pdr rOXrBMdioAQePEDHAi0onkxcac2FowI= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-443-m_K2I5gQOuuQX2n7dp2kYA-1; Tue, 28 Apr 2026 15:06:39 -0400 X-MC-Unique: m_K2I5gQOuuQX2n7dp2kYA-1 X-Mimecast-MFC-AGG-ID: m_K2I5gQOuuQX2n7dp2kYA_1777403196 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9112119560A3; Tue, 28 Apr 2026 19:06:35 +0000 (UTC) Received: from GoldenWind.lan (unknown [10.22.88.40]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D5C011800352; Tue, 28 Apr 2026 19:06:31 +0000 (UTC) From: Lyude Paul To: nouveau@lists.freedesktop.org, Gary Guo , Daniel Almeida , rust-for-linux@vger.kernel.org, Danilo Krummrich , dri-devel@lists.freedesktop.org Cc: Matthew Maurer , FUJITA Tomonori , Lorenzo Stoakes , christian.koenig@amd.com, Asahi Lina , Miguel Ojeda , Andreas Hindborg , Simona Vetter , Alice Ryhl , Boqun Feng , Sumit Semwal , Krishna Ketan Rai , linux-media@vger.kernel.org, Shankari Anand , David Airlie , Benno Lossin , Viresh Kumar , linaro-mm-sig@lists.linaro.org, Asahi Lina , Greg Kroah-Hartman , kernel@vger.kernel.org Subject: [PATCH v13 3/5] rust: drm: gem/shmem: Add DmaResvGuard helper Date: Tue, 28 Apr 2026 15:03:43 -0400 Message-ID: <20260428190605.3355690-4-lyude@redhat.com> In-Reply-To: <20260428190605.3355690-1-lyude@redhat.com> References: <20260428190605.3355690-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-MFC-PROC-ID: 4WqrQIMQYh4TOQOeKNNqvA6CLf6YaB7ys6fOUL-jZsw_1777403196 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true 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" Just a temporary holdover to make locking/unlocking the dma_resv lock much easier. Signed-off-by: Lyude Paul Co-authored-by: Alexandre Courbot --- rust/kernel/drm/gem/shmem.rs | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/rust/kernel/drm/gem/shmem.rs b/rust/kernel/drm/gem/shmem.rs index 35d7523e164ff..92ec2b67ed023 100644 --- a/rust/kernel/drm/gem/shmem.rs +++ b/rust/kernel/drm/gem/shmem.rs @@ -27,7 +27,10 @@ Deref, DerefMut, // }, - ptr::NonNull, + ptr::{ + self, + NonNull, // + }, }; use gem::{ BaseObjectPrivate, @@ -224,3 +227,28 @@ impl driver::AllocImpl for Object { dumb_map_offset: None, }; } + +/// Private helper-type for holding the `dma_resv` object for a GEM shmem object. +/// +/// When this is dropped, the `dma_resv` lock is dropped as well. +/// +// TODO: This should be replace with a WwMutex equivalent once we have such bindings in the kernel. +struct DmaResvGuard<'a, T: DriverObject>(&'a Object); + +impl<'a, T: DriverObject> DmaResvGuard<'a, T> { + #[inline(always)] + fn new(obj: &'a Object) -> Self { + // SAFETY: This lock is initialized throughout the lifetime of `object`. + unsafe { bindings::dma_resv_lock(obj.raw_dma_resv(), ptr::null_mut()) }; + + Self(obj) + } +} + +impl<'a, T: DriverObject> Drop for DmaResvGuard<'a, T> { + #[inline(always)] + fn drop(&mut self) { + // SAFETY: We are releasing the lock grabbed during the creation of this object. + unsafe { bindings::dma_resv_unlock(self.0.raw_dma_resv()) }; + } +} -- 2.54.0