From patchwork Wed Mar 5 22:59:43 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lyude Paul X-Patchwork-Id: 14003654 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 C71DAC19F32 for ; Wed, 5 Mar 2025 23:08:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 303F010E85E; Wed, 5 Mar 2025 23:08:42 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="TmJHuMyH"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id E8C7B10E85E for ; Wed, 5 Mar 2025 23:08:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741216120; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2YYipArKfP/H/ebwT6dHqlh88VV98EgX7zofrorIO0I=; b=TmJHuMyHTIoaw/yq5+Ey6K+SqyyM8NTgtlxxeY8FQDmga8YsNY+4YWFJyhJR3OlBnB5S2Q MjBE6+pZj0HOVKnXxLkXwHd56z7VMCcMerFiwTiQNy9R4oM5p3PUWNb5olSnr8VX9LsT/u TNfivwGaFuZI5/boyhsy8GOFE/+hh7Y= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-64-lGH8R1nMOOuHUE3SfhubMQ-1; Wed, 05 Mar 2025 18:08:34 -0500 X-MC-Unique: lGH8R1nMOOuHUE3SfhubMQ-1 X-Mimecast-MFC-AGG-ID: lGH8R1nMOOuHUE3SfhubMQ_1741216111 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B94781801A03; Wed, 5 Mar 2025 23:08:31 +0000 (UTC) Received: from chopper.redhat.com (unknown [10.22.88.81]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0DC5A300019E; Wed, 5 Mar 2025 23:08:27 +0000 (UTC) From: Lyude Paul To: dri-devel@lists.freedesktop.org, rust-for-linux@vger.kernel.org Cc: Danilo Krummrich , mcanal@igalia.com, Alice Ryhl , Maxime Ripard , Simona Vetter , Daniel Almeida , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?B?= =?utf-8?q?j=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Trevor Gross , linux-kernel@vger.kernel.org (open list) Subject: [RFC v3 27/33] rust: drm/kms: Add DriverCrtc::atomic_begin() and atomic_flush() Date: Wed, 5 Mar 2025 17:59:43 -0500 Message-ID: <20250305230406.567126-28-lyude@redhat.com> In-Reply-To: <20250305230406.567126-1-lyude@redhat.com> References: <20250305230406.567126-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 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" Optional trait methods for implementing the atomic_begin and atomic_flush callbacks for a CRTC. Signed-off-by: Lyude Paul --- rust/kernel/drm/kms/crtc.rs | 90 ++++++++++++++++++++++++++++++++++++- 1 file changed, 88 insertions(+), 2 deletions(-) diff --git a/rust/kernel/drm/kms/crtc.rs b/rust/kernel/drm/kms/crtc.rs index aaa208b35c3c1..131d10505ba07 100644 --- a/rust/kernel/drm/kms/crtc.rs +++ b/rust/kernel/drm/kms/crtc.rs @@ -90,8 +90,16 @@ pub trait DriverCrtc: Send + Sync + Sized { mode_set: None, mode_valid: None, mode_fixup: None, - atomic_begin: None, - atomic_flush: None, + atomic_begin: if Self::HAS_ATOMIC_BEGIN { + Some(atomic_begin_callback::) + } else { + None + }, + atomic_flush: if Self::HAS_ATOMIC_FLUSH { + Some(atomic_flush_callback::) + } else { + None + }, mode_set_nofb: None, mode_set_base: None, mode_set_base_atomic: None, @@ -132,6 +140,36 @@ fn atomic_check( ) -> Result { build_error::build_error("This should not be reachable") } + + /// The optional [`drm_crtc_helper_funcs.atomic_begin`] hook. + /// + /// This hook will be called before a set of [`Plane`] updates are performed for the given + /// [`Crtc`]. + /// + /// [`drm_crtc_helper_funcs.atomic_begin`]: srctree/include/drm/drm_modeset_helper_vtables.h + fn atomic_begin( + _crtc: &Crtc, + _old_state: &CrtcState, + _new_state: CrtcStateMutator<'_, CrtcState>, + _state: &AtomicStateMutator, + ) { + build_error::build_error("This should not be reachable") + } + + /// The optional [`drm_crtc_helper_funcs.atomic_flush`] hook. + /// + /// This hook will be called after a set of [`Plane`] updates are performed for the given + /// [`Crtc`]. + /// + /// [`drm_crtc_helper_funcs.atomic_flush`]: srctree/include/drm/drm_modeset_helper_vtables.h + fn atomic_flush( + _crtc: &Crtc, + _old_state: &CrtcState, + _new_state: CrtcStateMutator<'_, CrtcState>, + _state: &AtomicStateMutator, + ) { + build_error::build_error("This should never be reachable") + } } /// The generated C vtable for a [`DriverCrtc`]. @@ -918,3 +956,51 @@ fn vtable(&self) -> *const Self::Vtable { Ok(0) }) } + +unsafe extern "C" fn atomic_begin_callback( + crtc: *mut bindings::drm_crtc, + state: *mut bindings::drm_atomic_state, +) { + // SAFETY: + // * We're guaranteed `crtc` is of type `Crtc` via type invariants. + // * We're guaranteed by DRM that `crtc` is pointing to a valid initialized state. + let crtc = unsafe { Crtc::from_raw(crtc) }; + + // SAFETY: We're guaranteed by DRM that `state` points to a valid instance of `drm_atomic_state` + let state = unsafe { AtomicStateMutator::new(NonNull::new_unchecked(state)) }; + + // SAFETY: We're guaranteed by DRM that both the old and new atomic state are present within + // this `drm_atomic_state` + let (old_state, new_state) = unsafe { + ( + state.get_old_crtc_state(crtc).unwrap_unchecked(), + state.get_new_crtc_state(crtc).unwrap_unchecked(), + ) + }; + + T::atomic_begin(crtc, old_state, new_state, &state); +} + +unsafe extern "C" fn atomic_flush_callback( + crtc: *mut bindings::drm_crtc, + state: *mut bindings::drm_atomic_state, +) { + // SAFETY: + // - We're guaranteed `crtc` is of type `Crtc` via type invariants. + // - We're guaranteed by DRM that `crtc` is pointing to a valid initialized state. + let crtc = unsafe { Crtc::from_raw(crtc) }; + + // SAFETY: We're guaranteed by DRM that `state` points to a valid instance of `drm_atomic_state` + let state = unsafe { AtomicStateMutator::new(NonNull::new_unchecked(state)) }; + + // SAFETY: We're in an atomic flush callback, so we know that both the new and old state are + // present + let (old_state, new_state) = unsafe { + ( + state.get_old_crtc_state(crtc).unwrap_unchecked(), + state.get_new_crtc_state(crtc).unwrap_unchecked(), + ) + }; + + T::atomic_flush(crtc, old_state, new_state, &state); +}