From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 3ABEE18FC80 for ; Thu, 12 Feb 2026 01:37:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770860275; cv=pass; b=YULHZA7Zj+xMduotEIpnyvyBDagVukgcx2h8OwCzr6Wv23jbXN7N4v2H612eLz/I9ydrsvOkbAEKx+jkxWRcg9WHpg8+fL9E6dtH5JM5RN8mmVQ+gEaEOGuTQc1dbcivqIiglPInnKPXlxKx0Qf/Eftb9s4QN0ow2tXj9apg/5s= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770860275; c=relaxed/simple; bh=e2pKVHLulcInCu/8yOAD7A6eTQ2bsk3vS1v5GIznOIk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TXj/FgC2bTi4GLEL8/SVv8bWFb9/+y2VCrsgLhJMN31v0GKVV6Kr0Qq0BsR1RiEPmZrZ8KlNAXdx75v+6tQc2DdiwDlimzxY3Uug0ZaCHbjt+EkPjOEnP3JiOm4QDTmqr1iVKxWPlkbJfbJWs/Z4Ipeqn32rz1QyXGHM+B5r/XU= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=deborah.brouwer@collabora.com header.b=Rc1wOu/Y; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=deborah.brouwer@collabora.com header.b="Rc1wOu/Y" ARC-Seal: i=1; a=rsa-sha256; t=1770860267; cv=none; d=zohomail.com; s=zohoarc; b=ZEmnQdou0gyHT4mOqey5l3P0+IRIKCwuLqdJ28xXxiwghhfG6ULWbea5Vokar2WykIqD+YDmUUQu7rR6WHGC9iGeFyMWRBcjPXTxJ3dapcOXuAJBFhO0w7OwhXxCkV0zf/YGP9CUkOZFWP6sUK5VlcY3j0sUEWjUhcyV0rPzRtY= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1770860267; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=IvH4x9/Iyadu1F8gOagQw1249jxBwYcCWXaExDogPN8=; b=Lszw8nMOHAgqPkQiewjm/zjLg4dvBoK3P/BG5cfqZdZ05Tn8fCr+H+gnlvJ4MPvxp8lkbBmTtJbgVKhTjCyvljw42JRGNMPrSLIfbo5zY+H0lf/G8/IUEyu3bOwD1R5d+PIpWsp68T9CxV5UFBEt08H6BWqp276cnqD07U5qifQ= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=deborah.brouwer@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1770860267; s=zohomail; d=collabora.com; i=deborah.brouwer@collabora.com; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=IvH4x9/Iyadu1F8gOagQw1249jxBwYcCWXaExDogPN8=; b=Rc1wOu/YxZAn0/KkF/U5/l8nxcjc0DuvMCpEbQtPxZLJG2M89kWWy15NdI9nLNun 3BC/sH2OK4a9YcjEXhfG1fjpc4ognA6Zlj4V8f6WHZnSR6dGId/hSeheIqw8D3ZLlbS A6hW0RqVb4WyIcKr/SGNnn3tx0//VRlWVy2PKPaw= Received: by mx.zohomail.com with SMTPS id 1770860265316717.0429461113662; Wed, 11 Feb 2026 17:37:45 -0800 (PST) From: Deborah Brouwer To: dri-devel@lists.freedesktop.org, rust-for-linux@vger.kernel.org Cc: daniel.almeida@collabora.com, aliceryhl@google.com, boris.brezillon@collabora.com, beata.michalska@arm.com, lyude@redhat.com, Deborah Brouwer Subject: [PATCH 10/12] drm/tyr: add a kernel buffer object Date: Wed, 11 Feb 2026 17:37:11 -0800 Message-ID: <20260212013713.304343-11-deborah.brouwer@collabora.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260212013713.304343-1-deborah.brouwer@collabora.com> References: <20260212013713.304343-1-deborah.brouwer@collabora.com> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Introduce a buffer object type (KernelBo) for internal driver allocations that are managed by the kernel rather than userspace. KernelBo wraps a GEM shmem object and automatically handles GPU virtual address space mapping during creation and unmapping on drop. This provides a safe and convenient way for the driver to both allocate and clean up internal buffers for kernel-managed resources. Co-developed-by: Boris Brezillon Signed-off-by: Boris Brezillon Signed-off-by: Deborah Brouwer --- drivers/gpu/drm/tyr/gem.rs | 74 +++++++++++++++++++++++++++++++++++--- 1 file changed, 70 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/tyr/gem.rs b/drivers/gpu/drm/tyr/gem.rs index 111acf33993f..3807810be7ea 100644 --- a/drivers/gpu/drm/tyr/gem.rs +++ b/drivers/gpu/drm/tyr/gem.rs @@ -4,6 +4,8 @@ //! This module provides buffer object (BO) management functionality using //! DRM's GEM subsystem with shmem backing. +use core::ops::Range; + use kernel::{ drm::{ gem, @@ -11,12 +13,22 @@ DeviceContext, // }, prelude::*, - sync::aref::ARef, // + sync::{ + aref::ARef, + Arc, + ArcBorrow, // + }, }; -use crate::driver::{ - TyrDrmDevice, - TyrDrmDriver, // +use crate::{ + driver::{ + TyrDrmDevice, + TyrDrmDriver, // + }, + vm::{ + Vm, + VmMapFlags, // + }, }; /// Tyr's DriverObject type for GEM objects. @@ -61,3 +73,57 @@ pub(crate) fn new_dummy_object(ddev: &TyrDrmDevice) -> Ok(bo) } + +/// A buffer object that is owned and managed by Tyr rather than userspace. +pub(crate) struct KernelBo { + #[expect(dead_code)] + pub(crate) bo: ARef, + vm: Arc, + va_range: Range, +} + +impl KernelBo { + /// Creates a new kernel-owned buffer object and maps it into GPU VA space. + #[expect(dead_code)] + pub(crate) fn new( + ddev: &TyrDrmDevice, + vm: ArcBorrow<'_, Vm>, + size: u64, + va: u64, + flags: VmMapFlags, + ) -> Result { + let bo = gem::shmem::Object::::new( + ddev, + size as usize, + shmem::ObjectConfig { + map_wc: true, + parent_resv_obj: None, + }, + BoCreateArgs { flags: 0 }, + )?; + + vm.map_bo_range(&bo, 0, size, va, flags)?; + + Ok(KernelBo { + bo, + vm: vm.into(), + va_range: va..(va + size), + }) + } +} + +impl Drop for KernelBo { + fn drop(&mut self) { + let va = self.va_range.start; + let size = self.va_range.end - self.va_range.start; + + if let Err(e) = self.vm.unmap_range(va, size) { + pr_err!( + "Failed to unmap KernelBo range {:#x}..{:#x}: {:?}\n", + self.va_range.start, + self.va_range.end, + e + ); + } + } +} -- 2.52.0