From nobody Thu Dec 18 16:33:13 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78EBCC83F1D for ; Sun, 27 Aug 2023 17:57:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230178AbjH0R4i (ORCPT ); Sun, 27 Aug 2023 13:56:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230015AbjH0R4O (ORCPT ); Sun, 27 Aug 2023 13:56:14 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E13D102 for ; Sun, 27 Aug 2023 10:56:12 -0700 (PDT) Received: from workpc.. (109-252-153-31.dynamic.spd-mgts.ru [109.252.153.31]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id C9C3066072AA; Sun, 27 Aug 2023 18:56:09 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1693158971; bh=2p4cHgA5Rx3A3NQCkFX1jrZwlzZfozBw87OZzukNw+A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jftUNFCa8Ei+fwTjpJd10zv1K/ITAyEDxBz4PtwU5RmQz1WqV5Zlmi7lL87/rxTYH ksaywQMhubqu3GmvBESOvFEsAOCvO9gsVSWycZm1F8BDV83hj7trHIncywLjrgL6gT uNZbQM/L/WwghJX3C2sPCJMjFRprEFHUShIfAjLB9laxhngaAShQVV4wt2Vp4nx0CF og+SGzxPDU1U93IsskKI/c4FDwWZ8PHjquX34Z0TTFQQWFWi+CeZKPagI5633k4inw 3ZgJrpgPTMX3LN37qOfYRhdhuK5X0BKMG8EZExSRtCVibamcLTs73+99IYYPC9BJNp 85c5OFX/JD7Cg== From: Dmitry Osipenko To: David Airlie , Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Daniel Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , =?UTF-8?q?Christian=20K=C3=B6nig?= , Qiang Yu , Steven Price , Boris Brezillon , Emma Anholt , Melissa Wen , Will Deacon , Peter Zijlstra , Boqun Feng , Mark Rutland Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com, virtualization@lists.linux-foundation.org, intel-gfx@lists.freedesktop.org Subject: [PATCH v15 12/23] drm/shmem-helper: Add and use pages_pin_count Date: Sun, 27 Aug 2023 20:54:38 +0300 Message-ID: <20230827175449.1766701-13-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230827175449.1766701-1-dmitry.osipenko@collabora.com> References: <20230827175449.1766701-1-dmitry.osipenko@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add separate pages_pin_count for tracking of whether drm-shmem pages are moveable or not. With the addition of memory shrinker support to drm-shmem, the pages_use_count will no longer determine whether pages are hard-pinned in memory, but whether pages exit and are soft-pinned (and could be swapped out). The pages_pin_count > 1 will hard-pin pages in memory. Suggested-by: Boris Brezillon Signed-off-by: Dmitry Osipenko --- drivers/gpu/drm/drm_gem_shmem_helper.c | 22 +++++++++++++++++----- include/drm/drm_gem_shmem_helper.h | 10 ++++++++++ 2 files changed, 27 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_g= em_shmem_helper.c index d545d3d227d7..1a7e5c332fd8 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -234,14 +234,22 @@ static int drm_gem_shmem_pin_locked(struct drm_gem_sh= mem_object *shmem) =20 dma_resv_assert_held(shmem->base.resv); =20 + if (kref_get_unless_zero(&shmem->pages_pin_count)) + return 0; + ret =3D drm_gem_shmem_get_pages_locked(shmem); + if (!ret) + kref_init(&shmem->pages_pin_count); =20 return ret; } =20 -static void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem) +static void drm_gem_shmem_kref_unpin_pages(struct kref *kref) { - dma_resv_assert_held(shmem->base.resv); + struct drm_gem_shmem_object *shmem; + + shmem =3D container_of(kref, struct drm_gem_shmem_object, + pages_pin_count); =20 drm_gem_shmem_put_pages_locked(shmem); } @@ -263,6 +271,9 @@ int drm_gem_shmem_pin(struct drm_gem_shmem_object *shme= m) =20 drm_WARN_ON(obj->dev, obj->import_attach); =20 + if (kref_get_unless_zero(&shmem->pages_pin_count)) + return 0; + ret =3D dma_resv_lock_interruptible(shmem->base.resv, NULL); if (ret) return ret; @@ -286,9 +297,10 @@ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *= shmem) =20 drm_WARN_ON(obj->dev, obj->import_attach); =20 - dma_resv_lock(shmem->base.resv, NULL); - drm_gem_shmem_unpin_locked(shmem); - dma_resv_unlock(shmem->base.resv); + if (kref_put_dma_resv(&shmem->pages_pin_count, + drm_gem_shmem_kref_unpin_pages, + obj->resv, NULL)) + dma_resv_unlock(obj->resv); } EXPORT_SYMBOL_GPL(drm_gem_shmem_unpin); =20 diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem= _helper.h index ec2d8b24e3cf..afb7cd671e2a 100644 --- a/include/drm/drm_gem_shmem_helper.h +++ b/include/drm/drm_gem_shmem_helper.h @@ -39,6 +39,16 @@ struct drm_gem_shmem_object { */ unsigned int pages_use_count; =20 + /** + * @pages_pin_count: + * + * Reference count on the pinned pages table. + * The pages allowed to be evicted and purged by memory + * shrinker only when the count is zero, otherwise pages + * are hard-pinned in memory. + */ + struct kref pages_pin_count; + /** * @madv: State for madvise * --=20 2.41.0