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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FA2DC4332F for ; Sun, 29 Oct 2023 23:09:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232273AbjJ2XJr (ORCPT ); Sun, 29 Oct 2023 19:09:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232760AbjJ2XJP (ORCPT ); Sun, 29 Oct 2023 19:09:15 -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 5585465BC for ; Sun, 29 Oct 2023 16:03:56 -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 298FC6607388; Sun, 29 Oct 2023 23:02:34 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1698620555; bh=kRBcrLAj4D2pvg6jvqHxVmGBnWprZUgp4H9azTfbRYE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kIcrT91R2KsnfqEJqrzr/8g5XvCiRTG15pQZrSdsY7CjrthMuTV7UzFCNftZBg1Kx BzICvJKEVCKLmItWaM3WtIcqVa7F6dbGZfLe6jAAXWpiMWZl1i3+1O8K+Ype8kWrOz R6zoBWI0WE2fxtmAVZ/QiFlmaqzr3yxhekXoIplfhC5oEQOTfVjZM1pgxrDQuYi+ca Htl/XMDw1kRYVtEv8jT3+GblNjOo069yvUlg0ld4ec99SHby87w0OznehkfMW/UDZJ et6pZ+ZDDBdzgezCpqkps5G+ApbO/NCPzb3BWIF5c+spZLGgtYOyxzsUNDY8//cQkK io8K/I6piPBhA== 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 Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com, virtualization@lists.linux-foundation.org Subject: [PATCH v18 06/26] drm/shmem-helper: Add and use pages_pin_count Date: Mon, 30 Oct 2023 02:01:45 +0300 Message-ID: <20231029230205.93277-7-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231029230205.93277-1-dmitry.osipenko@collabora.com> References: <20231029230205.93277-1-dmitry.osipenko@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 exist and are soft-pinned (and could be swapped out). The pages_pin_count > 1 will hard-pin pages in memory. Reviewed-by: Boris Brezillon Suggested-by: Boris Brezillon Signed-off-by: Dmitry Osipenko --- drivers/gpu/drm/drm_gem_shmem_helper.c | 25 +++++++++++++++++-------- include/drm/drm_gem_shmem_helper.h | 11 +++++++++++ 2 files changed, 28 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 2cc0601865f6..b9b71a1a563a 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -156,6 +156,7 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) drm_gem_shmem_put_pages_locked(shmem); drm_WARN_ON(obj->dev, shmem->pages_use_count); + drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_pin_count)); dma_resv_unlock(shmem->base.resv); } @@ -234,18 +235,16 @@ static int drm_gem_shmem_pin_locked(struct drm_gem_shmem_object *shmem) dma_resv_assert_held(shmem->base.resv); + if (refcount_inc_not_zero(&shmem->pages_pin_count)) + return 0; + ret = drm_gem_shmem_get_pages_locked(shmem); + if (!ret) + refcount_set(&shmem->pages_pin_count, 1); return ret; } -static void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem) -{ - dma_resv_assert_held(shmem->base.resv); - - drm_gem_shmem_put_pages_locked(shmem); -} - /** * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object * @shmem: shmem GEM object @@ -263,6 +262,9 @@ int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem) drm_WARN_ON(obj->dev, obj->import_attach); + if (refcount_inc_not_zero(&shmem->pages_pin_count)) + return 0; + ret = dma_resv_lock_interruptible(shmem->base.resv, NULL); if (ret) return ret; @@ -286,8 +288,14 @@ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem) drm_WARN_ON(obj->dev, obj->import_attach); + if (refcount_dec_not_one(&shmem->pages_pin_count)) + return; + dma_resv_lock(shmem->base.resv, NULL); - drm_gem_shmem_unpin_locked(shmem); + + if (refcount_dec_and_test(&shmem->pages_pin_count)) + drm_gem_shmem_put_pages_locked(shmem); + dma_resv_unlock(shmem->base.resv); } EXPORT_SYMBOL_GPL(drm_gem_shmem_unpin); @@ -632,6 +640,7 @@ void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem, if (shmem->base.import_attach) return; + drm_printf_indent(p, indent, "pages_pin_count=%u\n", refcount_read(&shmem->pages_pin_count)); drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count); drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count); drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr); diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h index 6ee4a4046980..5088bd623518 100644 --- a/include/drm/drm_gem_shmem_helper.h +++ b/include/drm/drm_gem_shmem_helper.h @@ -39,6 +39,17 @@ struct drm_gem_shmem_object { */ unsigned int pages_use_count; + /** + * @pages_pin_count: + * + * Reference count on the pinned pages table. + * + * Pages are hard-pinned and reside in memory if count + * greater than zero. Otherwise, when count is zero, the pages are + * allowed to be evicted and purged by memory shrinker. + */ + refcount_t pages_pin_count; + /** * @madv: State for madvise * -- 2.41.0