From nobody Thu Feb 12 06:34:17 2026 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 04046EEAA7C for ; Thu, 14 Sep 2023 23:29:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231126AbjINX3X (ORCPT ); Thu, 14 Sep 2023 19:29:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230324AbjINX3M (ORCPT ); Thu, 14 Sep 2023 19:29:12 -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 3E0F02710 for ; Thu, 14 Sep 2023 16:29:08 -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 DF3C16607356; Fri, 15 Sep 2023 00:29:05 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1694734147; bh=WO04qyK07S2NqVZi3rKtftqpx6J1ujZZfJYpj019Mzw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GGQK1nzymMp6iAUQ3PbgGWllfZJYeGClC/iwjy20ZMSlG6iMLrWfLgXihMmUqBC2k sulcYSwqx7pRCdIqq0E3bCswGqWTuQ7W+hU7DQ6nlnSA6amTl8JzmasQui5om/tSc9 Lnz4ttfQdlRtqTR0HjORtVxCCkmF7xqZngZNvNsWu1uBXhqY+Qo8N4UpmFOtaHhNF2 Jo/W+cpIQ2/FtaTWK4n37IrR+7PLLTJtfQd7b/8NlH1TFunlqis+hjrOcq3e1DYtFi PRNjfqIoEu1Q70tfNB3yGCods5qsx8eDGDtjqLWBK9OtL7dRt0w0+kjeIHIluIW5zL eYqa61Bu0r1Ag== 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 v17 07/18] drm/shmem-helper: Use refcount_t for pages_use_count Date: Fri, 15 Sep 2023 02:27:10 +0300 Message-ID: <20230914232721.408581-8-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230914232721.408581-1-dmitry.osipenko@collabora.com> References: <20230914232721.408581-1-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" Use atomic refcount_t helper for pages_use_count to optimize pin/unpin functions by skipping reservation locking while GEM's pin refcount > 1. Suggested-by: Boris Brezillon Signed-off-by: Dmitry Osipenko Reviewed-by: Boris Brezillon --- drivers/gpu/drm/drm_gem_shmem_helper.c | 33 +++++++++++-------------- drivers/gpu/drm/lima/lima_gem.c | 2 +- drivers/gpu/drm/panfrost/panfrost_mmu.c | 2 +- include/drm/drm_gem_shmem_helper.h | 2 +- 4 files changed, 18 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_g= em_shmem_helper.c index 286f0ca51309..e9d9fbd52b34 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -155,7 +155,7 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *sh= mem) if (shmem->pages) drm_gem_shmem_put_pages_locked(shmem); =20 - drm_WARN_ON(obj->dev, shmem->pages_use_count); + drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_use_count)); =20 dma_resv_unlock(shmem->base.resv); } @@ -172,14 +172,13 @@ static int drm_gem_shmem_get_pages_locked(struct drm_= gem_shmem_object *shmem) =20 dma_resv_assert_held(shmem->base.resv); =20 - if (shmem->pages_use_count++ > 0) + if (refcount_inc_not_zero(&shmem->pages_use_count)) return 0; =20 pages =3D drm_gem_get_pages(obj); if (IS_ERR(pages)) { drm_dbg_kms(obj->dev, "Failed to get pages (%ld)\n", PTR_ERR(pages)); - shmem->pages_use_count =3D 0; return PTR_ERR(pages); } =20 @@ -195,6 +194,8 @@ static int drm_gem_shmem_get_pages_locked(struct drm_ge= m_shmem_object *shmem) =20 shmem->pages =3D pages; =20 + refcount_set(&shmem->pages_use_count, 1); + return 0; } =20 @@ -210,21 +211,17 @@ void drm_gem_shmem_put_pages_locked(struct drm_gem_sh= mem_object *shmem) =20 dma_resv_assert_held(shmem->base.resv); =20 - if (drm_WARN_ON_ONCE(obj->dev, !shmem->pages_use_count)) - return; - - if (--shmem->pages_use_count > 0) - return; - + if (refcount_dec_and_test(&shmem->pages_use_count)) { #ifdef CONFIG_X86 - if (shmem->map_wc) - set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT); + if (shmem->map_wc) + set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT); #endif =20 - drm_gem_put_pages(obj, shmem->pages, - shmem->pages_mark_dirty_on_put, - shmem->pages_mark_accessed_on_put); - shmem->pages =3D NULL; + drm_gem_put_pages(obj, shmem->pages, + shmem->pages_mark_dirty_on_put, + shmem->pages_mark_accessed_on_put); + shmem->pages =3D NULL; + } } EXPORT_SYMBOL_GPL(drm_gem_shmem_put_pages_locked); =20 @@ -551,8 +548,8 @@ static void drm_gem_shmem_vm_open(struct vm_area_struct= *vma) * mmap'd, vm_open() just grabs an additional reference for the new * mm the vma is getting copied into (ie. on fork()). */ - if (!drm_WARN_ON_ONCE(obj->dev, !shmem->pages_use_count)) - shmem->pages_use_count++; + drm_WARN_ON_ONCE(obj->dev, + !refcount_inc_not_zero(&shmem->pages_use_count)); =20 dma_resv_unlock(shmem->base.resv); =20 @@ -640,7 +637,7 @@ void drm_gem_shmem_print_info(const struct drm_gem_shme= m_object *shmem, return; =20 drm_printf_indent(p, indent, "pages_pin_count=3D%u\n", refcount_read(&shm= em->pages_pin_count)); - drm_printf_indent(p, indent, "pages_use_count=3D%u\n", shmem->pages_use_c= ount); + drm_printf_indent(p, indent, "pages_use_count=3D%u\n", refcount_read(&shm= em->pages_use_count)); drm_printf_indent(p, indent, "vmap_use_count=3D%u\n", shmem->vmap_use_cou= nt); drm_printf_indent(p, indent, "vaddr=3D%p\n", shmem->vaddr); } diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_ge= m.c index 62d4a409faa8..988e74f67465 100644 --- a/drivers/gpu/drm/lima/lima_gem.c +++ b/drivers/gpu/drm/lima/lima_gem.c @@ -47,7 +47,7 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *v= m) } =20 bo->base.pages =3D pages; - bo->base.pages_use_count =3D 1; + refcount_set(&bo->base.pages_use_count, 1); =20 mapping_set_unevictable(mapping); } diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panf= rost/panfrost_mmu.c index 7771769f0ce0..a91252053aa3 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -487,7 +487,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_= device *pfdev, int as, goto err_unlock; } bo->base.pages =3D pages; - bo->base.pages_use_count =3D 1; + refcount_set(&bo->base.pages_use_count, 1); } else { pages =3D bo->base.pages; if (pages[page_offset]) { diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem= _helper.h index 268b3127d150..3947f5c6bff7 100644 --- a/include/drm/drm_gem_shmem_helper.h +++ b/include/drm/drm_gem_shmem_helper.h @@ -37,7 +37,7 @@ struct drm_gem_shmem_object { * Reference count on the pages table. * The pages are put when the count reaches zero. */ - unsigned int pages_use_count; + refcount_t pages_use_count; =20 /** * @pages_pin_count: --=20 2.41.0