From nobody Tue Sep 9 22:10:00 2025 Received: from madrid.collaboradmins.com (madrid.collaboradmins.com [46.235.227.194]) (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 B611237165 for ; Fri, 5 Jan 2024 18:46:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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 (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="Orc0Lbil" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1704480417; bh=VsBjkTOcwbyuFJpRhuegYHZ49VVIN8ewlBAH0e+7sVA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Orc0LbilUVWlNlvBsm0E/hJbQQYhdvegtDXch5wqjb2KfB2jn302D63iqJ/SxqCn9 kwDmYI78YaT3s3o6AepJ6rf5Mp83sI4ubF0tQ8C+CFHEgGkKWR6eb24LZYdMAaUaZo XIdBzcWntXUyfnW4LgCAsfPQNq9HsHRwid2WVwSNd7DCaU6NkA97ZfUIpPhT0Jneis MSxaPmb6tzT9JABHd5yreuMs5PJDW3O668rlfgPsadqLzXYxkHrx9MYqWypy5y4bA2 7P4MhNuY7SWPrZed/pr/L4d79uijdA7+VanX/69XJIORyrzGAjZFIqOZKNWkPvpzTh c1f9iiErqQjxw== Received: from workpc.. (cola.collaboradmins.com [195.201.22.229]) (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 madrid.collaboradmins.com (Postfix) with ESMTPSA id F20EB3782046; Fri, 5 Jan 2024 18:46:55 +0000 (UTC) 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 v19 08/30] drm/shmem-helper: Use refcount_t for pages_use_count Date: Fri, 5 Jan 2024 21:46:02 +0300 Message-ID: <20240105184624.508603-9-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240105184624.508603-1-dmitry.osipenko@collabora.com> References: <20240105184624.508603-1-dmitry.osipenko@collabora.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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. Acked-by: Maxime Ripard Reviewed-by: Boris Brezillon Suggested-by: Boris Brezillon Signed-off-by: Dmitry Osipenko --- 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 55b9dd3d4b18..cacf0f8c42e2 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)); drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_pin_count)); =20 dma_resv_unlock(shmem->base.resv); @@ -173,14 +173,13 @@ 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 @@ -196,6 +195,8 @@ 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 @@ -211,21 +212,17 @@ 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 @@ -552,8 +549,8 @@ 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 @@ -641,7 +638,7 @@ 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 433bda72e59b..2a97aa85416b 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 1ab081bd81a8..bd5a0073009d 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -489,7 +489,7 @@ 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 c708a9f45cbd..2c5dc62df20c 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 2.43.0