From nobody Mon Sep 15 21:10:56 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 C1D14C678D5 for ; Tue, 10 Jan 2023 18:35:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239377AbjAJSf1 (ORCPT ); Tue, 10 Jan 2023 13:35:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239567AbjAJSeJ (ORCPT ); Tue, 10 Jan 2023 13:34:09 -0500 Received: from msg-2.mailo.com (msg-2.mailo.com [213.182.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF5FAA2AB8 for ; Tue, 10 Jan 2023 10:29:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=mailo.com; s=mailo; t=1673375390; bh=miL+U54u+zbwiY1zJpyFrSycjgOcARyuIyOdsIcqAwg=; h=X-EA-Auth:Date:From:To:Cc:Subject:Message-ID:References: MIME-Version:Content-Type:In-Reply-To; b=BYQiFU30yqi3X9Qb4kRZ8o9LFNNvhMCAUgZ/MCb1uHXjZGWjvqwhsovnaKEOyrOdk 4Ed8rhTJtcn6oZXKpfH81pQmyeSqcnfapPAFm/fxpI2d/D0fJN55wyPq+gTwe6pjoP 7nIiumflzQDbVCQGmxksKZWRJR3j1Yc+FD9iw0IQ= Received: by b-4.in.mailobj.net [192.168.90.14] with ESMTP via ip-206.mailobj.net [213.182.55.206] Tue, 10 Jan 2023 19:29:49 +0100 (CET) X-EA-Auth: 2yCuNAG5h3cTxbwR5VlwuO7IDCj5y64ot8HtV0N6YfFg/GXhAXaQHiEkliEtmYzUP0x8v2nBHL0uNeYy54P+K5wul7dZ2llz Date: Tue, 10 Jan 2023 23:59:44 +0530 From: Deepak R Varma To: Zhenyu Wang , Zhi Wang , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Daniel Vetter , intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Saurabh Singh Sengar , Praveen Kumar Subject: [PATCH 1/2] drm/i915/gvt: Avoid full proxy f_ops for scan_nonprivbb debug attributes Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Using DEFINE_SIMPLE_ATTRIBUTE macro with the debugfs_create_file() function adds the overhead of introducing a proxy file operation functions to wrap the original read/write inside file removal protection functions. This adds significant overhead in terms of introducing and managing the proxy factory file operations structure and function wrapping at runtime. As a replacement, a combination of DEFINE_DEBUGFS_ATTRIBUTE macro paired with debugfs_create_file_unsafe() is suggested to be used instead. The DEFINE_DEBUGFS_ATTRIBUTE utilises debugfs_file_get() and debugfs_file_put() wrappers to protect the original read and write function calls for the debug attributes. There is no need for any runtime proxy file operations to be managed by the debugfs core. Following coccicheck make command helped identify this change: make coccicheck M=3Ddrivers/gpu/drm/i915/ MODE=3Dpatch COCCI=3D./scripts/co= ccinelle/api/debugfs/debugfs_simple_attr.cocci Signed-off-by: Deepak R Varma --- drivers/gpu/drm/i915/gvt/debugfs.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/debugfs.c b/drivers/gpu/drm/i915/gvt/= debugfs.c index 0616b73175f3..03f081c3d9a4 100644 --- a/drivers/gpu/drm/i915/gvt/debugfs.c +++ b/drivers/gpu/drm/i915/gvt/debugfs.c @@ -147,9 +147,9 @@ vgpu_scan_nonprivbb_set(void *data, u64 val) return 0; } =20 -DEFINE_SIMPLE_ATTRIBUTE(vgpu_scan_nonprivbb_fops, - vgpu_scan_nonprivbb_get, vgpu_scan_nonprivbb_set, - "0x%llx\n"); +DEFINE_DEBUGFS_ATTRIBUTE(vgpu_scan_nonprivbb_fops, + vgpu_scan_nonprivbb_get, vgpu_scan_nonprivbb_set, + "0x%llx\n"); =20 static int vgpu_status_get(void *data, u64 *val) { @@ -180,8 +180,8 @@ void intel_gvt_debugfs_add_vgpu(struct intel_vgpu *vgpu) =20 debugfs_create_file("mmio_diff", 0444, vgpu->debugfs, vgpu, &vgpu_mmio_diff_fops); - debugfs_create_file("scan_nonprivbb", 0644, vgpu->debugfs, vgpu, - &vgpu_scan_nonprivbb_fops); + debugfs_create_file_unsafe("scan_nonprivbb", 0644, vgpu->debugfs, vgpu, + &vgpu_scan_nonprivbb_fops); debugfs_create_file("status", 0644, vgpu->debugfs, vgpu, &vgpu_status_fops); } --=20 2.34.1