From patchwork Tue Jan 10 20:20:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Deepak R Varma X-Patchwork-Id: 13095635 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BA2FBC46467 for ; Tue, 10 Jan 2023 20:20:20 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8E20010E0F3; Tue, 10 Jan 2023 20:20:19 +0000 (UTC) Received: from msg-1.mailo.com (msg-1.mailo.com [213.182.54.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 911BB10E0F3 for ; Tue, 10 Jan 2023 20:20:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=mailo.com; s=mailo; t=1673382014; bh=3IN9oMdJEqlNBIK1U/bjP9YXRSbJh4/m3TFLBgmJQjI=; h=X-EA-Auth:Date:From:To:Cc:Subject:Message-ID:MIME-Version: Content-Type; b=PkLGkBDZMDIMzc1ZUqgcyv2wtAU5J4WrlCj5Gt/uw9+WrxuWBhUiPXinVBOirqn4S 5vXM3auhPPhwgflkNf0oWVy97405s1+2SSOUEZhb6w93CiFlhCRX2mmnUomEyuzb4V 9ZtpT23PtPkFuM6QKRTLi1dPHuE+XeROjZ7lSecI= Received: by b-6.in.mailobj.net [192.168.90.16] with ESMTP via ip-206.mailobj.net [213.182.55.206] Tue, 10 Jan 2023 21:20:14 +0100 (CET) X-EA-Auth: KbkOyS25WULzAeG0UfhXEQVuLt1NKF3jwhnHNmxVSoeI5v0VIWxMywgam6RktIG0CCef3vfPkXKBPQpRHPbc2td67xmxw839 Date: Wed, 11 Jan 2023 01:50:06 +0530 From: Deepak R Varma To: Alain Volmat , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/sti: Avoid full proxy f_ops for sti debug attributes Message-ID: MIME-Version: 1.0 Content-Disposition: inline X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Praveen Kumar , Saurabh Singh Sengar Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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=drivers/gpu/drm/i915/ MODE=patch COCCI=./scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci Signed-off-by: Deepak R Varma --- Note: Change cross compile tested using stm32_defconfig for arm drivers/gpu/drm/sti/sti_drv.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c index ef6a4e63198f..c9be82043638 100644 --- a/drivers/gpu/drm/sti/sti_drv.c +++ b/drivers/gpu/drm/sti/sti_drv.c @@ -67,8 +67,8 @@ static int sti_drm_fps_set(void *data, u64 val) return 0; } -DEFINE_SIMPLE_ATTRIBUTE(sti_drm_fps_fops, - sti_drm_fps_get, sti_drm_fps_set, "%llu\n"); +DEFINE_DEBUGFS_ATTRIBUTE(sti_drm_fps_fops, + sti_drm_fps_get, sti_drm_fps_set, "%llu\n"); static int sti_drm_fps_dbg_show(struct seq_file *s, void *data) { @@ -97,8 +97,8 @@ static void sti_drm_dbg_init(struct drm_minor *minor) ARRAY_SIZE(sti_drm_dbg_list), minor->debugfs_root, minor); - debugfs_create_file("fps_show", S_IRUGO | S_IWUSR, minor->debugfs_root, - minor->dev, &sti_drm_fps_fops); + debugfs_create_file_unsafe("fps_show", S_IRUGO | S_IWUSR, minor->debugfs_root, + minor->dev, &sti_drm_fps_fops); DRM_INFO("%s: debugfs installed\n", DRIVER_NAME); }