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 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 9B258C32793 for ; Wed, 18 Jan 2023 13:19:30 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0882010E748; Wed, 18 Jan 2023 13:19:27 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id A240D10E746; Wed, 18 Jan 2023 13:19:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1674047964; x=1705583964; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=kzLml9umll/jySx2BG9X7bAHoHA4VT9Pp+QU8OB+mAA=; b=UVl4G2O1QkAY65fIK8kow6YdBEb0BsbnBjdD+J6R5IhWY8bqjyQz6kJh wj1M+6jqrGiLuR5ZbuPowwOvcDBxzZiibTAv7xWfTV0lPFmQRV4MRoYEX xa4YXnjFLI9SQQpOLGodiiizP9kTQKgdYo2vNc2vyJifR88EdA1IZpWIy vHz+ry2pMBjAb9tllpkGhuy7H2MkZrIjOfX4Me5DaDYVI5OMkcHwGesXu vxyX1WBcvLSzdqoq8+8cQex3yxrfV9F/4vfuHwavAlMwD8K3MhtwmiDJA TPo7FV+qsAbh1ypJCj3Gf/hWME24DWj+NX5gi/mtz8VJWt8LdCGN54tiX g==; X-IronPort-AV: E=McAfee;i="6500,9779,10593"; a="322668441" X-IronPort-AV: E=Sophos;i="5.97,226,1669104000"; d="scan'208";a="322668441" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2023 05:19:24 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10593"; a="767735729" X-IronPort-AV: E=Sophos;i="5.97,226,1669104000"; d="scan'208";a="767735729" Received: from llvincen-mobl.ger.corp.intel.com (HELO [10.213.215.37]) ([10.213.215.37]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2023 05:19:21 -0800 Message-ID: <10d6fd71-7c03-a820-c984-7466b0aad044@linux.intel.com> Date: Wed, 18 Jan 2023 13:19:18 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Content-Language: en-US To: David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org References: <20230117175236.22317-1-nirmoy.das@intel.com> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc In-Reply-To: <20230117175236.22317-1-nirmoy.das@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Intel-gfx] [PATCH 1/2] drm/drm_vma_manager: Add drm_vma_node_allow_once() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Chris Wilson , Maxime Ripard , Thomas Zimmermann , Nirmoy Das Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Hi Dave & Daniel, On 17/01/2023 17:52, Nirmoy Das wrote: > Currently there is no easy way for a drm driver to safely check and allow > drm_vma_offset_node for a drm file just once. Allow drm drivers to call > non-refcounted version of drm_vma_node_allow() so that a driver doesn't > need to keep track of each drm_vma_node_allow() to call subsequent > drm_vma_node_revoke() to prevent memory leak. > > Cc: Maarten Lankhorst > Cc: Maxime Ripard > Cc: Thomas Zimmermann > Cc: David Airlie > Cc: Daniel Vetter > Cc: Tvrtko Ursulin > Cc: Andi Shyti Okay to take this via drm-intel? Do we need an additional r-b from the DRM core side? Regards, Tvrtko > Suggested-by: Chris Wilson > Signed-off-by: Nirmoy Das > --- > drivers/gpu/drm/drm_vma_manager.c | 76 ++++++++++++++++++++++--------- > include/drm/drm_vma_manager.h | 1 + > 2 files changed, 55 insertions(+), 22 deletions(-) > > diff --git a/drivers/gpu/drm/drm_vma_manager.c b/drivers/gpu/drm/drm_vma_manager.c > index 7de37f8c68fd..83229a031af0 100644 > --- a/drivers/gpu/drm/drm_vma_manager.c > +++ b/drivers/gpu/drm/drm_vma_manager.c > @@ -240,27 +240,8 @@ void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, > } > EXPORT_SYMBOL(drm_vma_offset_remove); > > -/** > - * drm_vma_node_allow - Add open-file to list of allowed users > - * @node: Node to modify > - * @tag: Tag of file to remove > - * > - * Add @tag to the list of allowed open-files for this node. If @tag is > - * already on this list, the ref-count is incremented. > - * > - * The list of allowed-users is preserved across drm_vma_offset_add() and > - * drm_vma_offset_remove() calls. You may even call it if the node is currently > - * not added to any offset-manager. > - * > - * You must remove all open-files the same number of times as you added them > - * before destroying the node. Otherwise, you will leak memory. > - * > - * This is locked against concurrent access internally. > - * > - * RETURNS: > - * 0 on success, negative error code on internal failure (out-of-mem) > - */ > -int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag) > +static int vma_node_allow(struct drm_vma_offset_node *node, > + struct drm_file *tag, bool ref_counted) > { > struct rb_node **iter; > struct rb_node *parent = NULL; > @@ -282,7 +263,8 @@ int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag) > entry = rb_entry(*iter, struct drm_vma_offset_file, vm_rb); > > if (tag == entry->vm_tag) { > - entry->vm_count++; > + if (ref_counted) > + entry->vm_count++; > goto unlock; > } else if (tag > entry->vm_tag) { > iter = &(*iter)->rb_right; > @@ -307,8 +289,58 @@ int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag) > kfree(new); > return ret; > } > + > +/** > + * drm_vma_node_allow - Add open-file to list of allowed users > + * @node: Node to modify > + * @tag: Tag of file to remove > + * > + * Add @tag to the list of allowed open-files for this node. If @tag is > + * already on this list, the ref-count is incremented. > + * > + * The list of allowed-users is preserved across drm_vma_offset_add() and > + * drm_vma_offset_remove() calls. You may even call it if the node is currently > + * not added to any offset-manager. > + * > + * You must remove all open-files the same number of times as you added them > + * before destroying the node. Otherwise, you will leak memory. > + * > + * This is locked against concurrent access internally. > + * > + * RETURNS: > + * 0 on success, negative error code on internal failure (out-of-mem) > + */ > +int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag) > +{ > + return vma_node_allow(node, tag, true); > +} > EXPORT_SYMBOL(drm_vma_node_allow); > > +/** > + * drm_vma_node_allow_once - Add open-file to list of allowed users > + * @node: Node to modify > + * @tag: Tag of file to remove > + * > + * Add @tag to the list of allowed open-files for this node. > + * > + * The list of allowed-users is preserved across drm_vma_offset_add() and > + * drm_vma_offset_remove() calls. You may even call it if the node is currently > + * not added to any offset-manager. > + * > + * This is not ref-counted unlike drm_vma_node_allow() hence drm_vma_node_revoke() > + * should only be called once after this. > + * > + * This is locked against concurrent access internally. > + * > + * RETURNS: > + * 0 on success, negative error code on internal failure (out-of-mem) > + */ > +int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag) > +{ > + return vma_node_allow(node, tag, false); > +} > +EXPORT_SYMBOL(drm_vma_node_allow_once); > + > /** > * drm_vma_node_revoke - Remove open-file from list of allowed users > * @node: Node to modify > diff --git a/include/drm/drm_vma_manager.h b/include/drm/drm_vma_manager.h > index 4f8c35206f7c..6c2a2f21dbf0 100644 > --- a/include/drm/drm_vma_manager.h > +++ b/include/drm/drm_vma_manager.h > @@ -74,6 +74,7 @@ void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, > struct drm_vma_offset_node *node); > > int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag); > +int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag); > void drm_vma_node_revoke(struct drm_vma_offset_node *node, > struct drm_file *tag); > bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,