From patchwork Tue Mar 25 13:19:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Hellstrom X-Patchwork-Id: 3887691 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 249C5BF540 for ; Tue, 25 Mar 2014 13:19:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 36DE62021B for ; Tue, 25 Mar 2014 13:19:55 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 602BE201FD for ; Tue, 25 Mar 2014 13:19:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9E80C6E28F; Tue, 25 Mar 2014 06:19:53 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from smtp-outbound-1.vmware.com (smtp-outbound-1.vmware.com [208.91.2.12]) by gabe.freedesktop.org (Postfix) with ESMTP id CB6F76E291 for ; Tue, 25 Mar 2014 06:19:48 -0700 (PDT) Received: from sc9-mailhost3.vmware.com (sc9-mailhost3.vmware.com [10.113.161.73]) by smtp-outbound-1.vmware.com (Postfix) with ESMTP id A6F7528465 for ; Tue, 25 Mar 2014 06:19:48 -0700 (PDT) Received: from zcs-prod-ext-mta-1.vmware.com (zcs-prod-ext-mta-1.vmware.com [10.113.62.223]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id A25A4402E1 for ; Tue, 25 Mar 2014 06:19:48 -0700 (PDT) Received: from zcs-prod-ext-mta-1.vmware.com (localhost.localdomain [127.0.0.1]) by zcs-prod-ext-mta-1.vmware.com (Postfix) with ESMTP id CF9FD120030; Tue, 25 Mar 2014 06:19:43 -0700 (PDT) Received: from ubuntu.localdomain (zimbra-prod-ext-proxy-vip.vmware.com [10.113.63.87]) by zcs-prod-ext-mta-1.vmware.com (Postfix) with ESMTPSA; Tue, 25 Mar 2014 06:19:42 -0700 (PDT) From: Thomas Hellstrom To: dri-devel@lists.freedesktop.org Subject: [PATCH 13/16] drm/ttm: Add a ttm_ref_object_exists function Date: Tue, 25 Mar 2014 14:19:05 +0100 Message-Id: <1395753548-17441-14-git-send-email-thellstrom@vmware.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1395753548-17441-1-git-send-email-thellstrom@vmware.com> References: <1395753548-17441-1-git-send-email-thellstrom@vmware.com> Cc: pv-drivers@vmware.com, Thomas Hellstrom , linux-graphics-maintainer@vmware.com X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A function to be used to check whether a caller has put a ref object (opened) a struct ttm_base_object Signed-off-by: Thomas Hellstrom Reviewed-by: Brian Paul --- drivers/gpu/drm/ttm/ttm_object.c | 46 ++++++++++++++++++++++++++++++++++++++ include/drm/ttm/ttm_object.h | 4 ++++ 2 files changed, 50 insertions(+) diff --git a/drivers/gpu/drm/ttm/ttm_object.c b/drivers/gpu/drm/ttm/ttm_object.c index 53b51c4..d2a0533 100644 --- a/drivers/gpu/drm/ttm/ttm_object.c +++ b/drivers/gpu/drm/ttm/ttm_object.c @@ -270,6 +270,52 @@ ttm_base_object_lookup_for_ref(struct ttm_object_device *tdev, uint32_t key) } EXPORT_SYMBOL(ttm_base_object_lookup_for_ref); +/** + * ttm_ref_object_exists - Check whether a caller has a valid ref object + * (has opened) a base object. + * + * @tfile: Pointer to a struct ttm_object_file identifying the caller. + * @base: Pointer to a struct base object. + * + * Checks wether the caller identified by @tfile has put a valid USAGE + * reference object on the base object identified by @base. + */ +bool ttm_ref_object_exists(struct ttm_object_file *tfile, + struct ttm_base_object *base) +{ + struct drm_open_hash *ht = &tfile->ref_hash[TTM_REF_USAGE]; + struct drm_hash_item *hash; + struct ttm_ref_object *ref; + + rcu_read_lock(); + if (unlikely(drm_ht_find_item_rcu(ht, base->hash.key, &hash) != 0)) + goto out_false; + + /* + * Verify that the ref object is really pointing to our base object. + * Our base object could actually be dead, and the ref object pointing + * to another base object with the same handle. + */ + ref = drm_hash_entry(hash, struct ttm_ref_object, hash); + if (unlikely(base != ref->obj)) + goto out_false; + + /* + * Verify that the ref->obj pointer was actually valid! + */ + rmb(); + if (unlikely(atomic_read(&ref->kref.refcount) == 0)) + goto out_false; + + rcu_read_unlock(); + return true; + + out_false: + rcu_read_unlock(); + return false; +} +EXPORT_SYMBOL(ttm_ref_object_exists); + int ttm_ref_object_add(struct ttm_object_file *tfile, struct ttm_base_object *base, enum ttm_ref_type ref_type, bool *existed) diff --git a/include/drm/ttm/ttm_object.h b/include/drm/ttm/ttm_object.h index 0097cc0..ed953f9 100644 --- a/include/drm/ttm/ttm_object.h +++ b/include/drm/ttm/ttm_object.h @@ -244,6 +244,10 @@ extern void ttm_base_object_unref(struct ttm_base_object **p_base); extern int ttm_ref_object_add(struct ttm_object_file *tfile, struct ttm_base_object *base, enum ttm_ref_type ref_type, bool *existed); + +extern bool ttm_ref_object_exists(struct ttm_object_file *tfile, + struct ttm_base_object *base); + /** * ttm_ref_object_base_unref *