From patchwork Fri Nov 14 12:18:57 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Harrison X-Patchwork-Id: 5305401 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4E00E9FBB9 for ; Fri, 14 Nov 2014 12:19:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 413BC201BC for ; Fri, 14 Nov 2014 12:19:33 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 39F832017D for ; Fri, 14 Nov 2014 12:19:32 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B045B6EDC6; Fri, 14 Nov 2014 04:19:31 -0800 (PST) X-Original-To: Intel-GFX@lists.freedesktop.org Delivered-To: Intel-GFX@lists.freedesktop.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id 796A16EDC4 for ; Fri, 14 Nov 2014 04:19:28 -0800 (PST) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 14 Nov 2014 04:19:28 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,385,1413270000"; d="scan'208";a="636945071" Received: from johnharr-linux.isw.intel.com ([10.102.226.51]) by orsmga002.jf.intel.com with ESMTP; 14 Nov 2014 04:19:27 -0800 From: John.C.Harrison@Intel.com To: Intel-GFX@Lists.FreeDesktop.Org Date: Fri, 14 Nov 2014 12:18:57 +0000 Message-Id: <1415967559-17074-7-git-send-email-John.C.Harrison@Intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1415967559-17074-1-git-send-email-John.C.Harrison@Intel.com> References: <1415967559-17074-1-git-send-email-John.C.Harrison@Intel.com> Organization: Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ Subject: [Intel-gfx] [PATCH v2 06/28] drm/i915: Ensure requests stick around during waits X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_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 From: John Harrison Added reference counting of the request structure around __wait_seqno() calls. This is a precursor to updating the wait code itself to take the request rather than a seqno. At that point, it would be a Bad Idea for a request object to be retired and freed while the wait code is still using it. Note that i915_wait_request() is safe without reference counting as the driver mutex lock is held for the duration. Thus it is not possible for a free to occur asynchronously. For: VIZ-4377 Signed-off-by: John Harrison --- drivers/gpu/drm/i915/i915_gem.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 86c7aa0..4dbfee3 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1442,10 +1442,12 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj, return ret; reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter); + i915_gem_request_reference(req); mutex_unlock(&dev->struct_mutex); ret = __i915_wait_seqno(ring, seqno, reset_counter, true, NULL, file_priv); mutex_lock(&dev->struct_mutex); + i915_gem_request_unreference(req); if (ret) return ret; @@ -2904,6 +2906,7 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file) struct drm_i915_private *dev_priv = dev->dev_private; struct drm_i915_gem_wait *args = data; struct drm_i915_gem_object *obj; + struct drm_i915_gem_request *req; struct intel_engine_cs *ring = NULL; unsigned reset_counter; u32 seqno = 0; @@ -2930,7 +2933,8 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file) if (!obj->active || !obj->last_read_req) goto out; - seqno = i915_gem_request_get_seqno(obj->last_read_req); + req = obj->last_read_req; + seqno = i915_gem_request_get_seqno(req); WARN_ON(seqno == 0); ring = obj->ring; @@ -2944,10 +2948,15 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file) drm_gem_object_unreference(&obj->base); reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter); + i915_gem_request_reference(req); mutex_unlock(&dev->struct_mutex); - return __i915_wait_seqno(ring, seqno, reset_counter, true, - &args->timeout_ns, file->driver_priv); + ret = __i915_wait_seqno(ring, seqno, reset_counter, true, &args->timeout_ns, + file->driver_priv); + mutex_lock(&dev->struct_mutex); + i915_gem_request_unreference(req); + mutex_unlock(&dev->struct_mutex); + return ret; out: drm_gem_object_unreference(&obj->base); @@ -4106,6 +4115,8 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file) target = request; } reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter); + if (target) + i915_gem_request_reference(target); spin_unlock(&file_priv->mm.lock); if (target == NULL) @@ -4117,6 +4128,10 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file) if (ret == 0) queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, 0); + mutex_lock(&dev->struct_mutex); + i915_gem_request_unreference(target); + mutex_unlock(&dev->struct_mutex); + return ret; }