From patchwork Sat Aug 17 14:47:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11099123 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BBE2B13A0 for ; Sat, 17 Aug 2019 14:48:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ACDE527EE2 for ; Sat, 17 Aug 2019 14:48:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A15A3284BD; Sat, 17 Aug 2019 14:48:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4E8C327EE2 for ; Sat, 17 Aug 2019 14:48:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 159906E517; Sat, 17 Aug 2019 14:48:02 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id CEA056E506; Sat, 17 Aug 2019 14:47:51 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 18173481-1500050 for multiple; Sat, 17 Aug 2019 15:47:39 +0100 From: Chris Wilson To: dri-devel@lists.freedesktop.org Subject: [PATCH 5/6] dma-fence: Simply wrap dma_fence_signal_locked with dma_fence_signal Date: Sat, 17 Aug 2019 15:47:35 +0100 Message-Id: <20190817144736.7826-5-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.23.0.rc1 In-Reply-To: <20190817144736.7826-1-chris@chris-wilson.co.uk> References: <20190817144736.7826-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Daniel Vetter , intel-gfx@lists.freedesktop.org, christian.koenig@amd.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Currently dma_fence_signal() tries to avoid the spinlock and only takes it if absolutely required to walk the callback list. However, to allow for some users to surreptitiously insert lazy signal callbacks that do not depend on enabling the signaling mechanism around every fence, we always need to notify the callbacks on signaling. As such, we will always need to take the spinlock and dma_fence_signal() effectively becomes a clone of dma_fence_signal_locked(). v2: Update the test_and_set_bit() before entering the spinlock. Signed-off-by: Chris Wilson Cc: Christian König Cc: Daniel Vetter --- drivers/dma-buf/dma-fence.c | 43 +++++++++++-------------------------- 1 file changed, 13 insertions(+), 30 deletions(-) diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index ff0cd6eae766..89d96e3e6df6 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -129,25 +129,16 @@ EXPORT_SYMBOL(dma_fence_context_alloc); int dma_fence_signal_locked(struct dma_fence *fence) { struct dma_fence_cb *cur, *tmp; - int ret = 0; lockdep_assert_held(fence->lock); - if (WARN_ON(!fence)) + if (unlikely(test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, + &fence->flags))) return -EINVAL; - if (test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { - ret = -EINVAL; - - /* - * we might have raced with the unlocked dma_fence_signal, - * still run through all callbacks - */ - } else { - fence->timestamp = ktime_get(); - set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags); - trace_dma_fence_signaled(fence); - } + fence->timestamp = ktime_get(); + set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags); + trace_dma_fence_signaled(fence); if (!list_empty(&fence->cb_list)) { list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) { @@ -156,7 +147,8 @@ int dma_fence_signal_locked(struct dma_fence *fence) } INIT_LIST_HEAD(&fence->cb_list); } - return ret; + + return 0; } EXPORT_SYMBOL(dma_fence_signal_locked); @@ -176,28 +168,19 @@ EXPORT_SYMBOL(dma_fence_signal_locked); int dma_fence_signal(struct dma_fence *fence) { unsigned long flags; + int ret; if (!fence) return -EINVAL; - if (test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) return -EINVAL; - fence->timestamp = ktime_get(); - set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags); - trace_dma_fence_signaled(fence); - - if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags)) { - struct dma_fence_cb *cur, *tmp; + spin_lock_irqsave(fence->lock, flags); + ret = dma_fence_signal_locked(fence); + spin_unlock_irqrestore(fence->lock, flags); - spin_lock_irqsave(fence->lock, flags); - list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) { - list_del_init(&cur->node); - cur->func(fence, cur); - } - spin_unlock_irqrestore(fence->lock, flags); - } - return 0; + return ret; } EXPORT_SYMBOL(dma_fence_signal);