From patchwork Tue Sep 29 10:55:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 263050 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CA3DC4727C for ; Tue, 29 Sep 2020 12:16:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10D042075A for ; Tue, 29 Sep 2020 12:16:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601381770; bh=TONmCrhRmlyoG/Lf9PQAI0I3daVMNT6ZohFbYpc+huA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0nbT2rtCJ3TgHGdmpB6Dl0oqKyX5ri/SN+fJFRq312al7U31VnjsfXxzFvtD1KbYf tmF8f5yXvbRtGKOlMbS+ymtbJlEa990zx/YyeG8fABQcMd1Ox29Pk1B6xHPxnyCCX9 d1LkzVfzMD+dKBRpwJYPQ7pFLYRY0qaT4doWOQNE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729682AbgI2MQI (ORCPT ); Tue, 29 Sep 2020 08:16:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:50310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730031AbgI2LhA (ORCPT ); Tue, 29 Sep 2020 07:37:00 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2F9C823E56; Tue, 29 Sep 2020 11:32:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601379129; bh=TONmCrhRmlyoG/Lf9PQAI0I3daVMNT6ZohFbYpc+huA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F270vKCGhGh5knNFVLBUXfXotUaPcJtBDIeGYMiZLgfJ167m2um/igOZknJeZH6C+ vshKhhJ3navJ4zli4EkpM/9q8Td/+lQTE1v52Y902vo4uu7L7OBpjz0Sma9qnhJILL Wsv7t8nLuadipzyWtpvffIV1FyAnbLebedMQcrVw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Wilson , Tvrtko Ursulin , Sasha Levin Subject: [PATCH 5.4 008/388] dma-fence: Serialise signal enabling (dma_fence_enable_sw_signaling) Date: Tue, 29 Sep 2020 12:55:39 +0200 Message-Id: <20200929110010.886993237@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929110010.467764689@linuxfoundation.org> References: <20200929110010.467764689@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chris Wilson [ Upstream commit 9c98f021e4e717ffd9948fa65340ea3ef12b7935 ] Make dma_fence_enable_sw_signaling() behave like its dma_fence_add_callback() and dma_fence_default_wait() counterparts and perform the test to enable signaling under the fence->lock, along with the action to do so. This ensure that should an implementation be trying to flush the cb_list (by signaling) on retirement before freeing the fence, it can do so in a race-free manner. See also 0fc89b6802ba ("dma-fence: Simply wrap dma_fence_signal_locked with dma_fence_signal"). v2: Refactor all 3 enable_signaling paths to use a common function. v3: Don't argue, just keep the tracepoint in the existing spot. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20191004101140.32713-1-chris@chris-wilson.co.uk Signed-off-by: Sasha Levin --- drivers/dma-buf/dma-fence.c | 78 +++++++++++++++++-------------------- 1 file changed, 35 insertions(+), 43 deletions(-) diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 2c136aee3e794..052a41e2451c1 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -273,6 +273,30 @@ void dma_fence_free(struct dma_fence *fence) } EXPORT_SYMBOL(dma_fence_free); +static bool __dma_fence_enable_signaling(struct dma_fence *fence) +{ + bool was_set; + + lockdep_assert_held(fence->lock); + + was_set = test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, + &fence->flags); + + if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + return false; + + if (!was_set && fence->ops->enable_signaling) { + trace_dma_fence_enable_signal(fence); + + if (!fence->ops->enable_signaling(fence)) { + dma_fence_signal_locked(fence); + return false; + } + } + + return true; +} + /** * dma_fence_enable_sw_signaling - enable signaling on fence * @fence: the fence to enable @@ -285,19 +309,12 @@ void dma_fence_enable_sw_signaling(struct dma_fence *fence) { unsigned long flags; - if (!test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, - &fence->flags) && - !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) && - fence->ops->enable_signaling) { - trace_dma_fence_enable_signal(fence); - - spin_lock_irqsave(fence->lock, flags); - - if (!fence->ops->enable_signaling(fence)) - dma_fence_signal_locked(fence); + if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + return; - spin_unlock_irqrestore(fence->lock, flags); - } + spin_lock_irqsave(fence->lock, flags); + __dma_fence_enable_signaling(fence); + spin_unlock_irqrestore(fence->lock, flags); } EXPORT_SYMBOL(dma_fence_enable_sw_signaling); @@ -331,7 +348,6 @@ int dma_fence_add_callback(struct dma_fence *fence, struct dma_fence_cb *cb, { unsigned long flags; int ret = 0; - bool was_set; if (WARN_ON(!fence || !func)) return -EINVAL; @@ -343,25 +359,14 @@ int dma_fence_add_callback(struct dma_fence *fence, struct dma_fence_cb *cb, spin_lock_irqsave(fence->lock, flags); - was_set = test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, - &fence->flags); - - if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) - ret = -ENOENT; - else if (!was_set && fence->ops->enable_signaling) { - trace_dma_fence_enable_signal(fence); - - if (!fence->ops->enable_signaling(fence)) { - dma_fence_signal_locked(fence); - ret = -ENOENT; - } - } - - if (!ret) { + if (__dma_fence_enable_signaling(fence)) { cb->func = func; list_add_tail(&cb->node, &fence->cb_list); - } else + } else { INIT_LIST_HEAD(&cb->node); + ret = -ENOENT; + } + spin_unlock_irqrestore(fence->lock, flags); return ret; @@ -461,7 +466,6 @@ dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout) struct default_wait_cb cb; unsigned long flags; signed long ret = timeout ? timeout : 1; - bool was_set; if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) return ret; @@ -473,21 +477,9 @@ dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout) goto out; } - was_set = test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, - &fence->flags); - - if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + if (!__dma_fence_enable_signaling(fence)) goto out; - if (!was_set && fence->ops->enable_signaling) { - trace_dma_fence_enable_signal(fence); - - if (!fence->ops->enable_signaling(fence)) { - dma_fence_signal_locked(fence); - goto out; - } - } - if (!timeout) { ret = 0; goto out;