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 X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 27117C07520 for ; Thu, 13 Sep 2018 13:52:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E341720C0A for ; Thu, 13 Sep 2018 13:52:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E341720C0A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731033AbeIMTCY (ORCPT ); Thu, 13 Sep 2018 15:02:24 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33564 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730327AbeIMTCX (ORCPT ); Thu, 13 Sep 2018 15:02:23 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id E1581D19; Thu, 13 Sep 2018 13:52:47 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Heiko Stuebner , Marc Zyngier , Olof Johansson , Sasha Levin Subject: [PATCH 4.18 044/197] iommu/rockchip: Handle errors returned from PM framework Date: Thu, 13 Sep 2018 15:29:53 +0200 Message-Id: <20180913131843.308288149@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180913131841.568116777@linuxfoundation.org> References: <20180913131841.568116777@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier [ Upstream commit 3fc7c5c0cff3150e471f5fd12f59971c6d2c6513 ] pm_runtime_get_if_in_use can fail: either PM has been disabled altogether (-EINVAL), or the device hasn't been enabled yet (0). Sadly, the Rockchip IOMMU driver tends to conflate the two things by considering a non-zero return value as successful. This has the consequence of hiding other bugs, so let's handle this case throughout the driver, with a WARN_ON_ONCE so that we can try and work out what happened. Fixes: 0f181d3cf7d98 ("iommu/rockchip: Add runtime PM support") Reviewed-by: Heiko Stuebner Signed-off-by: Marc Zyngier Signed-off-by: Olof Johansson Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/rockchip-iommu.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) --- a/drivers/iommu/rockchip-iommu.c +++ b/drivers/iommu/rockchip-iommu.c @@ -521,10 +521,11 @@ static irqreturn_t rk_iommu_irq(int irq, u32 int_status; dma_addr_t iova; irqreturn_t ret = IRQ_NONE; - int i; + int i, err; - if (WARN_ON(!pm_runtime_get_if_in_use(iommu->dev))) - return 0; + err = pm_runtime_get_if_in_use(iommu->dev); + if (WARN_ON_ONCE(err <= 0)) + return ret; if (WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks))) goto out; @@ -620,11 +621,15 @@ static void rk_iommu_zap_iova(struct rk_ spin_lock_irqsave(&rk_domain->iommus_lock, flags); list_for_each(pos, &rk_domain->iommus) { struct rk_iommu *iommu; + int ret; iommu = list_entry(pos, struct rk_iommu, node); /* Only zap TLBs of IOMMUs that are powered on. */ - if (pm_runtime_get_if_in_use(iommu->dev)) { + ret = pm_runtime_get_if_in_use(iommu->dev); + if (WARN_ON_ONCE(ret < 0)) + continue; + if (ret) { WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks)); rk_iommu_zap_lines(iommu, iova, size); @@ -891,6 +896,7 @@ static void rk_iommu_detach_device(struc struct rk_iommu *iommu; struct rk_iommu_domain *rk_domain = to_rk_domain(domain); unsigned long flags; + int ret; /* Allow 'virtual devices' (eg drm) to detach from domain */ iommu = rk_iommu_from_dev(dev); @@ -909,7 +915,9 @@ static void rk_iommu_detach_device(struc list_del_init(&iommu->node); spin_unlock_irqrestore(&rk_domain->iommus_lock, flags); - if (pm_runtime_get_if_in_use(iommu->dev)) { + ret = pm_runtime_get_if_in_use(iommu->dev); + WARN_ON_ONCE(ret < 0); + if (ret > 0) { rk_iommu_disable(iommu); pm_runtime_put(iommu->dev); } @@ -946,7 +954,8 @@ static int rk_iommu_attach_device(struct list_add_tail(&iommu->node, &rk_domain->iommus); spin_unlock_irqrestore(&rk_domain->iommus_lock, flags); - if (!pm_runtime_get_if_in_use(iommu->dev)) + ret = pm_runtime_get_if_in_use(iommu->dev); + if (!ret || WARN_ON_ONCE(ret < 0)) return 0; ret = rk_iommu_enable(iommu);