From patchwork Tue Nov 14 13:55:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13455319 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 048FAC07545 for ; Tue, 14 Nov 2023 13:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229645AbjKNN4m (ORCPT ); Tue, 14 Nov 2023 08:56:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232040AbjKNN4j (ORCPT ); Tue, 14 Nov 2023 08:56:39 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E195D4B; Tue, 14 Nov 2023 05:56:34 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7492C433CB; Tue, 14 Nov 2023 13:56:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699970193; bh=FQzhhHnHVLuWZguWtCeMQCQce7lbuXpiz5kGYt0gjTI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n1pE7bt2zjsr5fCQayJMtmeTKpYw9ejeIOJCj/heI2mhqOc4YBsxFuhsLK+Z0XG+t 0QKJTmjGJ4PaHrBdPzL0hZcCIk7JFunIlKryWjb7YTLRiCvwqoswcUDcuU7YBv0L+H sTlTAotjjcfJksXzZkXrnv/X3RdErT7VeA9i59wGYjUzn3jWk+D9dpdpGXuJLNdTFJ 3O4FlL+vzkOq/eNVeLSwpLf7Of4OtRj4G3mIr2e3K0Ka6SdSmihQHkZvLiLChsBsh0 1FzXuFEbjsvyJnvt7aOiWo6qfWrq/w1BDy1RM1BGa9gSZDy1WHd9SUKWL1mF1iz12e XoivxJP+BzVfg== Received: from johan by xi.lan with local (Exim 4.96.2) (envelope-from ) id 1r2tu2-0008PP-24; Tue, 14 Nov 2023 14:56:30 +0100 From: Johan Hovold To: Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , Bjorn Helgaas Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Manivannan Sadhasivam , Rob Herring , Nirmal Patel , Jonathan Derrick , linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org, Michael Bottini , "David E . Box" Subject: [PATCH 1/6] PCI/ASPM: Add locked helper for enabling link state Date: Tue, 14 Nov 2023 14:55:48 +0100 Message-ID: <20231114135553.32301-2-johan+linaro@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231114135553.32301-1-johan+linaro@kernel.org> References: <20231114135553.32301-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add a helper for enabling link states that can be used in contexts where a pci_bus_sem read lock is already held (e.g. from pci_walk_bus()). This helper will be used to fix a couple of potential deadlocks where the current helper is called with the lock already held, hence the CC stable tag. Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR") Cc: stable@vger.kernel.org # 6.3 Cc: Michael Bottini Cc: David E. Box Signed-off-by: Johan Hovold Reviewed-by: Manivannan Sadhasivam --- drivers/pci/pcie/aspm.c | 53 +++++++++++++++++++++++++++++++---------- include/linux/pci.h | 3 +++ 2 files changed, 43 insertions(+), 13 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 50b04ae5c394..8cf8cc2d6bba 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1109,17 +1109,7 @@ int pci_disable_link_state(struct pci_dev *pdev, int state) } EXPORT_SYMBOL(pci_disable_link_state); -/** - * pci_enable_link_state - Clear and set the default device link state so that - * the link may be allowed to enter the specified states. Note that if the - * BIOS didn't grant ASPM control to the OS, this does nothing because we can't - * touch the LNKCTL register. Also note that this does not enable states - * disabled by pci_disable_link_state(). Return 0 or a negative errno. - * - * @pdev: PCI device - * @state: Mask of ASPM link states to enable - */ -int pci_enable_link_state(struct pci_dev *pdev, int state) +static int __pci_enable_link_state(struct pci_dev *pdev, int state, bool locked) { struct pcie_link_state *link = pcie_aspm_get_link(pdev); @@ -1136,7 +1126,8 @@ int pci_enable_link_state(struct pci_dev *pdev, int state) return -EPERM; } - down_read(&pci_bus_sem); + if (!locked) + down_read(&pci_bus_sem); mutex_lock(&aspm_lock); link->aspm_default = 0; if (state & PCIE_LINK_STATE_L0S) @@ -1157,12 +1148,48 @@ int pci_enable_link_state(struct pci_dev *pdev, int state) link->clkpm_default = (state & PCIE_LINK_STATE_CLKPM) ? 1 : 0; pcie_set_clkpm(link, policy_to_clkpm_state(link)); mutex_unlock(&aspm_lock); - up_read(&pci_bus_sem); + if (!locked) + up_read(&pci_bus_sem); return 0; } + +/** + * pci_enable_link_state - Clear and set the default device link state so that + * the link may be allowed to enter the specified states. Note that if the + * BIOS didn't grant ASPM control to the OS, this does nothing because we can't + * touch the LNKCTL register. Also note that this does not enable states + * disabled by pci_disable_link_state(). Return 0 or a negative errno. + * + * @pdev: PCI device + * @state: Mask of ASPM link states to enable + */ +int pci_enable_link_state(struct pci_dev *pdev, int state) +{ + return __pci_enable_link_state(pdev, state, false); +} EXPORT_SYMBOL(pci_enable_link_state); +/** + * pci_enable_link_state - Clear and set the default device link state so that + * the link may be allowed to enter the specified states. Note that if the + * BIOS didn't grant ASPM control to the OS, this does nothing because we can't + * touch the LNKCTL register. Also note that this does not enable states + * disabled by pci_disable_link_state(). Return 0 or a negative errno. + * + * @pdev: PCI device + * @state: Mask of ASPM link states to enable + * + * Context: Caller holds pci_bus_sem read lock. + */ +int pci_enable_link_state_locked(struct pci_dev *pdev, int state) +{ + lockdep_assert_held_read(&pci_bus_sem); + + return __pci_enable_link_state(pdev, state, true); +} +EXPORT_SYMBOL(pci_enable_link_state_locked); + static int pcie_aspm_set_policy(const char *val, const struct kernel_param *kp) { diff --git a/include/linux/pci.h b/include/linux/pci.h index 60ca768bc867..dea043bc1e38 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1829,6 +1829,7 @@ extern bool pcie_ports_native; int pci_disable_link_state(struct pci_dev *pdev, int state); int pci_disable_link_state_locked(struct pci_dev *pdev, int state); int pci_enable_link_state(struct pci_dev *pdev, int state); +int pci_enable_link_state_locked(struct pci_dev *pdev, int state); void pcie_no_aspm(void); bool pcie_aspm_support_enabled(void); bool pcie_aspm_enabled(struct pci_dev *pdev); @@ -1839,6 +1840,8 @@ static inline int pci_disable_link_state_locked(struct pci_dev *pdev, int state) { return 0; } static inline int pci_enable_link_state(struct pci_dev *pdev, int state) { return 0; } +static inline int pci_enable_link_state_locked(struct pci_dev *pdev, int state) +{ return 0; } static inline void pcie_no_aspm(void) { } static inline bool pcie_aspm_support_enabled(void) { return false; } static inline bool pcie_aspm_enabled(struct pci_dev *pdev) { return false; } From patchwork Tue Nov 14 13:55:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13455320 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F7BBC07CB1 for ; Tue, 14 Nov 2023 13:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232007AbjKNN4p (ORCPT ); Tue, 14 Nov 2023 08:56:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49490 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231889AbjKNN4j (ORCPT ); Tue, 14 Nov 2023 08:56:39 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BD4E1BF; Tue, 14 Nov 2023 05:56:35 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D1843C4167D; Tue, 14 Nov 2023 13:56:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699970193; bh=p5enpBm/h3uKua9dX8qlaS0tuKFBhLHUpM9Hd7d/DZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=socAihQ3HhCJY6z/F1yux89ciHZ0i9NTT73CZGbk2iSRhZrNiwOchaHzlSlA4x7mL Jh4QM7ItBKDZ7uvt+YBwdLHluA4bRtiOHB9puOtJVrH5qYkAkdFSJ4RyZ4K1pqPdQk 05axIFOg4Fj8Z2e/ZPr4P3ECM6EB7jOamGMzz+83rXjq3+SB6Zot6mAiEiW0UVk+3n BmGlycYYJsSd/S+e8MeN+OvJcmpDhKFMUZOZT06+LH8LE8ekq2/TFUmBOjwoKLLcnC 7mTgPdbWtX+7/9iEi/vQXd4cG4nrCU1iz5x9Ey8dAOhYMA6IvF3upeRRZ+FJnD4xwi kmfFcMjOGmyoA== Received: from johan by xi.lan with local (Exim 4.96.2) (envelope-from ) id 1r2tu2-0008PR-2N; Tue, 14 Nov 2023 14:56:30 +0100 From: Johan Hovold To: Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , Bjorn Helgaas Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Manivannan Sadhasivam , Rob Herring , Nirmal Patel , Jonathan Derrick , linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org, Michael Bottini , "David E . Box" Subject: [PATCH 2/6] PCI: vmd: Fix deadlock when enabling ASPM Date: Tue, 14 Nov 2023 14:55:49 +0100 Message-ID: <20231114135553.32301-3-johan+linaro@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231114135553.32301-1-johan+linaro@kernel.org> References: <20231114135553.32301-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The vmd_pm_enable_quirk() helper is called from pci_walk_bus() during probe to enable ASPM for controllers with VMD_FEAT_BIOS_PM_QUIRK set. Since pci_walk_bus() already holds a pci_bus_sem read lock, use the new locked helper to enable link states in order to avoid a potential deadlock (e.g. in case someone takes a write lock before reacquiring the read lock). Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR") Cc: stable@vger.kernel.org # 6.3 Cc: Michael Bottini Cc: David E. Box Signed-off-by: Johan Hovold Reviewed-by: Manivannan Sadhasivam --- drivers/pci/controller/vmd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 94ba61fe1c44..0452cbc362ee 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -751,7 +751,7 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) if (!(features & VMD_FEAT_BIOS_PM_QUIRK)) return 0; - pci_enable_link_state(pdev, PCIE_LINK_STATE_ALL); + pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR); if (!pos) From patchwork Tue Nov 14 13:55:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13455318 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB5E4C0755A for ; Tue, 14 Nov 2023 13:56:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232262AbjKNN4n (ORCPT ); Tue, 14 Nov 2023 08:56:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232168AbjKNN4k (ORCPT ); Tue, 14 Nov 2023 08:56:40 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C022D55; Tue, 14 Nov 2023 05:56:35 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA8C7C43397; Tue, 14 Nov 2023 13:56:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699970193; bh=FBrVwkCNQ13rjcfw1rE/Ykhh7nhHv9rEy/bYSmsBegQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BBHOHfNckzRz7mnu26EM4ZGNdr34Tk+SyDvwuccRYDg3/vBsf5XfdAI532RpNgedV N2JcKrllILDtvNuhJ1nbPIeWY5nSHp8yMzs02lrEnGHsngcHmdgVmFYB5nTN+iedLp dvT6K9UjGj7xIwUy0BOu+U75X49pqAxeZkUf7ZxLMW3AZ48e94dDU7baWsnE/IUxOa iaaixLJK/z0HBKHZwYXQuw/48ot5+xto239+Sedo42JooeUiqBl1f8et7L58/eNSHe YuICzi3eeb6/fxPrdVYw8HwDXX7YFZzoBaJw4GEid+wCUMf1pJd2tiDkUHS0LBHoQ/ u85joJ6WXsyug== Received: from johan by xi.lan with local (Exim 4.96.2) (envelope-from ) id 1r2tu2-0008PT-2c; Tue, 14 Nov 2023 14:56:30 +0100 From: Johan Hovold To: Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , Bjorn Helgaas Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Manivannan Sadhasivam , Rob Herring , Nirmal Patel , Jonathan Derrick , linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , Manivannan Sadhasivam Subject: [PATCH 3/6] PCI: qcom: Fix deadlock when enabling ASPM Date: Tue, 14 Nov 2023 14:55:50 +0100 Message-ID: <20231114135553.32301-4-johan+linaro@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231114135553.32301-1-johan+linaro@kernel.org> References: <20231114135553.32301-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The qcom_pcie_enable_aspm() helper is called from pci_walk_bus() during host init to enable ASPM. Since pci_walk_bus() already holds a pci_bus_sem read lock, use the new locked helper to enable link states in order to avoid a potential deadlock (e.g. in case someone takes a write lock before reacquiring the read lock). This issue was reported by lockdep: ============================================ WARNING: possible recursive locking detected 6.7.0-rc1 #4 Not tainted -------------------------------------------- kworker/u16:6/147 is trying to acquire lock: ffffbf3ff9d2cfa0 (pci_bus_sem){++++}-{3:3}, at: pci_enable_link_state+0x74/0x1e8 but task is already holding lock: ffffbf3ff9d2cfa0 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x34/0xbc other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(pci_bus_sem); lock(pci_bus_sem); *** DEADLOCK *** Fixes: 9f4f3dfad8cf ("PCI: qcom: Enable ASPM for platforms supporting 1.9.0 ops") Cc: Manivannan Sadhasivam Signed-off-by: Johan Hovold Reviewed-by: Manivannan Sadhasivam --- drivers/pci/controller/dwc/pcie-qcom.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index ce3ece28fed2..21523115f6a4 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -971,7 +971,7 @@ static int qcom_pcie_enable_aspm(struct pci_dev *pdev, void *userdata) { /* Downstream devices need to be in D0 state before enabling PCI PM substates */ pci_set_power_state(pdev, PCI_D0); - pci_enable_link_state(pdev, PCIE_LINK_STATE_ALL); + pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); return 0; } From patchwork Tue Nov 14 13:55:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13455315 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 782ADC4332F for ; Tue, 14 Nov 2023 13:56:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230053AbjKNN4l (ORCPT ); Tue, 14 Nov 2023 08:56:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232027AbjKNN4j (ORCPT ); Tue, 14 Nov 2023 08:56:39 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20F5FD50; Tue, 14 Nov 2023 05:56:34 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B15D0C433CD; Tue, 14 Nov 2023 13:56:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699970193; bh=eo9kfCbX6q6KqiGf0IQeZw8TC/sg5ZoML6hbCiQxCyA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hvzgQs4/9S5RUfSUDfl+ZBXj8xB4XpWCi1gh6wnZMfzRCKuYG5KTLn6y4h4DuADRA oCa5tYe+ekj/mzp5YSjsWpZ2ILuTsBhlr/KuBHdZlMyxnxNTWg9sYZwd2yJEqavC0/ LsJfY+IPxeWYpZcBJvx/XVnxsriQqgUo9bFQkTqvoJq4RKZA2xsFGNjt2z+k84xlSN qeOlTdksrKdZc1Az0YZoHAso558mOYRAKeudnfYMQ77IAKelqIDXCMQNqIj28cKbNm E1OSs/RawbAUAJ2Nym5MugY8Gubl6pA7BUIyiiUdKscX5F3dMO5qEgjIB3NCp7TBeO WgnjHWVXRD1Lg== Received: from johan by xi.lan with local (Exim 4.96.2) (envelope-from ) id 1r2tu2-0008PV-2s; Tue, 14 Nov 2023 14:56:30 +0100 From: Johan Hovold To: Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , Bjorn Helgaas Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Manivannan Sadhasivam , Rob Herring , Nirmal Patel , Jonathan Derrick , linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH 4/6] PCI: qcom: Clean up ASPM comment Date: Tue, 14 Nov 2023 14:55:51 +0100 Message-ID: <20231114135553.32301-5-johan+linaro@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231114135553.32301-1-johan+linaro@kernel.org> References: <20231114135553.32301-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Break up the newly added ASPM comment so that it fits within the soft 80 character limit and becomes more readable. Signed-off-by: Johan Hovold --- drivers/pci/controller/dwc/pcie-qcom.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 21523115f6a4..a6f08acff3d4 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -969,7 +969,10 @@ static int qcom_pcie_post_init_2_7_0(struct qcom_pcie *pcie) static int qcom_pcie_enable_aspm(struct pci_dev *pdev, void *userdata) { - /* Downstream devices need to be in D0 state before enabling PCI PM substates */ + /* + * Downstream devices need to be in D0 state before enabling PCI PM + * substates. + */ pci_set_power_state(pdev, PCI_D0); pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); From patchwork Tue Nov 14 13:55:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13455314 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D852C4167D for ; Tue, 14 Nov 2023 13:56:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230089AbjKNN4j (ORCPT ); Tue, 14 Nov 2023 08:56:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231895AbjKNN4h (ORCPT ); Tue, 14 Nov 2023 08:56:37 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13043D4D; Tue, 14 Nov 2023 05:56:34 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA2BFC433C9; Tue, 14 Nov 2023 13:56:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699970193; bh=ccp3ogSsb4odknXliurziQtdOSnVHJBmXHc1B6Tc75s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cqjCpx50IAiQYCU9k/IfgDPeIhFv+9uWmWFC6j2KoAkGQmt2kEAeY29cU/peo05pd mhPyqxa1sMwBW46MTeju7iHCWPFWOvJv6N6K5ZBrldwxnYVuvva41K+vR2H9s9+Ucw z5SFcCofn3ybaamOymSBoMfR7oVVcjqZzIvF7Dg7Byb9NnWwu6QBdGa/JwEVLrnxTi E6YJejE+CF7P272F1nJyC0QGl2ojxS98dzoyuIhUcOEHtIFtbApWpXkNRGLvOZsC9A oX/1obd0/Q3XG7FsvQO4lcQ8aP9MDLvnUFV3T+44UlhgnB6dZVxhE3r48J75wNi+iP P/FJXHIESqxuA== Received: from johan by xi.lan with local (Exim 4.96.2) (envelope-from ) id 1r2tu2-0008PX-3C; Tue, 14 Nov 2023 14:56:31 +0100 From: Johan Hovold To: Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , Bjorn Helgaas Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Manivannan Sadhasivam , Rob Herring , Nirmal Patel , Jonathan Derrick , linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH 5/6] PCI/ASPM: Clean up disable link state parameter Date: Tue, 14 Nov 2023 14:55:52 +0100 Message-ID: <20231114135553.32301-6-johan+linaro@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231114135553.32301-1-johan+linaro@kernel.org> References: <20231114135553.32301-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Replace the current 'sem' parameter to the __pci_disable_link_state() helper with a more descriptive 'locked' parameter, which indicates whether a pci_bus_sem read lock is already held. Signed-off-by: Johan Hovold Reviewed-by: Manivannan Sadhasivam --- drivers/pci/pcie/aspm.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 8cf8cc2d6bba..19b7256d2dc9 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1041,7 +1041,7 @@ static struct pcie_link_state *pcie_aspm_get_link(struct pci_dev *pdev) return bridge->link_state; } -static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) +static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool locked) { struct pcie_link_state *link = pcie_aspm_get_link(pdev); @@ -1060,7 +1060,7 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) return -EPERM; } - if (sem) + if (!locked) down_read(&pci_bus_sem); mutex_lock(&aspm_lock); if (state & PCIE_LINK_STATE_L0S) @@ -1082,7 +1082,7 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) link->clkpm_disable = 1; pcie_set_clkpm(link, policy_to_clkpm_state(link)); mutex_unlock(&aspm_lock); - if (sem) + if (!locked) up_read(&pci_bus_sem); return 0; @@ -1090,7 +1090,7 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) int pci_disable_link_state_locked(struct pci_dev *pdev, int state) { - return __pci_disable_link_state(pdev, state, false); + return __pci_disable_link_state(pdev, state, true); } EXPORT_SYMBOL(pci_disable_link_state_locked); @@ -1105,7 +1105,7 @@ EXPORT_SYMBOL(pci_disable_link_state_locked); */ int pci_disable_link_state(struct pci_dev *pdev, int state) { - return __pci_disable_link_state(pdev, state, true); + return __pci_disable_link_state(pdev, state, false); } EXPORT_SYMBOL(pci_disable_link_state); From patchwork Tue Nov 14 13:55:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13455316 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6D05C072A2 for ; Tue, 14 Nov 2023 13:56:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232345AbjKNN4m (ORCPT ); Tue, 14 Nov 2023 08:56:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231935AbjKNN4j (ORCPT ); Tue, 14 Nov 2023 08:56:39 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 359F7D51; Tue, 14 Nov 2023 05:56:34 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2E42C43391; Tue, 14 Nov 2023 13:56:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699970193; bh=IyFpJ4IPW+04Qg7uetnTuAVDseZG4Zu5u7tnsvS+xhA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SeWpsd+8blmriSQBMZBlDg9HTiPOqC/TQjd6pKDcunLzqR3jShDyFDuVGX3o+W+XL Qoas/TI4ZoSf+VvVCy+P07qZYXvxi7ChCBAtOpvPnbQinxnLfLcuAuTbeAOpTkbOuQ i8wswos2HLxVIWnBf2h2TXvEL8GoEUBo47tOC/L2ugI/3E+n7o+q+N5+mqYJOBpgnY +UpX+ekmhHjqTIQDRuTjxbdrsokfqOrV5SdFdKfOzRvpTLvEMGsBjJM6Ns/kuFAArc PpdVsvyLFgEZJ1jFRzTWNb0rwCc82mDHeIZ806JJ3F+rGx/KyHm+KiumEl5rD92iFh couZyIiRK1mWQ== Received: from johan by xi.lan with local (Exim 4.96.2) (envelope-from ) id 1r2tu3-0008PZ-0I; Tue, 14 Nov 2023 14:56:31 +0100 From: Johan Hovold To: Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , Bjorn Helgaas Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Manivannan Sadhasivam , Rob Herring , Nirmal Patel , Jonathan Derrick , linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH 6/6] PCI/ASPM: Add lockdep assert to link state helper Date: Tue, 14 Nov 2023 14:55:53 +0100 Message-ID: <20231114135553.32301-7-johan+linaro@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231114135553.32301-1-johan+linaro@kernel.org> References: <20231114135553.32301-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add a lockdep assert to the locked disable link state helper which should only be called with a pci_bus_sem read lock held. Signed-off-by: Johan Hovold Reviewed-by: Manivannan Sadhasivam --- drivers/pci/pcie/aspm.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 19b7256d2dc9..ef2e7a186f57 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1090,6 +1090,8 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool locked int pci_disable_link_state_locked(struct pci_dev *pdev, int state) { + lockdep_assert_held_read(&pci_bus_sem); + return __pci_disable_link_state(pdev, state, true); } EXPORT_SYMBOL(pci_disable_link_state_locked);