From patchwork Tue Oct 11 03:41:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 1688438 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.a=rsa-sha256 header.s=20210705 header.b=KvTiubgO; dkim-atps=neutral Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4MmhST6V44z23k2 for ; Tue, 11 Oct 2022 14:42:48 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1oi6A9-0005lK-N3; Tue, 11 Oct 2022 03:42:37 +0000 Received: from smtp-relay-canonical-1.internal ([10.131.114.174] helo=smtp-relay-canonical-1.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1oi6A7-0005kc-TG for kernel-team@lists.ubuntu.com; Tue, 11 Oct 2022 03:42:35 +0000 Received: from localhost.localdomain (unknown [10.101.196.174]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-1.canonical.com (Postfix) with ESMTPSA id A47A242C01 for ; Tue, 11 Oct 2022 03:42:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1665459755; bh=JS9ptWz8NTc8Zmva6dSxLsU9+wHd5dPydoivDmYiY4M=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=KvTiubgOnQVq5D/oiZ3xkuv45FIN3j+OKn+frStM0UVvtwp2HmHxJFVKPOZqSl6Zd azJhTqxSIPOWEfy+QE1c0GyB1pW8iHisFsO3XfxoB7zj1fh5oQ1WrvqBcus8gTdjmv Yf8jyIkbDgFFc42hHMT0PlziUU36vxgOy+loZw3xNPFiup1UPGqa8BlHqTdXzhTQfZ Mwi7sEO0XXFkS5YMqwAb3YoQcv26XJrYxXr7gLq6OUv7wT/SyHionEehii5JgT9CaI vZkI4NW4nJFDzd+uRkvG5rdrhdHmhSaeqcBp51cW2SBr+MV9CgMrTSkJD03MsRz6Q0 iK/ZqOubzJkoA== From: Kai-Heng Feng To: kernel-team@lists.ubuntu.com Subject: [J/K] [PATCH 04/10] PCI/PTM: Add pci_suspend_ptm() and pci_resume_ptm() Date: Tue, 11 Oct 2022 11:41:32 +0800 Message-Id: <20221011034139.731146-5-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221011034139.731146-1-kai.heng.feng@canonical.com> References: <20221011034139.731146-1-kai.heng.feng@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Bjorn Helgaas BugLink: https://bugs.launchpad.net/bugs/1988797 We disable PTM during suspend because that allows some Root Ports to enter lower-power PM states, which means we also need to disable PTM for all downstream devices. Add pci_suspend_ptm() and pci_resume_ptm() for this purpose. pci_enable_ptm() and pci_disable_ptm() are for drivers to use to enable or disable PTM. They use dev->ptm_enabled to keep track of whether PTM should be enabled. pci_suspend_ptm() and pci_resume_ptm() are PCI core-internal functions to temporarily disable PTM during suspend and (depending on dev->ptm_enabled) re-enable PTM during resume. Enable/disable/suspend/resume all use internal __pci_enable_ptm() and __pci_disable_ptm() functions that only update the PTM Control register. Outline: pci_enable_ptm(struct pci_dev *dev) { __pci_enable_ptm(dev); dev->ptm_enabled = 1; pci_ptm_info(dev); } pci_disable_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) { __pci_disable_ptm(dev); dev->ptm_enabled = 0; } } pci_suspend_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) __pci_disable_ptm(dev); } pci_resume_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) __pci_enable_ptm(dev); } Nothing currently calls pci_resume_ptm(); the suspend path saves the PTM state before disabling PTM, so the PTM state restore in the resume path implicitly re-enables it. A future change will use pci_resume_ptm() to fix some problems with this approach. Link: https://lore.kernel.org/r/20220909202505.314195-5-helgaas@kernel.org Tested-by: Rajvi Jingar Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg (cherry picked from commit e8bdc5ea481638e0a4fd5639050d2b170417f493 linux-next) Signed-off-by: Kai-Heng Feng --- drivers/pci/pci.c | 4 +-- drivers/pci/pci.h | 6 ++-- drivers/pci/pcie/ptm.c | 71 +++++++++++++++++++++++++++++++++--------- include/linux/pci.h | 2 ++ 4 files changed, 65 insertions(+), 18 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4df9ce7ad9502..b80ca8f1af565 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2739,7 +2739,7 @@ int pci_prepare_to_sleep(struct pci_dev *dev) * lower-power idle state as a whole. */ if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) - pci_disable_ptm(dev); + pci_suspend_ptm(dev); pci_enable_wake(dev, target_state, wakeup); @@ -2797,7 +2797,7 @@ int pci_finish_runtime_suspend(struct pci_dev *dev) * lower-power idle state as a whole. */ if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) - pci_disable_ptm(dev); + pci_suspend_ptm(dev); __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev)); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 92d8c92662a46..6a8f71dd136bb 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -507,11 +507,13 @@ static inline int pci_iov_bus_range(struct pci_bus *bus) #ifdef CONFIG_PCIE_PTM void pci_save_ptm_state(struct pci_dev *dev); void pci_restore_ptm_state(struct pci_dev *dev); -void pci_disable_ptm(struct pci_dev *dev); +void pci_suspend_ptm(struct pci_dev *dev); +void pci_resume_ptm(struct pci_dev *dev); #else static inline void pci_save_ptm_state(struct pci_dev *dev) { } static inline void pci_restore_ptm_state(struct pci_dev *dev) { } -static inline void pci_disable_ptm(struct pci_dev *dev) { } +static inline void pci_suspend_ptm(struct pci_dev *dev) { } +static inline void pci_resume_ptm(struct pci_dev *dev) { } #endif unsigned long pci_cardbus_resource_alignment(struct resource *); diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c index ba1d50c965fa1..70a28b74e721d 100644 --- a/drivers/pci/pcie/ptm.c +++ b/drivers/pci/pcie/ptm.c @@ -29,7 +29,7 @@ static void pci_ptm_info(struct pci_dev *dev) dev->ptm_root ? " (root)" : "", clock_desc); } -void pci_disable_ptm(struct pci_dev *dev) +static void __pci_disable_ptm(struct pci_dev *dev) { u16 ptm = dev->ptm_cap; u16 ctrl; @@ -42,6 +42,21 @@ void pci_disable_ptm(struct pci_dev *dev) pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl); } +/** + * pci_disable_ptm() - Disable Precision Time Measurement + * @dev: PCI device + * + * Disable Precision Time Measurement for @dev. + */ +void pci_disable_ptm(struct pci_dev *dev) +{ + if (dev->ptm_enabled) { + __pci_disable_ptm(dev); + dev->ptm_enabled = 0; + } +} +EXPORT_SYMBOL(pci_disable_ptm); + void pci_save_ptm_state(struct pci_dev *dev) { u16 ptm = dev->ptm_cap; @@ -151,18 +166,8 @@ void pci_ptm_init(struct pci_dev *dev) pci_enable_ptm(dev, NULL); } -/** - * pci_enable_ptm() - Enable Precision Time Measurement - * @dev: PCI device - * @granularity: pointer to return granularity - * - * Enable Precision Time Measurement for @dev. If successful and - * @granularity is non-NULL, return the Effective Granularity. - * - * Return: zero if successful, or -EINVAL if @dev lacks a PTM Capability or - * is not a PTM Root and lacks an upstream path of PTM-enabled devices. - */ -int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) +/* Enable PTM in the Control register if possible */ +static int __pci_enable_ptm(struct pci_dev *dev) { u16 ptm = dev->ptm_cap; struct pci_dev *ups; @@ -191,8 +196,29 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) ctrl |= PCI_PTM_CTRL_ROOT; pci_write_config_dword(dev, ptm + PCI_PTM_CTRL, ctrl); - dev->ptm_enabled = 1; + return 0; +} +/** + * pci_enable_ptm() - Enable Precision Time Measurement + * @dev: PCI device + * @granularity: pointer to return granularity + * + * Enable Precision Time Measurement for @dev. If successful and + * @granularity is non-NULL, return the Effective Granularity. + * + * Return: zero if successful, or -EINVAL if @dev lacks a PTM Capability or + * is not a PTM Root and lacks an upstream path of PTM-enabled devices. + */ +int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) +{ + int rc; + + rc = __pci_enable_ptm(dev); + if (rc) + return rc; + + dev->ptm_enabled = 1; pci_ptm_info(dev); if (granularity) @@ -201,6 +227,23 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) } EXPORT_SYMBOL(pci_enable_ptm); +/* + * Disable PTM, but preserve dev->ptm_enabled so we silently re-enable it on + * resume if necessary. + */ +void pci_suspend_ptm(struct pci_dev *dev) +{ + if (dev->ptm_enabled) + __pci_disable_ptm(dev); +} + +/* If PTM was enabled before suspend, re-enable it when resuming */ +void pci_resume_ptm(struct pci_dev *dev) +{ + if (dev->ptm_enabled) + __pci_enable_ptm(dev); +} + bool pcie_ptm_enabled(struct pci_dev *dev) { if (!dev) diff --git a/include/linux/pci.h b/include/linux/pci.h index 0459903f21021..0bf33019b30ee 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1682,10 +1682,12 @@ bool pci_ats_disabled(void); #ifdef CONFIG_PCIE_PTM int pci_enable_ptm(struct pci_dev *dev, u8 *granularity); +void pci_disable_ptm(struct pci_dev *dev); bool pcie_ptm_enabled(struct pci_dev *dev); #else static inline int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) { return -EINVAL; } +static inline void pci_disable_ptm(struct pci_dev *dev) { } static inline bool pcie_ptm_enabled(struct pci_dev *dev) { return false; } #endif