From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755413AbcJZSBf (ORCPT ); Wed, 26 Oct 2016 14:01:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44258 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933999AbcJZSB3 (ORCPT ); Wed, 26 Oct 2016 14:01:29 -0400 Subject: [PATCH 3/5] PCI: Extract link retraining from pcie_aspm_configure_common_clock() From: Alex Williamson To: linux-pci@vger.kernel.org Cc: bhelgaas@google.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Date: Wed, 26 Oct 2016 12:01:28 -0600 Message-ID: <20161026180128.23495.19403.stgit@gimli.home> In-Reply-To: <20161026175156.23495.12980.stgit@gimli.home> References: <20161026175156.23495.12980.stgit@gimli.home> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 26 Oct 2016 18:01:29 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: Alex Williamson --- drivers/pci/pci.c | 29 +++++++++++++++++++++++++++++ drivers/pci/pcie/aspm.c | 17 +---------------- include/linux/pci.h | 1 + 3 files changed, 31 insertions(+), 16 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6d6cf89..4d327d4 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4729,6 +4729,35 @@ int pcie_set_mps(struct pci_dev *dev, int mps) } EXPORT_SYMBOL(pcie_set_mps); +int pcie_retrain_link(struct pci_dev *dev) +{ + int ret; + u16 lnksta; + unsigned long timeout; + + /* Can only retrain from downstream ports */ + if (!pci_is_pcie(dev) || + (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM && + pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)) + return -EINVAL; + + ret = pcie_capability_set_word(dev, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_RL); + if (ret) + return ret; + + timeout = jiffies + HZ; /* Retraining timeout */ + for (;;) { + pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta); + if (!(lnksta & PCI_EXP_LNKSTA_LT) || + time_after(jiffies, timeout)) + break; + msleep(1); + } + + return (lnksta & PCI_EXP_LNKSTA_LT) ? -EBUSY : 0; +} +EXPORT_SYMBOL(pcie_retrain_link); + int pcie_get_link(struct pci_dev *dev, enum pci_bus_speed *speed, enum pcie_link_width *width) { diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 0ec649d..482d60c 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -91,8 +91,6 @@ struct pcie_link_state { [POLICY_POWERSAVE] = "powersave" }; -#define LINK_RETRAIN_TIMEOUT HZ - static int policy_to_aspm_state(struct pcie_link_state *link) { switch (aspm_policy) { @@ -222,20 +220,7 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link) pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16); /* Retrain link */ - reg16 |= PCI_EXP_LNKCTL_RL; - pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16); - - /* Wait for link training end. Break out after waiting for timeout */ - start_jiffies = jiffies; - for (;;) { - pcie_capability_read_word(parent, PCI_EXP_LNKSTA, ®16); - if (!(reg16 & PCI_EXP_LNKSTA_LT)) - break; - if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) - break; - msleep(1); - } - if (!(reg16 & PCI_EXP_LNKSTA_LT)) + if (!pcie_retrain_link(parent)) return; /* Training failed. Restore common clock configurations */ diff --git a/include/linux/pci.h b/include/linux/pci.h index fbfbb40..eb0e9be 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1024,6 +1024,7 @@ static inline int pci_is_managed(struct pci_dev *pdev) int pcie_set_readrq(struct pci_dev *dev, int rq); int pcie_get_mps(struct pci_dev *dev); int pcie_set_mps(struct pci_dev *dev, int mps); +int pcie_retrain_link(struct pci_dev *dev); int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed, enum pcie_link_width *width); int pcie_get_link(struct pci_dev *dev, enum pci_bus_speed *speed,