diff options
Diffstat (limited to 'drivers/pci/pcie/bw_notification.c')
| -rw-r--r-- | drivers/pci/pcie/bw_notification.c | 138 |
1 files changed, 0 insertions, 138 deletions
diff --git a/drivers/pci/pcie/bw_notification.c b/drivers/pci/pcie/bw_notification.c deleted file mode 100644 index 565d23cccb8b..000000000000 --- a/drivers/pci/pcie/bw_notification.c +++ /dev/null @@ -1,138 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0+ -/* - * PCI Express Link Bandwidth Notification services driver - * Author: Alexandru Gagniuc <mr.nuke.me@gmail.com> - * - * Copyright (C) 2019, Dell Inc - * - * The PCIe Link Bandwidth Notification provides a way to notify the - * operating system when the link width or data rate changes. This - * capability is required for all root ports and downstream ports - * supporting links wider than x1 and/or multiple link speeds. - * - * This service port driver hooks into the bandwidth notification interrupt - * and warns when links become degraded in operation. - */ - -#define dev_fmt(fmt) "bw_notification: " fmt - -#include "../pci.h" -#include "portdrv.h" - -static bool pcie_link_bandwidth_notification_supported(struct pci_dev *dev) -{ - int ret; - u32 lnk_cap; - - ret = pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnk_cap); - return (ret == PCIBIOS_SUCCESSFUL) && (lnk_cap & PCI_EXP_LNKCAP_LBNC); -} - -static void pcie_enable_link_bandwidth_notification(struct pci_dev *dev) -{ - u16 lnk_ctl; - - pcie_capability_write_word(dev, PCI_EXP_LNKSTA, PCI_EXP_LNKSTA_LBMS); - - pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctl); - lnk_ctl |= PCI_EXP_LNKCTL_LBMIE; - pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl); -} - -static void pcie_disable_link_bandwidth_notification(struct pci_dev *dev) -{ - u16 lnk_ctl; - - pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctl); - lnk_ctl &= ~PCI_EXP_LNKCTL_LBMIE; - pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl); -} - -static irqreturn_t pcie_bw_notification_irq(int irq, void *context) -{ - struct pcie_device *srv = context; - struct pci_dev *port = srv->port; - u16 link_status, events; - int ret; - - ret = pcie_capability_read_word(port, PCI_EXP_LNKSTA, &link_status); - events = link_status & PCI_EXP_LNKSTA_LBMS; - - if (ret != PCIBIOS_SUCCESSFUL || !events) - return IRQ_NONE; - - pcie_capability_write_word(port, PCI_EXP_LNKSTA, events); - pcie_update_link_speed(port->subordinate, link_status); - return IRQ_WAKE_THREAD; -} - -static irqreturn_t pcie_bw_notification_handler(int irq, void *context) -{ - struct pcie_device *srv = context; - struct pci_dev *port = srv->port; - struct pci_dev *dev; - - /* - * Print status from downstream devices, not this root port or - * downstream switch port. - */ - down_read(&pci_bus_sem); - list_for_each_entry(dev, &port->subordinate->devices, bus_list) - pcie_report_downtraining(dev); - up_read(&pci_bus_sem); - - return IRQ_HANDLED; -} - -static int pcie_bandwidth_notification_probe(struct pcie_device *srv) -{ - int ret; - - /* Single-width or single-speed ports do not have to support this. */ - if (!pcie_link_bandwidth_notification_supported(srv->port)) - return -ENODEV; - - ret = request_threaded_irq(srv->irq, pcie_bw_notification_irq, - pcie_bw_notification_handler, - IRQF_SHARED, "PCIe BW notif", srv); - if (ret) - return ret; - - pcie_enable_link_bandwidth_notification(srv->port); - pci_info(srv->port, "enabled with IRQ %d\n", srv->irq); - - return 0; -} - -static void pcie_bandwidth_notification_remove(struct pcie_device *srv) -{ - pcie_disable_link_bandwidth_notification(srv->port); - free_irq(srv->irq, srv); -} - -static int pcie_bandwidth_notification_suspend(struct pcie_device *srv) -{ - pcie_disable_link_bandwidth_notification(srv->port); - return 0; -} - -static int pcie_bandwidth_notification_resume(struct pcie_device *srv) -{ - pcie_enable_link_bandwidth_notification(srv->port); - return 0; -} - -static struct pcie_port_service_driver pcie_bandwidth_notification_driver = { - .name = "pcie_bw_notification", - .port_type = PCIE_ANY_PORT, - .service = PCIE_PORT_SERVICE_BWNOTIF, - .probe = pcie_bandwidth_notification_probe, - .suspend = pcie_bandwidth_notification_suspend, - .resume = pcie_bandwidth_notification_resume, - .remove = pcie_bandwidth_notification_remove, -}; - -int __init pcie_bandwidth_notification_init(void) -{ - return pcie_port_service_register(&pcie_bandwidth_notification_driver); -} |