1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * PCI Express Hot Plug Controller Driver 4 * 5 * Copyright (C) 1995,2001 Compaq Computer Corporation 6 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) 7 * Copyright (C) 2001 IBM Corp. 8 * Copyright (C) 2003-2004 Intel Corporation 9 * 10 * All rights reserved. 11 * 12 * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com> 13 * 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/types.h> 18 #include <linux/pci.h> 19 #include "../pci.h" 20 #include "pciehp.h" 21 22 /** 23 * pciehp_configure_device() - enumerate PCI devices below a hotplug bridge 24 * @ctrl: PCIe hotplug controller 25 * 26 * Enumerate PCI devices below a hotplug bridge and add them to the system. 27 * Return 0 on success, %-EEXIST if the devices are already enumerated or 28 * %-ENODEV if enumeration failed. 29 */ 30 int pciehp_configure_device(struct controller *ctrl) 31 { 32 struct pci_dev *dev; 33 struct pci_dev *bridge = ctrl->pcie->port; 34 struct pci_bus *parent = bridge->subordinate; 35 int num, ret = 0; 36 37 pci_lock_rescan_remove(); 38 39 dev = pci_get_slot(parent, PCI_DEVFN(0, 0)); 40 if (dev) { 41 /* 42 * The device is already there. Either configured by the 43 * boot firmware or a previous hotplug event. 44 */ 45 ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n", 46 pci_name(dev), pci_domain_nr(parent), parent->number); 47 pci_dev_put(dev); 48 ret = -EEXIST; 49 goto out; 50 } 51 52 num = pci_scan_slot(parent, PCI_DEVFN(0, 0)); 53 if (num == 0) { 54 ctrl_err(ctrl, "No new device found\n"); 55 ret = -ENODEV; 56 goto out; 57 } 58 59 for_each_pci_bridge(dev, parent) 60 pci_hp_add_bridge(dev); 61 62 pci_assign_unassigned_bridge_resources(bridge); 63 pcie_bus_configure_settings(parent); 64 pci_bus_add_devices(parent); 65 66 out: 67 pci_unlock_rescan_remove(); 68 return ret; 69 } 70 71 /** 72 * pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge 73 * @ctrl: PCIe hotplug controller 74 * @presence: whether the card is still present in the slot; 75 * true for safe removal via sysfs or an Attention Button press, 76 * false for surprise removal 77 * 78 * Unbind PCI devices below a hotplug bridge from their drivers and remove 79 * them from the system. Safely removed devices are quiesced. Surprise 80 * removed devices are marked as such to prevent further accesses. 81 */ 82 void pciehp_unconfigure_device(struct controller *ctrl, bool presence) 83 { 84 struct pci_dev *dev, *temp; 85 struct pci_bus *parent = ctrl->pcie->port->subordinate; 86 u16 command; 87 88 ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n", 89 __func__, pci_domain_nr(parent), parent->number); 90 91 if (!presence) 92 pci_walk_bus(parent, pci_dev_set_disconnected, NULL); 93 94 pci_lock_rescan_remove(); 95 96 /* 97 * Stopping an SR-IOV PF device removes all the associated VFs, 98 * which will update the bus->devices list and confuse the 99 * iterator. Therefore, iterate in reverse so we remove the VFs 100 * first, then the PF. We do the same in pci_stop_bus_device(). 101 */ 102 list_for_each_entry_safe_reverse(dev, temp, &parent->devices, 103 bus_list) { 104 pci_dev_get(dev); 105 pci_stop_and_remove_bus_device(dev); 106 /* 107 * Ensure that no new Requests will be generated from 108 * the device. 109 */ 110 if (presence) { 111 pci_read_config_word(dev, PCI_COMMAND, &command); 112 command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR); 113 command |= PCI_COMMAND_INTX_DISABLE; 114 pci_write_config_word(dev, PCI_COMMAND, command); 115 } 116 pci_dev_put(dev); 117 } 118 119 pci_unlock_rescan_remove(); 120 } 121