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 #define dev_fmt(fmt) "pciehp: " fmt 17 18 #include <linux/kernel.h> 19 #include <linux/types.h> 20 #include <linux/pci.h> 21 #include "../pci.h" 22 #include "pciehp.h" 23 24 /** 25 * pciehp_configure_device() - enumerate PCI devices below a hotplug bridge 26 * @ctrl: PCIe hotplug controller 27 * 28 * Enumerate PCI devices below a hotplug bridge and add them to the system. 29 * Return 0 on success, %-EEXIST if the devices are already enumerated or 30 * %-ENODEV if enumeration failed. 31 */ 32 int pciehp_configure_device(struct controller *ctrl) 33 { 34 struct pci_dev *dev; 35 struct pci_dev *bridge = ctrl->pcie->port; 36 struct pci_bus *parent = bridge->subordinate; 37 int num, ret = 0; 38 39 pci_lock_rescan_remove(); 40 41 dev = pci_get_slot(parent, PCI_DEVFN(0, 0)); 42 if (dev) { 43 /* 44 * The device is already there. Either configured by the 45 * boot firmware or a previous hotplug event. 46 */ 47 ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n", 48 pci_name(dev), pci_domain_nr(parent), parent->number); 49 pci_dev_put(dev); 50 ret = -EEXIST; 51 goto out; 52 } 53 54 num = pci_scan_slot(parent, PCI_DEVFN(0, 0)); 55 if (num == 0) { 56 ctrl_err(ctrl, "No new device found\n"); 57 ret = -ENODEV; 58 goto out; 59 } 60 61 for_each_pci_bridge(dev, parent) 62 pci_hp_add_bridge(dev); 63 64 pci_assign_unassigned_bridge_resources(bridge); 65 pcie_bus_configure_settings(parent); 66 67 /* 68 * Release reset_lock during driver binding 69 * to avoid AB-BA deadlock with device_lock. 70 */ 71 up_read(&ctrl->reset_lock); 72 pci_bus_add_devices(parent); 73 down_read_nested(&ctrl->reset_lock, ctrl->depth); 74 75 dev = pci_get_slot(parent, PCI_DEVFN(0, 0)); 76 ctrl->dsn = pci_get_dsn(dev); 77 pci_dev_put(dev); 78 79 out: 80 pci_unlock_rescan_remove(); 81 return ret; 82 } 83 84 /** 85 * pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge 86 * @ctrl: PCIe hotplug controller 87 * @presence: whether the card is still present in the slot; 88 * true for safe removal via sysfs or an Attention Button press, 89 * false for surprise removal 90 * 91 * Unbind PCI devices below a hotplug bridge from their drivers and remove 92 * them from the system. Safely removed devices are quiesced. Surprise 93 * removed devices are marked as such to prevent further accesses. 94 */ 95 void pciehp_unconfigure_device(struct controller *ctrl, bool presence) 96 { 97 struct pci_dev *dev, *temp; 98 struct pci_bus *parent = ctrl->pcie->port->subordinate; 99 u16 command; 100 101 ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n", 102 __func__, pci_domain_nr(parent), parent->number); 103 104 if (!presence) 105 pci_walk_bus(parent, pci_dev_set_disconnected, NULL); 106 107 pci_lock_rescan_remove(); 108 109 /* 110 * Stopping an SR-IOV PF device removes all the associated VFs, 111 * which will update the bus->devices list and confuse the 112 * iterator. Therefore, iterate in reverse so we remove the VFs 113 * first, then the PF. We do the same in pci_stop_bus_device(). 114 */ 115 list_for_each_entry_safe_reverse(dev, temp, &parent->devices, 116 bus_list) { 117 pci_dev_get(dev); 118 119 /* 120 * Release reset_lock during driver unbinding 121 * to avoid AB-BA deadlock with device_lock. 122 */ 123 up_read(&ctrl->reset_lock); 124 pci_stop_and_remove_bus_device(dev); 125 down_read_nested(&ctrl->reset_lock, ctrl->depth); 126 127 /* 128 * Ensure that no new Requests will be generated from 129 * the device. 130 */ 131 if (presence) { 132 pci_read_config_word(dev, PCI_COMMAND, &command); 133 command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR); 134 command |= PCI_COMMAND_INTX_DISABLE; 135 pci_write_config_word(dev, PCI_COMMAND, command); 136 } 137 pci_dev_put(dev); 138 } 139 140 pci_unlock_rescan_remove(); 141 } 142