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/module.h> 17 #include <linux/kernel.h> 18 #include <linux/types.h> 19 #include <linux/pci.h> 20 #include "../pci.h" 21 #include "pciehp.h" 22 23 int pciehp_configure_device(struct slot *p_slot) 24 { 25 struct pci_dev *dev; 26 struct pci_dev *bridge = p_slot->ctrl->pcie->port; 27 struct pci_bus *parent = bridge->subordinate; 28 int num, ret = 0; 29 struct controller *ctrl = p_slot->ctrl; 30 31 pci_lock_rescan_remove(); 32 33 dev = pci_get_slot(parent, PCI_DEVFN(0, 0)); 34 if (dev) { 35 /* 36 * The device is already there. Either configured by the 37 * boot firmware or a previous hotplug event. 38 */ 39 ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n", 40 pci_name(dev), pci_domain_nr(parent), parent->number); 41 pci_dev_put(dev); 42 ret = -EEXIST; 43 goto out; 44 } 45 46 num = pci_scan_slot(parent, PCI_DEVFN(0, 0)); 47 if (num == 0) { 48 ctrl_err(ctrl, "No new device found\n"); 49 ret = -ENODEV; 50 goto out; 51 } 52 53 for_each_pci_bridge(dev, parent) 54 pci_hp_add_bridge(dev); 55 56 pci_assign_unassigned_bridge_resources(bridge); 57 pcie_bus_configure_settings(parent); 58 pci_bus_add_devices(parent); 59 60 out: 61 pci_unlock_rescan_remove(); 62 return ret; 63 } 64 65 int pciehp_unconfigure_device(struct slot *p_slot) 66 { 67 int rc = 0; 68 u8 presence = 0; 69 struct pci_dev *dev, *temp; 70 struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate; 71 u16 command; 72 struct controller *ctrl = p_slot->ctrl; 73 74 ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n", 75 __func__, pci_domain_nr(parent), parent->number); 76 pciehp_get_adapter_status(p_slot, &presence); 77 78 pci_lock_rescan_remove(); 79 80 /* 81 * Stopping an SR-IOV PF device removes all the associated VFs, 82 * which will update the bus->devices list and confuse the 83 * iterator. Therefore, iterate in reverse so we remove the VFs 84 * first, then the PF. We do the same in pci_stop_bus_device(). 85 */ 86 list_for_each_entry_safe_reverse(dev, temp, &parent->devices, 87 bus_list) { 88 pci_dev_get(dev); 89 if (!presence) { 90 pci_dev_set_disconnected(dev, NULL); 91 if (pci_has_subordinate(dev)) 92 pci_walk_bus(dev->subordinate, 93 pci_dev_set_disconnected, NULL); 94 } 95 pci_stop_and_remove_bus_device(dev); 96 /* 97 * Ensure that no new Requests will be generated from 98 * the device. 99 */ 100 if (presence) { 101 pci_read_config_word(dev, PCI_COMMAND, &command); 102 command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR); 103 command |= PCI_COMMAND_INTX_DISABLE; 104 pci_write_config_word(dev, PCI_COMMAND, command); 105 } 106 pci_dev_put(dev); 107 } 108 109 pci_unlock_rescan_remove(); 110 return rc; 111 } 112