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1// SPDX-License-Identifier: GPL-2.0+2/*3 * PCI Express Hot Plug Controller Driver4 *5 * Copyright (C) 1995,2001 Compaq Computer Corporation6 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)7 * Copyright (C) 2001 IBM Corp.8 * Copyright (C) 2003-2004 Intel Corporation9 *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: " fmt17 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 bridge26 * @ctrl: PCIe hotplug controller27 *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 or30 * %-ENODEV if enumeration failed.31 */32int 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 the45 * 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 binding69 * 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 bridge86 * @ctrl: PCIe hotplug controller87 * @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 removal90 *91 * Unbind PCI devices below a hotplug bridge from their drivers and remove92 * them from the system. Safely removed devices are quiesced. Surprise93 * removed devices are marked as such to prevent further accesses.94 */95void 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 the112 * iterator. Therefore, iterate in reverse so we remove the VFs113 * 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 unbinding121 * 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 from129 * 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