LXR linux/drivers/pci/hotplug/pciehp

   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 */
  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 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        pci_bus_add_devices(parent);
  67
  68 out:
  69        pci_unlock_rescan_remove();
  70        return ret;
  71}
  72
  73/**
  74 * pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge
  75 * @ctrl: PCIe hotplug controller
  76 * @presence: whether the card is still present in the slot;
  77 *      true for safe removal via sysfs or an Attention Button press,
  78 *      false for surprise removal
  79 *
  80 * Unbind PCI devices below a hotplug bridge from their drivers and remove
  81 * them from the system.  Safely removed devices are quiesced.  Surprise
  82 * removed devices are marked as such to prevent further accesses.
  83 */
  84void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
  85{
  86        struct pci_dev *dev, *temp;
  87        struct pci_bus *parent = ctrl->pcie->port->subordinate;
  88        u16 command;
  89
  90        ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
  91                 __func__, pci_domain_nr(parent), parent->number);
  92
  93        if (!presence)
  94                pci_walk_bus(parent, pci_dev_set_disconnected, NULL);
  95
  96        pci_lock_rescan_remove();
  97
  98        /*
  99         * Stopping an SR-IOV PF device removes all the associated VFs,
 100         * which will update the bus->devices list and confuse the
 101         * iterator.  Therefore, iterate in reverse so we remove the VFs
 102         * first, then the PF.  We do the same in pci_stop_bus_device().
 103         */
 104        list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
 105                                         bus_list) {
 106                pci_dev_get(dev);
 107                pci_stop_and_remove_bus_device(dev);
 108                /*
 109                 * Ensure that no new Requests will be generated from
 110                 * the device.
 111                 */
 112                if (presence) {
 113                        pci_read_config_word(dev, PCI_COMMAND, &command);
 114                        command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
 115                        command |= PCI_COMMAND_INTX_DISABLE;
 116                        pci_write_config_word(dev, PCI_COMMAND, command);
 117                }
 118                pci_dev_put(dev);
 119        }
 120
 121        pci_unlock_rescan_remove();
 122}
 123