LXR linux/arch/powerpc/kernel/pci-hotplug.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Derived from "arch/powerpc/platforms/pseries/pci_dlpar.c"
   4 *
   5 * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
   6 * Copyright (C) 2005 International Business Machines
   7 *
   8 * Updates, 2005, John Rose <johnrose@austin.ibm.com>
   9 * Updates, 2005, Linas Vepstas <linas@austin.ibm.com>
  10 * Updates, 2013, Gavin Shan <shangw@linux.vnet.ibm.com>
  11 */
  12
  13#include <linux/pci.h>
  14#include <linux/export.h>
  15#include <asm/pci-bridge.h>
  16#include <asm/ppc-pci.h>
  17#include <asm/firmware.h>
  18#include <asm/eeh.h>
  19
  20static struct pci_bus *find_bus_among_children(struct pci_bus *bus,
  21                                               struct device_node *dn)
  22{
  23        struct pci_bus *child = NULL;
  24        struct pci_bus *tmp;
  25
  26        if (pci_bus_to_OF_node(bus) == dn)
  27                return bus;
  28
  29        list_for_each_entry(tmp, &bus->children, node) {
  30                child = find_bus_among_children(tmp, dn);
  31                if (child)
  32                        break;
  33        }
  34
  35        return child;
  36}
  37
  38struct pci_bus *pci_find_bus_by_node(struct device_node *dn)
  39{
  40        struct pci_dn *pdn = PCI_DN(dn);
  41
  42        if (!pdn  || !pdn->phb || !pdn->phb->bus)
  43                return NULL;
  44
  45        return find_bus_among_children(pdn->phb->bus, dn);
  46}
  47EXPORT_SYMBOL_GPL(pci_find_bus_by_node);
  48
  49/**
  50 * pcibios_release_device - release PCI device
  51 * @dev: PCI device
  52 *
  53 * The function is called before releasing the indicated PCI device.
  54 */
  55void pcibios_release_device(struct pci_dev *dev)
  56{
  57        struct pci_controller *phb = pci_bus_to_host(dev->bus);
  58        struct pci_dn *pdn = pci_get_pdn(dev);
  59
  60        eeh_remove_device(dev);
  61
  62        if (phb->controller_ops.release_device)
  63                phb->controller_ops.release_device(dev);
  64
  65        /* free()ing the pci_dn has been deferred to us, do it now */
  66        if (pdn && (pdn->flags & PCI_DN_FLAG_DEAD)) {
  67                pci_dbg(dev, "freeing dead pdn\n");
  68                kfree(pdn);
  69        }
  70}
  71
  72/**
  73 * pci_hp_remove_devices - remove all devices under this bus
  74 * @bus: the indicated PCI bus
  75 *
  76 * Remove all of the PCI devices under this bus both from the
  77 * linux pci device tree, and from the powerpc EEH address cache.
  78 */
  79void pci_hp_remove_devices(struct pci_bus *bus)
  80{
  81        struct pci_dev *dev, *tmp;
  82        struct pci_bus *child_bus;
  83
  84        /* First go down child busses */
  85        list_for_each_entry(child_bus, &bus->children, node)
  86                pci_hp_remove_devices(child_bus);
  87
  88        pr_debug("PCI: Removing devices on bus %04x:%02x\n",
  89                 pci_domain_nr(bus),  bus->number);
  90        list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
  91                pr_debug("   Removing %s...\n", pci_name(dev));
  92                pci_stop_and_remove_bus_device(dev);
  93        }
  94}
  95EXPORT_SYMBOL_GPL(pci_hp_remove_devices);
  96
  97/**
  98 * pci_hp_add_devices - adds new pci devices to bus
  99 * @bus: the indicated PCI bus
 100 *
 101 * This routine will find and fixup new pci devices under
 102 * the indicated bus. This routine presumes that there
 103 * might already be some devices under this bridge, so
 104 * it carefully tries to add only new devices.  (And that
 105 * is how this routine differs from other, similar pcibios
 106 * routines.)
 107 */
 108void pci_hp_add_devices(struct pci_bus *bus)
 109{
 110        int slotno, mode, max;
 111        struct pci_dev *dev;
 112        struct pci_controller *phb;
 113        struct device_node *dn = pci_bus_to_OF_node(bus);
 114
 115        phb = pci_bus_to_host(bus);
 116
 117        mode = PCI_PROBE_NORMAL;
 118        if (phb->controller_ops.probe_mode)
 119                mode = phb->controller_ops.probe_mode(bus);
 120
 121        if (mode == PCI_PROBE_DEVTREE) {
 122                /* use ofdt-based probe */
 123                of_rescan_bus(dn, bus);
 124        } else if (mode == PCI_PROBE_NORMAL &&
 125                   dn->child && PCI_DN(dn->child)) {
 126                /*
 127                 * Use legacy probe. In the partial hotplug case, we
 128                 * probably have grandchildren devices unplugged. So
 129                 * we don't check the return value from pci_scan_slot() in
 130                 * order for fully rescan all the way down to pick them up.
 131                 * They can have been removed during partial hotplug.
 132                 */
 133                slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
 134                pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
 135                max = bus->busn_res.start;
 136                /*
 137                 * Scan bridges that are already configured. We don't touch
 138                 * them unless they are misconfigured (which will be done in
 139                 * the second scan below).
 140                 */
 141                for_each_pci_bridge(dev, bus)
 142                        max = pci_scan_bridge(bus, dev, max, 0);
 143
 144                /* Scan bridges that need to be reconfigured */
 145                for_each_pci_bridge(dev, bus)
 146                        max = pci_scan_bridge(bus, dev, max, 1);
 147        }
 148        pcibios_finish_adding_to_bus(bus);
 149}
 150EXPORT_SYMBOL_GPL(pci_hp_add_devices);
 151