arch/powerpc/kernel/pci-hotplug.c

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