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        if (phb->controller_ops.release_device)
  61                phb->controller_ops.release_device(dev);
  62
  63        /* free()ing the pci_dn has been deferred to us, do it now */
  64        if (pdn && (pdn->flags & PCI_DN_FLAG_DEAD)) {
  65                pci_dbg(dev, "freeing dead pdn\n");
  66                kfree(pdn);
  67        }
  68}
  69
  70/**
  71 * pci_hp_remove_devices - remove all devices under this bus
  72 * @bus: the indicated PCI bus
  73 *
  74 * Remove all of the PCI devices under this bus both from the
  75 * linux pci device tree, and from the powerpc EEH address cache.
  76 */
  77void pci_hp_remove_devices(struct pci_bus *bus)
  78{
  79        struct pci_dev *dev, *tmp;
  80        struct pci_bus *child_bus;
  81
  82        /* First go down child busses */
  83        list_for_each_entry(child_bus, &bus->children, node)
  84                pci_hp_remove_devices(child_bus);
  85
  86        pr_debug("PCI: Removing devices on bus %04x:%02x\n",
  87                 pci_domain_nr(bus),  bus->number);
  88        list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
  89                pr_debug("   Removing %s...\n", pci_name(dev));
  90                pci_stop_and_remove_bus_device(dev);
  91        }
  92}
  93EXPORT_SYMBOL_GPL(pci_hp_remove_devices);
  94
  95/**
  96 * pci_hp_add_devices - adds new pci devices to bus
  97 * @bus: the indicated PCI bus
  98 *
  99 * This routine will find and fixup new pci devices under
 100 * the indicated bus. This routine presumes that there
 101 * might already be some devices under this bridge, so
 102 * it carefully tries to add only new devices.  (And that
 103 * is how this routine differs from other, similar pcibios
 104 * routines.)
 105 */
 106void pci_hp_add_devices(struct pci_bus *bus)
 107{
 108        int slotno, mode, max;
 109        struct pci_dev *dev;
 110        struct pci_controller *phb;
 111        struct device_node *dn = pci_bus_to_OF_node(bus);
 112
 113        phb = pci_bus_to_host(bus);
 114
 115        mode = PCI_PROBE_NORMAL;
 116        if (phb->controller_ops.probe_mode)
 117                mode = phb->controller_ops.probe_mode(bus);
 118
 119        if (mode == PCI_PROBE_DEVTREE) {
 120                /* use ofdt-based probe */
 121                of_rescan_bus(dn, bus);
 122        } else if (mode == PCI_PROBE_NORMAL &&
 123                   dn->child && PCI_DN(dn->child)) {
 124                /*
 125                 * Use legacy probe. In the partial hotplug case, we
 126                 * probably have grandchildren devices unplugged. So
 127                 * we don't check the return value from pci_scan_slot() in
 128                 * order for fully rescan all the way down to pick them up.
 129                 * They can have been removed during partial hotplug.
 130                 */
 131                slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
 132                pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
 133                max = bus->busn_res.start;
 134                /*
 135                 * Scan bridges that are already configured. We don't touch
 136                 * them unless they are misconfigured (which will be done in
 137                 * the second scan below).
 138                 */
 139                for_each_pci_bridge(dev, bus)
 140                        max = pci_scan_bridge(bus, dev, max, 0);
 141
 142                /* Scan bridges that need to be reconfigured */
 143                for_each_pci_bridge(dev, bus)
 144                        max = pci_scan_bridge(bus, dev, max, 1);
 145        }
 146        pcibios_finish_adding_to_bus(bus);
 147}
 148EXPORT_SYMBOL_GPL(pci_hp_add_devices);
 149