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 <linux/of.h>
16#include <asm/pci-bridge.h>
17#include <asm/ppc-pci.h>
18#include <asm/firmware.h>
19#include <asm/eeh.h>
20
21static struct pci_bus *find_bus_among_children(struct pci_bus *bus,
22 struct device_node *dn)
23{
24 struct pci_bus *child = NULL;
25 struct pci_bus *tmp;
26
27 if (pci_bus_to_OF_node(bus) == dn)
28 return bus;
29
30 list_for_each_entry(tmp, &bus->children, node) {
31 child = find_bus_among_children(bus: tmp, dn);
32 if (child)
33 break;
34 }
35
36 return child;
37}
38
39struct pci_bus *pci_find_bus_by_node(struct device_node *dn)
40{
41 struct pci_dn *pdn = PCI_DN(dn);
42
43 if (!pdn || !pdn->phb || !pdn->phb->bus)
44 return NULL;
45
46 return find_bus_among_children(bus: pdn->phb->bus, dn);
47}
48EXPORT_SYMBOL_GPL(pci_find_bus_by_node);
49
50/**
51 * pcibios_release_device - release PCI device
52 * @dev: PCI device
53 *
54 * The function is called before releasing the indicated PCI device.
55 */
56void pcibios_release_device(struct pci_dev *dev)
57{
58 struct pci_controller *phb = pci_bus_to_host(dev->bus);
59 struct pci_dn *pdn = pci_get_pdn(dev);
60
61 if (phb->controller_ops.release_device)
62 phb->controller_ops.release_device(dev);
63
64 /* free()ing the pci_dn has been deferred to us, do it now */
65 if (pdn && (pdn->flags & PCI_DN_FLAG_DEAD)) {
66 pci_dbg(dev, "freeing dead pdn\n");
67 kfree(objp: pdn);
68 }
69}
70
71/**
72 * pci_hp_remove_devices - remove all devices under this bus
73 * @bus: the indicated PCI bus
74 *
75 * Remove all of the PCI devices under this bus both from the
76 * linux pci device tree, and from the powerpc EEH address cache.
77 */
78void pci_hp_remove_devices(struct pci_bus *bus)
79{
80 struct pci_dev *dev, *tmp;
81 struct pci_bus *child_bus;
82
83 /* First go down child busses */
84 list_for_each_entry(child_bus, &bus->children, node)
85 pci_hp_remove_devices(bus: child_bus);
86
87 pr_debug("PCI: Removing devices on bus %04x:%02x\n",
88 pci_domain_nr(bus), bus->number);
89 list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
90 pr_debug(" Removing %s...\n", pci_name(dev));
91 pci_stop_and_remove_bus_device(dev);
92 }
93}
94EXPORT_SYMBOL_GPL(pci_hp_remove_devices);
95
96/**
97 * pci_hp_add_devices - adds new pci devices to bus
98 * @bus: the indicated PCI bus
99 *
100 * This routine will find and fixup new pci devices under
101 * the indicated bus. This routine presumes that there
102 * might already be some devices under this bridge, so
103 * it carefully tries to add only new devices. (And that
104 * is how this routine differs from other, similar pcibios
105 * routines.)
106 */
107void pci_hp_add_devices(struct pci_bus *bus)
108{
109 int slotno, mode, max;
110 struct pci_dev *dev;
111 struct pci_controller *phb;
112 struct device_node *dn = pci_bus_to_OF_node(bus);
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 max = bus->busn_res.start;
135 /*
136 * Scan bridges that are already configured. We don't touch
137 * them unless they are misconfigured (which will be done in
138 * the second scan below).
139 */
140 for_each_pci_bridge(dev, bus)
141 max = pci_scan_bridge(bus, dev, max, pass: 0);
142
143 /* Scan bridges that need to be reconfigured */
144 for_each_pci_bridge(dev, bus)
145 max = pci_scan_bridge(bus, dev, max, pass: 1);
146 }
147 pcibios_finish_adding_to_bus(bus);
148}
149EXPORT_SYMBOL_GPL(pci_hp_add_devices);
150

source code of linux/arch/powerpc/kernel/pci-hotplug.c