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
21 static 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(tmp, dn);
32 if (child)
33 break;
34 }
35
36 return child;
37 }
38
39 struct 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(pdn->phb->bus, dn);
47 }
48 EXPORT_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 */
56 void 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(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 */
78 void 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(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 }
94 EXPORT_SYMBOL_GPL(pci_hp_remove_devices);
95
96 static void traverse_siblings_and_scan_slot(struct device_node *start, struct pci_bus *bus)
97 {
98 struct device_node *dn;
99 int slotno;
100
101 u32 class = 0;
102
103 if (!of_property_read_u32(start->child, "class-code", &class)) {
104 /* Call of pci_scan_slot for non-bridge/EP case */
105 if (!((class >> 8) == PCI_CLASS_BRIDGE_PCI)) {
106 slotno = PCI_SLOT(PCI_DN(start->child)->devfn);
107 pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
108 return;
109 }
110 }
111
112 /* Iterate all siblings */
113 for_each_child_of_node(start, dn) {
114 class = 0;
115
116 if (!of_property_read_u32(start->child, "class-code", &class)) {
117 /* Call of pci_scan_slot on each sibling-nodes/bridge-ports */
118 if ((class >> 8) == PCI_CLASS_BRIDGE_PCI) {
119 slotno = PCI_SLOT(PCI_DN(dn)->devfn);
120 pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
121 }
122 }
123 }
124 }
125
126 /**
127 * pci_hp_add_devices - adds new pci devices to bus
128 * @bus: the indicated PCI bus
129 *
130 * This routine will find and fixup new pci devices under
131 * the indicated bus. This routine presumes that there
132 * might already be some devices under this bridge, so
133 * it carefully tries to add only new devices. (And that
134 * is how this routine differs from other, similar pcibios
135 * routines.)
136 */
137 void pci_hp_add_devices(struct pci_bus *bus)
138 {
139 int mode, max;
140 struct pci_dev *dev;
141 struct pci_controller *phb;
142 struct device_node *dn = pci_bus_to_OF_node(bus);
143
144 phb = pci_bus_to_host(bus);
145
146 mode = PCI_PROBE_NORMAL;
147 if (phb->controller_ops.probe_mode)
148 mode = phb->controller_ops.probe_mode(bus);
149
150 if (mode == PCI_PROBE_DEVTREE) {
151 /* use ofdt-based probe */
152 of_rescan_bus(dn, bus);
153 } else if (mode == PCI_PROBE_NORMAL &&
154 dn->child && PCI_DN(dn->child)) {
155 /*
156 * Use legacy probe. In the partial hotplug case, we
157 * probably have grandchildren devices unplugged. So
158 * we don't check the return value from pci_scan_slot() in
159 * order for fully rescan all the way down to pick them up.
160 * They can have been removed during partial hotplug.
161 */
162 traverse_siblings_and_scan_slot(dn, bus);
163 max = bus->busn_res.start;
164 /*
165 * Scan bridges that are already configured. We don't touch
166 * them unless they are misconfigured (which will be done in
167 * the second scan below).
168 */
169 for_each_pci_bridge(dev, bus)
170 max = pci_scan_bridge(bus, dev, max, 0);
171
172 /* Scan bridges that need to be reconfigured */
173 for_each_pci_bridge(dev, bus)
174 max = pci_scan_bridge(bus, dev, max, 1);
175 }
176 pcibios_finish_adding_to_bus(bus);
177 }
178 EXPORT_SYMBOL_GPL(pci_hp_add_devices);
179
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