xref: /linux/arch/powerpc/kernel/pci-hotplug.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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);
147