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 /**
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  */
107 void 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, 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, 1);
146 	}
147 	pcibios_finish_adding_to_bus(bus);
148 }
149 EXPORT_SYMBOL_GPL(pci_hp_add_devices);
150