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 
20 static 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 
38 struct 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 }
47 EXPORT_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  */
55 void 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 	eeh_remove_device(dev);
61 
62 	if (phb->controller_ops.release_device)
63 		phb->controller_ops.release_device(dev);
64 
65 	/* free()ing the pci_dn has been deferred to us, do it now */
66 	if (pdn && (pdn->flags & PCI_DN_FLAG_DEAD)) {
67 		pci_dbg(dev, "freeing dead pdn\n");
68 		kfree(pdn);
69 	}
70 }
71 
72 /**
73  * pci_hp_remove_devices - remove all devices under this bus
74  * @bus: the indicated PCI bus
75  *
76  * Remove all of the PCI devices under this bus both from the
77  * linux pci device tree, and from the powerpc EEH address cache.
78  */
79 void pci_hp_remove_devices(struct pci_bus *bus)
80 {
81 	struct pci_dev *dev, *tmp;
82 	struct pci_bus *child_bus;
83 
84 	/* First go down child busses */
85 	list_for_each_entry(child_bus, &bus->children, node)
86 		pci_hp_remove_devices(child_bus);
87 
88 	pr_debug("PCI: Removing devices on bus %04x:%02x\n",
89 		 pci_domain_nr(bus),  bus->number);
90 	list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
91 		pr_debug("   Removing %s...\n", pci_name(dev));
92 		pci_stop_and_remove_bus_device(dev);
93 	}
94 }
95 EXPORT_SYMBOL_GPL(pci_hp_remove_devices);
96 
97 /**
98  * pci_hp_add_devices - adds new pci devices to bus
99  * @bus: the indicated PCI bus
100  *
101  * This routine will find and fixup new pci devices under
102  * the indicated bus. This routine presumes that there
103  * might already be some devices under this bridge, so
104  * it carefully tries to add only new devices.  (And that
105  * is how this routine differs from other, similar pcibios
106  * routines.)
107  */
108 void pci_hp_add_devices(struct pci_bus *bus)
109 {
110 	int slotno, mode, max;
111 	struct pci_dev *dev;
112 	struct pci_controller *phb;
113 	struct device_node *dn = pci_bus_to_OF_node(bus);
114 
115 	phb = pci_bus_to_host(bus);
116 
117 	mode = PCI_PROBE_NORMAL;
118 	if (phb->controller_ops.probe_mode)
119 		mode = phb->controller_ops.probe_mode(bus);
120 
121 	if (mode == PCI_PROBE_DEVTREE) {
122 		/* use ofdt-based probe */
123 		of_rescan_bus(dn, bus);
124 	} else if (mode == PCI_PROBE_NORMAL &&
125 		   dn->child && PCI_DN(dn->child)) {
126 		/*
127 		 * Use legacy probe. In the partial hotplug case, we
128 		 * probably have grandchildren devices unplugged. So
129 		 * we don't check the return value from pci_scan_slot() in
130 		 * order for fully rescan all the way down to pick them up.
131 		 * They can have been removed during partial hotplug.
132 		 */
133 		slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
134 		pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
135 		max = bus->busn_res.start;
136 		/*
137 		 * Scan bridges that are already configured. We don't touch
138 		 * them unless they are misconfigured (which will be done in
139 		 * the second scan below).
140 		 */
141 		for_each_pci_bridge(dev, bus)
142 			max = pci_scan_bridge(bus, dev, max, 0);
143 
144 		/* Scan bridges that need to be reconfigured */
145 		for_each_pci_bridge(dev, bus)
146 			max = pci_scan_bridge(bus, dev, max, 1);
147 	}
148 	pcibios_finish_adding_to_bus(bus);
149 }
150 EXPORT_SYMBOL_GPL(pci_hp_add_devices);
151