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(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(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(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(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, 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}
149EXPORT_SYMBOL_GPL(pci_hp_add_devices);
150