1 /*
2  * PCI Dynamic LPAR, PCI Hot Plug and PCI EEH recovery code
3  * for RPA-compliant PPC64 platform.
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  *
10  * All rights reserved.
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or (at
15  * your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful, but
18  * WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
20  * NON INFRINGEMENT.  See the GNU General Public License for more
21  * details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26  */
27 
28 #include <linux/pci.h>
29 #include <linux/export.h>
30 #include <asm/pci-bridge.h>
31 #include <asm/ppc-pci.h>
32 #include <asm/firmware.h>
33 #include <asm/eeh.h>
34 
35 static struct pci_bus *
36 find_bus_among_children(struct pci_bus *bus,
37                         struct device_node *dn)
38 {
39 	struct pci_bus *child = NULL;
40 	struct pci_bus *tmp;
41 	struct device_node *busdn;
42 
43 	busdn = pci_bus_to_OF_node(bus);
44 	if (busdn == dn)
45 		return bus;
46 
47 	list_for_each_entry(tmp, &bus->children, node) {
48 		child = find_bus_among_children(tmp, dn);
49 		if (child)
50 			break;
51 	};
52 	return child;
53 }
54 
55 struct pci_bus *
56 pcibios_find_pci_bus(struct device_node *dn)
57 {
58 	struct pci_dn *pdn = dn->data;
59 
60 	if (!pdn  || !pdn->phb || !pdn->phb->bus)
61 		return NULL;
62 
63 	return find_bus_among_children(pdn->phb->bus, dn);
64 }
65 EXPORT_SYMBOL_GPL(pcibios_find_pci_bus);
66 
67 struct pci_controller *init_phb_dynamic(struct device_node *dn)
68 {
69 	struct pci_controller *phb;
70 
71 	pr_debug("PCI: Initializing new hotplug PHB %s\n", dn->full_name);
72 
73 	phb = pcibios_alloc_controller(dn);
74 	if (!phb)
75 		return NULL;
76 	rtas_setup_phb(phb);
77 	pci_process_bridge_OF_ranges(phb, dn, 0);
78 
79 	pci_devs_phb_init_dynamic(phb);
80 
81 	/* Create EEH devices for the PHB */
82 	eeh_dev_phb_init_dynamic(phb);
83 
84 	if (dn->child)
85 		eeh_add_device_tree_early(dn);
86 
87 	pcibios_scan_phb(phb);
88 	pcibios_finish_adding_to_bus(phb->bus);
89 
90 	return phb;
91 }
92 EXPORT_SYMBOL_GPL(init_phb_dynamic);
93 
94 /* RPA-specific bits for removing PHBs */
95 int remove_phb_dynamic(struct pci_controller *phb)
96 {
97 	struct pci_bus *b = phb->bus;
98 	struct resource *res;
99 	int rc, i;
100 
101 	pr_debug("PCI: Removing PHB %04x:%02x...\n",
102 		 pci_domain_nr(b), b->number);
103 
104 	/* We cannot to remove a root bus that has children */
105 	if (!(list_empty(&b->children) && list_empty(&b->devices)))
106 		return -EBUSY;
107 
108 	/* We -know- there aren't any child devices anymore at this stage
109 	 * and thus, we can safely unmap the IO space as it's not in use
110 	 */
111 	res = &phb->io_resource;
112 	if (res->flags & IORESOURCE_IO) {
113 		rc = pcibios_unmap_io_space(b);
114 		if (rc) {
115 			printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
116 			       __func__, b->name);
117 			return 1;
118 		}
119 	}
120 
121 	/* Unregister the bridge device from sysfs and remove the PCI bus */
122 	device_unregister(b->bridge);
123 	phb->bus = NULL;
124 	pci_remove_bus(b);
125 
126 	/* Now release the IO resource */
127 	if (res->flags & IORESOURCE_IO)
128 		release_resource(res);
129 
130 	/* Release memory resources */
131 	for (i = 0; i < 3; ++i) {
132 		res = &phb->mem_resources[i];
133 		if (!(res->flags & IORESOURCE_MEM))
134 			continue;
135 		release_resource(res);
136 	}
137 
138 	/* Free pci_controller data structure */
139 	pcibios_free_controller(phb);
140 
141 	return 0;
142 }
143 EXPORT_SYMBOL_GPL(remove_phb_dynamic);
144