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 #include "pseries.h"
36 
37 static struct pci_bus *
38 find_bus_among_children(struct pci_bus *bus,
39                         struct device_node *dn)
40 {
41 	struct pci_bus *child = NULL;
42 	struct pci_bus *tmp;
43 	struct device_node *busdn;
44 
45 	busdn = pci_bus_to_OF_node(bus);
46 	if (busdn == dn)
47 		return bus;
48 
49 	list_for_each_entry(tmp, &bus->children, node) {
50 		child = find_bus_among_children(tmp, dn);
51 		if (child)
52 			break;
53 	};
54 	return child;
55 }
56 
57 struct pci_bus *
58 pcibios_find_pci_bus(struct device_node *dn)
59 {
60 	struct pci_dn *pdn = dn->data;
61 
62 	if (!pdn  || !pdn->phb || !pdn->phb->bus)
63 		return NULL;
64 
65 	return find_bus_among_children(pdn->phb->bus, dn);
66 }
67 EXPORT_SYMBOL_GPL(pcibios_find_pci_bus);
68 
69 struct pci_controller *init_phb_dynamic(struct device_node *dn)
70 {
71 	struct pci_controller *phb;
72 
73 	pr_debug("PCI: Initializing new hotplug PHB %s\n", dn->full_name);
74 
75 	phb = pcibios_alloc_controller(dn);
76 	if (!phb)
77 		return NULL;
78 	rtas_setup_phb(phb);
79 	pci_process_bridge_OF_ranges(phb, dn, 0);
80 	phb->controller_ops = pseries_pci_controller_ops;
81 
82 	pci_devs_phb_init_dynamic(phb);
83 
84 	/* Create EEH devices for the PHB */
85 	eeh_dev_phb_init_dynamic(phb);
86 
87 	if (dn->child)
88 		eeh_add_device_tree_early(PCI_DN(dn));
89 
90 	pcibios_scan_phb(phb);
91 	pcibios_finish_adding_to_bus(phb->bus);
92 
93 	return phb;
94 }
95 EXPORT_SYMBOL_GPL(init_phb_dynamic);
96 
97 /* RPA-specific bits for removing PHBs */
98 int remove_phb_dynamic(struct pci_controller *phb)
99 {
100 	struct pci_bus *b = phb->bus;
101 	struct resource *res;
102 	int rc, i;
103 
104 	pr_debug("PCI: Removing PHB %04x:%02x...\n",
105 		 pci_domain_nr(b), b->number);
106 
107 	/* We cannot to remove a root bus that has children */
108 	if (!(list_empty(&b->children) && list_empty(&b->devices)))
109 		return -EBUSY;
110 
111 	/* We -know- there aren't any child devices anymore at this stage
112 	 * and thus, we can safely unmap the IO space as it's not in use
113 	 */
114 	res = &phb->io_resource;
115 	if (res->flags & IORESOURCE_IO) {
116 		rc = pcibios_unmap_io_space(b);
117 		if (rc) {
118 			printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
119 			       __func__, b->name);
120 			return 1;
121 		}
122 	}
123 
124 	/* Remove the PCI bus and unregister the bridge device from sysfs */
125 	phb->bus = NULL;
126 	pci_remove_bus(b);
127 	device_unregister(b->bridge);
128 
129 	/* Now release the IO resource */
130 	if (res->flags & IORESOURCE_IO)
131 		release_resource(res);
132 
133 	/* Release memory resources */
134 	for (i = 0; i < 3; ++i) {
135 		res = &phb->mem_resources[i];
136 		if (!(res->flags & IORESOURCE_MEM))
137 			continue;
138 		release_resource(res);
139 	}
140 
141 	/* Free pci_controller data structure */
142 	pcibios_free_controller(phb);
143 
144 	return 0;
145 }
146 EXPORT_SYMBOL_GPL(remove_phb_dynamic);
147