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 <asm/pci-bridge.h>
30 
31 static struct pci_bus *
32 find_bus_among_children(struct pci_bus *bus,
33                         struct device_node *dn)
34 {
35 	struct pci_bus *child = NULL;
36 	struct list_head *tmp;
37 	struct device_node *busdn;
38 
39 	busdn = pci_bus_to_OF_node(bus);
40 	if (busdn == dn)
41 		return bus;
42 
43 	list_for_each(tmp, &bus->children) {
44 		child = find_bus_among_children(pci_bus_b(tmp), dn);
45 		if (child)
46 			break;
47 	};
48 	return child;
49 }
50 
51 struct pci_bus *
52 pcibios_find_pci_bus(struct device_node *dn)
53 {
54 	struct pci_dn *pdn = dn->data;
55 
56 	if (!pdn  || !pdn->phb || !pdn->phb->bus)
57 		return NULL;
58 
59 	return find_bus_among_children(pdn->phb->bus, dn);
60 }
61 
62 /**
63  * pcibios_remove_pci_devices - remove all devices under this bus
64  *
65  * Remove all of the PCI devices under this bus both from the
66  * linux pci device tree, and from the powerpc EEH address cache.
67  */
68 void
69 pcibios_remove_pci_devices(struct pci_bus *bus)
70 {
71 	struct pci_dev *dev, *tmp;
72 
73 	list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
74 		eeh_remove_bus_device(dev);
75 		pci_remove_bus_device(dev);
76 	}
77 }
78 
79 /* Must be called before pci_bus_add_devices */
80 void
81 pcibios_fixup_new_pci_devices(struct pci_bus *bus, int fix_bus)
82 {
83 	struct pci_dev *dev;
84 
85 	list_for_each_entry(dev, &bus->devices, bus_list) {
86 		/*
87 		 * Skip already-present devices (which are on the
88 		 * global device list.)
89 		 */
90 		if (list_empty(&dev->global_list)) {
91 			int i;
92 
93 			/* Need to setup IOMMU tables */
94 			ppc_md.iommu_dev_setup(dev);
95 
96 			if(fix_bus)
97 				pcibios_fixup_device_resources(dev, bus);
98 			pci_read_irq_line(dev);
99 			for (i = 0; i < PCI_NUM_RESOURCES; i++) {
100 				struct resource *r = &dev->resource[i];
101 
102 				if (r->parent || !r->start || !r->flags)
103 					continue;
104 				pci_claim_resource(dev, i);
105 			}
106 		}
107 	}
108 }
109 
110 static int
111 pcibios_pci_config_bridge(struct pci_dev *dev)
112 {
113 	u8 sec_busno;
114 	struct pci_bus *child_bus;
115 	struct pci_dev *child_dev;
116 
117 	/* Get busno of downstream bus */
118 	pci_read_config_byte(dev, PCI_SECONDARY_BUS, &sec_busno);
119 
120 	/* Add to children of PCI bridge dev->bus */
121 	child_bus = pci_add_new_bus(dev->bus, dev, sec_busno);
122 	if (!child_bus) {
123 		printk (KERN_ERR "%s: could not add second bus\n", __FUNCTION__);
124 		return -EIO;
125 	}
126 	sprintf(child_bus->name, "PCI Bus #%02x", child_bus->number);
127 
128 	pci_scan_child_bus(child_bus);
129 
130 	list_for_each_entry(child_dev, &child_bus->devices, bus_list) {
131 		eeh_add_device_late(child_dev);
132 	}
133 
134 	/* Fixup new pci devices without touching bus struct */
135 	pcibios_fixup_new_pci_devices(child_bus, 0);
136 
137 	/* Make the discovered devices available */
138 	pci_bus_add_devices(child_bus);
139 	return 0;
140 }
141 
142 /**
143  * pcibios_add_pci_devices - adds new pci devices to bus
144  *
145  * This routine will find and fixup new pci devices under
146  * the indicated bus. This routine presumes that there
147  * might already be some devices under this bridge, so
148  * it carefully tries to add only new devices.  (And that
149  * is how this routine differs from other, similar pcibios
150  * routines.)
151  */
152 void
153 pcibios_add_pci_devices(struct pci_bus * bus)
154 {
155 	int slotno, num;
156 	struct pci_dev *dev;
157 	struct device_node *dn = pci_bus_to_OF_node(bus);
158 
159 	eeh_add_device_tree_early(dn);
160 
161 	/* pci_scan_slot should find all children */
162 	slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
163 	num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
164 	if (num) {
165 		pcibios_fixup_new_pci_devices(bus, 1);
166 		pci_bus_add_devices(bus);
167 	}
168 
169 	list_for_each_entry(dev, &bus->devices, bus_list) {
170 		eeh_add_device_late (dev);
171 		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
172 			pcibios_pci_config_bridge(dev);
173 	}
174 }
175