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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 *
find_bus_among_children(struct pci_bus * bus,struct device_node * dn)36 find_bus_among_children(struct pci_bus *bus,
37                         struct device_node *dn)
38 {
39 	struct pci_bus *child = NULL;
40 	struct list_head *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(tmp, &bus->children) {
48 		child = find_bus_among_children(pci_bus_b(tmp), dn);
49 		if (child)
50 			break;
51 	};
52 	return child;
53 }
54 
55 struct pci_bus *
pcibios_find_pci_bus(struct device_node * dn)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 /**
68  * pcibios_remove_pci_devices - remove all devices under this bus
69  *
70  * Remove all of the PCI devices under this bus both from the
71  * linux pci device tree, and from the powerpc EEH address cache.
72  */
pcibios_remove_pci_devices(struct pci_bus * bus)73 void pcibios_remove_pci_devices(struct pci_bus *bus)
74 {
75  	struct pci_dev *dev, *tmp;
76 	struct pci_bus *child_bus;
77 
78 	/* First go down child busses */
79 	list_for_each_entry(child_bus, &bus->children, node)
80 		pcibios_remove_pci_devices(child_bus);
81 
82 	pr_debug("PCI: Removing devices on bus %04x:%02x\n",
83 		 pci_domain_nr(bus),  bus->number);
84 	list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
85 		pr_debug("     * Removing %s...\n", pci_name(dev));
86 		eeh_remove_bus_device(dev);
87  		pci_stop_and_remove_bus_device(dev);
88  	}
89 }
90 EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices);
91 
92 /**
93  * pcibios_add_pci_devices - adds new pci devices to bus
94  *
95  * This routine will find and fixup new pci devices under
96  * the indicated bus. This routine presumes that there
97  * might already be some devices under this bridge, so
98  * it carefully tries to add only new devices.  (And that
99  * is how this routine differs from other, similar pcibios
100  * routines.)
101  */
pcibios_add_pci_devices(struct pci_bus * bus)102 void pcibios_add_pci_devices(struct pci_bus * bus)
103 {
104 	int slotno, num, mode, pass, max;
105 	struct pci_dev *dev;
106 	struct device_node *dn = pci_bus_to_OF_node(bus);
107 
108 	eeh_add_device_tree_early(dn);
109 
110 	mode = PCI_PROBE_NORMAL;
111 	if (ppc_md.pci_probe_mode)
112 		mode = ppc_md.pci_probe_mode(bus);
113 
114 	if (mode == PCI_PROBE_DEVTREE) {
115 		/* use ofdt-based probe */
116 		of_rescan_bus(dn, bus);
117 	} else if (mode == PCI_PROBE_NORMAL) {
118 		/* use legacy probe */
119 		slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
120 		num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
121 		if (!num)
122 			return;
123 		pcibios_setup_bus_devices(bus);
124 		max = bus->secondary;
125 		for (pass=0; pass < 2; pass++)
126 			list_for_each_entry(dev, &bus->devices, bus_list) {
127 			if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
128 			    dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
129 				max = pci_scan_bridge(bus, dev, max, pass);
130 		}
131 	}
132 	pcibios_finish_adding_to_bus(bus);
133 }
134 EXPORT_SYMBOL_GPL(pcibios_add_pci_devices);
135 
init_phb_dynamic(struct device_node * dn)136 struct pci_controller * __devinit init_phb_dynamic(struct device_node *dn)
137 {
138 	struct pci_controller *phb;
139 
140 	pr_debug("PCI: Initializing new hotplug PHB %s\n", dn->full_name);
141 
142 	phb = pcibios_alloc_controller(dn);
143 	if (!phb)
144 		return NULL;
145 	rtas_setup_phb(phb);
146 	pci_process_bridge_OF_ranges(phb, dn, 0);
147 
148 	pci_devs_phb_init_dynamic(phb);
149 
150 	/* Create EEH devices for the PHB */
151 	eeh_dev_phb_init_dynamic(phb);
152 
153 	if (dn->child)
154 		eeh_add_device_tree_early(dn);
155 
156 	pcibios_scan_phb(phb);
157 	pcibios_finish_adding_to_bus(phb->bus);
158 
159 	return phb;
160 }
161 EXPORT_SYMBOL_GPL(init_phb_dynamic);
162 
163 /* RPA-specific bits for removing PHBs */
remove_phb_dynamic(struct pci_controller * phb)164 int remove_phb_dynamic(struct pci_controller *phb)
165 {
166 	struct pci_bus *b = phb->bus;
167 	struct resource *res;
168 	int rc, i;
169 
170 	pr_debug("PCI: Removing PHB %04x:%02x...\n",
171 		 pci_domain_nr(b), b->number);
172 
173 	/* We cannot to remove a root bus that has children */
174 	if (!(list_empty(&b->children) && list_empty(&b->devices)))
175 		return -EBUSY;
176 
177 	/* We -know- there aren't any child devices anymore at this stage
178 	 * and thus, we can safely unmap the IO space as it's not in use
179 	 */
180 	res = &phb->io_resource;
181 	if (res->flags & IORESOURCE_IO) {
182 		rc = pcibios_unmap_io_space(b);
183 		if (rc) {
184 			printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
185 			       __func__, b->name);
186 			return 1;
187 		}
188 	}
189 
190 	/* Unregister the bridge device from sysfs and remove the PCI bus */
191 	device_unregister(b->bridge);
192 	phb->bus = NULL;
193 	pci_remove_bus(b);
194 
195 	/* Now release the IO resource */
196 	if (res->flags & IORESOURCE_IO)
197 		release_resource(res);
198 
199 	/* Release memory resources */
200 	for (i = 0; i < 3; ++i) {
201 		res = &phb->mem_resources[i];
202 		if (!(res->flags & IORESOURCE_MEM))
203 			continue;
204 		release_resource(res);
205 	}
206 
207 	/* Free pci_controller data structure */
208 	pcibios_free_controller(phb);
209 
210 	return 0;
211 }
212 EXPORT_SYMBOL_GPL(remove_phb_dynamic);
213