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 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 *
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  * @bus: the indicated PCI bus
70  * @purge_pe: destroy the PE on removal of PCI devices
71  *
72  * Remove all of the PCI devices under this bus both from the
73  * linux pci device tree, and from the powerpc EEH address cache.
74  * By default, the corresponding PE will be destroied during the
75  * normal PCI hotplug path. For PCI hotplug during EEH recovery,
76  * the corresponding PE won't be destroied and deallocated.
77  */
78 void __pcibios_remove_pci_devices(struct pci_bus *bus, int purge_pe)
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 		__pcibios_remove_pci_devices(child_bus, purge_pe);
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(dev, tmp, &bus->devices, bus_list) {
90 		pr_debug("     * Removing %s...\n", pci_name(dev));
91 		eeh_remove_bus_device(dev, purge_pe);
92 		pci_stop_and_remove_bus_device(dev);
93 	}
94 }
95 
96 /**
97  * pcibios_remove_pci_devices - remove all devices under this bus
98  *
99  * Remove all of the PCI devices under this bus both from the
100  * linux pci device tree, and from the powerpc EEH address cache.
101  */
102 void pcibios_remove_pci_devices(struct pci_bus *bus)
103 {
104 	__pcibios_remove_pci_devices(bus, 1);
105 }
106 EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices);
107 
108 /**
109  * pcibios_add_pci_devices - adds new pci devices to bus
110  *
111  * This routine will find and fixup new pci devices under
112  * the indicated bus. This routine presumes that there
113  * might already be some devices under this bridge, so
114  * it carefully tries to add only new devices.  (And that
115  * is how this routine differs from other, similar pcibios
116  * routines.)
117  */
118 void pcibios_add_pci_devices(struct pci_bus * bus)
119 {
120 	int slotno, num, mode, pass, max;
121 	struct pci_dev *dev;
122 	struct device_node *dn = pci_bus_to_OF_node(bus);
123 
124 	eeh_add_device_tree_early(dn);
125 
126 	mode = PCI_PROBE_NORMAL;
127 	if (ppc_md.pci_probe_mode)
128 		mode = ppc_md.pci_probe_mode(bus);
129 
130 	if (mode == PCI_PROBE_DEVTREE) {
131 		/* use ofdt-based probe */
132 		of_rescan_bus(dn, bus);
133 	} else if (mode == PCI_PROBE_NORMAL) {
134 		/* use legacy probe */
135 		slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
136 		num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
137 		if (!num)
138 			return;
139 		pcibios_setup_bus_devices(bus);
140 		max = bus->busn_res.start;
141 		for (pass=0; pass < 2; pass++)
142 			list_for_each_entry(dev, &bus->devices, bus_list) {
143 			if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
144 			    dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
145 				max = pci_scan_bridge(bus, dev, max, pass);
146 		}
147 	}
148 	pcibios_finish_adding_to_bus(bus);
149 }
150 EXPORT_SYMBOL_GPL(pcibios_add_pci_devices);
151 
152 struct pci_controller *init_phb_dynamic(struct device_node *dn)
153 {
154 	struct pci_controller *phb;
155 
156 	pr_debug("PCI: Initializing new hotplug PHB %s\n", dn->full_name);
157 
158 	phb = pcibios_alloc_controller(dn);
159 	if (!phb)
160 		return NULL;
161 	rtas_setup_phb(phb);
162 	pci_process_bridge_OF_ranges(phb, dn, 0);
163 
164 	pci_devs_phb_init_dynamic(phb);
165 
166 	/* Create EEH devices for the PHB */
167 	eeh_dev_phb_init_dynamic(phb);
168 
169 	if (dn->child)
170 		eeh_add_device_tree_early(dn);
171 
172 	pcibios_scan_phb(phb);
173 	pcibios_finish_adding_to_bus(phb->bus);
174 
175 	return phb;
176 }
177 EXPORT_SYMBOL_GPL(init_phb_dynamic);
178 
179 /* RPA-specific bits for removing PHBs */
180 int remove_phb_dynamic(struct pci_controller *phb)
181 {
182 	struct pci_bus *b = phb->bus;
183 	struct resource *res;
184 	int rc, i;
185 
186 	pr_debug("PCI: Removing PHB %04x:%02x...\n",
187 		 pci_domain_nr(b), b->number);
188 
189 	/* We cannot to remove a root bus that has children */
190 	if (!(list_empty(&b->children) && list_empty(&b->devices)))
191 		return -EBUSY;
192 
193 	/* We -know- there aren't any child devices anymore at this stage
194 	 * and thus, we can safely unmap the IO space as it's not in use
195 	 */
196 	res = &phb->io_resource;
197 	if (res->flags & IORESOURCE_IO) {
198 		rc = pcibios_unmap_io_space(b);
199 		if (rc) {
200 			printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
201 			       __func__, b->name);
202 			return 1;
203 		}
204 	}
205 
206 	/* Unregister the bridge device from sysfs and remove the PCI bus */
207 	device_unregister(b->bridge);
208 	phb->bus = NULL;
209 	pci_remove_bus(b);
210 
211 	/* Now release the IO resource */
212 	if (res->flags & IORESOURCE_IO)
213 		release_resource(res);
214 
215 	/* Release memory resources */
216 	for (i = 0; i < 3; ++i) {
217 		res = &phb->mem_resources[i];
218 		if (!(res->flags & IORESOURCE_MEM))
219 			continue;
220 		release_resource(res);
221 	}
222 
223 	/* Free pci_controller data structure */
224 	pcibios_free_controller(phb);
225 
226 	return 0;
227 }
228 EXPORT_SYMBOL_GPL(remove_phb_dynamic);
229