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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * pci_dn.c
3 *
4 * Copyright (C) 2001 Todd Inglett, IBM Corporation
5 *
6 * PCI manipulation via device_nodes.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22#include <linux/kernel.h>
23#include <linux/pci.h>
24#include <linux/string.h>
25#include <linux/init.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090026#include <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28#include <asm/io.h>
29#include <asm/prom.h>
30#include <asm/pci-bridge.h>
Stephen Rothwelld3878992005-09-28 02:50:25 +100031#include <asm/ppc-pci.h>
Stephen Rothwell095eed42006-05-19 16:54:42 +100032#include <asm/firmware.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34/*
35 * Traverse_func that inits the PCI fields of the device node.
36 * NOTE: this *must* be done before read/write config to the device.
37 */
Kumar Gala2eb4afb2009-04-30 09:26:21 +000038void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039{
40 struct pci_controller *phb = data;
Stephen Rothwelle2eb6392007-04-03 22:26:41 +100041 const int *type =
42 of_get_property(dn, "ibm,pci-config-space-type", NULL);
Jeremy Kerra7f67bd2006-07-12 15:35:54 +100043 const u32 *regs;
Paul Mackerras16353172005-09-06 13:17:54 +100044 struct pci_dn *pdn;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Stephen Rothwell7b2c3c52007-09-17 14:08:06 +100046 pdn = alloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
Paul Mackerras16353172005-09-06 13:17:54 +100047 if (pdn == NULL)
48 return NULL;
49 memset(pdn, 0, sizeof(*pdn));
50 dn->data = pdn;
51 pdn->node = dn;
52 pdn->phb = phb;
Stephen Rothwelle2eb6392007-04-03 22:26:41 +100053 regs = of_get_property(dn, "reg", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 if (regs) {
55 /* First register entry is addr (00BBSS00) */
Paul Mackerras16353172005-09-06 13:17:54 +100056 pdn->busno = (regs[0] >> 16) & 0xff;
57 pdn->devfn = (regs[0] >> 8) & 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 }
59
Paul Mackerras16353172005-09-06 13:17:54 +100060 pdn->pci_ext_config_space = (type && *type == 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 return NULL;
62}
63
64/*
65 * Traverse a device tree stopping each PCI device in the tree.
66 * This is done depth first. As each node is processed, a "pre"
67 * function is called and the children are processed recursively.
68 *
69 * The "pre" func returns a value. If non-zero is returned from
70 * the "pre" func, the traversal stops and this value is returned.
71 * This return value is useful when using traverse as a method of
72 * finding a device.
73 *
74 * NOTE: we do not run the func for devices that do not appear to
75 * be PCI except for the start node which we assume (this is good
76 * because the start node is often a phb which may be missing PCI
77 * properties).
78 * We use the class-code as an indicator. If we run into
79 * one of these nodes we also assume its siblings are non-pci for
80 * performance.
81 */
82void *traverse_pci_devices(struct device_node *start, traverse_func pre,
83 void *data)
84{
85 struct device_node *dn, *nextdn;
86 void *ret;
87
88 /* We started with a phb, iterate all childs */
89 for (dn = start->child; dn; dn = nextdn) {
Jeremy Kerra7f67bd2006-07-12 15:35:54 +100090 const u32 *classp;
91 u32 class;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93 nextdn = NULL;
Stephen Rothwelle2eb6392007-04-03 22:26:41 +100094 classp = of_get_property(dn, "class-code", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 class = classp ? *classp : 0;
96
97 if (pre && ((ret = pre(dn, data)) != NULL))
98 return ret;
99
100 /* If we are a PCI bridge, go down */
101 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
102 (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
103 /* Depth first...do children */
104 nextdn = dn->child;
105 else if (dn->sibling)
106 /* ok, try next sibling instead. */
107 nextdn = dn->sibling;
108 if (!nextdn) {
109 /* Walk up to next valid sibling. */
110 do {
111 dn = dn->parent;
112 if (dn == start)
113 return NULL;
114 } while (dn->sibling == NULL);
115 nextdn = dn->sibling;
116 }
117 }
118 return NULL;
119}
120
Linas Vepstas18126f32005-11-03 18:49:38 -0600121/**
122 * pci_devs_phb_init_dynamic - setup pci devices under this PHB
123 * phb: pci-to-host bridge (top-level bridge connecting to cpu)
124 *
125 * This routine is called both during boot, (before the memory
126 * subsystem is set up, before kmalloc is valid) and during the
127 * dynamic lpar operation of adding a PHB to a running system.
128 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
130{
Stephen Rothwell44ef3392007-12-10 14:33:21 +1100131 struct device_node *dn = phb->dn;
Paul Mackerras16353172005-09-06 13:17:54 +1000132 struct pci_dn *pdn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
134 /* PHB nodes themselves must not match */
Paul Mackerras16353172005-09-06 13:17:54 +1000135 update_dn_pci_info(dn, phb);
136 pdn = dn->data;
137 if (pdn) {
138 pdn->devfn = pdn->busno = -1;
139 pdn->phb = phb;
140 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
142 /* Update dn->phb ptrs for new phb and children devices */
143 traverse_pci_devices(dn, update_dn_pci_info, phb);
144}
145
146/*
147 * Traversal func that looks for a <busno,devfcn> value.
Paul Mackerras16353172005-09-06 13:17:54 +1000148 * If found, the pci_dn is returned (thus terminating the traversal).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 */
150static void *is_devfn_node(struct device_node *dn, void *data)
151{
152 int busno = ((unsigned long)data >> 8) & 0xff;
153 int devfn = ((unsigned long)data) & 0xff;
Paul Mackerras16353172005-09-06 13:17:54 +1000154 struct pci_dn *pci = dn->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
Paul Mackerras16353172005-09-06 13:17:54 +1000156 if (pci && (devfn == pci->devfn) && (busno == pci->busno))
157 return dn;
158 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159}
160
161/*
162 * This is the "slow" path for looking up a device_node from a
163 * pci_dev. It will hunt for the device under its parent's
164 * phb and then update sysdata for a future fastpath.
165 *
166 * It may also do fixups on the actual device since this happens
167 * on the first read/write.
168 *
169 * Note that it also must deal with devices that don't exist.
170 * In this case it may probe for real hardware ("just in case")
171 * and add a device_node to the device tree if necessary.
172 *
173 */
174struct device_node *fetch_dev_dn(struct pci_dev *dev)
175{
176 struct device_node *orig_dn = dev->sysdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 struct device_node *dn;
178 unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
179
Paul Mackerras16353172005-09-06 13:17:54 +1000180 dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 if (dn)
182 dev->sysdata = dn;
183 return dn;
184}
185EXPORT_SYMBOL(fetch_dev_dn);
186
Linas Vepstas18126f32005-11-03 18:49:38 -0600187/**
188 * pci_devs_phb_init - Initialize phbs and pci devs under them.
189 *
190 * This routine walks over all phb's (pci-host bridges) on the
191 * system, and sets up assorted pci-related structures
192 * (including pci info in the device node structs) for each
193 * pci device found underneath. This routine runs once,
194 * early in the boot sequence.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 */
196void __init pci_devs_phb_init(void)
197{
198 struct pci_controller *phb, *tmp;
199
200 /* This must be done first so the device nodes have valid pci info! */
201 list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
202 pci_devs_phb_init_dynamic(phb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203}