4 * Copyright (C) 2001 Todd Inglett, IBM Corporation
6 * PCI manipulation via device_nodes.
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.
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.
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
22 #include <linux/kernel.h>
23 #include <linux/pci.h>
24 #include <linux/string.h>
25 #include <linux/init.h>
29 #include <asm/pci-bridge.h>
34 * Traverse_func that inits the PCI fields of the device node.
35 * NOTE: this *must* be done before read/write config to the device.
37 static void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
39 struct pci_controller *phb = data;
43 regs = (u32 *)get_property(dn, "reg", NULL);
45 /* First register entry is addr (00BBSS00) */
46 dn->busno = (regs[0] >> 16) & 0xff;
47 dn->devfn = (regs[0] >> 8) & 0xff;
53 * Traverse a device tree stopping each PCI device in the tree.
54 * This is done depth first. As each node is processed, a "pre"
55 * function is called and the children are processed recursively.
57 * The "pre" func returns a value. If non-zero is returned from
58 * the "pre" func, the traversal stops and this value is returned.
59 * This return value is useful when using traverse as a method of
62 * NOTE: we do not run the func for devices that do not appear to
63 * be PCI except for the start node which we assume (this is good
64 * because the start node is often a phb which may be missing PCI
66 * We use the class-code as an indicator. If we run into
67 * one of these nodes we also assume its siblings are non-pci for
70 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
73 struct device_node *dn, *nextdn;
76 /* We started with a phb, iterate all childs */
77 for (dn = start->child; dn; dn = nextdn) {
81 classp = (u32 *)get_property(dn, "class-code", NULL);
82 class = classp ? *classp : 0;
84 if (pre && ((ret = pre(dn, data)) != NULL))
87 /* If we are a PCI bridge, go down */
88 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
89 (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
90 /* Depth first...do children */
93 /* ok, try next sibling instead. */
96 /* Walk up to next valid sibling. */
101 } while (dn->sibling == NULL);
102 nextdn = dn->sibling;
108 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
110 struct device_node * dn = (struct device_node *) phb->arch_data;
112 /* PHB nodes themselves must not match */
113 dn->devfn = dn->busno = -1;
116 /* Update dn->phb ptrs for new phb and children devices */
117 traverse_pci_devices(dn, update_dn_pci_info, phb);
121 * Traversal func that looks for a <busno,devfcn> value.
122 * If found, the device_node is returned (thus terminating the traversal).
124 static void *is_devfn_node(struct device_node *dn, void *data)
126 int busno = ((unsigned long)data >> 8) & 0xff;
127 int devfn = ((unsigned long)data) & 0xff;
129 return ((devfn == dn->devfn) && (busno == dn->busno)) ? dn : NULL;
133 * This is the "slow" path for looking up a device_node from a
134 * pci_dev. It will hunt for the device under its parent's
135 * phb and then update sysdata for a future fastpath.
137 * It may also do fixups on the actual device since this happens
138 * on the first read/write.
140 * Note that it also must deal with devices that don't exist.
141 * In this case it may probe for real hardware ("just in case")
142 * and add a device_node to the device tree if necessary.
145 struct device_node *fetch_dev_dn(struct pci_dev *dev)
147 struct device_node *orig_dn = dev->sysdata;
148 struct pci_controller *phb = orig_dn->phb; /* assume same phb as orig_dn */
149 struct device_node *phb_dn;
150 struct device_node *dn;
151 unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
153 phb_dn = phb->arch_data;
154 dn = traverse_pci_devices(phb_dn, is_devfn_node, (void *)searchval);
159 EXPORT_SYMBOL(fetch_dev_dn);
163 * Actually initialize the phbs.
164 * The buswalk on this phb has not happened yet.
166 void __init pci_devs_phb_init(void)
168 struct pci_controller *phb, *tmp;
170 /* This must be done first so the device nodes have valid pci info! */
171 list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
172 pci_devs_phb_init_dynamic(phb);