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/delay.h>
25 #include <linux/string.h>
26 #include <linux/init.h>
27 #include <linux/bootmem.h>
30 #include <asm/pgtable.h>
33 #include <asm/machdep.h>
34 #include <asm/pci-bridge.h>
35 #include <asm/ppcdebug.h>
37 #include <asm/iommu.h>
42 * Traverse_func that inits the PCI fields of the device node.
43 * NOTE: this *must* be done before read/write config to the device.
45 static void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
47 struct pci_controller *phb = data;
51 regs = (u32 *)get_property(dn, "reg", NULL);
53 /* First register entry is addr (00BBSS00) */
54 dn->busno = (regs[0] >> 16) & 0xff;
55 dn->devfn = (regs[0] >> 8) & 0xff;
61 * Traverse a device tree stopping each PCI device in the tree.
62 * This is done depth first. As each node is processed, a "pre"
63 * function is called and the children are processed recursively.
65 * The "pre" func returns a value. If non-zero is returned from
66 * the "pre" func, the traversal stops and this value is returned.
67 * This return value is useful when using traverse as a method of
70 * NOTE: we do not run the func for devices that do not appear to
71 * be PCI except for the start node which we assume (this is good
72 * because the start node is often a phb which may be missing PCI
74 * We use the class-code as an indicator. If we run into
75 * one of these nodes we also assume its siblings are non-pci for
78 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
81 struct device_node *dn, *nextdn;
84 /* We started with a phb, iterate all childs */
85 for (dn = start->child; dn; dn = nextdn) {
89 classp = (u32 *)get_property(dn, "class-code", NULL);
90 class = classp ? *classp : 0;
92 if (pre && ((ret = pre(dn, data)) != NULL))
95 /* If we are a PCI bridge, go down */
96 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
97 (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
98 /* Depth first...do children */
100 else if (dn->sibling)
101 /* ok, try next sibling instead. */
102 nextdn = dn->sibling;
104 /* Walk up to next valid sibling. */
109 } while (dn->sibling == NULL);
110 nextdn = dn->sibling;
116 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
118 struct device_node * dn = (struct device_node *) phb->arch_data;
120 /* PHB nodes themselves must not match */
121 dn->devfn = dn->busno = -1;
124 /* Update dn->phb ptrs for new phb and children devices */
125 traverse_pci_devices(dn, update_dn_pci_info, phb);
129 * Traversal func that looks for a <busno,devfcn> value.
130 * If found, the device_node is returned (thus terminating the traversal).
132 static void *is_devfn_node(struct device_node *dn, void *data)
134 int busno = ((unsigned long)data >> 8) & 0xff;
135 int devfn = ((unsigned long)data) & 0xff;
137 return ((devfn == dn->devfn) && (busno == dn->busno)) ? dn : NULL;
141 * This is the "slow" path for looking up a device_node from a
142 * pci_dev. It will hunt for the device under its parent's
143 * phb and then update sysdata for a future fastpath.
145 * It may also do fixups on the actual device since this happens
146 * on the first read/write.
148 * Note that it also must deal with devices that don't exist.
149 * In this case it may probe for real hardware ("just in case")
150 * and add a device_node to the device tree if necessary.
153 struct device_node *fetch_dev_dn(struct pci_dev *dev)
155 struct device_node *orig_dn = dev->sysdata;
156 struct pci_controller *phb = orig_dn->phb; /* assume same phb as orig_dn */
157 struct device_node *phb_dn;
158 struct device_node *dn;
159 unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
161 phb_dn = phb->arch_data;
162 dn = traverse_pci_devices(phb_dn, is_devfn_node, (void *)searchval);
167 EXPORT_SYMBOL(fetch_dev_dn);
171 * Actually initialize the phbs.
172 * The buswalk on this phb has not happened yet.
174 void __init pci_devs_phb_init(void)
176 struct pci_controller *phb, *tmp;
178 /* This must be done first so the device nodes have valid pci info! */
179 list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
180 pci_devs_phb_init_dynamic(phb);
184 static void __init pci_fixup_bus_sysdata_list(struct list_head *bus_list)
188 list_for_each_entry(bus, bus_list, node) {
190 bus->sysdata = bus->self->sysdata;
191 pci_fixup_bus_sysdata_list(&bus->children);
196 * Fixup the bus->sysdata ptrs to point to the bus' device_node.
197 * This is done late in pcibios_init(). We do this mostly for
198 * sanity, but pci_dma.c uses these at DMA time so they must be
200 * To do this we recurse down the bus hierarchy. Note that PHB's
201 * have bus->self == NULL, but fortunately bus->sysdata is already
202 * correct in this case.
204 void __init pci_fix_bus_sysdata(void)
206 pci_fixup_bus_sysdata_list(&pci_root_buses);