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 * __init update_dn_pci_info(struct device_node *dn, void *data)
47 struct pci_controller *phb = data;
49 char *device_type = get_property(dn, "device_type", NULL);
53 if (device_type && (strcmp(device_type, "pci") == 0) &&
54 (get_property(dn, "class-code", NULL) == 0)) {
55 /* special case for PHB's. Sigh. */
56 regs = (u32 *)get_property(dn, "bus-range", NULL);
59 model = (char *)get_property(dn, "model", NULL);
61 if (strstr(model, "U3"))
64 dn->devfn = 0; /* assumption */
66 regs = (u32 *)get_property(dn, "reg", NULL);
68 /* First register entry is addr (00BBSS00) */
69 dn->busno = (regs[0] >> 16) & 0xff;
70 dn->devfn = (regs[0] >> 8) & 0xff;
77 * Traverse a device tree stopping each PCI device in the tree.
78 * This is done depth first. As each node is processed, a "pre"
79 * function is called and the children are processed recursively.
81 * The "pre" func returns a value. If non-zero is returned from
82 * the "pre" func, the traversal stops and this value is returned.
83 * This return value is useful when using traverse as a method of
86 * NOTE: we do not run the func for devices that do not appear to
87 * be PCI except for the start node which we assume (this is good
88 * because the start node is often a phb which may be missing PCI
90 * We use the class-code as an indicator. If we run into
91 * one of these nodes we also assume its siblings are non-pci for
94 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
97 struct device_node *dn, *nextdn;
100 if (pre && ((ret = pre(start, data)) != NULL))
102 for (dn = start->child; dn; dn = nextdn) {
104 if (get_property(dn, "class-code", NULL)) {
105 if (pre && ((ret = pre(dn, data)) != NULL))
108 /* Depth first...do children */
110 else if (dn->sibling)
111 /* ok, try next sibling instead. */
112 nextdn = dn->sibling;
115 /* Walk up to next valid sibling. */
120 } while (dn->sibling == NULL);
121 nextdn = dn->sibling;
128 * Same as traverse_pci_devices except this does it for all phbs.
130 static void *traverse_all_pci_devices(traverse_func pre)
132 struct pci_controller *phb, *tmp;
135 list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
136 if ((ret = traverse_pci_devices(phb->arch_data, pre, phb))
144 * Traversal func that looks for a <busno,devfcn> value.
145 * If found, the device_node is returned (thus terminating the traversal).
147 static void *is_devfn_node(struct device_node *dn, void *data)
149 int busno = ((unsigned long)data >> 8) & 0xff;
150 int devfn = ((unsigned long)data) & 0xff;
151 return ((devfn == dn->devfn) && (busno == dn->busno)) ? dn : NULL;
155 * This is the "slow" path for looking up a device_node from a
156 * pci_dev. It will hunt for the device under its parent's
157 * phb and then update sysdata for a future fastpath.
159 * It may also do fixups on the actual device since this happens
160 * on the first read/write.
162 * Note that it also must deal with devices that don't exist.
163 * In this case it may probe for real hardware ("just in case")
164 * and add a device_node to the device tree if necessary.
167 struct device_node *fetch_dev_dn(struct pci_dev *dev)
169 struct device_node *orig_dn = dev->sysdata;
170 struct pci_controller *phb = orig_dn->phb; /* assume same phb as orig_dn */
171 struct device_node *phb_dn;
172 struct device_node *dn;
173 unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
175 phb_dn = phb->arch_data;
176 dn = traverse_pci_devices(phb_dn, is_devfn_node, (void *)searchval);
179 /* ToDo: call some device init hook here */
183 EXPORT_SYMBOL(fetch_dev_dn);
187 * Actually initialize the phbs.
188 * The buswalk on this phb has not happened yet.
190 void __init pci_devs_phb_init(void)
192 /* This must be done first so the device nodes have valid pci info! */
193 traverse_all_pci_devices(update_dn_pci_info);
197 static void __init pci_fixup_bus_sysdata_list(struct list_head *bus_list)
199 struct list_head *ln;
202 for (ln = bus_list->next; ln != bus_list; ln = ln->next) {
205 bus->sysdata = bus->self->sysdata;
206 pci_fixup_bus_sysdata_list(&bus->children);
211 * Fixup the bus->sysdata ptrs to point to the bus' device_node.
212 * This is done late in pcibios_init(). We do this mostly for
213 * sanity, but pci_dma.c uses these at DMA time so they must be
215 * To do this we recurse down the bus hierarchy. Note that PHB's
216 * have bus->self == NULL, but fortunately bus->sysdata is already
217 * correct in this case.
219 void __init pci_fix_bus_sysdata(void)
221 pci_fixup_bus_sysdata_list(&pci_root_buses);