1 /*
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/export.h>
26 #include <linux/init.h>
27 #include <linux/gfp.h>
28
29 #include <asm/io.h>
30 #include <asm/prom.h>
31 #include <asm/pci-bridge.h>
32 #include <asm/ppc-pci.h>
33 #include <asm/firmware.h>
34
35 /*
36 * Traverse_func that inits the PCI fields of the device node.
37 * NOTE: this *must* be done before read/write config to the device.
38 */
update_dn_pci_info(struct device_node * dn,void * data)39 void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
40 {
41 struct pci_controller *phb = data;
42 const int *type =
43 of_get_property(dn, "ibm,pci-config-space-type", NULL);
44 const u32 *regs;
45 struct pci_dn *pdn;
46
47 pdn = zalloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
48 if (pdn == NULL)
49 return NULL;
50 dn->data = pdn;
51 pdn->node = dn;
52 pdn->phb = phb;
53 #ifdef CONFIG_PPC_POWERNV
54 pdn->pe_number = IODA_INVALID_PE;
55 #endif
56 regs = of_get_property(dn, "reg", NULL);
57 if (regs) {
58 /* First register entry is addr (00BBSS00) */
59 pdn->busno = (regs[0] >> 16) & 0xff;
60 pdn->devfn = (regs[0] >> 8) & 0xff;
61 }
62
63 pdn->pci_ext_config_space = (type && *type == 1);
64 return NULL;
65 }
66
67 /*
68 * Traverse a device tree stopping each PCI device in the tree.
69 * This is done depth first. As each node is processed, a "pre"
70 * function is called and the children are processed recursively.
71 *
72 * The "pre" func returns a value. If non-zero is returned from
73 * the "pre" func, the traversal stops and this value is returned.
74 * This return value is useful when using traverse as a method of
75 * finding a device.
76 *
77 * NOTE: we do not run the func for devices that do not appear to
78 * be PCI except for the start node which we assume (this is good
79 * because the start node is often a phb which may be missing PCI
80 * properties).
81 * We use the class-code as an indicator. If we run into
82 * one of these nodes we also assume its siblings are non-pci for
83 * performance.
84 */
traverse_pci_devices(struct device_node * start,traverse_func pre,void * data)85 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
86 void *data)
87 {
88 struct device_node *dn, *nextdn;
89 void *ret;
90
91 /* We started with a phb, iterate all childs */
92 for (dn = start->child; dn; dn = nextdn) {
93 const u32 *classp;
94 u32 class;
95
96 nextdn = NULL;
97 classp = of_get_property(dn, "class-code", NULL);
98 class = classp ? *classp : 0;
99
100 if (pre && ((ret = pre(dn, data)) != NULL))
101 return ret;
102
103 /* If we are a PCI bridge, go down */
104 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
105 (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
106 /* Depth first...do children */
107 nextdn = dn->child;
108 else if (dn->sibling)
109 /* ok, try next sibling instead. */
110 nextdn = dn->sibling;
111 if (!nextdn) {
112 /* Walk up to next valid sibling. */
113 do {
114 dn = dn->parent;
115 if (dn == start)
116 return NULL;
117 } while (dn->sibling == NULL);
118 nextdn = dn->sibling;
119 }
120 }
121 return NULL;
122 }
123
124 /**
125 * pci_devs_phb_init_dynamic - setup pci devices under this PHB
126 * phb: pci-to-host bridge (top-level bridge connecting to cpu)
127 *
128 * This routine is called both during boot, (before the memory
129 * subsystem is set up, before kmalloc is valid) and during the
130 * dynamic lpar operation of adding a PHB to a running system.
131 */
pci_devs_phb_init_dynamic(struct pci_controller * phb)132 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
133 {
134 struct device_node *dn = phb->dn;
135 struct pci_dn *pdn;
136
137 /* PHB nodes themselves must not match */
138 update_dn_pci_info(dn, phb);
139 pdn = dn->data;
140 if (pdn) {
141 pdn->devfn = pdn->busno = -1;
142 pdn->phb = phb;
143 }
144
145 /* Update dn->phb ptrs for new phb and children devices */
146 traverse_pci_devices(dn, update_dn_pci_info, phb);
147 }
148
149 /**
150 * pci_devs_phb_init - Initialize phbs and pci devs under them.
151 *
152 * This routine walks over all phb's (pci-host bridges) on the
153 * system, and sets up assorted pci-related structures
154 * (including pci info in the device node structs) for each
155 * pci device found underneath. This routine runs once,
156 * early in the boot sequence.
157 */
pci_devs_phb_init(void)158 void __init pci_devs_phb_init(void)
159 {
160 struct pci_controller *phb, *tmp;
161
162 /* This must be done first so the device nodes have valid pci info! */
163 list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
164 pci_devs_phb_init_dynamic(phb);
165 }
166