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
pci_get_pdn(struct pci_dev * pdev)35 struct pci_dn *pci_get_pdn(struct pci_dev *pdev)
36 {
37 struct device_node *dn = pci_device_to_OF_node(pdev);
38 if (!dn)
39 return NULL;
40 return PCI_DN(dn);
41 }
42
43 /*
44 * Traverse_func that inits the PCI fields of the device node.
45 * NOTE: this *must* be done before read/write config to the device.
46 */
update_dn_pci_info(struct device_node * dn,void * data)47 void *update_dn_pci_info(struct device_node *dn, void *data)
48 {
49 struct pci_controller *phb = data;
50 const __be32 *type = of_get_property(dn, "ibm,pci-config-space-type", NULL);
51 const __be32 *regs;
52 struct pci_dn *pdn;
53
54 pdn = zalloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
55 if (pdn == NULL)
56 return NULL;
57 dn->data = pdn;
58 pdn->node = dn;
59 pdn->phb = phb;
60 #ifdef CONFIG_PPC_POWERNV
61 pdn->pe_number = IODA_INVALID_PE;
62 #endif
63 regs = of_get_property(dn, "reg", NULL);
64 if (regs) {
65 u32 addr = of_read_number(regs, 1);
66
67 /* First register entry is addr (00BBSS00) */
68 pdn->busno = (addr >> 16) & 0xff;
69 pdn->devfn = (addr >> 8) & 0xff;
70 }
71
72 pdn->pci_ext_config_space = (type && of_read_number(type, 1) == 1);
73 return NULL;
74 }
75
76 /*
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.
80 *
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
84 * finding a device.
85 *
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
89 * properties).
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
92 * performance.
93 */
traverse_pci_devices(struct device_node * start,traverse_func pre,void * data)94 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
95 void *data)
96 {
97 struct device_node *dn, *nextdn;
98 void *ret;
99
100 /* We started with a phb, iterate all childs */
101 for (dn = start->child; dn; dn = nextdn) {
102 const __be32 *classp;
103 u32 class = 0;
104
105 nextdn = NULL;
106 classp = of_get_property(dn, "class-code", NULL);
107 if (classp)
108 class = of_read_number(classp, 1);
109
110 if (pre && ((ret = pre(dn, data)) != NULL))
111 return ret;
112
113 /* If we are a PCI bridge, go down */
114 if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
115 (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
116 /* Depth first...do children */
117 nextdn = dn->child;
118 else if (dn->sibling)
119 /* ok, try next sibling instead. */
120 nextdn = dn->sibling;
121 if (!nextdn) {
122 /* Walk up to next valid sibling. */
123 do {
124 dn = dn->parent;
125 if (dn == start)
126 return NULL;
127 } while (dn->sibling == NULL);
128 nextdn = dn->sibling;
129 }
130 }
131 return NULL;
132 }
133
134 /**
135 * pci_devs_phb_init_dynamic - setup pci devices under this PHB
136 * phb: pci-to-host bridge (top-level bridge connecting to cpu)
137 *
138 * This routine is called both during boot, (before the memory
139 * subsystem is set up, before kmalloc is valid) and during the
140 * dynamic lpar operation of adding a PHB to a running system.
141 */
pci_devs_phb_init_dynamic(struct pci_controller * phb)142 void pci_devs_phb_init_dynamic(struct pci_controller *phb)
143 {
144 struct device_node *dn = phb->dn;
145 struct pci_dn *pdn;
146
147 /* PHB nodes themselves must not match */
148 update_dn_pci_info(dn, phb);
149 pdn = dn->data;
150 if (pdn) {
151 pdn->devfn = pdn->busno = -1;
152 pdn->phb = phb;
153 }
154
155 /* Update dn->phb ptrs for new phb and children devices */
156 traverse_pci_devices(dn, update_dn_pci_info, phb);
157 }
158
159 /**
160 * pci_devs_phb_init - Initialize phbs and pci devs under them.
161 *
162 * This routine walks over all phb's (pci-host bridges) on the
163 * system, and sets up assorted pci-related structures
164 * (including pci info in the device node structs) for each
165 * pci device found underneath. This routine runs once,
166 * early in the boot sequence.
167 */
pci_devs_phb_init(void)168 void __init pci_devs_phb_init(void)
169 {
170 struct pci_controller *phb, *tmp;
171
172 /* This must be done first so the device nodes have valid pci info! */
173 list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
174 pci_devs_phb_init_dynamic(phb);
175 }
176