summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/pci_dn.c
blob: d5e36e5dc7c21368cb088c21013c961d9f232328 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/*
 * pci_dn.c
 *
 * Copyright (C) 2001 Todd Inglett, IBM Corporation
 *
 * PCI manipulation via device_nodes.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *    
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/init.h>

#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/firmware.h>

/*
 * Traverse_func that inits the PCI fields of the device node.
 * NOTE: this *must* be done before read/write config to the device.
 */
void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
{
	struct pci_controller *phb = data;
	const int *type =
		of_get_property(dn, "ibm,pci-config-space-type", NULL);
	const u32 *regs;
	struct pci_dn *pdn;

	pdn = alloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
	if (pdn == NULL)
		return NULL;
	memset(pdn, 0, sizeof(*pdn));
	dn->data = pdn;
	pdn->node = dn;
	pdn->phb = phb;
	regs = of_get_property(dn, "reg", NULL);
	if (regs) {
		/* First register entry is addr (00BBSS00)  */
		pdn->busno = (regs[0] >> 16) & 0xff;
		pdn->devfn = (regs[0] >> 8) & 0xff;
	}

	pdn->pci_ext_config_space = (type && *type == 1);
	return NULL;
}

/*
 * Traverse a device tree stopping each PCI device in the tree.
 * This is done depth first.  As each node is processed, a "pre"
 * function is called and the children are processed recursively.
 *
 * The "pre" func returns a value.  If non-zero is returned from
 * the "pre" func, the traversal stops and this value is returned.
 * This return value is useful when using traverse as a method of
 * finding a device.
 *
 * NOTE: we do not run the func for devices that do not appear to
 * be PCI except for the start node which we assume (this is good
 * because the start node is often a phb which may be missing PCI
 * properties).
 * We use the class-code as an indicator. If we run into
 * one of these nodes we also assume its siblings are non-pci for
 * performance.
 */
void *traverse_pci_devices(struct device_node *start, traverse_func pre,
		void *data)
{
	struct device_node *dn, *nextdn;
	void *ret;

	/* We started with a phb, iterate all childs */
	for (dn = start->child; dn; dn = nextdn) {
		const u32 *classp;
		u32 class;

		nextdn = NULL;
		classp = of_get_property(dn, "class-code", NULL);
		class = classp ? *classp : 0;

		if (pre && ((ret = pre(dn, data)) != NULL))
			return ret;

		/* If we are a PCI bridge, go down */
		if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
				  (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
			/* Depth first...do children */
			nextdn = dn->child;
		else if (dn->sibling)
			/* ok, try next sibling instead. */
			nextdn = dn->sibling;
		if (!nextdn) {
			/* Walk up to next valid sibling. */
			do {
				dn = dn->parent;
				if (dn == start)
					return NULL;
			} while (dn->sibling == NULL);
			nextdn = dn->sibling;
		}
	}
	return NULL;
}

/** 
 * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 *
 * This routine is called both during boot, (before the memory
 * subsystem is set up, before kmalloc is valid) and during the 
 * dynamic lpar operation of adding a PHB to a running system.
 */
void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
{
	struct device_node *dn = phb->dn;
	struct pci_dn *pdn;

	/* PHB nodes themselves must not match */
	update_dn_pci_info(dn, phb);
	pdn = dn->data;
	if (pdn) {
		pdn->devfn = pdn->busno = -1;
		pdn->phb = phb;
	}

	/* Update dn->phb ptrs for new phb and children devices */
	traverse_pci_devices(dn, update_dn_pci_info, phb);
}

/*
 * Traversal func that looks for a <busno,devfcn> value.
 * If found, the pci_dn is returned (thus terminating the traversal).
 */
static void *is_devfn_node(struct device_node *dn, void *data)
{
	int busno = ((unsigned long)data >> 8) & 0xff;
	int devfn = ((unsigned long)data) & 0xff;
	struct pci_dn *pci = dn->data;

	if (pci && (devfn == pci->devfn) && (busno == pci->busno))
		return dn;
	return NULL;
}

/*
 * This is the "slow" path for looking up a device_node from a
 * pci_dev.  It will hunt for the device under its parent's
 * phb and then update sysdata for a future fastpath.
 *
 * It may also do fixups on the actual device since this happens
 * on the first read/write.
 *
 * Note that it also must deal with devices that don't exist.
 * In this case it may probe for real hardware ("just in case")
 * and add a device_node to the device tree if necessary.
 *
 */
struct device_node *fetch_dev_dn(struct pci_dev *dev)
{
	struct device_node *orig_dn = dev->sysdata;
	struct device_node *dn;
	unsigned long searchval = (dev->bus->number << 8) | dev->devfn;

	dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
	if (dn)
		dev->sysdata = dn;
	return dn;
}
EXPORT_SYMBOL(fetch_dev_dn);

/** 
 * pci_devs_phb_init - Initialize phbs and pci devs under them.
 * 
 * This routine walks over all phb's (pci-host bridges) on the
 * system, and sets up assorted pci-related structures 
 * (including pci info in the device node structs) for each
 * pci device found underneath.  This routine runs once,
 * early in the boot sequence.
 */
void __init pci_devs_phb_init(void)
{
	struct pci_controller *phb, *tmp;

	/* This must be done first so the device nodes have valid pci info! */
	list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
		pci_devs_phb_init_dynamic(phb);
}