bus.c revision 7c94def89aa5091706e03b98047c074d7ac74af0 
1/*
2 *	drivers/pci/bus.c
3 *
4 * From setup-res.c, by:
5 *	Dave Rusling (david.rusling@reo.mts.dec.com)
6 *	David Mosberger (davidm@cs.arizona.edu)
7 *	David Miller (davem@redhat.com)
8 *	Ivan Kokshaysky (ink@jurassic.park.msu.ru)
9 */
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/pci.h>
13#include <linux/errno.h>
14#include <linux/ioport.h>
15#include <linux/proc_fs.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18
19#include "pci.h"
20
21void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
22			  unsigned int flags)
23{
24	struct pci_bus_resource *bus_res;
25
26	bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
27	if (!bus_res) {
28		dev_err(&bus->dev, "can't add %pR resource\n", res);
29		return;
30	}
31
32	bus_res->res = res;
33	bus_res->flags = flags;
34	list_add_tail(&bus_res->list, &bus->resources);
35}
36
37struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
38{
39	struct pci_bus_resource *bus_res;
40
41	if (n < PCI_BRIDGE_RESOURCE_NUM)
42		return bus->resource[n];
43
44	n -= PCI_BRIDGE_RESOURCE_NUM;
45	list_for_each_entry(bus_res, &bus->resources, list) {
46		if (n-- == 0)
47			return bus_res->res;
48	}
49	return NULL;
50}
51EXPORT_SYMBOL_GPL(pci_bus_resource_n);
52
53void pci_bus_remove_resources(struct pci_bus *bus)
54{
55	struct pci_bus_resource *bus_res, *tmp;
56	int i;
57
58	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
59		bus->resource[i] = NULL;
60
61	list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
62		list_del(&bus_res->list);
63		kfree(bus_res);
64	}
65}
66
67/**
68 * pci_bus_alloc_resource - allocate a resource from a parent bus
69 * @bus: PCI bus
70 * @res: resource to allocate
71 * @size: size of resource to allocate
72 * @align: alignment of resource to allocate
73 * @min: minimum /proc/iomem address to allocate
74 * @type_mask: IORESOURCE_* type flags
75 * @alignf: resource alignment function
76 * @alignf_data: data argument for resource alignment function
77 *
78 * Given the PCI bus a device resides on, the size, minimum address,
79 * alignment and type, try to find an acceptable resource allocation
80 * for a specific device resource.
81 */
82int
83pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
84		resource_size_t size, resource_size_t align,
85		resource_size_t min, unsigned int type_mask,
86		resource_size_t (*alignf)(void *,
87					  const struct resource *,
88					  resource_size_t,
89					  resource_size_t),
90		void *alignf_data)
91{
92	int i, ret = -ENOMEM;
93	struct resource *r;
94	resource_size_t max = -1;
95
96	type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
97
98	/* don't allocate too high if the pref mem doesn't support 64bit*/
99	if (!(res->flags & IORESOURCE_MEM_64))
100		max = PCIBIOS_MAX_MEM_32;
101
102	pci_bus_for_each_resource(bus, r, i) {
103		if (!r)
104			continue;
105
106		/* type_mask must match */
107		if ((res->flags ^ r->flags) & type_mask)
108			continue;
109
110		/* We cannot allocate a non-prefetching resource
111		   from a pre-fetching area */
112		if ((r->flags & IORESOURCE_PREFETCH) &&
113		    !(res->flags & IORESOURCE_PREFETCH))
114			continue;
115
116		/* Ok, try it out.. */
117		ret = allocate_resource(r, res, size,
118					r->start ? : min,
119					max, align,
120					alignf, alignf_data);
121		if (ret == 0)
122			break;
123	}
124	return ret;
125}
126
127/**
128 * pci_bus_add_device - add a single device
129 * @dev: device to add
130 *
131 * This adds a single pci device to the global
132 * device list and adds sysfs and procfs entries
133 */
134int pci_bus_add_device(struct pci_dev *dev)
135{
136	int retval;
137	retval = device_add(&dev->dev);
138	if (retval)
139		return retval;
140
141	dev->is_added = 1;
142	pci_proc_attach_device(dev);
143	pci_create_sysfs_dev_files(dev);
144	return 0;
145}
146
147/**
148 * pci_bus_add_child - add a child bus
149 * @bus: bus to add
150 *
151 * This adds sysfs entries for a single bus
152 */
153int pci_bus_add_child(struct pci_bus *bus)
154{
155	int retval;
156
157	if (bus->bridge)
158		bus->dev.parent = bus->bridge;
159
160	retval = device_register(&bus->dev);
161	if (retval)
162		return retval;
163
164	bus->is_added = 1;
165
166	retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity);
167	if (retval)
168		return retval;
169
170	retval = device_create_file(&bus->dev, &dev_attr_cpulistaffinity);
171
172	/* Create legacy_io and legacy_mem files for this bus */
173	pci_create_legacy_files(bus);
174
175	return retval;
176}
177
178/**
179 * pci_bus_add_devices - insert newly discovered PCI devices
180 * @bus: bus to check for new devices
181 *
182 * Add newly discovered PCI devices (which are on the bus->devices
183 * list) to the global PCI device list, add the sysfs and procfs
184 * entries.  Where a bridge is found, add the discovered bus to
185 * the parents list of child buses, and recurse (breadth-first
186 * to be compatible with 2.4)
187 *
188 * Call hotplug for each new devices.
189 */
190void pci_bus_add_devices(const struct pci_bus *bus)
191{
192	struct pci_dev *dev;
193	struct pci_bus *child;
194	int retval;
195
196	list_for_each_entry(dev, &bus->devices, bus_list) {
197		/* Skip already-added devices */
198		if (dev->is_added)
199			continue;
200		retval = pci_bus_add_device(dev);
201		if (retval)
202			dev_err(&dev->dev, "Error adding device, continuing\n");
203	}
204
205	list_for_each_entry(dev, &bus->devices, bus_list) {
206		BUG_ON(!dev->is_added);
207
208		child = dev->subordinate;
209		/*
210		 * If there is an unattached subordinate bus, attach
211		 * it and then scan for unattached PCI devices.
212		 */
213		if (!child)
214			continue;
215		if (list_empty(&child->node)) {
216			down_write(&pci_bus_sem);
217			list_add_tail(&child->node, &dev->bus->children);
218			up_write(&pci_bus_sem);
219		}
220		pci_bus_add_devices(child);
221
222		/*
223		 * register the bus with sysfs as the parent is now
224		 * properly registered.
225		 */
226		if (child->is_added)
227			continue;
228		retval = pci_bus_add_child(child);
229		if (retval)
230			dev_err(&dev->dev, "Error adding bus, continuing\n");
231	}
232}
233
234void pci_enable_bridges(struct pci_bus *bus)
235{
236	struct pci_dev *dev;
237	int retval;
238
239	list_for_each_entry(dev, &bus->devices, bus_list) {
240		if (dev->subordinate) {
241			if (!pci_is_enabled(dev)) {
242				retval = pci_enable_device(dev);
243				if (retval)
244					dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
245				pci_set_master(dev);
246			}
247			pci_enable_bridges(dev->subordinate);
248		}
249	}
250}
251
252/** pci_walk_bus - walk devices on/under bus, calling callback.
253 *  @top      bus whose devices should be walked
254 *  @cb       callback to be called for each device found
255 *  @userdata arbitrary pointer to be passed to callback.
256 *
257 *  Walk the given bus, including any bridged devices
258 *  on buses under this bus.  Call the provided callback
259 *  on each device found.
260 *
261 *  We check the return of @cb each time. If it returns anything
262 *  other than 0, we break out.
263 *
264 */
265void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
266		  void *userdata)
267{
268	struct pci_dev *dev;
269	struct pci_bus *bus;
270	struct list_head *next;
271	int retval;
272
273	bus = top;
274	down_read(&pci_bus_sem);
275	next = top->devices.next;
276	for (;;) {
277		if (next == &bus->devices) {
278			/* end of this bus, go up or finish */
279			if (bus == top)
280				break;
281			next = bus->self->bus_list.next;
282			bus = bus->self->bus;
283			continue;
284		}
285		dev = list_entry(next, struct pci_dev, bus_list);
286		if (dev->subordinate) {
287			/* this is a pci-pci bridge, do its devices next */
288			next = dev->subordinate->devices.next;
289			bus = dev->subordinate;
290		} else
291			next = dev->bus_list.next;
292
293		/* Run device routines with the device locked */
294		device_lock(&dev->dev);
295		retval = cb(dev, userdata);
296		device_unlock(&dev->dev);
297		if (retval)
298			break;
299	}
300	up_read(&pci_bus_sem);
301}
302EXPORT_SYMBOL_GPL(pci_walk_bus);
303
304EXPORT_SYMBOL(pci_bus_alloc_resource);
305EXPORT_SYMBOL_GPL(pci_bus_add_device);
306EXPORT_SYMBOL(pci_bus_add_devices);
307EXPORT_SYMBOL(pci_enable_bridges);
308