xref: /linux/drivers/pci/bus.c (revision 47902f3611b392209e2a412bf7ec02dca95e666d)
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 
21 void 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 
37 struct 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 }
51 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
52 
53 void 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] = 0;
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  */
82 int
83 pci_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  */
134 int 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  */
153 int 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  */
190 void 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 
234 void 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 				pci_set_master(dev);
244 			}
245 			pci_enable_bridges(dev->subordinate);
246 		}
247 	}
248 }
249 
250 /** pci_walk_bus - walk devices on/under bus, calling callback.
251  *  @top      bus whose devices should be walked
252  *  @cb       callback to be called for each device found
253  *  @userdata arbitrary pointer to be passed to callback.
254  *
255  *  Walk the given bus, including any bridged devices
256  *  on buses under this bus.  Call the provided callback
257  *  on each device found.
258  *
259  *  We check the return of @cb each time. If it returns anything
260  *  other than 0, we break out.
261  *
262  */
263 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
264 		  void *userdata)
265 {
266 	struct pci_dev *dev;
267 	struct pci_bus *bus;
268 	struct list_head *next;
269 	int retval;
270 
271 	bus = top;
272 	down_read(&pci_bus_sem);
273 	next = top->devices.next;
274 	for (;;) {
275 		if (next == &bus->devices) {
276 			/* end of this bus, go up or finish */
277 			if (bus == top)
278 				break;
279 			next = bus->self->bus_list.next;
280 			bus = bus->self->bus;
281 			continue;
282 		}
283 		dev = list_entry(next, struct pci_dev, bus_list);
284 		if (dev->subordinate) {
285 			/* this is a pci-pci bridge, do its devices next */
286 			next = dev->subordinate->devices.next;
287 			bus = dev->subordinate;
288 		} else
289 			next = dev->bus_list.next;
290 
291 		/* Run device routines with the device locked */
292 		device_lock(&dev->dev);
293 		retval = cb(dev, userdata);
294 		device_unlock(&dev->dev);
295 		if (retval)
296 			break;
297 	}
298 	up_read(&pci_bus_sem);
299 }
300 
301 EXPORT_SYMBOL(pci_bus_alloc_resource);
302 EXPORT_SYMBOL_GPL(pci_bus_add_device);
303 EXPORT_SYMBOL(pci_bus_add_devices);
304 EXPORT_SYMBOL(pci_enable_bridges);
305