xref: /openbmc/linux/drivers/pci/bus.c (revision d0b73b48)
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_add_resource_offset(struct list_head *resources, struct resource *res,
22 			     resource_size_t offset)
23 {
24 	struct pci_host_bridge_window *window;
25 
26 	window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL);
27 	if (!window) {
28 		printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
29 		return;
30 	}
31 
32 	window->res = res;
33 	window->offset = offset;
34 	list_add_tail(&window->list, resources);
35 }
36 EXPORT_SYMBOL(pci_add_resource_offset);
37 
38 void pci_add_resource(struct list_head *resources, struct resource *res)
39 {
40 	pci_add_resource_offset(resources, res, 0);
41 }
42 EXPORT_SYMBOL(pci_add_resource);
43 
44 void pci_free_resource_list(struct list_head *resources)
45 {
46 	struct pci_host_bridge_window *window, *tmp;
47 
48 	list_for_each_entry_safe(window, tmp, resources, list) {
49 		list_del(&window->list);
50 		kfree(window);
51 	}
52 }
53 EXPORT_SYMBOL(pci_free_resource_list);
54 
55 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
56 			  unsigned int flags)
57 {
58 	struct pci_bus_resource *bus_res;
59 
60 	bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
61 	if (!bus_res) {
62 		dev_err(&bus->dev, "can't add %pR resource\n", res);
63 		return;
64 	}
65 
66 	bus_res->res = res;
67 	bus_res->flags = flags;
68 	list_add_tail(&bus_res->list, &bus->resources);
69 }
70 
71 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
72 {
73 	struct pci_bus_resource *bus_res;
74 
75 	if (n < PCI_BRIDGE_RESOURCE_NUM)
76 		return bus->resource[n];
77 
78 	n -= PCI_BRIDGE_RESOURCE_NUM;
79 	list_for_each_entry(bus_res, &bus->resources, list) {
80 		if (n-- == 0)
81 			return bus_res->res;
82 	}
83 	return NULL;
84 }
85 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
86 
87 void pci_bus_remove_resources(struct pci_bus *bus)
88 {
89 	int i;
90 	struct pci_bus_resource *bus_res, *tmp;
91 
92 	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
93 		bus->resource[i] = NULL;
94 
95 	list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
96 		list_del(&bus_res->list);
97 		kfree(bus_res);
98 	}
99 }
100 
101 /**
102  * pci_bus_alloc_resource - allocate a resource from a parent bus
103  * @bus: PCI bus
104  * @res: resource to allocate
105  * @size: size of resource to allocate
106  * @align: alignment of resource to allocate
107  * @min: minimum /proc/iomem address to allocate
108  * @type_mask: IORESOURCE_* type flags
109  * @alignf: resource alignment function
110  * @alignf_data: data argument for resource alignment function
111  *
112  * Given the PCI bus a device resides on, the size, minimum address,
113  * alignment and type, try to find an acceptable resource allocation
114  * for a specific device resource.
115  */
116 int
117 pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
118 		resource_size_t size, resource_size_t align,
119 		resource_size_t min, unsigned int type_mask,
120 		resource_size_t (*alignf)(void *,
121 					  const struct resource *,
122 					  resource_size_t,
123 					  resource_size_t),
124 		void *alignf_data)
125 {
126 	int i, ret = -ENOMEM;
127 	struct resource *r;
128 	resource_size_t max = -1;
129 
130 	type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
131 
132 	/* don't allocate too high if the pref mem doesn't support 64bit*/
133 	if (!(res->flags & IORESOURCE_MEM_64))
134 		max = PCIBIOS_MAX_MEM_32;
135 
136 	pci_bus_for_each_resource(bus, r, i) {
137 		if (!r)
138 			continue;
139 
140 		/* type_mask must match */
141 		if ((res->flags ^ r->flags) & type_mask)
142 			continue;
143 
144 		/* We cannot allocate a non-prefetching resource
145 		   from a pre-fetching area */
146 		if ((r->flags & IORESOURCE_PREFETCH) &&
147 		    !(res->flags & IORESOURCE_PREFETCH))
148 			continue;
149 
150 		/* Ok, try it out.. */
151 		ret = allocate_resource(r, res, size,
152 					r->start ? : min,
153 					max, align,
154 					alignf, alignf_data);
155 		if (ret == 0)
156 			break;
157 	}
158 	return ret;
159 }
160 
161 /**
162  * pci_bus_add_device - add a single device
163  * @dev: device to add
164  *
165  * This adds a single pci device to the global
166  * device list and adds sysfs and procfs entries
167  */
168 int pci_bus_add_device(struct pci_dev *dev)
169 {
170 	int retval;
171 
172 	pci_fixup_device(pci_fixup_final, dev);
173 
174 	retval = pcibios_add_device(dev);
175 	if (retval)
176 		return retval;
177 
178 	retval = device_add(&dev->dev);
179 	if (retval)
180 		return retval;
181 
182 	dev->is_added = 1;
183 	pci_proc_attach_device(dev);
184 	pci_create_sysfs_dev_files(dev);
185 	return 0;
186 }
187 
188 /**
189  * pci_bus_add_child - add a child bus
190  * @bus: bus to add
191  *
192  * This adds sysfs entries for a single bus
193  */
194 int pci_bus_add_child(struct pci_bus *bus)
195 {
196 	int retval;
197 
198 	if (bus->bridge)
199 		bus->dev.parent = bus->bridge;
200 
201 	retval = device_register(&bus->dev);
202 	if (retval)
203 		return retval;
204 
205 	bus->is_added = 1;
206 
207 	/* Create legacy_io and legacy_mem files for this bus */
208 	pci_create_legacy_files(bus);
209 
210 	return retval;
211 }
212 
213 /**
214  * pci_bus_add_devices - insert newly discovered PCI devices
215  * @bus: bus to check for new devices
216  *
217  * Add newly discovered PCI devices (which are on the bus->devices
218  * list) to the global PCI device list, add the sysfs and procfs
219  * entries.  Where a bridge is found, add the discovered bus to
220  * the parents list of child buses, and recurse (breadth-first
221  * to be compatible with 2.4)
222  *
223  * Call hotplug for each new devices.
224  */
225 void pci_bus_add_devices(const struct pci_bus *bus)
226 {
227 	struct pci_dev *dev;
228 	struct pci_bus *child;
229 	int retval;
230 
231 	list_for_each_entry(dev, &bus->devices, bus_list) {
232 		/* Skip already-added devices */
233 		if (dev->is_added)
234 			continue;
235 		retval = pci_bus_add_device(dev);
236 		if (retval)
237 			dev_err(&dev->dev, "Error adding device, continuing\n");
238 	}
239 
240 	list_for_each_entry(dev, &bus->devices, bus_list) {
241 		BUG_ON(!dev->is_added);
242 
243 		child = dev->subordinate;
244 		/*
245 		 * If there is an unattached subordinate bus, attach
246 		 * it and then scan for unattached PCI devices.
247 		 */
248 		if (!child)
249 			continue;
250 		if (list_empty(&child->node)) {
251 			down_write(&pci_bus_sem);
252 			list_add_tail(&child->node, &dev->bus->children);
253 			up_write(&pci_bus_sem);
254 		}
255 		pci_bus_add_devices(child);
256 
257 		/*
258 		 * register the bus with sysfs as the parent is now
259 		 * properly registered.
260 		 */
261 		if (child->is_added)
262 			continue;
263 		retval = pci_bus_add_child(child);
264 		if (retval)
265 			dev_err(&dev->dev, "Error adding bus, continuing\n");
266 	}
267 }
268 
269 void pci_enable_bridges(struct pci_bus *bus)
270 {
271 	struct pci_dev *dev;
272 	int retval;
273 
274 	list_for_each_entry(dev, &bus->devices, bus_list) {
275 		if (dev->subordinate) {
276 			if (!pci_is_enabled(dev)) {
277 				retval = pci_enable_device(dev);
278 				if (retval)
279 					dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
280 				pci_set_master(dev);
281 			}
282 			pci_enable_bridges(dev->subordinate);
283 		}
284 	}
285 }
286 
287 /** pci_walk_bus - walk devices on/under bus, calling callback.
288  *  @top      bus whose devices should be walked
289  *  @cb       callback to be called for each device found
290  *  @userdata arbitrary pointer to be passed to callback.
291  *
292  *  Walk the given bus, including any bridged devices
293  *  on buses under this bus.  Call the provided callback
294  *  on each device found.
295  *
296  *  We check the return of @cb each time. If it returns anything
297  *  other than 0, we break out.
298  *
299  */
300 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
301 		  void *userdata)
302 {
303 	struct pci_dev *dev;
304 	struct pci_bus *bus;
305 	struct list_head *next;
306 	int retval;
307 
308 	bus = top;
309 	down_read(&pci_bus_sem);
310 	next = top->devices.next;
311 	for (;;) {
312 		if (next == &bus->devices) {
313 			/* end of this bus, go up or finish */
314 			if (bus == top)
315 				break;
316 			next = bus->self->bus_list.next;
317 			bus = bus->self->bus;
318 			continue;
319 		}
320 		dev = list_entry(next, struct pci_dev, bus_list);
321 		if (dev->subordinate) {
322 			/* this is a pci-pci bridge, do its devices next */
323 			next = dev->subordinate->devices.next;
324 			bus = dev->subordinate;
325 		} else
326 			next = dev->bus_list.next;
327 
328 		retval = cb(dev, userdata);
329 		if (retval)
330 			break;
331 	}
332 	up_read(&pci_bus_sem);
333 }
334 EXPORT_SYMBOL_GPL(pci_walk_bus);
335 
336 EXPORT_SYMBOL(pci_bus_alloc_resource);
337 EXPORT_SYMBOL_GPL(pci_bus_add_device);
338 EXPORT_SYMBOL(pci_bus_add_devices);
339 EXPORT_SYMBOL(pci_enable_bridges);
340