xref: /openbmc/linux/drivers/pci/bus.c (revision 7b6d864b)
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 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
162 
163 /**
164  * pci_bus_add_device - start driver for a single device
165  * @dev: device to add
166  *
167  * This adds add sysfs entries and start device drivers
168  */
169 int pci_bus_add_device(struct pci_dev *dev)
170 {
171 	int retval;
172 
173 	/*
174 	 * Can not put in pci_device_add yet because resources
175 	 * are not assigned yet for some devices.
176 	 */
177 	pci_fixup_device(pci_fixup_final, dev);
178 	pci_create_sysfs_dev_files(dev);
179 
180 	dev->match_driver = true;
181 	retval = device_attach(&dev->dev);
182 	WARN_ON(retval < 0);
183 
184 	dev->is_added = 1;
185 
186 	return 0;
187 }
188 
189 /**
190  * pci_bus_add_devices - start driver for PCI devices
191  * @bus: bus to check for new devices
192  *
193  * Start driver for PCI devices and add some sysfs entries.
194  */
195 void pci_bus_add_devices(const struct pci_bus *bus)
196 {
197 	struct pci_dev *dev;
198 	struct pci_bus *child;
199 	int retval;
200 
201 	list_for_each_entry(dev, &bus->devices, bus_list) {
202 		/* Skip already-added devices */
203 		if (dev->is_added)
204 			continue;
205 		retval = pci_bus_add_device(dev);
206 		if (retval)
207 			dev_err(&dev->dev, "Error adding device (%d)\n",
208 				retval);
209 	}
210 
211 	list_for_each_entry(dev, &bus->devices, bus_list) {
212 		BUG_ON(!dev->is_added);
213 		child = dev->subordinate;
214 		if (child)
215 			pci_bus_add_devices(child);
216 	}
217 }
218 
219 void pci_enable_bridges(struct pci_bus *bus)
220 {
221 	struct pci_dev *dev;
222 	int retval;
223 
224 	list_for_each_entry(dev, &bus->devices, bus_list) {
225 		if (dev->subordinate) {
226 			if (!pci_is_enabled(dev)) {
227 				retval = pci_enable_device(dev);
228 				if (retval)
229 					dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
230 				pci_set_master(dev);
231 			}
232 			pci_enable_bridges(dev->subordinate);
233 		}
234 	}
235 }
236 
237 /** pci_walk_bus - walk devices on/under bus, calling callback.
238  *  @top      bus whose devices should be walked
239  *  @cb       callback to be called for each device found
240  *  @userdata arbitrary pointer to be passed to callback.
241  *
242  *  Walk the given bus, including any bridged devices
243  *  on buses under this bus.  Call the provided callback
244  *  on each device found.
245  *
246  *  We check the return of @cb each time. If it returns anything
247  *  other than 0, we break out.
248  *
249  */
250 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
251 		  void *userdata)
252 {
253 	struct pci_dev *dev;
254 	struct pci_bus *bus;
255 	struct list_head *next;
256 	int retval;
257 
258 	bus = top;
259 	down_read(&pci_bus_sem);
260 	next = top->devices.next;
261 	for (;;) {
262 		if (next == &bus->devices) {
263 			/* end of this bus, go up or finish */
264 			if (bus == top)
265 				break;
266 			next = bus->self->bus_list.next;
267 			bus = bus->self->bus;
268 			continue;
269 		}
270 		dev = list_entry(next, struct pci_dev, bus_list);
271 		if (dev->subordinate) {
272 			/* this is a pci-pci bridge, do its devices next */
273 			next = dev->subordinate->devices.next;
274 			bus = dev->subordinate;
275 		} else
276 			next = dev->bus_list.next;
277 
278 		retval = cb(dev, userdata);
279 		if (retval)
280 			break;
281 	}
282 	up_read(&pci_bus_sem);
283 }
284 EXPORT_SYMBOL_GPL(pci_walk_bus);
285 
286 struct pci_bus *pci_bus_get(struct pci_bus *bus)
287 {
288 	if (bus)
289 		get_device(&bus->dev);
290 	return bus;
291 }
292 EXPORT_SYMBOL(pci_bus_get);
293 
294 void pci_bus_put(struct pci_bus *bus)
295 {
296 	if (bus)
297 		put_device(&bus->dev);
298 }
299 EXPORT_SYMBOL(pci_bus_put);
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