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/slab.h>
17
18 #include "pci.h"
19
pci_add_resource_offset(struct list_head * resources,struct resource * res,resource_size_t offset)20 void pci_add_resource_offset(struct list_head *resources, struct resource *res,
21 resource_size_t offset)
22 {
23 struct pci_host_bridge_window *window;
24
25 window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL);
26 if (!window) {
27 printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
28 return;
29 }
30
31 window->res = res;
32 window->offset = offset;
33 list_add_tail(&window->list, resources);
34 }
35 EXPORT_SYMBOL(pci_add_resource_offset);
36
pci_add_resource(struct list_head * resources,struct resource * res)37 void pci_add_resource(struct list_head *resources, struct resource *res)
38 {
39 pci_add_resource_offset(resources, res, 0);
40 }
41 EXPORT_SYMBOL(pci_add_resource);
42
pci_free_resource_list(struct list_head * resources)43 void pci_free_resource_list(struct list_head *resources)
44 {
45 struct pci_host_bridge_window *window, *tmp;
46
47 list_for_each_entry_safe(window, tmp, resources, list) {
48 list_del(&window->list);
49 kfree(window);
50 }
51 }
52 EXPORT_SYMBOL(pci_free_resource_list);
53
pci_bus_add_resource(struct pci_bus * bus,struct resource * res,unsigned int flags)54 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
55 unsigned int flags)
56 {
57 struct pci_bus_resource *bus_res;
58
59 bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
60 if (!bus_res) {
61 dev_err(&bus->dev, "can't add %pR resource\n", res);
62 return;
63 }
64
65 bus_res->res = res;
66 bus_res->flags = flags;
67 list_add_tail(&bus_res->list, &bus->resources);
68 }
69
pci_bus_resource_n(const struct pci_bus * bus,int n)70 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
71 {
72 struct pci_bus_resource *bus_res;
73
74 if (n < PCI_BRIDGE_RESOURCE_NUM)
75 return bus->resource[n];
76
77 n -= PCI_BRIDGE_RESOURCE_NUM;
78 list_for_each_entry(bus_res, &bus->resources, list) {
79 if (n-- == 0)
80 return bus_res->res;
81 }
82 return NULL;
83 }
84 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
85
pci_bus_remove_resources(struct pci_bus * bus)86 void pci_bus_remove_resources(struct pci_bus *bus)
87 {
88 int i;
89 struct pci_bus_resource *bus_res, *tmp;
90
91 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
92 bus->resource[i] = NULL;
93
94 list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
95 list_del(&bus_res->list);
96 kfree(bus_res);
97 }
98 }
99
100 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
101 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
102 static struct pci_bus_region pci_64_bit = {0,
103 (dma_addr_t) 0xffffffffffffffffULL};
104 static struct pci_bus_region pci_high = {(dma_addr_t) 0x100000000ULL,
105 (dma_addr_t) 0xffffffffffffffffULL};
106 #endif
107
108 /*
109 * @res contains CPU addresses. Clip it so the corresponding bus addresses
110 * on @bus are entirely within @region. This is used to control the bus
111 * addresses of resources we allocate, e.g., we may need a resource that
112 * can be mapped by a 32-bit BAR.
113 */
pci_clip_resource_to_region(struct pci_bus * bus,struct resource * res,struct pci_bus_region * region)114 static void pci_clip_resource_to_region(struct pci_bus *bus,
115 struct resource *res,
116 struct pci_bus_region *region)
117 {
118 struct pci_bus_region r;
119
120 pcibios_resource_to_bus(bus, &r, res);
121 if (r.start < region->start)
122 r.start = region->start;
123 if (r.end > region->end)
124 r.end = region->end;
125
126 if (r.end < r.start)
127 res->end = res->start - 1;
128 else
129 pcibios_bus_to_resource(bus, res, &r);
130 }
131
pci_bus_alloc_from_region(struct pci_bus * bus,struct resource * res,resource_size_t size,resource_size_t align,resource_size_t min,unsigned long type_mask,resource_size_t (* alignf)(void *,const struct resource *,resource_size_t,resource_size_t),void * alignf_data,struct pci_bus_region * region)132 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
133 resource_size_t size, resource_size_t align,
134 resource_size_t min, unsigned long type_mask,
135 resource_size_t (*alignf)(void *,
136 const struct resource *,
137 resource_size_t,
138 resource_size_t),
139 void *alignf_data,
140 struct pci_bus_region *region)
141 {
142 int i, ret;
143 struct resource *r, avail;
144 resource_size_t max;
145
146 type_mask |= IORESOURCE_TYPE_BITS;
147
148 pci_bus_for_each_resource(bus, r, i) {
149 resource_size_t min_used = min;
150
151 if (!r)
152 continue;
153
154 /* type_mask must match */
155 if ((res->flags ^ r->flags) & type_mask)
156 continue;
157
158 /* We cannot allocate a non-prefetching resource
159 from a pre-fetching area */
160 if ((r->flags & IORESOURCE_PREFETCH) &&
161 !(res->flags & IORESOURCE_PREFETCH))
162 continue;
163
164 avail = *r;
165 pci_clip_resource_to_region(bus, &avail, region);
166
167 /*
168 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
169 * protect badly documented motherboard resources, but if
170 * this is an already-configured bridge window, its start
171 * overrides "min".
172 */
173 if (avail.start)
174 min_used = avail.start;
175
176 max = avail.end;
177
178 /* Ok, try it out.. */
179 ret = allocate_resource(r, res, size, min_used, max,
180 align, alignf, alignf_data);
181 if (ret == 0)
182 return 0;
183 }
184 return -ENOMEM;
185 }
186
187 /**
188 * pci_bus_alloc_resource - allocate a resource from a parent bus
189 * @bus: PCI bus
190 * @res: resource to allocate
191 * @size: size of resource to allocate
192 * @align: alignment of resource to allocate
193 * @min: minimum /proc/iomem address to allocate
194 * @type_mask: IORESOURCE_* type flags
195 * @alignf: resource alignment function
196 * @alignf_data: data argument for resource alignment function
197 *
198 * Given the PCI bus a device resides on, the size, minimum address,
199 * alignment and type, try to find an acceptable resource allocation
200 * for a specific device resource.
201 */
pci_bus_alloc_resource(struct pci_bus * bus,struct resource * res,resource_size_t size,resource_size_t align,resource_size_t min,unsigned long type_mask,resource_size_t (* alignf)(void *,const struct resource *,resource_size_t,resource_size_t),void * alignf_data)202 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
203 resource_size_t size, resource_size_t align,
204 resource_size_t min, unsigned long type_mask,
205 resource_size_t (*alignf)(void *,
206 const struct resource *,
207 resource_size_t,
208 resource_size_t),
209 void *alignf_data)
210 {
211 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
212 int rc;
213
214 if (res->flags & IORESOURCE_MEM_64) {
215 rc = pci_bus_alloc_from_region(bus, res, size, align, min,
216 type_mask, alignf, alignf_data,
217 &pci_high);
218 if (rc == 0)
219 return 0;
220
221 return pci_bus_alloc_from_region(bus, res, size, align, min,
222 type_mask, alignf, alignf_data,
223 &pci_64_bit);
224 }
225 #endif
226
227 return pci_bus_alloc_from_region(bus, res, size, align, min,
228 type_mask, alignf, alignf_data,
229 &pci_32_bit);
230 }
231 EXPORT_SYMBOL(pci_bus_alloc_resource);
232
233 /*
234 * The @idx resource of @dev should be a PCI-PCI bridge window. If this
235 * resource fits inside a window of an upstream bridge, do nothing. If it
236 * overlaps an upstream window but extends outside it, clip the resource so
237 * it fits completely inside.
238 */
pci_bus_clip_resource(struct pci_dev * dev,int idx)239 bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
240 {
241 struct pci_bus *bus = dev->bus;
242 struct resource *res = &dev->resource[idx];
243 struct resource orig_res = *res;
244 struct resource *r;
245 int i;
246
247 pci_bus_for_each_resource(bus, r, i) {
248 resource_size_t start, end;
249
250 if (!r)
251 continue;
252
253 if (resource_type(res) != resource_type(r))
254 continue;
255
256 start = max(r->start, res->start);
257 end = min(r->end, res->end);
258
259 if (start > end)
260 continue; /* no overlap */
261
262 if (res->start == start && res->end == end)
263 return false; /* no change */
264
265 res->start = start;
266 res->end = end;
267 dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n",
268 &orig_res, res);
269
270 return true;
271 }
272
273 return false;
274 }
275
pcibios_resource_survey_bus(struct pci_bus * bus)276 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
277
278 /**
279 * pci_bus_add_device - start driver for a single device
280 * @dev: device to add
281 *
282 * This adds add sysfs entries and start device drivers
283 */
pci_bus_add_device(struct pci_dev * dev)284 void pci_bus_add_device(struct pci_dev *dev)
285 {
286 int retval;
287
288 /*
289 * Can not put in pci_device_add yet because resources
290 * are not assigned yet for some devices.
291 */
292 pci_fixup_device(pci_fixup_final, dev);
293 pci_create_sysfs_dev_files(dev);
294 pci_proc_attach_device(dev);
295
296 dev->match_driver = true;
297 retval = device_attach(&dev->dev);
298 WARN_ON(retval < 0);
299
300 dev->is_added = 1;
301 }
302 EXPORT_SYMBOL_GPL(pci_bus_add_device);
303
304 /**
305 * pci_bus_add_devices - start driver for PCI devices
306 * @bus: bus to check for new devices
307 *
308 * Start driver for PCI devices and add some sysfs entries.
309 */
pci_bus_add_devices(const struct pci_bus * bus)310 void pci_bus_add_devices(const struct pci_bus *bus)
311 {
312 struct pci_dev *dev;
313 struct pci_bus *child;
314
315 list_for_each_entry(dev, &bus->devices, bus_list) {
316 /* Skip already-added devices */
317 if (dev->is_added)
318 continue;
319 pci_bus_add_device(dev);
320 }
321
322 list_for_each_entry(dev, &bus->devices, bus_list) {
323 BUG_ON(!dev->is_added);
324 child = dev->subordinate;
325 if (child)
326 pci_bus_add_devices(child);
327 }
328 }
329 EXPORT_SYMBOL(pci_bus_add_devices);
330
331 /** pci_walk_bus - walk devices on/under bus, calling callback.
332 * @top bus whose devices should be walked
333 * @cb callback to be called for each device found
334 * @userdata arbitrary pointer to be passed to callback.
335 *
336 * Walk the given bus, including any bridged devices
337 * on buses under this bus. Call the provided callback
338 * on each device found.
339 *
340 * We check the return of @cb each time. If it returns anything
341 * other than 0, we break out.
342 *
343 */
pci_walk_bus(struct pci_bus * top,int (* cb)(struct pci_dev *,void *),void * userdata)344 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
345 void *userdata)
346 {
347 struct pci_dev *dev;
348 struct pci_bus *bus;
349 struct list_head *next;
350 int retval;
351
352 bus = top;
353 down_read(&pci_bus_sem);
354 next = top->devices.next;
355 for (;;) {
356 if (next == &bus->devices) {
357 /* end of this bus, go up or finish */
358 if (bus == top)
359 break;
360 next = bus->self->bus_list.next;
361 bus = bus->self->bus;
362 continue;
363 }
364 dev = list_entry(next, struct pci_dev, bus_list);
365 if (dev->subordinate) {
366 /* this is a pci-pci bridge, do its devices next */
367 next = dev->subordinate->devices.next;
368 bus = dev->subordinate;
369 } else
370 next = dev->bus_list.next;
371
372 retval = cb(dev, userdata);
373 if (retval)
374 break;
375 }
376 up_read(&pci_bus_sem);
377 }
378 EXPORT_SYMBOL_GPL(pci_walk_bus);
379
pci_bus_get(struct pci_bus * bus)380 struct pci_bus *pci_bus_get(struct pci_bus *bus)
381 {
382 if (bus)
383 get_device(&bus->dev);
384 return bus;
385 }
386 EXPORT_SYMBOL(pci_bus_get);
387
pci_bus_put(struct pci_bus * bus)388 void pci_bus_put(struct pci_bus *bus)
389 {
390 if (bus)
391 put_device(&bus->dev);
392 }
393 EXPORT_SYMBOL(pci_bus_put);
394
395