• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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