1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * From setup-res.c, by:
4  *	Dave Rusling (david.rusling@reo.mts.dec.com)
5  *	David Mosberger (davidm@cs.arizona.edu)
6  *	David Miller (davem@redhat.com)
7  *	Ivan Kokshaysky (ink@jurassic.park.msu.ru)
8  */
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/pci.h>
12 #include <linux/errno.h>
13 #include <linux/ioport.h>
14 #include <linux/proc_fs.h>
15 #include <linux/slab.h>
16 
17 #include "pci.h"
18 
pci_add_resource_offset(struct list_head * resources,struct resource * res,resource_size_t offset)19 void pci_add_resource_offset(struct list_head *resources, struct resource *res,
20 			     resource_size_t offset)
21 {
22 	struct resource_entry *entry;
23 
24 	entry = resource_list_create_entry(res, 0);
25 	if (!entry) {
26 		pr_err("PCI: can't add host bridge window %pR\n", res);
27 		return;
28 	}
29 
30 	entry->offset = offset;
31 	resource_list_add_tail(entry, resources);
32 }
33 EXPORT_SYMBOL(pci_add_resource_offset);
34 
pci_add_resource(struct list_head * resources,struct resource * res)35 void pci_add_resource(struct list_head *resources, struct resource *res)
36 {
37 	pci_add_resource_offset(resources, res, 0);
38 }
39 EXPORT_SYMBOL(pci_add_resource);
40 
pci_free_resource_list(struct list_head * resources)41 void pci_free_resource_list(struct list_head *resources)
42 {
43 	resource_list_free(resources);
44 }
45 EXPORT_SYMBOL(pci_free_resource_list);
46 
pci_bus_add_resource(struct pci_bus * bus,struct resource * res,unsigned int flags)47 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
48 			  unsigned int flags)
49 {
50 	struct pci_bus_resource *bus_res;
51 
52 	bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
53 	if (!bus_res) {
54 		dev_err(&bus->dev, "can't add %pR resource\n", res);
55 		return;
56 	}
57 
58 	bus_res->res = res;
59 	bus_res->flags = flags;
60 	list_add_tail(&bus_res->list, &bus->resources);
61 }
62 
pci_bus_resource_n(const struct pci_bus * bus,int n)63 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
64 {
65 	struct pci_bus_resource *bus_res;
66 
67 	if (n < PCI_BRIDGE_RESOURCE_NUM)
68 		return bus->resource[n];
69 
70 	n -= PCI_BRIDGE_RESOURCE_NUM;
71 	list_for_each_entry(bus_res, &bus->resources, list) {
72 		if (n-- == 0)
73 			return bus_res->res;
74 	}
75 	return NULL;
76 }
77 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
78 
pci_bus_remove_resources(struct pci_bus * bus)79 void pci_bus_remove_resources(struct pci_bus *bus)
80 {
81 	int i;
82 	struct pci_bus_resource *bus_res, *tmp;
83 
84 	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
85 		bus->resource[i] = NULL;
86 
87 	list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
88 		list_del(&bus_res->list);
89 		kfree(bus_res);
90 	}
91 }
92 
devm_request_pci_bus_resources(struct device * dev,struct list_head * resources)93 int devm_request_pci_bus_resources(struct device *dev,
94 				   struct list_head *resources)
95 {
96 	struct resource_entry *win;
97 	struct resource *parent, *res;
98 	int err;
99 
100 	resource_list_for_each_entry(win, resources) {
101 		res = win->res;
102 		switch (resource_type(res)) {
103 		case IORESOURCE_IO:
104 			parent = &ioport_resource;
105 			break;
106 		case IORESOURCE_MEM:
107 			parent = &iomem_resource;
108 			break;
109 		default:
110 			continue;
111 		}
112 
113 		err = devm_request_resource(dev, parent, res);
114 		if (err)
115 			return err;
116 	}
117 
118 	return 0;
119 }
120 EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources);
121 
122 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
123 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
124 static struct pci_bus_region pci_64_bit = {0,
125 				(pci_bus_addr_t) 0xffffffffffffffffULL};
126 static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
127 				(pci_bus_addr_t) 0xffffffffffffffffULL};
128 #endif
129 
130 /*
131  * @res contains CPU addresses.  Clip it so the corresponding bus addresses
132  * on @bus are entirely within @region.  This is used to control the bus
133  * addresses of resources we allocate, e.g., we may need a resource that
134  * can be mapped by a 32-bit BAR.
135  */
pci_clip_resource_to_region(struct pci_bus * bus,struct resource * res,struct pci_bus_region * region)136 static void pci_clip_resource_to_region(struct pci_bus *bus,
137 					struct resource *res,
138 					struct pci_bus_region *region)
139 {
140 	struct pci_bus_region r;
141 
142 	pcibios_resource_to_bus(bus, &r, res);
143 	if (r.start < region->start)
144 		r.start = region->start;
145 	if (r.end > region->end)
146 		r.end = region->end;
147 
148 	if (r.end < r.start)
149 		res->end = res->start - 1;
150 	else
151 		pcibios_bus_to_resource(bus, res, &r);
152 }
153 
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)154 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
155 		resource_size_t size, resource_size_t align,
156 		resource_size_t min, unsigned long type_mask,
157 		resource_size_t (*alignf)(void *,
158 					  const struct resource *,
159 					  resource_size_t,
160 					  resource_size_t),
161 		void *alignf_data,
162 		struct pci_bus_region *region)
163 {
164 	int i, ret;
165 	struct resource *r, avail;
166 	resource_size_t max;
167 
168 	type_mask |= IORESOURCE_TYPE_BITS;
169 
170 	pci_bus_for_each_resource(bus, r, i) {
171 		resource_size_t min_used = min;
172 
173 		if (!r)
174 			continue;
175 
176 		/* type_mask must match */
177 		if ((res->flags ^ r->flags) & type_mask)
178 			continue;
179 
180 		/* We cannot allocate a non-prefetching resource
181 		   from a pre-fetching area */
182 		if ((r->flags & IORESOURCE_PREFETCH) &&
183 		    !(res->flags & IORESOURCE_PREFETCH))
184 			continue;
185 
186 		avail = *r;
187 		pci_clip_resource_to_region(bus, &avail, region);
188 
189 		/*
190 		 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
191 		 * protect badly documented motherboard resources, but if
192 		 * this is an already-configured bridge window, its start
193 		 * overrides "min".
194 		 */
195 		if (avail.start)
196 			min_used = avail.start;
197 
198 		max = avail.end;
199 
200 		/* Ok, try it out.. */
201 		ret = allocate_resource(r, res, size, min_used, max,
202 					align, alignf, alignf_data);
203 		if (ret == 0)
204 			return 0;
205 	}
206 	return -ENOMEM;
207 }
208 
209 /**
210  * pci_bus_alloc_resource - allocate a resource from a parent bus
211  * @bus: PCI bus
212  * @res: resource to allocate
213  * @size: size of resource to allocate
214  * @align: alignment of resource to allocate
215  * @min: minimum /proc/iomem address to allocate
216  * @type_mask: IORESOURCE_* type flags
217  * @alignf: resource alignment function
218  * @alignf_data: data argument for resource alignment function
219  *
220  * Given the PCI bus a device resides on, the size, minimum address,
221  * alignment and type, try to find an acceptable resource allocation
222  * for a specific device resource.
223  */
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)224 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
225 		resource_size_t size, resource_size_t align,
226 		resource_size_t min, unsigned long type_mask,
227 		resource_size_t (*alignf)(void *,
228 					  const struct resource *,
229 					  resource_size_t,
230 					  resource_size_t),
231 		void *alignf_data)
232 {
233 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
234 	int rc;
235 
236 	if (res->flags & IORESOURCE_MEM_64) {
237 		rc = pci_bus_alloc_from_region(bus, res, size, align, min,
238 					       type_mask, alignf, alignf_data,
239 					       &pci_high);
240 		if (rc == 0)
241 			return 0;
242 
243 		return pci_bus_alloc_from_region(bus, res, size, align, min,
244 						 type_mask, alignf, alignf_data,
245 						 &pci_64_bit);
246 	}
247 #endif
248 
249 	return pci_bus_alloc_from_region(bus, res, size, align, min,
250 					 type_mask, alignf, alignf_data,
251 					 &pci_32_bit);
252 }
253 EXPORT_SYMBOL(pci_bus_alloc_resource);
254 
255 /*
256  * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
257  * resource fits inside a window of an upstream bridge, do nothing.  If it
258  * overlaps an upstream window but extends outside it, clip the resource so
259  * it fits completely inside.
260  */
pci_bus_clip_resource(struct pci_dev * dev,int idx)261 bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
262 {
263 	struct pci_bus *bus = dev->bus;
264 	struct resource *res = &dev->resource[idx];
265 	struct resource orig_res = *res;
266 	struct resource *r;
267 	int i;
268 
269 	pci_bus_for_each_resource(bus, r, i) {
270 		resource_size_t start, end;
271 
272 		if (!r)
273 			continue;
274 
275 		if (resource_type(res) != resource_type(r))
276 			continue;
277 
278 		start = max(r->start, res->start);
279 		end = min(r->end, res->end);
280 
281 		if (start > end)
282 			continue;	/* no overlap */
283 
284 		if (res->start == start && res->end == end)
285 			return false;	/* no change */
286 
287 		res->start = start;
288 		res->end = end;
289 		res->flags &= ~IORESOURCE_UNSET;
290 		orig_res.flags &= ~IORESOURCE_UNSET;
291 		pci_info(dev, "%pR clipped to %pR\n", &orig_res, res);
292 
293 		return true;
294 	}
295 
296 	return false;
297 }
298 
pcibios_resource_survey_bus(struct pci_bus * bus)299 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
300 
pcibios_bus_add_device(struct pci_dev * pdev)301 void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
302 
303 /**
304  * pci_bus_add_device - start driver for a single device
305  * @dev: device to add
306  *
307  * This adds add sysfs entries and start device drivers
308  */
pci_bus_add_device(struct pci_dev * dev)309 void pci_bus_add_device(struct pci_dev *dev)
310 {
311 	int retval;
312 
313 	/*
314 	 * Can not put in pci_device_add yet because resources
315 	 * are not assigned yet for some devices.
316 	 */
317 	pcibios_bus_add_device(dev);
318 	pci_fixup_device(pci_fixup_final, dev);
319 	pci_create_sysfs_dev_files(dev);
320 	pci_proc_attach_device(dev);
321 	pci_bridge_d3_update(dev);
322 
323 	dev->match_driver = true;
324 	retval = device_attach(&dev->dev);
325 	if (retval < 0 && retval != -EPROBE_DEFER)
326 		pci_warn(dev, "device attach failed (%d)\n", retval);
327 
328 	pci_dev_assign_added(dev, true);
329 }
330 EXPORT_SYMBOL_GPL(pci_bus_add_device);
331 
332 /**
333  * pci_bus_add_devices - start driver for PCI devices
334  * @bus: bus to check for new devices
335  *
336  * Start driver for PCI devices and add some sysfs entries.
337  */
pci_bus_add_devices(const struct pci_bus * bus)338 void pci_bus_add_devices(const struct pci_bus *bus)
339 {
340 	struct pci_dev *dev;
341 	struct pci_bus *child;
342 
343 	list_for_each_entry(dev, &bus->devices, bus_list) {
344 		/* Skip already-added devices */
345 		if (pci_dev_is_added(dev))
346 			continue;
347 		pci_bus_add_device(dev);
348 	}
349 
350 	list_for_each_entry(dev, &bus->devices, bus_list) {
351 		/* Skip if device attach failed */
352 		if (!pci_dev_is_added(dev))
353 			continue;
354 		child = dev->subordinate;
355 		if (child)
356 			pci_bus_add_devices(child);
357 	}
358 }
359 EXPORT_SYMBOL(pci_bus_add_devices);
360 
361 /** pci_walk_bus - walk devices on/under bus, calling callback.
362  *  @top      bus whose devices should be walked
363  *  @cb       callback to be called for each device found
364  *  @userdata arbitrary pointer to be passed to callback.
365  *
366  *  Walk the given bus, including any bridged devices
367  *  on buses under this bus.  Call the provided callback
368  *  on each device found.
369  *
370  *  We check the return of @cb each time. If it returns anything
371  *  other than 0, we break out.
372  *
373  */
pci_walk_bus(struct pci_bus * top,int (* cb)(struct pci_dev *,void *),void * userdata)374 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
375 		  void *userdata)
376 {
377 	struct pci_dev *dev;
378 	struct pci_bus *bus;
379 	struct list_head *next;
380 	int retval;
381 
382 	bus = top;
383 	down_read(&pci_bus_sem);
384 	next = top->devices.next;
385 	for (;;) {
386 		if (next == &bus->devices) {
387 			/* end of this bus, go up or finish */
388 			if (bus == top)
389 				break;
390 			next = bus->self->bus_list.next;
391 			bus = bus->self->bus;
392 			continue;
393 		}
394 		dev = list_entry(next, struct pci_dev, bus_list);
395 		if (dev->subordinate) {
396 			/* this is a pci-pci bridge, do its devices next */
397 			next = dev->subordinate->devices.next;
398 			bus = dev->subordinate;
399 		} else
400 			next = dev->bus_list.next;
401 
402 		retval = cb(dev, userdata);
403 		if (retval)
404 			break;
405 	}
406 	up_read(&pci_bus_sem);
407 }
408 EXPORT_SYMBOL_GPL(pci_walk_bus);
409 
pci_bus_get(struct pci_bus * bus)410 struct pci_bus *pci_bus_get(struct pci_bus *bus)
411 {
412 	if (bus)
413 		get_device(&bus->dev);
414 	return bus;
415 }
416 
pci_bus_put(struct pci_bus * bus)417 void pci_bus_put(struct pci_bus *bus)
418 {
419 	if (bus)
420 		put_device(&bus->dev);
421 }
422