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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
21void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
22 unsigned int flags)
23{
24 struct pci_bus_resource *bus_res;
25
26 bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
27 if (!bus_res) {
28 dev_err(&bus->dev, "can't add %pR resource\n", res);
29 return;
30 }
31
32 bus_res->res = res;
33 bus_res->flags = flags;
34 list_add_tail(&bus_res->list, &bus->resources);
35}
36
37struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
38{
39 struct pci_bus_resource *bus_res;
40
41 if (n < PCI_BRIDGE_RESOURCE_NUM)
42 return bus->resource[n];
43
44 n -= PCI_BRIDGE_RESOURCE_NUM;
45 list_for_each_entry(bus_res, &bus->resources, list) {
46 if (n-- == 0)
47 return bus_res->res;
48 }
49 return NULL;
50}
51EXPORT_SYMBOL_GPL(pci_bus_resource_n);
52
53void pci_bus_remove_resources(struct pci_bus *bus)
54{
55 struct pci_bus_resource *bus_res, *tmp;
56 int i;
57
58 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
59 bus->resource[i] = NULL;
60
61 list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
62 list_del(&bus_res->list);
63 kfree(bus_res);
64 }
65}
66
67/**
68 * pci_bus_alloc_resource - allocate a resource from a parent bus
69 * @bus: PCI bus
70 * @res: resource to allocate
71 * @size: size of resource to allocate
72 * @align: alignment of resource to allocate
73 * @min: minimum /proc/iomem address to allocate
74 * @type_mask: IORESOURCE_* type flags
75 * @alignf: resource alignment function
76 * @alignf_data: data argument for resource alignment function
77 *
78 * Given the PCI bus a device resides on, the size, minimum address,
79 * alignment and type, try to find an acceptable resource allocation
80 * for a specific device resource.
81 */
82int
83pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
84 resource_size_t size, resource_size_t align,
85 resource_size_t min, unsigned int type_mask,
86 resource_size_t (*alignf)(void *,
87 const struct resource *,
88 resource_size_t,
89 resource_size_t),
90 void *alignf_data)
91{
92 int i, ret = -ENOMEM;
93 struct resource *r;
94 resource_size_t max = -1;
95
96 type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
97
98 /* don't allocate too high if the pref mem doesn't support 64bit*/
99 if (!(res->flags & IORESOURCE_MEM_64))
100 max = PCIBIOS_MAX_MEM_32;
101
102 pci_bus_for_each_resource(bus, r, i) {
103 if (!r)
104 continue;
105
106 /* type_mask must match */
107 if ((res->flags ^ r->flags) & type_mask)
108 continue;
109
110 /* We cannot allocate a non-prefetching resource
111 from a pre-fetching area */
112 if ((r->flags & IORESOURCE_PREFETCH) &&
113 !(res->flags & IORESOURCE_PREFETCH))
114 continue;
115
116 /* Ok, try it out.. */
117 ret = allocate_resource(r, res, size,
118 r->start ? : min,
119 max, align,
120 alignf, alignf_data);
121 if (ret == 0)
122 break;
123 }
124 return ret;
125}
126
127/**
128 * pci_bus_add_device - add a single device
129 * @dev: device to add
130 *
131 * This adds a single pci device to the global
132 * device list and adds sysfs and procfs entries
133 */
134int pci_bus_add_device(struct pci_dev *dev)
135{
136 int retval;
137 retval = device_add(&dev->dev);
138 if (retval)
139 return retval;
140
141 dev->is_added = 1;
142 pci_proc_attach_device(dev);
143 pci_create_sysfs_dev_files(dev);
144 return 0;
145}
146
147/**
148 * pci_bus_add_child - add a child bus
149 * @bus: bus to add
150 *
151 * This adds sysfs entries for a single bus
152 */
153int pci_bus_add_child(struct pci_bus *bus)
154{
155 int retval;
156
157 if (bus->bridge)
158 bus->dev.parent = bus->bridge;
159
160 retval = device_register(&bus->dev);
161 if (retval)
162 return retval;
163
164 bus->is_added = 1;
165
166 /* Create legacy_io and legacy_mem files for this bus */
167 pci_create_legacy_files(bus);
168
169 return retval;
170}
171
172/**
173 * pci_bus_add_devices - insert newly discovered PCI devices
174 * @bus: bus to check for new devices
175 *
176 * Add newly discovered PCI devices (which are on the bus->devices
177 * list) to the global PCI device list, add the sysfs and procfs
178 * entries. Where a bridge is found, add the discovered bus to
179 * the parents list of child buses, and recurse (breadth-first
180 * to be compatible with 2.4)
181 *
182 * Call hotplug for each new devices.
183 */
184void pci_bus_add_devices(const struct pci_bus *bus)
185{
186 struct pci_dev *dev;
187 struct pci_bus *child;
188 int retval;
189
190 list_for_each_entry(dev, &bus->devices, bus_list) {
191 /* Skip already-added devices */
192 if (dev->is_added)
193 continue;
194 retval = pci_bus_add_device(dev);
195 if (retval)
196 dev_err(&dev->dev, "Error adding device, continuing\n");
197 }
198
199 list_for_each_entry(dev, &bus->devices, bus_list) {
200 BUG_ON(!dev->is_added);
201
202 child = dev->subordinate;
203 /*
204 * If there is an unattached subordinate bus, attach
205 * it and then scan for unattached PCI devices.
206 */
207 if (!child)
208 continue;
209 if (list_empty(&child->node)) {
210 down_write(&pci_bus_sem);
211 list_add_tail(&child->node, &dev->bus->children);
212 up_write(&pci_bus_sem);
213 }
214 pci_bus_add_devices(child);
215
216 /*
217 * register the bus with sysfs as the parent is now
218 * properly registered.
219 */
220 if (child->is_added)
221 continue;
222 retval = pci_bus_add_child(child);
223 if (retval)
224 dev_err(&dev->dev, "Error adding bus, continuing\n");
225 }
226}
227
228void pci_enable_bridges(struct pci_bus *bus)
229{
230 struct pci_dev *dev;
231 int retval;
232
233 list_for_each_entry(dev, &bus->devices, bus_list) {
234 if (dev->subordinate) {
235 if (!pci_is_enabled(dev)) {
236 retval = pci_enable_device(dev);
237 if (retval)
238 dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
239 pci_set_master(dev);
240 }
241 pci_enable_bridges(dev->subordinate);
242 }
243 }
244}
245
246/** pci_walk_bus - walk devices on/under bus, calling callback.
247 * @top bus whose devices should be walked
248 * @cb callback to be called for each device found
249 * @userdata arbitrary pointer to be passed to callback.
250 *
251 * Walk the given bus, including any bridged devices
252 * on buses under this bus. Call the provided callback
253 * on each device found.
254 *
255 * We check the return of @cb each time. If it returns anything
256 * other than 0, we break out.
257 *
258 */
259void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
260 void *userdata)
261{
262 struct pci_dev *dev;
263 struct pci_bus *bus;
264 struct list_head *next;
265 int retval;
266
267 bus = top;
268 down_read(&pci_bus_sem);
269 next = top->devices.next;
270 for (;;) {
271 if (next == &bus->devices) {
272 /* end of this bus, go up or finish */
273 if (bus == top)
274 break;
275 next = bus->self->bus_list.next;
276 bus = bus->self->bus;
277 continue;
278 }
279 dev = list_entry(next, struct pci_dev, bus_list);
280 if (dev->subordinate) {
281 /* this is a pci-pci bridge, do its devices next */
282 next = dev->subordinate->devices.next;
283 bus = dev->subordinate;
284 } else
285 next = dev->bus_list.next;
286
287 /* Run device routines with the device locked */
288 device_lock(&dev->dev);
289 retval = cb(dev, userdata);
290 device_unlock(&dev->dev);
291 if (retval)
292 break;
293 }
294 up_read(&pci_bus_sem);
295}
296EXPORT_SYMBOL_GPL(pci_walk_bus);
297
298EXPORT_SYMBOL(pci_bus_alloc_resource);
299EXPORT_SYMBOL_GPL(pci_bus_add_device);
300EXPORT_SYMBOL(pci_bus_add_devices);
301EXPORT_SYMBOL(pci_enable_bridges);
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
19void 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}
33EXPORT_SYMBOL(pci_add_resource_offset);
34
35void pci_add_resource(struct list_head *resources, struct resource *res)
36{
37 pci_add_resource_offset(resources, res, 0);
38}
39EXPORT_SYMBOL(pci_add_resource);
40
41void pci_free_resource_list(struct list_head *resources)
42{
43 resource_list_free(resources);
44}
45EXPORT_SYMBOL(pci_free_resource_list);
46
47void 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
63struct 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}
77EXPORT_SYMBOL_GPL(pci_bus_resource_n);
78
79void 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
93int 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}
120EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources);
121
122static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
123#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
124static struct pci_bus_region pci_64_bit = {0,
125 (pci_bus_addr_t) 0xffffffffffffffffULL};
126static 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 */
136static 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
154static 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 /* Don't bother if available space isn't large enough */
201 if (size > max - min_used + 1)
202 continue;
203
204 /* Ok, try it out.. */
205 ret = allocate_resource(r, res, size, min_used, max,
206 align, alignf, alignf_data);
207 if (ret == 0)
208 return 0;
209 }
210 return -ENOMEM;
211}
212
213/**
214 * pci_bus_alloc_resource - allocate a resource from a parent bus
215 * @bus: PCI bus
216 * @res: resource to allocate
217 * @size: size of resource to allocate
218 * @align: alignment of resource to allocate
219 * @min: minimum /proc/iomem address to allocate
220 * @type_mask: IORESOURCE_* type flags
221 * @alignf: resource alignment function
222 * @alignf_data: data argument for resource alignment function
223 *
224 * Given the PCI bus a device resides on, the size, minimum address,
225 * alignment and type, try to find an acceptable resource allocation
226 * for a specific device resource.
227 */
228int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
229 resource_size_t size, resource_size_t align,
230 resource_size_t min, unsigned long type_mask,
231 resource_size_t (*alignf)(void *,
232 const struct resource *,
233 resource_size_t,
234 resource_size_t),
235 void *alignf_data)
236{
237#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
238 int rc;
239
240 if (res->flags & IORESOURCE_MEM_64) {
241 rc = pci_bus_alloc_from_region(bus, res, size, align, min,
242 type_mask, alignf, alignf_data,
243 &pci_high);
244 if (rc == 0)
245 return 0;
246
247 return pci_bus_alloc_from_region(bus, res, size, align, min,
248 type_mask, alignf, alignf_data,
249 &pci_64_bit);
250 }
251#endif
252
253 return pci_bus_alloc_from_region(bus, res, size, align, min,
254 type_mask, alignf, alignf_data,
255 &pci_32_bit);
256}
257EXPORT_SYMBOL(pci_bus_alloc_resource);
258
259/*
260 * The @idx resource of @dev should be a PCI-PCI bridge window. If this
261 * resource fits inside a window of an upstream bridge, do nothing. If it
262 * overlaps an upstream window but extends outside it, clip the resource so
263 * it fits completely inside.
264 */
265bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
266{
267 struct pci_bus *bus = dev->bus;
268 struct resource *res = &dev->resource[idx];
269 struct resource orig_res = *res;
270 struct resource *r;
271 int i;
272
273 pci_bus_for_each_resource(bus, r, i) {
274 resource_size_t start, end;
275
276 if (!r)
277 continue;
278
279 if (resource_type(res) != resource_type(r))
280 continue;
281
282 start = max(r->start, res->start);
283 end = min(r->end, res->end);
284
285 if (start > end)
286 continue; /* no overlap */
287
288 if (res->start == start && res->end == end)
289 return false; /* no change */
290
291 res->start = start;
292 res->end = end;
293 res->flags &= ~IORESOURCE_UNSET;
294 orig_res.flags &= ~IORESOURCE_UNSET;
295 pci_info(dev, "%pR clipped to %pR\n", &orig_res, res);
296
297 return true;
298 }
299
300 return false;
301}
302
303void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
304
305void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
306
307/**
308 * pci_bus_add_device - start driver for a single device
309 * @dev: device to add
310 *
311 * This adds add sysfs entries and start device drivers
312 */
313void pci_bus_add_device(struct pci_dev *dev)
314{
315 int retval;
316
317 /*
318 * Can not put in pci_device_add yet because resources
319 * are not assigned yet for some devices.
320 */
321 pcibios_bus_add_device(dev);
322 pci_fixup_device(pci_fixup_final, dev);
323 pci_create_sysfs_dev_files(dev);
324 pci_proc_attach_device(dev);
325 pci_bridge_d3_update(dev);
326
327 dev->match_driver = true;
328 retval = device_attach(&dev->dev);
329 if (retval < 0 && retval != -EPROBE_DEFER)
330 pci_warn(dev, "device attach failed (%d)\n", retval);
331
332 pci_dev_assign_added(dev, true);
333}
334EXPORT_SYMBOL_GPL(pci_bus_add_device);
335
336/**
337 * pci_bus_add_devices - start driver for PCI devices
338 * @bus: bus to check for new devices
339 *
340 * Start driver for PCI devices and add some sysfs entries.
341 */
342void pci_bus_add_devices(const struct pci_bus *bus)
343{
344 struct pci_dev *dev;
345 struct pci_bus *child;
346
347 list_for_each_entry(dev, &bus->devices, bus_list) {
348 /* Skip already-added devices */
349 if (pci_dev_is_added(dev))
350 continue;
351 pci_bus_add_device(dev);
352 }
353
354 list_for_each_entry(dev, &bus->devices, bus_list) {
355 /* Skip if device attach failed */
356 if (!pci_dev_is_added(dev))
357 continue;
358 child = dev->subordinate;
359 if (child)
360 pci_bus_add_devices(child);
361 }
362}
363EXPORT_SYMBOL(pci_bus_add_devices);
364
365/** pci_walk_bus - walk devices on/under bus, calling callback.
366 * @top bus whose devices should be walked
367 * @cb callback to be called for each device found
368 * @userdata arbitrary pointer to be passed to callback.
369 *
370 * Walk the given bus, including any bridged devices
371 * on buses under this bus. Call the provided callback
372 * on each device found.
373 *
374 * We check the return of @cb each time. If it returns anything
375 * other than 0, we break out.
376 *
377 */
378void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
379 void *userdata)
380{
381 struct pci_dev *dev;
382 struct pci_bus *bus;
383 struct list_head *next;
384 int retval;
385
386 bus = top;
387 down_read(&pci_bus_sem);
388 next = top->devices.next;
389 for (;;) {
390 if (next == &bus->devices) {
391 /* end of this bus, go up or finish */
392 if (bus == top)
393 break;
394 next = bus->self->bus_list.next;
395 bus = bus->self->bus;
396 continue;
397 }
398 dev = list_entry(next, struct pci_dev, bus_list);
399 if (dev->subordinate) {
400 /* this is a pci-pci bridge, do its devices next */
401 next = dev->subordinate->devices.next;
402 bus = dev->subordinate;
403 } else
404 next = dev->bus_list.next;
405
406 retval = cb(dev, userdata);
407 if (retval)
408 break;
409 }
410 up_read(&pci_bus_sem);
411}
412EXPORT_SYMBOL_GPL(pci_walk_bus);
413
414struct pci_bus *pci_bus_get(struct pci_bus *bus)
415{
416 if (bus)
417 get_device(&bus->dev);
418 return bus;
419}
420
421void pci_bus_put(struct pci_bus *bus)
422{
423 if (bus)
424 put_device(&bus->dev);
425}