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
20void pci_add_resource_offset(struct list_head *resources, struct resource *res,
21			     resource_size_t offset)
22{
23	struct resource_entry *entry;
24
25	entry = resource_list_create_entry(res, 0);
26	if (!entry) {
27		printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
28		return;
29	}
30
31	entry->offset = offset;
32	resource_list_add_tail(entry, resources);
33}
34EXPORT_SYMBOL(pci_add_resource_offset);
35
36void pci_add_resource(struct list_head *resources, struct resource *res)
37{
38	pci_add_resource_offset(resources, res, 0);
39}
40EXPORT_SYMBOL(pci_add_resource);
41
42void pci_free_resource_list(struct list_head *resources)
43{
44	resource_list_free(resources);
45}
46EXPORT_SYMBOL(pci_free_resource_list);
47
48void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
49			  unsigned int flags)
50{
51	struct pci_bus_resource *bus_res;
52
53	bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
54	if (!bus_res) {
55		dev_err(&bus->dev, "can't add %pR resource\n", res);
56		return;
57	}
58
59	bus_res->res = res;
60	bus_res->flags = flags;
61	list_add_tail(&bus_res->list, &bus->resources);
62}
63
64struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
65{
66	struct pci_bus_resource *bus_res;
67
68	if (n < PCI_BRIDGE_RESOURCE_NUM)
69		return bus->resource[n];
70
71	n -= PCI_BRIDGE_RESOURCE_NUM;
72	list_for_each_entry(bus_res, &bus->resources, list) {
73		if (n-- == 0)
74			return bus_res->res;
75	}
76	return NULL;
77}
78EXPORT_SYMBOL_GPL(pci_bus_resource_n);
79
80void pci_bus_remove_resources(struct pci_bus *bus)
81{
82	int i;
83	struct pci_bus_resource *bus_res, *tmp;
84
85	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
86		bus->resource[i] = NULL;
87
88	list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
89		list_del(&bus_res->list);
90		kfree(bus_res);
91	}
92}
93
94static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
95#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
96static struct pci_bus_region pci_64_bit = {0,
97				(pci_bus_addr_t) 0xffffffffffffffffULL};
98static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
99				(pci_bus_addr_t) 0xffffffffffffffffULL};
100#endif
101
102/*
103 * @res contains CPU addresses.  Clip it so the corresponding bus addresses
104 * on @bus are entirely within @region.  This is used to control the bus
105 * addresses of resources we allocate, e.g., we may need a resource that
106 * can be mapped by a 32-bit BAR.
107 */
108static void pci_clip_resource_to_region(struct pci_bus *bus,
109					struct resource *res,
110					struct pci_bus_region *region)
111{
112	struct pci_bus_region r;
113
114	pcibios_resource_to_bus(bus, &r, res);
115	if (r.start < region->start)
116		r.start = region->start;
117	if (r.end > region->end)
118		r.end = region->end;
119
120	if (r.end < r.start)
121		res->end = res->start - 1;
122	else
123		pcibios_bus_to_resource(bus, res, &r);
124}
125
126static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
127		resource_size_t size, resource_size_t align,
128		resource_size_t min, unsigned long type_mask,
129		resource_size_t (*alignf)(void *,
130					  const struct resource *,
131					  resource_size_t,
132					  resource_size_t),
133		void *alignf_data,
134		struct pci_bus_region *region)
135{
136	int i, ret;
137	struct resource *r, avail;
138	resource_size_t max;
139
140	type_mask |= IORESOURCE_TYPE_BITS;
141
142	pci_bus_for_each_resource(bus, r, i) {
143		resource_size_t min_used = min;
144
145		if (!r)
146			continue;
147
148		/* type_mask must match */
149		if ((res->flags ^ r->flags) & type_mask)
150			continue;
151
152		/* We cannot allocate a non-prefetching resource
153		   from a pre-fetching area */
154		if ((r->flags & IORESOURCE_PREFETCH) &&
155		    !(res->flags & IORESOURCE_PREFETCH))
156			continue;
157
158		avail = *r;
159		pci_clip_resource_to_region(bus, &avail, region);
160
161		/*
162		 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
163		 * protect badly documented motherboard resources, but if
164		 * this is an already-configured bridge window, its start
165		 * overrides "min".
166		 */
167		if (avail.start)
168			min_used = avail.start;
169
170		max = avail.end;
171
172		/* Ok, try it out.. */
173		ret = allocate_resource(r, res, size, min_used, max,
174					align, alignf, alignf_data);
175		if (ret == 0)
176			return 0;
177	}
178	return -ENOMEM;
179}
180
181/**
182 * pci_bus_alloc_resource - allocate a resource from a parent bus
183 * @bus: PCI bus
184 * @res: resource to allocate
185 * @size: size of resource to allocate
186 * @align: alignment of resource to allocate
187 * @min: minimum /proc/iomem address to allocate
188 * @type_mask: IORESOURCE_* type flags
189 * @alignf: resource alignment function
190 * @alignf_data: data argument for resource alignment function
191 *
192 * Given the PCI bus a device resides on, the size, minimum address,
193 * alignment and type, try to find an acceptable resource allocation
194 * for a specific device resource.
195 */
196int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
197		resource_size_t size, resource_size_t align,
198		resource_size_t min, unsigned long type_mask,
199		resource_size_t (*alignf)(void *,
200					  const struct resource *,
201					  resource_size_t,
202					  resource_size_t),
203		void *alignf_data)
204{
205#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
206	int rc;
207
208	if (res->flags & IORESOURCE_MEM_64) {
209		rc = pci_bus_alloc_from_region(bus, res, size, align, min,
210					       type_mask, alignf, alignf_data,
211					       &pci_high);
212		if (rc == 0)
213			return 0;
214
215		return pci_bus_alloc_from_region(bus, res, size, align, min,
216						 type_mask, alignf, alignf_data,
217						 &pci_64_bit);
218	}
219#endif
220
221	return pci_bus_alloc_from_region(bus, res, size, align, min,
222					 type_mask, alignf, alignf_data,
223					 &pci_32_bit);
224}
225EXPORT_SYMBOL(pci_bus_alloc_resource);
226
227/*
228 * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
229 * resource fits inside a window of an upstream bridge, do nothing.  If it
230 * overlaps an upstream window but extends outside it, clip the resource so
231 * it fits completely inside.
232 */
233bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
234{
235	struct pci_bus *bus = dev->bus;
236	struct resource *res = &dev->resource[idx];
237	struct resource orig_res = *res;
238	struct resource *r;
239	int i;
240
241	pci_bus_for_each_resource(bus, r, i) {
242		resource_size_t start, end;
243
244		if (!r)
245			continue;
246
247		if (resource_type(res) != resource_type(r))
248			continue;
249
250		start = max(r->start, res->start);
251		end = min(r->end, res->end);
252
253		if (start > end)
254			continue;	/* no overlap */
255
256		if (res->start == start && res->end == end)
257			return false;	/* no change */
258
259		res->start = start;
260		res->end = end;
261		res->flags &= ~IORESOURCE_UNSET;
262		orig_res.flags &= ~IORESOURCE_UNSET;
263		dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n",
264				 &orig_res, res);
265
266		return true;
267	}
268
269	return false;
270}
271
272void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
273
274/**
275 * pci_bus_add_device - start driver for a single device
276 * @dev: device to add
277 *
278 * This adds add sysfs entries and start device drivers
279 */
280void pci_bus_add_device(struct pci_dev *dev)
281{
282	int retval;
283
284	/*
285	 * Can not put in pci_device_add yet because resources
286	 * are not assigned yet for some devices.
287	 */
288	pci_fixup_device(pci_fixup_final, dev);
289	pci_create_sysfs_dev_files(dev);
290	pci_proc_attach_device(dev);
291
292	dev->match_driver = true;
293	retval = device_attach(&dev->dev);
294	WARN_ON(retval < 0);
295
296	dev->is_added = 1;
297}
298EXPORT_SYMBOL_GPL(pci_bus_add_device);
299
300/**
301 * pci_bus_add_devices - start driver for PCI devices
302 * @bus: bus to check for new devices
303 *
304 * Start driver for PCI devices and add some sysfs entries.
305 */
306void pci_bus_add_devices(const struct pci_bus *bus)
307{
308	struct pci_dev *dev;
309	struct pci_bus *child;
310
311	list_for_each_entry(dev, &bus->devices, bus_list) {
312		/* Skip already-added devices */
313		if (dev->is_added)
314			continue;
315		pci_bus_add_device(dev);
316	}
317
318	list_for_each_entry(dev, &bus->devices, bus_list) {
319		BUG_ON(!dev->is_added);
320		child = dev->subordinate;
321		if (child)
322			pci_bus_add_devices(child);
323	}
324}
325EXPORT_SYMBOL(pci_bus_add_devices);
326
327/** pci_walk_bus - walk devices on/under bus, calling callback.
328 *  @top      bus whose devices should be walked
329 *  @cb       callback to be called for each device found
330 *  @userdata arbitrary pointer to be passed to callback.
331 *
332 *  Walk the given bus, including any bridged devices
333 *  on buses under this bus.  Call the provided callback
334 *  on each device found.
335 *
336 *  We check the return of @cb each time. If it returns anything
337 *  other than 0, we break out.
338 *
339 */
340void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
341		  void *userdata)
342{
343	struct pci_dev *dev;
344	struct pci_bus *bus;
345	struct list_head *next;
346	int retval;
347
348	bus = top;
349	down_read(&pci_bus_sem);
350	next = top->devices.next;
351	for (;;) {
352		if (next == &bus->devices) {
353			/* end of this bus, go up or finish */
354			if (bus == top)
355				break;
356			next = bus->self->bus_list.next;
357			bus = bus->self->bus;
358			continue;
359		}
360		dev = list_entry(next, struct pci_dev, bus_list);
361		if (dev->subordinate) {
362			/* this is a pci-pci bridge, do its devices next */
363			next = dev->subordinate->devices.next;
364			bus = dev->subordinate;
365		} else
366			next = dev->bus_list.next;
367
368		retval = cb(dev, userdata);
369		if (retval)
370			break;
371	}
372	up_read(&pci_bus_sem);
373}
374EXPORT_SYMBOL_GPL(pci_walk_bus);
375
376struct pci_bus *pci_bus_get(struct pci_bus *bus)
377{
378	if (bus)
379		get_device(&bus->dev);
380	return bus;
381}
382EXPORT_SYMBOL(pci_bus_get);
383
384void pci_bus_put(struct pci_bus *bus)
385{
386	if (bus)
387		put_device(&bus->dev);
388}
389EXPORT_SYMBOL(pci_bus_put);
390
391