Linux Audio

Check our new training course

Loading...
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Support routines for initializing a PCI subsystem
  4 *
  5 * Extruded from code written by
  6 *      Dave Rusling (david.rusling@reo.mts.dec.com)
  7 *      David Mosberger (davidm@cs.arizona.edu)
  8 *	David Miller (davem@redhat.com)
  9 *
 10 * Fixed for multiple PCI buses, 1999 Andrea Arcangeli <andrea@suse.de>
 11 *
 12 * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
 13 *	     Resource sorting
 14 */
 15
 16#include <linux/kernel.h>
 17#include <linux/export.h>
 18#include <linux/pci.h>
 19#include <linux/errno.h>
 20#include <linux/ioport.h>
 21#include <linux/cache.h>
 22#include <linux/slab.h>
 23#include "pci.h"
 24
 25static void pci_std_update_resource(struct pci_dev *dev, int resno)
 26{
 27	struct pci_bus_region region;
 28	bool disable;
 29	u16 cmd;
 30	u32 new, check, mask;
 31	int reg;
 32	struct resource *res = dev->resource + resno;
 33	const char *res_name = pci_resource_name(dev, resno);
 34
 35	/* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
 36	if (dev->is_virtfn)
 37		return;
 38
 39	/*
 40	 * Ignore resources for unimplemented BARs and unused resource slots
 41	 * for 64 bit BARs.
 42	 */
 43	if (!res->flags)
 44		return;
 45
 46	if (res->flags & IORESOURCE_UNSET)
 47		return;
 48
 49	/*
 50	 * Ignore non-moveable resources.  This might be legacy resources for
 51	 * which no functional BAR register exists or another important
 52	 * system resource we shouldn't move around.
 53	 */
 54	if (res->flags & IORESOURCE_PCI_FIXED)
 55		return;
 56
 57	pcibios_resource_to_bus(dev->bus, &region, res);
 58	new = region.start;
 59
 60	if (res->flags & IORESOURCE_IO) {
 61		mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
 62		new |= res->flags & ~PCI_BASE_ADDRESS_IO_MASK;
 63	} else if (resno == PCI_ROM_RESOURCE) {
 64		mask = PCI_ROM_ADDRESS_MASK;
 65	} else {
 66		mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
 67		new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 68	}
 69
 70	if (resno < PCI_ROM_RESOURCE) {
 71		reg = PCI_BASE_ADDRESS_0 + 4 * resno;
 72	} else if (resno == PCI_ROM_RESOURCE) {
 73
 74		/*
 75		 * Apparently some Matrox devices have ROM BARs that read
 76		 * as zero when disabled, so don't update ROM BARs unless
 77		 * they're enabled.  See
 78		 * https://lore.kernel.org/r/43147B3D.1030309@vc.cvut.cz/
 79		 * But we must update ROM BAR for buggy devices where even a
 80		 * disabled ROM can conflict with other BARs.
 81		 */
 82		if (!(res->flags & IORESOURCE_ROM_ENABLE) &&
 83		    !dev->rom_bar_overlap)
 84			return;
 85
 86		reg = dev->rom_base_reg;
 87		if (res->flags & IORESOURCE_ROM_ENABLE)
 88			new |= PCI_ROM_ADDRESS_ENABLE;
 89	} else
 90		return;
 91
 92	/*
 93	 * We can't update a 64-bit BAR atomically, so when possible,
 94	 * disable decoding so that a half-updated BAR won't conflict
 95	 * with another device.
 96	 */
 97	disable = (res->flags & IORESOURCE_MEM_64) && !dev->mmio_always_on;
 98	if (disable) {
 99		pci_read_config_word(dev, PCI_COMMAND, &cmd);
100		pci_write_config_word(dev, PCI_COMMAND,
101				      cmd & ~PCI_COMMAND_MEMORY);
102	}
103
104	pci_write_config_dword(dev, reg, new);
105	pci_read_config_dword(dev, reg, &check);
106
107	if ((new ^ check) & mask) {
108		pci_err(dev, "%s: error updating (%#010x != %#010x)\n",
109			res_name, new, check);
110	}
111
112	if (res->flags & IORESOURCE_MEM_64) {
113		new = region.start >> 16 >> 16;
114		pci_write_config_dword(dev, reg + 4, new);
115		pci_read_config_dword(dev, reg + 4, &check);
116		if (check != new) {
117			pci_err(dev, "%s: error updating (high %#010x != %#010x)\n",
118				res_name, new, check);
119		}
120	}
121
122	if (disable)
123		pci_write_config_word(dev, PCI_COMMAND, cmd);
124}
125
126void pci_update_resource(struct pci_dev *dev, int resno)
127{
128	if (resno <= PCI_ROM_RESOURCE)
129		pci_std_update_resource(dev, resno);
130#ifdef CONFIG_PCI_IOV
131	else if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
132		pci_iov_update_resource(dev, resno);
133#endif
134}
135
136int pci_claim_resource(struct pci_dev *dev, int resource)
137{
138	struct resource *res = &dev->resource[resource];
139	const char *res_name = pci_resource_name(dev, resource);
140	struct resource *root, *conflict;
141
142	if (res->flags & IORESOURCE_UNSET) {
143		pci_info(dev, "%s %pR: can't claim; no address assigned\n",
144			 res_name, res);
145		return -EINVAL;
146	}
147
148	/*
149	 * If we have a shadow copy in RAM, the PCI device doesn't respond
150	 * to the shadow range, so we don't need to claim it, and upstream
151	 * bridges don't need to route the range to the device.
152	 */
153	if (res->flags & IORESOURCE_ROM_SHADOW)
154		return 0;
155
156	root = pci_find_parent_resource(dev, res);
157	if (!root) {
158		pci_info(dev, "%s %pR: can't claim; no compatible bridge window\n",
159			 res_name, res);
160		res->flags |= IORESOURCE_UNSET;
161		return -EINVAL;
162	}
163
164	conflict = request_resource_conflict(root, res);
165	if (conflict) {
166		pci_info(dev, "%s %pR: can't claim; address conflict with %s %pR\n",
167			 res_name, res, conflict->name, conflict);
168		res->flags |= IORESOURCE_UNSET;
169		return -EBUSY;
170	}
171
172	return 0;
173}
174EXPORT_SYMBOL(pci_claim_resource);
175
176void pci_disable_bridge_window(struct pci_dev *dev)
177{
178	/* MMIO Base/Limit */
179	pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0);
180
181	/* Prefetchable MMIO Base/Limit */
182	pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
183	pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0);
184	pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff);
185}
186
187/*
188 * Generic function that returns a value indicating that the device's
189 * original BIOS BAR address was not saved and so is not available for
190 * reinstatement.
191 *
192 * Can be over-ridden by architecture specific code that implements
193 * reinstatement functionality rather than leaving it disabled when
194 * normal allocation attempts fail.
195 */
196resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx)
197{
198	return 0;
199}
200
201static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
202		int resno, resource_size_t size)
203{
204	struct resource *root, *conflict;
205	resource_size_t fw_addr, start, end;
206	const char *res_name = pci_resource_name(dev, resno);
207
208	fw_addr = pcibios_retrieve_fw_addr(dev, resno);
209	if (!fw_addr)
210		return -ENOMEM;
211
212	start = res->start;
213	end = res->end;
214	resource_set_range(res, fw_addr, size);
 
215	res->flags &= ~IORESOURCE_UNSET;
216
217	root = pci_find_parent_resource(dev, res);
218	if (!root) {
219		/*
220		 * If dev is behind a bridge, accesses will only reach it
221		 * if res is inside the relevant bridge window.
222		 */
223		if (pci_upstream_bridge(dev))
224			return -ENXIO;
225
226		/*
227		 * On the root bus, assume the host bridge will forward
228		 * everything.
229		 */
230		if (res->flags & IORESOURCE_IO)
231			root = &ioport_resource;
232		else
233			root = &iomem_resource;
234	}
235
236	pci_info(dev, "%s: trying firmware assignment %pR\n", res_name, res);
 
237	conflict = request_resource_conflict(root, res);
238	if (conflict) {
239		pci_info(dev, "%s %pR: conflicts with %s %pR\n", res_name, res,
240			 conflict->name, conflict);
241		res->start = start;
242		res->end = end;
243		res->flags |= IORESOURCE_UNSET;
244		return -EBUSY;
245	}
246	return 0;
247}
248
249/*
250 * We don't have to worry about legacy ISA devices, so nothing to do here.
251 * This is marked as __weak because multiple architectures define it; it should
252 * eventually go away.
253 */
254resource_size_t __weak pcibios_align_resource(void *data,
255					      const struct resource *res,
256					      resource_size_t size,
257					      resource_size_t align)
258{
259       return res->start;
260}
261
262static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
263		int resno, resource_size_t size, resource_size_t align)
264{
265	struct resource *res = dev->resource + resno;
266	resource_size_t min;
267	int ret;
268
269	min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
270
271	/*
272	 * First, try exact prefetching match.  Even if a 64-bit
273	 * prefetchable bridge window is below 4GB, we can't put a 32-bit
274	 * prefetchable resource in it because pbus_size_mem() assumes a
275	 * 64-bit window will contain no 32-bit resources.  If we assign
276	 * things differently than they were sized, not everything will fit.
277	 */
278	ret = pci_bus_alloc_resource(bus, res, size, align, min,
279				     IORESOURCE_PREFETCH | IORESOURCE_MEM_64,
280				     pcibios_align_resource, dev);
281	if (ret == 0)
282		return 0;
283
284	/*
285	 * If the prefetchable window is only 32 bits wide, we can put
286	 * 64-bit prefetchable resources in it.
287	 */
288	if ((res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) ==
289	     (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) {
290		ret = pci_bus_alloc_resource(bus, res, size, align, min,
291					     IORESOURCE_PREFETCH,
292					     pcibios_align_resource, dev);
293		if (ret == 0)
294			return 0;
295	}
296
297	/*
298	 * If we didn't find a better match, we can put any memory resource
299	 * in a non-prefetchable window.  If this resource is 32 bits and
300	 * non-prefetchable, the first call already tried the only possibility
301	 * so we don't need to try again.
302	 */
303	if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64))
304		ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
305					     pcibios_align_resource, dev);
306
307	return ret;
308}
309
310static int _pci_assign_resource(struct pci_dev *dev, int resno,
311				resource_size_t size, resource_size_t min_align)
312{
313	struct pci_bus *bus;
314	int ret;
315
316	bus = dev->bus;
317	while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
318		if (!bus->parent || !bus->self->transparent)
319			break;
320		bus = bus->parent;
321	}
322
323	return ret;
324}
325
326int pci_assign_resource(struct pci_dev *dev, int resno)
327{
328	struct resource *res = dev->resource + resno;
329	const char *res_name = pci_resource_name(dev, resno);
330	resource_size_t align, size;
331	int ret;
332
333	if (res->flags & IORESOURCE_PCI_FIXED)
334		return 0;
335
336	res->flags |= IORESOURCE_UNSET;
337	align = pci_resource_alignment(dev, res);
338	if (!align) {
339		pci_info(dev, "%s %pR: can't assign; bogus alignment\n",
340			 res_name, res);
341		return -EINVAL;
342	}
343
344	size = resource_size(res);
345	ret = _pci_assign_resource(dev, resno, size, align);
346
347	/*
348	 * If we failed to assign anything, let's try the address
349	 * where firmware left it.  That at least has a chance of
350	 * working, which is better than just leaving it disabled.
351	 */
352	if (ret < 0) {
353		pci_info(dev, "%s %pR: can't assign; no space\n", res_name, res);
354		ret = pci_revert_fw_address(res, dev, resno, size);
355	}
356
357	if (ret < 0) {
358		pci_info(dev, "%s %pR: failed to assign\n", res_name, res);
359		return ret;
360	}
361
362	res->flags &= ~IORESOURCE_UNSET;
363	res->flags &= ~IORESOURCE_STARTALIGN;
364	pci_info(dev, "%s %pR: assigned\n", res_name, res);
365	if (resno < PCI_BRIDGE_RESOURCES)
366		pci_update_resource(dev, resno);
367
368	return 0;
369}
370EXPORT_SYMBOL(pci_assign_resource);
371
372int pci_reassign_resource(struct pci_dev *dev, int resno,
373			  resource_size_t addsize, resource_size_t min_align)
374{
375	struct resource *res = dev->resource + resno;
376	const char *res_name = pci_resource_name(dev, resno);
377	unsigned long flags;
378	resource_size_t new_size;
379	int ret;
380
381	if (res->flags & IORESOURCE_PCI_FIXED)
382		return 0;
383
384	flags = res->flags;
385	res->flags |= IORESOURCE_UNSET;
386	if (!res->parent) {
387		pci_info(dev, "%s %pR: can't reassign; unassigned resource\n",
388			 res_name, res);
389		return -EINVAL;
390	}
391
392	/* already aligned with min_align */
393	new_size = resource_size(res) + addsize;
394	ret = _pci_assign_resource(dev, resno, new_size, min_align);
395	if (ret) {
396		res->flags = flags;
397		pci_info(dev, "%s %pR: failed to expand by %#llx\n",
398			 res_name, res, (unsigned long long) addsize);
399		return ret;
400	}
401
402	res->flags &= ~IORESOURCE_UNSET;
403	res->flags &= ~IORESOURCE_STARTALIGN;
404	pci_info(dev, "%s %pR: reassigned; expanded by %#llx\n",
405		 res_name, res, (unsigned long long) addsize);
406	if (resno < PCI_BRIDGE_RESOURCES)
407		pci_update_resource(dev, resno);
408
409	return 0;
410}
411
412void pci_release_resource(struct pci_dev *dev, int resno)
413{
414	struct resource *res = dev->resource + resno;
415	const char *res_name = pci_resource_name(dev, resno);
416
417	pci_info(dev, "%s %pR: releasing\n", res_name, res);
418
419	if (!res->parent)
420		return;
421
422	release_resource(res);
423	res->end = resource_size(res) - 1;
424	res->start = 0;
425	res->flags |= IORESOURCE_UNSET;
426}
427EXPORT_SYMBOL(pci_release_resource);
428
429int pci_resize_resource(struct pci_dev *dev, int resno, int size)
430{
431	struct resource *res = dev->resource + resno;
432	struct pci_host_bridge *host;
433	int old, ret;
434	u32 sizes;
435	u16 cmd;
436
437	/* Check if we must preserve the firmware's resource assignment */
438	host = pci_find_host_bridge(dev->bus);
439	if (host->preserve_config)
440		return -ENOTSUPP;
441
442	/* Make sure the resource isn't assigned before resizing it. */
443	if (!(res->flags & IORESOURCE_UNSET))
444		return -EBUSY;
445
446	pci_read_config_word(dev, PCI_COMMAND, &cmd);
447	if (cmd & PCI_COMMAND_MEMORY)
448		return -EBUSY;
449
450	sizes = pci_rebar_get_possible_sizes(dev, resno);
451	if (!sizes)
452		return -ENOTSUPP;
453
454	if (!(sizes & BIT(size)))
455		return -EINVAL;
456
457	old = pci_rebar_get_current_size(dev, resno);
458	if (old < 0)
459		return old;
460
461	ret = pci_rebar_set_size(dev, resno, size);
462	if (ret)
463		return ret;
464
465	resource_set_size(res, pci_rebar_size_to_bytes(size));
466
467	/* Check if the new config works by trying to assign everything. */
468	if (dev->bus->self) {
469		ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
470		if (ret)
471			goto error_resize;
472	}
473	return 0;
474
475error_resize:
476	pci_rebar_set_size(dev, resno, old);
477	resource_set_size(res, pci_rebar_size_to_bytes(old));
478	return ret;
479}
480EXPORT_SYMBOL(pci_resize_resource);
481
482int pci_enable_resources(struct pci_dev *dev, int mask)
483{
484	u16 cmd, old_cmd;
485	int i;
486	struct resource *r;
487	const char *r_name;
488
489	pci_read_config_word(dev, PCI_COMMAND, &cmd);
490	old_cmd = cmd;
491
492	pci_dev_for_each_resource(dev, r, i) {
493		if (!(mask & (1 << i)))
494			continue;
495
496		r_name = pci_resource_name(dev, i);
497
498		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
499			continue;
500		if ((i == PCI_ROM_RESOURCE) &&
501				(!(r->flags & IORESOURCE_ROM_ENABLE)))
502			continue;
503
504		if (r->flags & IORESOURCE_UNSET) {
505			pci_err(dev, "%s %pR: not assigned; can't enable device\n",
506				r_name, r);
507			return -EINVAL;
508		}
509
510		if (!r->parent) {
511			pci_err(dev, "%s %pR: not claimed; can't enable device\n",
512				r_name, r);
513			return -EINVAL;
514		}
515
516		if (r->flags & IORESOURCE_IO)
517			cmd |= PCI_COMMAND_IO;
518		if (r->flags & IORESOURCE_MEM)
519			cmd |= PCI_COMMAND_MEMORY;
520	}
521
522	if (cmd != old_cmd) {
523		pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
524		pci_write_config_word(dev, PCI_COMMAND, cmd);
525	}
526	return 0;
527}
v6.2
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Support routines for initializing a PCI subsystem
  4 *
  5 * Extruded from code written by
  6 *      Dave Rusling (david.rusling@reo.mts.dec.com)
  7 *      David Mosberger (davidm@cs.arizona.edu)
  8 *	David Miller (davem@redhat.com)
  9 *
 10 * Fixed for multiple PCI buses, 1999 Andrea Arcangeli <andrea@suse.de>
 11 *
 12 * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
 13 *	     Resource sorting
 14 */
 15
 16#include <linux/kernel.h>
 17#include <linux/export.h>
 18#include <linux/pci.h>
 19#include <linux/errno.h>
 20#include <linux/ioport.h>
 21#include <linux/cache.h>
 22#include <linux/slab.h>
 23#include "pci.h"
 24
 25static void pci_std_update_resource(struct pci_dev *dev, int resno)
 26{
 27	struct pci_bus_region region;
 28	bool disable;
 29	u16 cmd;
 30	u32 new, check, mask;
 31	int reg;
 32	struct resource *res = dev->resource + resno;
 
 33
 34	/* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
 35	if (dev->is_virtfn)
 36		return;
 37
 38	/*
 39	 * Ignore resources for unimplemented BARs and unused resource slots
 40	 * for 64 bit BARs.
 41	 */
 42	if (!res->flags)
 43		return;
 44
 45	if (res->flags & IORESOURCE_UNSET)
 46		return;
 47
 48	/*
 49	 * Ignore non-moveable resources.  This might be legacy resources for
 50	 * which no functional BAR register exists or another important
 51	 * system resource we shouldn't move around.
 52	 */
 53	if (res->flags & IORESOURCE_PCI_FIXED)
 54		return;
 55
 56	pcibios_resource_to_bus(dev->bus, &region, res);
 57	new = region.start;
 58
 59	if (res->flags & IORESOURCE_IO) {
 60		mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
 61		new |= res->flags & ~PCI_BASE_ADDRESS_IO_MASK;
 62	} else if (resno == PCI_ROM_RESOURCE) {
 63		mask = PCI_ROM_ADDRESS_MASK;
 64	} else {
 65		mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
 66		new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
 67	}
 68
 69	if (resno < PCI_ROM_RESOURCE) {
 70		reg = PCI_BASE_ADDRESS_0 + 4 * resno;
 71	} else if (resno == PCI_ROM_RESOURCE) {
 72
 73		/*
 74		 * Apparently some Matrox devices have ROM BARs that read
 75		 * as zero when disabled, so don't update ROM BARs unless
 76		 * they're enabled.  See
 77		 * https://lore.kernel.org/r/43147B3D.1030309@vc.cvut.cz/
 78		 * But we must update ROM BAR for buggy devices where even a
 79		 * disabled ROM can conflict with other BARs.
 80		 */
 81		if (!(res->flags & IORESOURCE_ROM_ENABLE) &&
 82		    !dev->rom_bar_overlap)
 83			return;
 84
 85		reg = dev->rom_base_reg;
 86		if (res->flags & IORESOURCE_ROM_ENABLE)
 87			new |= PCI_ROM_ADDRESS_ENABLE;
 88	} else
 89		return;
 90
 91	/*
 92	 * We can't update a 64-bit BAR atomically, so when possible,
 93	 * disable decoding so that a half-updated BAR won't conflict
 94	 * with another device.
 95	 */
 96	disable = (res->flags & IORESOURCE_MEM_64) && !dev->mmio_always_on;
 97	if (disable) {
 98		pci_read_config_word(dev, PCI_COMMAND, &cmd);
 99		pci_write_config_word(dev, PCI_COMMAND,
100				      cmd & ~PCI_COMMAND_MEMORY);
101	}
102
103	pci_write_config_dword(dev, reg, new);
104	pci_read_config_dword(dev, reg, &check);
105
106	if ((new ^ check) & mask) {
107		pci_err(dev, "BAR %d: error updating (%#08x != %#08x)\n",
108			resno, new, check);
109	}
110
111	if (res->flags & IORESOURCE_MEM_64) {
112		new = region.start >> 16 >> 16;
113		pci_write_config_dword(dev, reg + 4, new);
114		pci_read_config_dword(dev, reg + 4, &check);
115		if (check != new) {
116			pci_err(dev, "BAR %d: error updating (high %#08x != %#08x)\n",
117				resno, new, check);
118		}
119	}
120
121	if (disable)
122		pci_write_config_word(dev, PCI_COMMAND, cmd);
123}
124
125void pci_update_resource(struct pci_dev *dev, int resno)
126{
127	if (resno <= PCI_ROM_RESOURCE)
128		pci_std_update_resource(dev, resno);
129#ifdef CONFIG_PCI_IOV
130	else if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
131		pci_iov_update_resource(dev, resno);
132#endif
133}
134
135int pci_claim_resource(struct pci_dev *dev, int resource)
136{
137	struct resource *res = &dev->resource[resource];
 
138	struct resource *root, *conflict;
139
140	if (res->flags & IORESOURCE_UNSET) {
141		pci_info(dev, "can't claim BAR %d %pR: no address assigned\n",
142			 resource, res);
143		return -EINVAL;
144	}
145
146	/*
147	 * If we have a shadow copy in RAM, the PCI device doesn't respond
148	 * to the shadow range, so we don't need to claim it, and upstream
149	 * bridges don't need to route the range to the device.
150	 */
151	if (res->flags & IORESOURCE_ROM_SHADOW)
152		return 0;
153
154	root = pci_find_parent_resource(dev, res);
155	if (!root) {
156		pci_info(dev, "can't claim BAR %d %pR: no compatible bridge window\n",
157			 resource, res);
158		res->flags |= IORESOURCE_UNSET;
159		return -EINVAL;
160	}
161
162	conflict = request_resource_conflict(root, res);
163	if (conflict) {
164		pci_info(dev, "can't claim BAR %d %pR: address conflict with %s %pR\n",
165			 resource, res, conflict->name, conflict);
166		res->flags |= IORESOURCE_UNSET;
167		return -EBUSY;
168	}
169
170	return 0;
171}
172EXPORT_SYMBOL(pci_claim_resource);
173
174void pci_disable_bridge_window(struct pci_dev *dev)
175{
176	/* MMIO Base/Limit */
177	pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0);
178
179	/* Prefetchable MMIO Base/Limit */
180	pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
181	pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0);
182	pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff);
183}
184
185/*
186 * Generic function that returns a value indicating that the device's
187 * original BIOS BAR address was not saved and so is not available for
188 * reinstatement.
189 *
190 * Can be over-ridden by architecture specific code that implements
191 * reinstatement functionality rather than leaving it disabled when
192 * normal allocation attempts fail.
193 */
194resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx)
195{
196	return 0;
197}
198
199static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
200		int resno, resource_size_t size)
201{
202	struct resource *root, *conflict;
203	resource_size_t fw_addr, start, end;
 
204
205	fw_addr = pcibios_retrieve_fw_addr(dev, resno);
206	if (!fw_addr)
207		return -ENOMEM;
208
209	start = res->start;
210	end = res->end;
211	res->start = fw_addr;
212	res->end = res->start + size - 1;
213	res->flags &= ~IORESOURCE_UNSET;
214
215	root = pci_find_parent_resource(dev, res);
216	if (!root) {
217		/*
218		 * If dev is behind a bridge, accesses will only reach it
219		 * if res is inside the relevant bridge window.
220		 */
221		if (pci_upstream_bridge(dev))
222			return -ENXIO;
223
224		/*
225		 * On the root bus, assume the host bridge will forward
226		 * everything.
227		 */
228		if (res->flags & IORESOURCE_IO)
229			root = &ioport_resource;
230		else
231			root = &iomem_resource;
232	}
233
234	pci_info(dev, "BAR %d: trying firmware assignment %pR\n",
235		 resno, res);
236	conflict = request_resource_conflict(root, res);
237	if (conflict) {
238		pci_info(dev, "BAR %d: %pR conflicts with %s %pR\n",
239			 resno, res, conflict->name, conflict);
240		res->start = start;
241		res->end = end;
242		res->flags |= IORESOURCE_UNSET;
243		return -EBUSY;
244	}
245	return 0;
246}
247
248/*
249 * We don't have to worry about legacy ISA devices, so nothing to do here.
250 * This is marked as __weak because multiple architectures define it; it should
251 * eventually go away.
252 */
253resource_size_t __weak pcibios_align_resource(void *data,
254					      const struct resource *res,
255					      resource_size_t size,
256					      resource_size_t align)
257{
258       return res->start;
259}
260
261static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
262		int resno, resource_size_t size, resource_size_t align)
263{
264	struct resource *res = dev->resource + resno;
265	resource_size_t min;
266	int ret;
267
268	min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
269
270	/*
271	 * First, try exact prefetching match.  Even if a 64-bit
272	 * prefetchable bridge window is below 4GB, we can't put a 32-bit
273	 * prefetchable resource in it because pbus_size_mem() assumes a
274	 * 64-bit window will contain no 32-bit resources.  If we assign
275	 * things differently than they were sized, not everything will fit.
276	 */
277	ret = pci_bus_alloc_resource(bus, res, size, align, min,
278				     IORESOURCE_PREFETCH | IORESOURCE_MEM_64,
279				     pcibios_align_resource, dev);
280	if (ret == 0)
281		return 0;
282
283	/*
284	 * If the prefetchable window is only 32 bits wide, we can put
285	 * 64-bit prefetchable resources in it.
286	 */
287	if ((res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) ==
288	     (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) {
289		ret = pci_bus_alloc_resource(bus, res, size, align, min,
290					     IORESOURCE_PREFETCH,
291					     pcibios_align_resource, dev);
292		if (ret == 0)
293			return 0;
294	}
295
296	/*
297	 * If we didn't find a better match, we can put any memory resource
298	 * in a non-prefetchable window.  If this resource is 32 bits and
299	 * non-prefetchable, the first call already tried the only possibility
300	 * so we don't need to try again.
301	 */
302	if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64))
303		ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
304					     pcibios_align_resource, dev);
305
306	return ret;
307}
308
309static int _pci_assign_resource(struct pci_dev *dev, int resno,
310				resource_size_t size, resource_size_t min_align)
311{
312	struct pci_bus *bus;
313	int ret;
314
315	bus = dev->bus;
316	while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
317		if (!bus->parent || !bus->self->transparent)
318			break;
319		bus = bus->parent;
320	}
321
322	return ret;
323}
324
325int pci_assign_resource(struct pci_dev *dev, int resno)
326{
327	struct resource *res = dev->resource + resno;
 
328	resource_size_t align, size;
329	int ret;
330
331	if (res->flags & IORESOURCE_PCI_FIXED)
332		return 0;
333
334	res->flags |= IORESOURCE_UNSET;
335	align = pci_resource_alignment(dev, res);
336	if (!align) {
337		pci_info(dev, "BAR %d: can't assign %pR (bogus alignment)\n",
338			 resno, res);
339		return -EINVAL;
340	}
341
342	size = resource_size(res);
343	ret = _pci_assign_resource(dev, resno, size, align);
344
345	/*
346	 * If we failed to assign anything, let's try the address
347	 * where firmware left it.  That at least has a chance of
348	 * working, which is better than just leaving it disabled.
349	 */
350	if (ret < 0) {
351		pci_info(dev, "BAR %d: no space for %pR\n", resno, res);
352		ret = pci_revert_fw_address(res, dev, resno, size);
353	}
354
355	if (ret < 0) {
356		pci_info(dev, "BAR %d: failed to assign %pR\n", resno, res);
357		return ret;
358	}
359
360	res->flags &= ~IORESOURCE_UNSET;
361	res->flags &= ~IORESOURCE_STARTALIGN;
362	pci_info(dev, "BAR %d: assigned %pR\n", resno, res);
363	if (resno < PCI_BRIDGE_RESOURCES)
364		pci_update_resource(dev, resno);
365
366	return 0;
367}
368EXPORT_SYMBOL(pci_assign_resource);
369
370int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsize,
371			resource_size_t min_align)
372{
373	struct resource *res = dev->resource + resno;
 
374	unsigned long flags;
375	resource_size_t new_size;
376	int ret;
377
378	if (res->flags & IORESOURCE_PCI_FIXED)
379		return 0;
380
381	flags = res->flags;
382	res->flags |= IORESOURCE_UNSET;
383	if (!res->parent) {
384		pci_info(dev, "BAR %d: can't reassign an unassigned resource %pR\n",
385			 resno, res);
386		return -EINVAL;
387	}
388
389	/* already aligned with min_align */
390	new_size = resource_size(res) + addsize;
391	ret = _pci_assign_resource(dev, resno, new_size, min_align);
392	if (ret) {
393		res->flags = flags;
394		pci_info(dev, "BAR %d: %pR (failed to expand by %#llx)\n",
395			 resno, res, (unsigned long long) addsize);
396		return ret;
397	}
398
399	res->flags &= ~IORESOURCE_UNSET;
400	res->flags &= ~IORESOURCE_STARTALIGN;
401	pci_info(dev, "BAR %d: reassigned %pR (expanded by %#llx)\n",
402		 resno, res, (unsigned long long) addsize);
403	if (resno < PCI_BRIDGE_RESOURCES)
404		pci_update_resource(dev, resno);
405
406	return 0;
407}
408
409void pci_release_resource(struct pci_dev *dev, int resno)
410{
411	struct resource *res = dev->resource + resno;
 
412
413	pci_info(dev, "BAR %d: releasing %pR\n", resno, res);
414
415	if (!res->parent)
416		return;
417
418	release_resource(res);
419	res->end = resource_size(res) - 1;
420	res->start = 0;
421	res->flags |= IORESOURCE_UNSET;
422}
423EXPORT_SYMBOL(pci_release_resource);
424
425int pci_resize_resource(struct pci_dev *dev, int resno, int size)
426{
427	struct resource *res = dev->resource + resno;
428	struct pci_host_bridge *host;
429	int old, ret;
430	u32 sizes;
431	u16 cmd;
432
433	/* Check if we must preserve the firmware's resource assignment */
434	host = pci_find_host_bridge(dev->bus);
435	if (host->preserve_config)
436		return -ENOTSUPP;
437
438	/* Make sure the resource isn't assigned before resizing it. */
439	if (!(res->flags & IORESOURCE_UNSET))
440		return -EBUSY;
441
442	pci_read_config_word(dev, PCI_COMMAND, &cmd);
443	if (cmd & PCI_COMMAND_MEMORY)
444		return -EBUSY;
445
446	sizes = pci_rebar_get_possible_sizes(dev, resno);
447	if (!sizes)
448		return -ENOTSUPP;
449
450	if (!(sizes & BIT(size)))
451		return -EINVAL;
452
453	old = pci_rebar_get_current_size(dev, resno);
454	if (old < 0)
455		return old;
456
457	ret = pci_rebar_set_size(dev, resno, size);
458	if (ret)
459		return ret;
460
461	res->end = res->start + pci_rebar_size_to_bytes(size) - 1;
462
463	/* Check if the new config works by trying to assign everything. */
464	if (dev->bus->self) {
465		ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
466		if (ret)
467			goto error_resize;
468	}
469	return 0;
470
471error_resize:
472	pci_rebar_set_size(dev, resno, old);
473	res->end = res->start + pci_rebar_size_to_bytes(old) - 1;
474	return ret;
475}
476EXPORT_SYMBOL(pci_resize_resource);
477
478int pci_enable_resources(struct pci_dev *dev, int mask)
479{
480	u16 cmd, old_cmd;
481	int i;
482	struct resource *r;
 
483
484	pci_read_config_word(dev, PCI_COMMAND, &cmd);
485	old_cmd = cmd;
486
487	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
488		if (!(mask & (1 << i)))
489			continue;
490
491		r = &dev->resource[i];
492
493		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
494			continue;
495		if ((i == PCI_ROM_RESOURCE) &&
496				(!(r->flags & IORESOURCE_ROM_ENABLE)))
497			continue;
498
499		if (r->flags & IORESOURCE_UNSET) {
500			pci_err(dev, "can't enable device: BAR %d %pR not assigned\n",
501				i, r);
502			return -EINVAL;
503		}
504
505		if (!r->parent) {
506			pci_err(dev, "can't enable device: BAR %d %pR not claimed\n",
507				i, r);
508			return -EINVAL;
509		}
510
511		if (r->flags & IORESOURCE_IO)
512			cmd |= PCI_COMMAND_IO;
513		if (r->flags & IORESOURCE_MEM)
514			cmd |= PCI_COMMAND_MEMORY;
515	}
516
517	if (cmd != old_cmd) {
518		pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
519		pci_write_config_word(dev, PCI_COMMAND, cmd);
520	}
521	return 0;
522}