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
pci_std_update_resource(struct pci_dev * dev,int resno)25 static 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, ®ion, 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 */
79 if (!(res->flags & IORESOURCE_ROM_ENABLE))
80 return;
81
82 reg = dev->rom_base_reg;
83 new |= PCI_ROM_ADDRESS_ENABLE;
84 } else
85 return;
86
87 /*
88 * We can't update a 64-bit BAR atomically, so when possible,
89 * disable decoding so that a half-updated BAR won't conflict
90 * with another device.
91 */
92 disable = (res->flags & IORESOURCE_MEM_64) && !dev->mmio_always_on;
93 if (disable) {
94 pci_read_config_word(dev, PCI_COMMAND, &cmd);
95 pci_write_config_word(dev, PCI_COMMAND,
96 cmd & ~PCI_COMMAND_MEMORY);
97 }
98
99 pci_write_config_dword(dev, reg, new);
100 pci_read_config_dword(dev, reg, &check);
101
102 if ((new ^ check) & mask) {
103 pci_err(dev, "BAR %d: error updating (%#08x != %#08x)\n",
104 resno, new, check);
105 }
106
107 if (res->flags & IORESOURCE_MEM_64) {
108 new = region.start >> 16 >> 16;
109 pci_write_config_dword(dev, reg + 4, new);
110 pci_read_config_dword(dev, reg + 4, &check);
111 if (check != new) {
112 pci_err(dev, "BAR %d: error updating (high %#08x != %#08x)\n",
113 resno, new, check);
114 }
115 }
116
117 if (disable)
118 pci_write_config_word(dev, PCI_COMMAND, cmd);
119 }
120
pci_update_resource(struct pci_dev * dev,int resno)121 void pci_update_resource(struct pci_dev *dev, int resno)
122 {
123 if (resno <= PCI_ROM_RESOURCE)
124 pci_std_update_resource(dev, resno);
125 #ifdef CONFIG_PCI_IOV
126 else if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
127 pci_iov_update_resource(dev, resno);
128 #endif
129 }
130
pci_claim_resource(struct pci_dev * dev,int resource)131 int pci_claim_resource(struct pci_dev *dev, int resource)
132 {
133 struct resource *res = &dev->resource[resource];
134 struct resource *root, *conflict;
135
136 if (res->flags & IORESOURCE_UNSET) {
137 pci_info(dev, "can't claim BAR %d %pR: no address assigned\n",
138 resource, res);
139 return -EINVAL;
140 }
141
142 /*
143 * If we have a shadow copy in RAM, the PCI device doesn't respond
144 * to the shadow range, so we don't need to claim it, and upstream
145 * bridges don't need to route the range to the device.
146 */
147 if (res->flags & IORESOURCE_ROM_SHADOW)
148 return 0;
149
150 root = pci_find_parent_resource(dev, res);
151 if (!root) {
152 pci_info(dev, "can't claim BAR %d %pR: no compatible bridge window\n",
153 resource, res);
154 res->flags |= IORESOURCE_UNSET;
155 return -EINVAL;
156 }
157
158 conflict = request_resource_conflict(root, res);
159 if (conflict) {
160 pci_info(dev, "can't claim BAR %d %pR: address conflict with %s %pR\n",
161 resource, res, conflict->name, conflict);
162 res->flags |= IORESOURCE_UNSET;
163 return -EBUSY;
164 }
165
166 return 0;
167 }
168 EXPORT_SYMBOL(pci_claim_resource);
169
pci_disable_bridge_window(struct pci_dev * dev)170 void pci_disable_bridge_window(struct pci_dev *dev)
171 {
172 /* MMIO Base/Limit */
173 pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0);
174
175 /* Prefetchable MMIO Base/Limit */
176 pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
177 pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0);
178 pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff);
179 }
180
181 /*
182 * Generic function that returns a value indicating that the device's
183 * original BIOS BAR address was not saved and so is not available for
184 * reinstatement.
185 *
186 * Can be over-ridden by architecture specific code that implements
187 * reinstatement functionality rather than leaving it disabled when
188 * normal allocation attempts fail.
189 */
pcibios_retrieve_fw_addr(struct pci_dev * dev,int idx)190 resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx)
191 {
192 return 0;
193 }
194
pci_revert_fw_address(struct resource * res,struct pci_dev * dev,int resno,resource_size_t size)195 static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
196 int resno, resource_size_t size)
197 {
198 struct resource *root, *conflict;
199 resource_size_t fw_addr, start, end;
200
201 fw_addr = pcibios_retrieve_fw_addr(dev, resno);
202 if (!fw_addr)
203 return -ENOMEM;
204
205 start = res->start;
206 end = res->end;
207 res->start = fw_addr;
208 res->end = res->start + size - 1;
209 res->flags &= ~IORESOURCE_UNSET;
210
211 root = pci_find_parent_resource(dev, res);
212 if (!root) {
213 if (res->flags & IORESOURCE_IO)
214 root = &ioport_resource;
215 else
216 root = &iomem_resource;
217 }
218
219 pci_info(dev, "BAR %d: trying firmware assignment %pR\n",
220 resno, res);
221 conflict = request_resource_conflict(root, res);
222 if (conflict) {
223 pci_info(dev, "BAR %d: %pR conflicts with %s %pR\n",
224 resno, res, conflict->name, conflict);
225 res->start = start;
226 res->end = end;
227 res->flags |= IORESOURCE_UNSET;
228 return -EBUSY;
229 }
230 return 0;
231 }
232
233 /*
234 * We don't have to worry about legacy ISA devices, so nothing to do here.
235 * This is marked as __weak because multiple architectures define it; it should
236 * eventually go away.
237 */
pcibios_align_resource(void * data,const struct resource * res,resource_size_t size,resource_size_t align)238 resource_size_t __weak pcibios_align_resource(void *data,
239 const struct resource *res,
240 resource_size_t size,
241 resource_size_t align)
242 {
243 return res->start;
244 }
245
__pci_assign_resource(struct pci_bus * bus,struct pci_dev * dev,int resno,resource_size_t size,resource_size_t align)246 static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
247 int resno, resource_size_t size, resource_size_t align)
248 {
249 struct resource *res = dev->resource + resno;
250 resource_size_t min;
251 int ret;
252
253 min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
254
255 /*
256 * First, try exact prefetching match. Even if a 64-bit
257 * prefetchable bridge window is below 4GB, we can't put a 32-bit
258 * prefetchable resource in it because pbus_size_mem() assumes a
259 * 64-bit window will contain no 32-bit resources. If we assign
260 * things differently than they were sized, not everything will fit.
261 */
262 ret = pci_bus_alloc_resource(bus, res, size, align, min,
263 IORESOURCE_PREFETCH | IORESOURCE_MEM_64,
264 pcibios_align_resource, dev);
265 if (ret == 0)
266 return 0;
267
268 /*
269 * If the prefetchable window is only 32 bits wide, we can put
270 * 64-bit prefetchable resources in it.
271 */
272 if ((res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) ==
273 (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) {
274 ret = pci_bus_alloc_resource(bus, res, size, align, min,
275 IORESOURCE_PREFETCH,
276 pcibios_align_resource, dev);
277 if (ret == 0)
278 return 0;
279 }
280
281 /*
282 * If we didn't find a better match, we can put any memory resource
283 * in a non-prefetchable window. If this resource is 32 bits and
284 * non-prefetchable, the first call already tried the only possibility
285 * so we don't need to try again.
286 */
287 if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64))
288 ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
289 pcibios_align_resource, dev);
290
291 return ret;
292 }
293
_pci_assign_resource(struct pci_dev * dev,int resno,resource_size_t size,resource_size_t min_align)294 static int _pci_assign_resource(struct pci_dev *dev, int resno,
295 resource_size_t size, resource_size_t min_align)
296 {
297 struct pci_bus *bus;
298 int ret;
299
300 bus = dev->bus;
301 while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
302 if (!bus->parent || !bus->self->transparent)
303 break;
304 bus = bus->parent;
305 }
306
307 return ret;
308 }
309
pci_assign_resource(struct pci_dev * dev,int resno)310 int pci_assign_resource(struct pci_dev *dev, int resno)
311 {
312 struct resource *res = dev->resource + resno;
313 resource_size_t align, size;
314 int ret;
315
316 if (res->flags & IORESOURCE_PCI_FIXED)
317 return 0;
318
319 res->flags |= IORESOURCE_UNSET;
320 align = pci_resource_alignment(dev, res);
321 if (!align) {
322 pci_info(dev, "BAR %d: can't assign %pR (bogus alignment)\n",
323 resno, res);
324 return -EINVAL;
325 }
326
327 size = resource_size(res);
328 ret = _pci_assign_resource(dev, resno, size, align);
329
330 /*
331 * If we failed to assign anything, let's try the address
332 * where firmware left it. That at least has a chance of
333 * working, which is better than just leaving it disabled.
334 */
335 if (ret < 0) {
336 pci_info(dev, "BAR %d: no space for %pR\n", resno, res);
337 ret = pci_revert_fw_address(res, dev, resno, size);
338 }
339
340 if (ret < 0) {
341 pci_info(dev, "BAR %d: failed to assign %pR\n", resno, res);
342 return ret;
343 }
344
345 res->flags &= ~IORESOURCE_UNSET;
346 res->flags &= ~IORESOURCE_STARTALIGN;
347 pci_info(dev, "BAR %d: assigned %pR\n", resno, res);
348 if (resno < PCI_BRIDGE_RESOURCES)
349 pci_update_resource(dev, resno);
350
351 return 0;
352 }
353 EXPORT_SYMBOL(pci_assign_resource);
354
pci_reassign_resource(struct pci_dev * dev,int resno,resource_size_t addsize,resource_size_t min_align)355 int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsize,
356 resource_size_t min_align)
357 {
358 struct resource *res = dev->resource + resno;
359 unsigned long flags;
360 resource_size_t new_size;
361 int ret;
362
363 if (res->flags & IORESOURCE_PCI_FIXED)
364 return 0;
365
366 flags = res->flags;
367 res->flags |= IORESOURCE_UNSET;
368 if (!res->parent) {
369 pci_info(dev, "BAR %d: can't reassign an unassigned resource %pR\n",
370 resno, res);
371 return -EINVAL;
372 }
373
374 /* already aligned with min_align */
375 new_size = resource_size(res) + addsize;
376 ret = _pci_assign_resource(dev, resno, new_size, min_align);
377 if (ret) {
378 res->flags = flags;
379 pci_info(dev, "BAR %d: %pR (failed to expand by %#llx)\n",
380 resno, res, (unsigned long long) addsize);
381 return ret;
382 }
383
384 res->flags &= ~IORESOURCE_UNSET;
385 res->flags &= ~IORESOURCE_STARTALIGN;
386 pci_info(dev, "BAR %d: reassigned %pR (expanded by %#llx)\n",
387 resno, res, (unsigned long long) addsize);
388 if (resno < PCI_BRIDGE_RESOURCES)
389 pci_update_resource(dev, resno);
390
391 return 0;
392 }
393
pci_release_resource(struct pci_dev * dev,int resno)394 void pci_release_resource(struct pci_dev *dev, int resno)
395 {
396 struct resource *res = dev->resource + resno;
397
398 pci_info(dev, "BAR %d: releasing %pR\n", resno, res);
399
400 if (!res->parent)
401 return;
402
403 release_resource(res);
404 res->end = resource_size(res) - 1;
405 res->start = 0;
406 res->flags |= IORESOURCE_UNSET;
407 }
408 EXPORT_SYMBOL(pci_release_resource);
409
pci_resize_resource(struct pci_dev * dev,int resno,int size)410 int pci_resize_resource(struct pci_dev *dev, int resno, int size)
411 {
412 struct resource *res = dev->resource + resno;
413 struct pci_host_bridge *host;
414 int old, ret;
415 u32 sizes;
416 u16 cmd;
417
418 /* Check if we must preserve the firmware's resource assignment */
419 host = pci_find_host_bridge(dev->bus);
420 if (host->preserve_config)
421 return -ENOTSUPP;
422
423 /* Make sure the resource isn't assigned before resizing it. */
424 if (!(res->flags & IORESOURCE_UNSET))
425 return -EBUSY;
426
427 pci_read_config_word(dev, PCI_COMMAND, &cmd);
428 if (cmd & PCI_COMMAND_MEMORY)
429 return -EBUSY;
430
431 sizes = pci_rebar_get_possible_sizes(dev, resno);
432 if (!sizes)
433 return -ENOTSUPP;
434
435 if (!(sizes & BIT(size)))
436 return -EINVAL;
437
438 old = pci_rebar_get_current_size(dev, resno);
439 if (old < 0)
440 return old;
441
442 ret = pci_rebar_set_size(dev, resno, size);
443 if (ret)
444 return ret;
445
446 res->end = res->start + pci_rebar_size_to_bytes(size) - 1;
447
448 /* Check if the new config works by trying to assign everything. */
449 if (dev->bus->self) {
450 ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
451 if (ret)
452 goto error_resize;
453 }
454 return 0;
455
456 error_resize:
457 pci_rebar_set_size(dev, resno, old);
458 res->end = res->start + pci_rebar_size_to_bytes(old) - 1;
459 return ret;
460 }
461 EXPORT_SYMBOL(pci_resize_resource);
462
pci_enable_resources(struct pci_dev * dev,int mask)463 int pci_enable_resources(struct pci_dev *dev, int mask)
464 {
465 u16 cmd, old_cmd;
466 int i;
467 struct resource *r;
468
469 pci_read_config_word(dev, PCI_COMMAND, &cmd);
470 old_cmd = cmd;
471
472 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
473 if (!(mask & (1 << i)))
474 continue;
475
476 r = &dev->resource[i];
477
478 if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
479 continue;
480 if ((i == PCI_ROM_RESOURCE) &&
481 (!(r->flags & IORESOURCE_ROM_ENABLE)))
482 continue;
483
484 if (r->flags & IORESOURCE_UNSET) {
485 pci_err(dev, "can't enable device: BAR %d %pR not assigned\n",
486 i, r);
487 return -EINVAL;
488 }
489
490 if (!r->parent) {
491 pci_err(dev, "can't enable device: BAR %d %pR not claimed\n",
492 i, r);
493 return -EINVAL;
494 }
495
496 if (r->flags & IORESOURCE_IO)
497 cmd |= PCI_COMMAND_IO;
498 if (r->flags & IORESOURCE_MEM)
499 cmd |= PCI_COMMAND_MEMORY;
500 }
501
502 if (cmd != old_cmd) {
503 pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
504 pci_write_config_word(dev, PCI_COMMAND, cmd);
505 }
506 return 0;
507 }
508