Line data Source code
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 :
25 0 : 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 0 : struct resource *res = dev->resource + resno;
33 :
34 : /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
35 0 : if (dev->is_virtfn)
36 0 : return;
37 :
38 : /*
39 : * Ignore resources for unimplemented BARs and unused resource slots
40 : * for 64 bit BARs.
41 : */
42 0 : if (!res->flags)
43 : return;
44 :
45 0 : 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 0 : if (res->flags & IORESOURCE_PCI_FIXED)
54 : return;
55 :
56 0 : pcibios_resource_to_bus(dev->bus, ®ion, res);
57 0 : new = region.start;
58 :
59 0 : if (res->flags & IORESOURCE_IO) {
60 0 : mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
61 0 : new |= res->flags & ~PCI_BASE_ADDRESS_IO_MASK;
62 0 : } else if (resno == PCI_ROM_RESOURCE) {
63 : mask = PCI_ROM_ADDRESS_MASK;
64 : } else {
65 0 : mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
66 0 : new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
67 : }
68 :
69 0 : if (resno < PCI_ROM_RESOURCE) {
70 0 : reg = PCI_BASE_ADDRESS_0 + 4 * resno;
71 0 : } 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 0 : if (!(res->flags & IORESOURCE_ROM_ENABLE) &&
82 0 : !dev->rom_bar_overlap)
83 : return;
84 :
85 0 : reg = dev->rom_base_reg;
86 0 : if (res->flags & IORESOURCE_ROM_ENABLE)
87 0 : 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 0 : disable = (res->flags & IORESOURCE_MEM_64) && !dev->mmio_always_on;
97 0 : if (disable) {
98 0 : pci_read_config_word(dev, PCI_COMMAND, &cmd);
99 0 : pci_write_config_word(dev, PCI_COMMAND,
100 0 : cmd & ~PCI_COMMAND_MEMORY);
101 : }
102 :
103 0 : pci_write_config_dword(dev, reg, new);
104 0 : pci_read_config_dword(dev, reg, &check);
105 :
106 0 : if ((new ^ check) & mask) {
107 0 : pci_err(dev, "BAR %d: error updating (%#08x != %#08x)\n",
108 : resno, new, check);
109 : }
110 :
111 0 : if (res->flags & IORESOURCE_MEM_64) {
112 0 : new = region.start >> 16 >> 16;
113 0 : pci_write_config_dword(dev, reg + 4, new);
114 0 : pci_read_config_dword(dev, reg + 4, &check);
115 0 : if (check != new) {
116 0 : pci_err(dev, "BAR %d: error updating (high %#08x != %#08x)\n",
117 : resno, new, check);
118 : }
119 : }
120 :
121 0 : if (disable)
122 0 : pci_write_config_word(dev, PCI_COMMAND, cmd);
123 : }
124 :
125 0 : void pci_update_resource(struct pci_dev *dev, int resno)
126 : {
127 0 : if (resno <= PCI_ROM_RESOURCE)
128 0 : 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 0 : }
134 :
135 0 : int pci_claim_resource(struct pci_dev *dev, int resource)
136 : {
137 0 : struct resource *res = &dev->resource[resource];
138 : struct resource *root, *conflict;
139 :
140 0 : if (res->flags & IORESOURCE_UNSET) {
141 0 : pci_info(dev, "can't claim BAR %d %pR: no address assigned\n",
142 : resource, res);
143 0 : 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 0 : if (res->flags & IORESOURCE_ROM_SHADOW)
152 : return 0;
153 :
154 0 : root = pci_find_parent_resource(dev, res);
155 0 : if (!root) {
156 0 : pci_info(dev, "can't claim BAR %d %pR: no compatible bridge window\n",
157 : resource, res);
158 0 : res->flags |= IORESOURCE_UNSET;
159 0 : return -EINVAL;
160 : }
161 :
162 0 : conflict = request_resource_conflict(root, res);
163 0 : if (conflict) {
164 0 : pci_info(dev, "can't claim BAR %d %pR: address conflict with %s %pR\n",
165 : resource, res, conflict->name, conflict);
166 0 : res->flags |= IORESOURCE_UNSET;
167 0 : return -EBUSY;
168 : }
169 :
170 : return 0;
171 : }
172 : EXPORT_SYMBOL(pci_claim_resource);
173 :
174 0 : void pci_disable_bridge_window(struct pci_dev *dev)
175 : {
176 : /* MMIO Base/Limit */
177 0 : pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0);
178 :
179 : /* Prefetchable MMIO Base/Limit */
180 0 : pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
181 0 : pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0);
182 0 : pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff);
183 0 : }
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 : */
194 0 : resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx)
195 : {
196 0 : return 0;
197 : }
198 :
199 0 : static 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 0 : fw_addr = pcibios_retrieve_fw_addr(dev, resno);
206 0 : if (!fw_addr)
207 : return -ENOMEM;
208 :
209 0 : start = res->start;
210 0 : end = res->end;
211 0 : res->start = fw_addr;
212 0 : res->end = res->start + size - 1;
213 0 : res->flags &= ~IORESOURCE_UNSET;
214 :
215 0 : root = pci_find_parent_resource(dev, res);
216 0 : 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 0 : 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 0 : if (res->flags & IORESOURCE_IO)
229 : root = &ioport_resource;
230 : else
231 0 : root = &iomem_resource;
232 : }
233 :
234 0 : pci_info(dev, "BAR %d: trying firmware assignment %pR\n",
235 : resno, res);
236 0 : conflict = request_resource_conflict(root, res);
237 0 : if (conflict) {
238 0 : pci_info(dev, "BAR %d: %pR conflicts with %s %pR\n",
239 : resno, res, conflict->name, conflict);
240 0 : res->start = start;
241 0 : res->end = end;
242 0 : res->flags |= IORESOURCE_UNSET;
243 0 : 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 : */
253 0 : resource_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 0 : return res->start;
259 : }
260 :
261 0 : static 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 0 : struct resource *res = dev->resource + resno;
265 : resource_size_t min;
266 : int ret;
267 :
268 0 : 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 0 : ret = pci_bus_alloc_resource(bus, res, size, align, min,
278 : IORESOURCE_PREFETCH | IORESOURCE_MEM_64,
279 : pcibios_align_resource, dev);
280 0 : 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 0 : if ((res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) ==
288 : (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) {
289 0 : ret = pci_bus_alloc_resource(bus, res, size, align, min,
290 : IORESOURCE_PREFETCH,
291 : pcibios_align_resource, dev);
292 0 : 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 0 : if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64))
303 0 : ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
304 : pcibios_align_resource, dev);
305 :
306 : return ret;
307 : }
308 :
309 0 : static 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 0 : bus = dev->bus;
316 0 : while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
317 0 : if (!bus->parent || !bus->self->transparent)
318 : break;
319 : bus = bus->parent;
320 : }
321 :
322 0 : return ret;
323 : }
324 :
325 0 : int pci_assign_resource(struct pci_dev *dev, int resno)
326 : {
327 0 : struct resource *res = dev->resource + resno;
328 : resource_size_t align, size;
329 : int ret;
330 :
331 0 : if (res->flags & IORESOURCE_PCI_FIXED)
332 : return 0;
333 :
334 0 : res->flags |= IORESOURCE_UNSET;
335 0 : align = pci_resource_alignment(dev, res);
336 0 : if (!align) {
337 0 : pci_info(dev, "BAR %d: can't assign %pR (bogus alignment)\n",
338 : resno, res);
339 0 : return -EINVAL;
340 : }
341 :
342 0 : size = resource_size(res);
343 0 : 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 0 : if (ret < 0) {
351 0 : pci_info(dev, "BAR %d: no space for %pR\n", resno, res);
352 0 : ret = pci_revert_fw_address(res, dev, resno, size);
353 : }
354 :
355 0 : if (ret < 0) {
356 0 : pci_info(dev, "BAR %d: failed to assign %pR\n", resno, res);
357 0 : return ret;
358 : }
359 :
360 0 : res->flags &= ~IORESOURCE_UNSET;
361 0 : res->flags &= ~IORESOURCE_STARTALIGN;
362 0 : pci_info(dev, "BAR %d: assigned %pR\n", resno, res);
363 0 : if (resno < PCI_BRIDGE_RESOURCES)
364 : pci_update_resource(dev, resno);
365 :
366 : return 0;
367 : }
368 : EXPORT_SYMBOL(pci_assign_resource);
369 :
370 0 : int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsize,
371 : resource_size_t min_align)
372 : {
373 0 : struct resource *res = dev->resource + resno;
374 : unsigned long flags;
375 : resource_size_t new_size;
376 : int ret;
377 :
378 0 : if (res->flags & IORESOURCE_PCI_FIXED)
379 : return 0;
380 :
381 0 : flags = res->flags;
382 0 : res->flags |= IORESOURCE_UNSET;
383 0 : if (!res->parent) {
384 0 : pci_info(dev, "BAR %d: can't reassign an unassigned resource %pR\n",
385 : resno, res);
386 0 : return -EINVAL;
387 : }
388 :
389 : /* already aligned with min_align */
390 0 : new_size = resource_size(res) + addsize;
391 0 : ret = _pci_assign_resource(dev, resno, new_size, min_align);
392 0 : if (ret) {
393 0 : res->flags = flags;
394 0 : pci_info(dev, "BAR %d: %pR (failed to expand by %#llx)\n",
395 : resno, res, (unsigned long long) addsize);
396 0 : return ret;
397 : }
398 :
399 0 : res->flags &= ~IORESOURCE_UNSET;
400 0 : res->flags &= ~IORESOURCE_STARTALIGN;
401 0 : pci_info(dev, "BAR %d: reassigned %pR (expanded by %#llx)\n",
402 : resno, res, (unsigned long long) addsize);
403 0 : if (resno < PCI_BRIDGE_RESOURCES)
404 : pci_update_resource(dev, resno);
405 :
406 : return 0;
407 : }
408 :
409 0 : void pci_release_resource(struct pci_dev *dev, int resno)
410 : {
411 0 : struct resource *res = dev->resource + resno;
412 :
413 0 : pci_info(dev, "BAR %d: releasing %pR\n", resno, res);
414 :
415 0 : if (!res->parent)
416 : return;
417 :
418 0 : release_resource(res);
419 0 : res->end = resource_size(res) - 1;
420 0 : res->start = 0;
421 0 : res->flags |= IORESOURCE_UNSET;
422 : }
423 : EXPORT_SYMBOL(pci_release_resource);
424 :
425 0 : int pci_resize_resource(struct pci_dev *dev, int resno, int size)
426 : {
427 0 : 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 0 : host = pci_find_host_bridge(dev->bus);
435 0 : if (host->preserve_config)
436 : return -ENOTSUPP;
437 :
438 : /* Make sure the resource isn't assigned before resizing it. */
439 0 : if (!(res->flags & IORESOURCE_UNSET))
440 : return -EBUSY;
441 :
442 0 : pci_read_config_word(dev, PCI_COMMAND, &cmd);
443 0 : if (cmd & PCI_COMMAND_MEMORY)
444 : return -EBUSY;
445 :
446 0 : sizes = pci_rebar_get_possible_sizes(dev, resno);
447 0 : if (!sizes)
448 : return -ENOTSUPP;
449 :
450 0 : if (!(sizes & BIT(size)))
451 : return -EINVAL;
452 :
453 0 : old = pci_rebar_get_current_size(dev, resno);
454 0 : if (old < 0)
455 : return old;
456 :
457 0 : ret = pci_rebar_set_size(dev, resno, size);
458 0 : if (ret)
459 : return ret;
460 :
461 0 : 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 0 : if (dev->bus->self) {
465 0 : ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
466 0 : if (ret)
467 : goto error_resize;
468 : }
469 : return 0;
470 :
471 : error_resize:
472 0 : pci_rebar_set_size(dev, resno, old);
473 0 : res->end = res->start + pci_rebar_size_to_bytes(old) - 1;
474 0 : return ret;
475 : }
476 : EXPORT_SYMBOL(pci_resize_resource);
477 :
478 0 : int pci_enable_resources(struct pci_dev *dev, int mask)
479 : {
480 : u16 cmd, old_cmd;
481 : int i;
482 : struct resource *r;
483 :
484 0 : pci_read_config_word(dev, PCI_COMMAND, &cmd);
485 0 : old_cmd = cmd;
486 :
487 0 : for (i = 0; i < PCI_NUM_RESOURCES; i++) {
488 0 : if (!(mask & (1 << i)))
489 0 : continue;
490 :
491 0 : r = &dev->resource[i];
492 :
493 0 : if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
494 0 : continue;
495 0 : if ((i == PCI_ROM_RESOURCE) &&
496 0 : (!(r->flags & IORESOURCE_ROM_ENABLE)))
497 0 : continue;
498 :
499 0 : if (r->flags & IORESOURCE_UNSET) {
500 0 : pci_err(dev, "can't enable device: BAR %d %pR not assigned\n",
501 : i, r);
502 0 : return -EINVAL;
503 : }
504 :
505 0 : if (!r->parent) {
506 0 : pci_err(dev, "can't enable device: BAR %d %pR not claimed\n",
507 : i, r);
508 0 : return -EINVAL;
509 : }
510 :
511 0 : if (r->flags & IORESOURCE_IO)
512 0 : cmd |= PCI_COMMAND_IO;
513 0 : if (r->flags & IORESOURCE_MEM)
514 0 : cmd |= PCI_COMMAND_MEMORY;
515 : }
516 :
517 0 : if (cmd != old_cmd) {
518 0 : pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
519 0 : pci_write_config_word(dev, PCI_COMMAND, cmd);
520 : }
521 : return 0;
522 : }
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