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 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 * 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 } 124 125 void 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 } 134 135 int 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 } 172 EXPORT_SYMBOL(pci_claim_resource); 173 174 void 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 */ 194 resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx) 195 { 196 return 0; 197 } 198 199 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 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 */ 253 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 return res->start; 259 } 260 261 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 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 } 308 309 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 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 } 324 325 int 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 } 368 EXPORT_SYMBOL(pci_assign_resource); 369 370 int 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 } 408 409 void 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 } 423 EXPORT_SYMBOL(pci_release_resource); 424 425 int 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; 470 471 error_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 } 476 EXPORT_SYMBOL(pci_resize_resource); 477 478 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 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 } 523