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 https://lkml.org/lkml/2005/8/30/138. 77 */ 78 if (!(res->flags & IORESOURCE_ROM_ENABLE)) 79 return; 80 81 reg = dev->rom_base_reg; 82 new |= PCI_ROM_ADDRESS_ENABLE; 83 } else 84 return; 85 86 /* 87 * We can't update a 64-bit BAR atomically, so when possible, 88 * disable decoding so that a half-updated BAR won't conflict 89 * with another device. 90 */ 91 disable = (res->flags & IORESOURCE_MEM_64) && !dev->mmio_always_on; 92 if (disable) { 93 pci_read_config_word(dev, PCI_COMMAND, &cmd); 94 pci_write_config_word(dev, PCI_COMMAND, 95 cmd & ~PCI_COMMAND_MEMORY); 96 } 97 98 pci_write_config_dword(dev, reg, new); 99 pci_read_config_dword(dev, reg, &check); 100 101 if ((new ^ check) & mask) { 102 pci_err(dev, "BAR %d: error updating (%#08x != %#08x)\n", 103 resno, new, check); 104 } 105 106 if (res->flags & IORESOURCE_MEM_64) { 107 new = region.start >> 16 >> 16; 108 pci_write_config_dword(dev, reg + 4, new); 109 pci_read_config_dword(dev, reg + 4, &check); 110 if (check != new) { 111 pci_err(dev, "BAR %d: error updating (high %#08x != %#08x)\n", 112 resno, new, check); 113 } 114 } 115 116 if (disable) 117 pci_write_config_word(dev, PCI_COMMAND, cmd); 118 } 119 120 void pci_update_resource(struct pci_dev *dev, int resno) 121 { 122 if (resno <= PCI_ROM_RESOURCE) 123 pci_std_update_resource(dev, resno); 124 #ifdef CONFIG_PCI_IOV 125 else if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END) 126 pci_iov_update_resource(dev, resno); 127 #endif 128 } 129 130 int pci_claim_resource(struct pci_dev *dev, int resource) 131 { 132 struct resource *res = &dev->resource[resource]; 133 struct resource *root, *conflict; 134 135 if (res->flags & IORESOURCE_UNSET) { 136 pci_info(dev, "can't claim BAR %d %pR: no address assigned\n", 137 resource, res); 138 return -EINVAL; 139 } 140 141 /* 142 * If we have a shadow copy in RAM, the PCI device doesn't respond 143 * to the shadow range, so we don't need to claim it, and upstream 144 * bridges don't need to route the range to the device. 145 */ 146 if (res->flags & IORESOURCE_ROM_SHADOW) 147 return 0; 148 149 root = pci_find_parent_resource(dev, res); 150 if (!root) { 151 pci_info(dev, "can't claim BAR %d %pR: no compatible bridge window\n", 152 resource, res); 153 res->flags |= IORESOURCE_UNSET; 154 return -EINVAL; 155 } 156 157 conflict = request_resource_conflict(root, res); 158 if (conflict) { 159 pci_info(dev, "can't claim BAR %d %pR: address conflict with %s %pR\n", 160 resource, res, conflict->name, conflict); 161 res->flags |= IORESOURCE_UNSET; 162 return -EBUSY; 163 } 164 165 return 0; 166 } 167 EXPORT_SYMBOL(pci_claim_resource); 168 169 void pci_disable_bridge_window(struct pci_dev *dev) 170 { 171 /* MMIO Base/Limit */ 172 pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0); 173 174 /* Prefetchable MMIO Base/Limit */ 175 pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0); 176 pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0); 177 pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff); 178 } 179 180 /* 181 * Generic function that returns a value indicating that the device's 182 * original BIOS BAR address was not saved and so is not available for 183 * reinstatement. 184 * 185 * Can be over-ridden by architecture specific code that implements 186 * reinstatement functionality rather than leaving it disabled when 187 * normal allocation attempts fail. 188 */ 189 resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx) 190 { 191 return 0; 192 } 193 194 static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev, 195 int resno, resource_size_t size) 196 { 197 struct resource *root, *conflict; 198 resource_size_t fw_addr, start, end; 199 200 fw_addr = pcibios_retrieve_fw_addr(dev, resno); 201 if (!fw_addr) 202 return -ENOMEM; 203 204 start = res->start; 205 end = res->end; 206 res->start = fw_addr; 207 res->end = res->start + size - 1; 208 res->flags &= ~IORESOURCE_UNSET; 209 210 root = pci_find_parent_resource(dev, res); 211 if (!root) { 212 if (res->flags & IORESOURCE_IO) 213 root = &ioport_resource; 214 else 215 root = &iomem_resource; 216 } 217 218 pci_info(dev, "BAR %d: trying firmware assignment %pR\n", 219 resno, res); 220 conflict = request_resource_conflict(root, res); 221 if (conflict) { 222 pci_info(dev, "BAR %d: %pR conflicts with %s %pR\n", 223 resno, res, conflict->name, conflict); 224 res->start = start; 225 res->end = end; 226 res->flags |= IORESOURCE_UNSET; 227 return -EBUSY; 228 } 229 return 0; 230 } 231 232 /* 233 * We don't have to worry about legacy ISA devices, so nothing to do here. 234 * This is marked as __weak because multiple architectures define it; it should 235 * eventually go away. 236 */ 237 resource_size_t __weak pcibios_align_resource(void *data, 238 const struct resource *res, 239 resource_size_t size, 240 resource_size_t align) 241 { 242 return res->start; 243 } 244 245 static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev, 246 int resno, resource_size_t size, resource_size_t align) 247 { 248 struct resource *res = dev->resource + resno; 249 resource_size_t min; 250 int ret; 251 252 min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM; 253 254 /* 255 * First, try exact prefetching match. Even if a 64-bit 256 * prefetchable bridge window is below 4GB, we can't put a 32-bit 257 * prefetchable resource in it because pbus_size_mem() assumes a 258 * 64-bit window will contain no 32-bit resources. If we assign 259 * things differently than they were sized, not everything will fit. 260 */ 261 ret = pci_bus_alloc_resource(bus, res, size, align, min, 262 IORESOURCE_PREFETCH | IORESOURCE_MEM_64, 263 pcibios_align_resource, dev); 264 if (ret == 0) 265 return 0; 266 267 /* 268 * If the prefetchable window is only 32 bits wide, we can put 269 * 64-bit prefetchable resources in it. 270 */ 271 if ((res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) == 272 (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) { 273 ret = pci_bus_alloc_resource(bus, res, size, align, min, 274 IORESOURCE_PREFETCH, 275 pcibios_align_resource, dev); 276 if (ret == 0) 277 return 0; 278 } 279 280 /* 281 * If we didn't find a better match, we can put any memory resource 282 * in a non-prefetchable window. If this resource is 32 bits and 283 * non-prefetchable, the first call already tried the only possibility 284 * so we don't need to try again. 285 */ 286 if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) 287 ret = pci_bus_alloc_resource(bus, res, size, align, min, 0, 288 pcibios_align_resource, dev); 289 290 return ret; 291 } 292 293 static int _pci_assign_resource(struct pci_dev *dev, int resno, 294 resource_size_t size, resource_size_t min_align) 295 { 296 struct pci_bus *bus; 297 int ret; 298 299 bus = dev->bus; 300 while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) { 301 if (!bus->parent || !bus->self->transparent) 302 break; 303 bus = bus->parent; 304 } 305 306 return ret; 307 } 308 309 int pci_assign_resource(struct pci_dev *dev, int resno) 310 { 311 struct resource *res = dev->resource + resno; 312 resource_size_t align, size; 313 int ret; 314 315 if (res->flags & IORESOURCE_PCI_FIXED) 316 return 0; 317 318 res->flags |= IORESOURCE_UNSET; 319 align = pci_resource_alignment(dev, res); 320 if (!align) { 321 pci_info(dev, "BAR %d: can't assign %pR (bogus alignment)\n", 322 resno, res); 323 return -EINVAL; 324 } 325 326 size = resource_size(res); 327 ret = _pci_assign_resource(dev, resno, size, align); 328 329 /* 330 * If we failed to assign anything, let's try the address 331 * where firmware left it. That at least has a chance of 332 * working, which is better than just leaving it disabled. 333 */ 334 if (ret < 0) { 335 pci_info(dev, "BAR %d: no space for %pR\n", resno, res); 336 ret = pci_revert_fw_address(res, dev, resno, size); 337 } 338 339 if (ret < 0) { 340 pci_info(dev, "BAR %d: failed to assign %pR\n", resno, res); 341 return ret; 342 } 343 344 res->flags &= ~IORESOURCE_UNSET; 345 res->flags &= ~IORESOURCE_STARTALIGN; 346 pci_info(dev, "BAR %d: assigned %pR\n", resno, res); 347 if (resno < PCI_BRIDGE_RESOURCES) 348 pci_update_resource(dev, resno); 349 350 return 0; 351 } 352 EXPORT_SYMBOL(pci_assign_resource); 353 354 int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsize, 355 resource_size_t min_align) 356 { 357 struct resource *res = dev->resource + resno; 358 unsigned long flags; 359 resource_size_t new_size; 360 int ret; 361 362 if (res->flags & IORESOURCE_PCI_FIXED) 363 return 0; 364 365 flags = res->flags; 366 res->flags |= IORESOURCE_UNSET; 367 if (!res->parent) { 368 pci_info(dev, "BAR %d: can't reassign an unassigned resource %pR\n", 369 resno, res); 370 return -EINVAL; 371 } 372 373 /* already aligned with min_align */ 374 new_size = resource_size(res) + addsize; 375 ret = _pci_assign_resource(dev, resno, new_size, min_align); 376 if (ret) { 377 res->flags = flags; 378 pci_info(dev, "BAR %d: %pR (failed to expand by %#llx)\n", 379 resno, res, (unsigned long long) addsize); 380 return ret; 381 } 382 383 res->flags &= ~IORESOURCE_UNSET; 384 res->flags &= ~IORESOURCE_STARTALIGN; 385 pci_info(dev, "BAR %d: reassigned %pR (expanded by %#llx)\n", 386 resno, res, (unsigned long long) addsize); 387 if (resno < PCI_BRIDGE_RESOURCES) 388 pci_update_resource(dev, resno); 389 390 return 0; 391 } 392 393 void pci_release_resource(struct pci_dev *dev, int resno) 394 { 395 struct resource *res = dev->resource + resno; 396 397 pci_info(dev, "BAR %d: releasing %pR\n", resno, res); 398 399 if (!res->parent) 400 return; 401 402 release_resource(res); 403 res->end = resource_size(res) - 1; 404 res->start = 0; 405 res->flags |= IORESOURCE_UNSET; 406 } 407 EXPORT_SYMBOL(pci_release_resource); 408 409 int pci_resize_resource(struct pci_dev *dev, int resno, int size) 410 { 411 struct resource *res = dev->resource + resno; 412 int old, ret; 413 u32 sizes; 414 u16 cmd; 415 416 /* Make sure the resource isn't assigned before resizing it. */ 417 if (!(res->flags & IORESOURCE_UNSET)) 418 return -EBUSY; 419 420 pci_read_config_word(dev, PCI_COMMAND, &cmd); 421 if (cmd & PCI_COMMAND_MEMORY) 422 return -EBUSY; 423 424 sizes = pci_rebar_get_possible_sizes(dev, resno); 425 if (!sizes) 426 return -ENOTSUPP; 427 428 if (!(sizes & BIT(size))) 429 return -EINVAL; 430 431 old = pci_rebar_get_current_size(dev, resno); 432 if (old < 0) 433 return old; 434 435 ret = pci_rebar_set_size(dev, resno, size); 436 if (ret) 437 return ret; 438 439 res->end = res->start + pci_rebar_size_to_bytes(size) - 1; 440 441 /* Check if the new config works by trying to assign everything. */ 442 if (dev->bus->self) { 443 ret = pci_reassign_bridge_resources(dev->bus->self, res->flags); 444 if (ret) 445 goto error_resize; 446 } 447 return 0; 448 449 error_resize: 450 pci_rebar_set_size(dev, resno, old); 451 res->end = res->start + pci_rebar_size_to_bytes(old) - 1; 452 return ret; 453 } 454 EXPORT_SYMBOL(pci_resize_resource); 455 456 int pci_enable_resources(struct pci_dev *dev, int mask) 457 { 458 u16 cmd, old_cmd; 459 int i; 460 struct resource *r; 461 462 pci_read_config_word(dev, PCI_COMMAND, &cmd); 463 old_cmd = cmd; 464 465 for (i = 0; i < PCI_NUM_RESOURCES; i++) { 466 if (!(mask & (1 << i))) 467 continue; 468 469 r = &dev->resource[i]; 470 471 if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM))) 472 continue; 473 if ((i == PCI_ROM_RESOURCE) && 474 (!(r->flags & IORESOURCE_ROM_ENABLE))) 475 continue; 476 477 if (r->flags & IORESOURCE_UNSET) { 478 pci_err(dev, "can't enable device: BAR %d %pR not assigned\n", 479 i, r); 480 return -EINVAL; 481 } 482 483 if (!r->parent) { 484 pci_err(dev, "can't enable device: BAR %d %pR not claimed\n", 485 i, r); 486 return -EINVAL; 487 } 488 489 if (r->flags & IORESOURCE_IO) 490 cmd |= PCI_COMMAND_IO; 491 if (r->flags & IORESOURCE_MEM) 492 cmd |= PCI_COMMAND_MEMORY; 493 } 494 495 if (cmd != old_cmd) { 496 pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd); 497 pci_write_config_word(dev, PCI_COMMAND, cmd); 498 } 499 return 0; 500 } 501