Furquan Shaikh | 6939574 | 2020-05-15 15:43:15 -0700 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | |
| 3 | #include <console/console.h> |
| 4 | #include <device/device.h> |
| 5 | #include <post.h> |
| 6 | |
| 7 | /** |
| 8 | * Round a number up to an alignment. |
| 9 | * |
| 10 | * @param val The starting value. |
| 11 | * @param pow Alignment as a power of two. |
| 12 | * @return Rounded up number. |
| 13 | */ |
| 14 | static resource_t round(resource_t val, unsigned long pow) |
| 15 | { |
| 16 | resource_t mask; |
| 17 | mask = (1ULL << pow) - 1ULL; |
| 18 | val += mask; |
| 19 | val &= ~mask; |
| 20 | return val; |
| 21 | } |
| 22 | |
| 23 | static const char *resource2str(struct resource *res) |
| 24 | { |
| 25 | if (res->flags & IORESOURCE_IO) |
| 26 | return "io"; |
| 27 | if (res->flags & IORESOURCE_PREFETCH) |
| 28 | return "prefmem"; |
| 29 | if (res->flags & IORESOURCE_MEM) |
| 30 | return "mem"; |
| 31 | return "undefined"; |
| 32 | } |
| 33 | |
| 34 | /** |
| 35 | * This function is the guts of the resource allocator. |
| 36 | * |
| 37 | * The problem. |
| 38 | * - Allocate resource locations for every device. |
| 39 | * - Don't overlap, and follow the rules of bridges. |
| 40 | * - Don't overlap with resources in fixed locations. |
| 41 | * - Be efficient so we don't have ugly strategies. |
| 42 | * |
| 43 | * The strategy. |
| 44 | * - Devices that have fixed addresses are the minority so don't |
| 45 | * worry about them too much. Instead only use part of the address |
| 46 | * space for devices with programmable addresses. This easily handles |
| 47 | * everything except bridges. |
| 48 | * |
| 49 | * - PCI devices are required to have their sizes and their alignments |
| 50 | * equal. In this case an optimal solution to the packing problem |
| 51 | * exists. Allocate all devices from highest alignment to least |
| 52 | * alignment or vice versa. Use this. |
| 53 | * |
| 54 | * - So we can handle more than PCI run two allocation passes on bridges. The |
| 55 | * first to see how large the resources are behind the bridge, and what |
| 56 | * their alignment requirements are. The second to assign a safe address to |
| 57 | * the devices behind the bridge. This allows us to treat a bridge as just |
| 58 | * a device with a couple of resources, and not need to special case it in |
| 59 | * the allocator. Also this allows handling of other types of bridges. |
| 60 | * |
| 61 | * @param bus The bus we are traversing. |
| 62 | * @param bridge The bridge resource which must contain the bus' resources. |
| 63 | * @param type_mask This value gets ANDed with the resource type. |
| 64 | * @param type This value must match the result of the AND. |
| 65 | * @return TODO |
| 66 | */ |
| 67 | static void compute_resources(struct bus *bus, struct resource *bridge, |
| 68 | unsigned long type_mask, unsigned long type) |
| 69 | { |
| 70 | const struct device *dev; |
| 71 | struct resource *resource; |
| 72 | resource_t base; |
| 73 | base = round(bridge->base, bridge->align); |
| 74 | |
| 75 | if (!bus) |
| 76 | return; |
| 77 | |
| 78 | printk(BIOS_SPEW, "%s %s: base: %llx size: %llx align: %d gran: %d" |
| 79 | " limit: %llx\n", dev_path(bus->dev), resource2str(bridge), |
| 80 | base, bridge->size, bridge->align, |
| 81 | bridge->gran, bridge->limit); |
| 82 | |
| 83 | /* For each child which is a bridge, compute the resource needs. */ |
| 84 | for (dev = bus->children; dev; dev = dev->sibling) { |
| 85 | struct resource *child_bridge; |
| 86 | |
| 87 | if (!dev->link_list) |
| 88 | continue; |
| 89 | |
| 90 | /* Find the resources with matching type flags. */ |
| 91 | for (child_bridge = dev->resource_list; child_bridge; |
| 92 | child_bridge = child_bridge->next) { |
| 93 | struct bus* link; |
| 94 | |
| 95 | if (!(child_bridge->flags & IORESOURCE_BRIDGE) |
| 96 | || (child_bridge->flags & type_mask) != type) |
| 97 | continue; |
| 98 | |
| 99 | /* |
| 100 | * Split prefetchable memory if combined. Many domains |
| 101 | * use the same address space for prefetchable memory |
| 102 | * and non-prefetchable memory. Bridges below them need |
| 103 | * it separated. Add the PREFETCH flag to the type_mask |
| 104 | * and type. |
| 105 | */ |
| 106 | link = dev->link_list; |
| 107 | while (link && link->link_num != |
| 108 | IOINDEX_LINK(child_bridge->index)) |
| 109 | link = link->next; |
| 110 | |
| 111 | if (link == NULL) { |
| 112 | printk(BIOS_ERR, "link %ld not found on %s\n", |
| 113 | IOINDEX_LINK(child_bridge->index), |
| 114 | dev_path(dev)); |
| 115 | } |
| 116 | |
| 117 | compute_resources(link, child_bridge, |
| 118 | type_mask | IORESOURCE_PREFETCH, |
| 119 | type | (child_bridge->flags & |
| 120 | IORESOURCE_PREFETCH)); |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | /* Remember we haven't found anything yet. */ |
| 125 | resource = NULL; |
| 126 | |
| 127 | /* |
| 128 | * Walk through all the resources on the current bus and compute the |
| 129 | * amount of address space taken by them. Take granularity and |
| 130 | * alignment into account. |
| 131 | */ |
| 132 | while ((dev = largest_resource(bus, &resource, type_mask, type))) { |
| 133 | |
| 134 | /* Size 0 resources can be skipped. */ |
| 135 | if (!resource->size) |
| 136 | continue; |
| 137 | |
| 138 | /* Propagate the resource alignment to the bridge resource. */ |
| 139 | if (resource->align > bridge->align) |
| 140 | bridge->align = resource->align; |
| 141 | |
| 142 | /* Propagate the resource limit to the bridge register. */ |
| 143 | if (bridge->limit > resource->limit) |
| 144 | bridge->limit = resource->limit; |
| 145 | |
| 146 | /* Warn if it looks like APICs aren't declared. */ |
| 147 | if ((resource->limit == 0xffffffff) && |
| 148 | (resource->flags & IORESOURCE_ASSIGNED)) { |
| 149 | printk(BIOS_ERR, |
| 150 | "Resource limit looks wrong! (no APIC?)\n"); |
| 151 | printk(BIOS_ERR, "%s %02lx limit %08llx\n", |
| 152 | dev_path(dev), resource->index, resource->limit); |
| 153 | } |
| 154 | |
| 155 | if (resource->flags & IORESOURCE_IO) { |
| 156 | /* |
| 157 | * Don't allow potential aliases over the legacy PCI |
| 158 | * expansion card addresses. The legacy PCI decodes |
| 159 | * only 10 bits, uses 0x100 - 0x3ff. Therefore, only |
| 160 | * 0x00 - 0xff can be used out of each 0x400 block of |
| 161 | * I/O space. |
| 162 | */ |
| 163 | if ((base & 0x300) != 0) { |
| 164 | base = (base & ~0x3ff) + 0x400; |
| 165 | } |
| 166 | /* |
| 167 | * Don't allow allocations in the VGA I/O range. |
| 168 | * PCI has special cases for that. |
| 169 | */ |
| 170 | else if ((base >= 0x3b0) && (base <= 0x3df)) { |
| 171 | base = 0x3e0; |
| 172 | } |
| 173 | } |
| 174 | /* Base must be aligned. */ |
| 175 | base = round(base, resource->align); |
| 176 | resource->base = base; |
| 177 | base += resource->size; |
| 178 | |
| 179 | printk(BIOS_SPEW, "%s %02lx * [0x%llx - 0x%llx] %s\n", |
| 180 | dev_path(dev), resource->index, resource->base, |
| 181 | resource->base + resource->size - 1, |
| 182 | resource2str(resource)); |
| 183 | } |
| 184 | |
| 185 | /* |
| 186 | * A PCI bridge resource does not need to be a power of two size, but |
| 187 | * it does have a minimum granularity. Round the size up to that |
| 188 | * minimum granularity so we know not to place something else at an |
| 189 | * address positively decoded by the bridge. |
| 190 | */ |
| 191 | bridge->size = round(base, bridge->gran) - |
| 192 | round(bridge->base, bridge->align); |
| 193 | |
| 194 | printk(BIOS_SPEW, "%s %s: base: %llx size: %llx align: %d gran: %d" |
| 195 | " limit: %llx done\n", dev_path(bus->dev), |
| 196 | resource2str(bridge), |
| 197 | base, bridge->size, bridge->align, bridge->gran, bridge->limit); |
| 198 | } |
| 199 | |
| 200 | /** |
| 201 | * This function is the second part of the resource allocator. |
| 202 | * |
| 203 | * See the compute_resources function for a more detailed explanation. |
| 204 | * |
| 205 | * This function assigns the resources a value. |
| 206 | * |
| 207 | * @param bus The bus we are traversing. |
| 208 | * @param bridge The bridge resource which must contain the bus' resources. |
| 209 | * @param type_mask This value gets ANDed with the resource type. |
| 210 | * @param type This value must match the result of the AND. |
| 211 | * |
| 212 | * @see compute_resources |
| 213 | */ |
| 214 | static void __allocate_resources(struct bus *bus, struct resource *bridge, |
| 215 | unsigned long type_mask, unsigned long type) |
| 216 | { |
| 217 | const struct device *dev; |
| 218 | struct resource *resource; |
| 219 | resource_t base; |
| 220 | base = bridge->base; |
| 221 | |
| 222 | if (!bus) |
| 223 | return; |
| 224 | |
| 225 | printk(BIOS_SPEW, "%s %s: base:%llx size:%llx align:%d gran:%d " |
| 226 | "limit:%llx\n", dev_path(bus->dev), |
| 227 | resource2str(bridge), |
| 228 | base, bridge->size, bridge->align, bridge->gran, bridge->limit); |
| 229 | |
| 230 | /* Remember we haven't found anything yet. */ |
| 231 | resource = NULL; |
| 232 | |
| 233 | /* |
| 234 | * Walk through all the resources on the current bus and allocate them |
| 235 | * address space. |
| 236 | */ |
| 237 | while ((dev = largest_resource(bus, &resource, type_mask, type))) { |
| 238 | |
| 239 | /* Propagate the bridge limit to the resource register. */ |
| 240 | if (resource->limit > bridge->limit) |
| 241 | resource->limit = bridge->limit; |
| 242 | |
| 243 | /* Size 0 resources can be skipped. */ |
Furquan Shaikh | 468bc6c | 2020-05-20 10:18:35 -0700 | [diff] [blame] | 244 | if (!resource->size) |
Furquan Shaikh | 6939574 | 2020-05-15 15:43:15 -0700 | [diff] [blame] | 245 | continue; |
Furquan Shaikh | 6939574 | 2020-05-15 15:43:15 -0700 | [diff] [blame] | 246 | |
| 247 | if (resource->flags & IORESOURCE_IO) { |
| 248 | /* |
| 249 | * Don't allow potential aliases over the legacy PCI |
| 250 | * expansion card addresses. The legacy PCI decodes |
| 251 | * only 10 bits, uses 0x100 - 0x3ff. Therefore, only |
| 252 | * 0x00 - 0xff can be used out of each 0x400 block of |
| 253 | * I/O space. |
| 254 | */ |
| 255 | if ((base & 0x300) != 0) { |
| 256 | base = (base & ~0x3ff) + 0x400; |
| 257 | } |
| 258 | /* |
| 259 | * Don't allow allocations in the VGA I/O range. |
| 260 | * PCI has special cases for that. |
| 261 | */ |
| 262 | else if ((base >= 0x3b0) && (base <= 0x3df)) { |
| 263 | base = 0x3e0; |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | if ((round(base, resource->align) + resource->size - 1) <= |
| 268 | resource->limit) { |
| 269 | /* Base must be aligned. */ |
| 270 | base = round(base, resource->align); |
| 271 | resource->base = base; |
| 272 | resource->limit = resource->base + resource->size - 1; |
| 273 | resource->flags |= IORESOURCE_ASSIGNED; |
| 274 | resource->flags &= ~IORESOURCE_STORED; |
| 275 | base += resource->size; |
| 276 | } else { |
| 277 | printk(BIOS_ERR, "!! Resource didn't fit !!\n"); |
| 278 | printk(BIOS_ERR, " aligned base %llx size %llx " |
| 279 | "limit %llx\n", round(base, resource->align), |
| 280 | resource->size, resource->limit); |
| 281 | printk(BIOS_ERR, " %llx needs to be <= %llx " |
| 282 | "(limit)\n", (round(base, resource->align) + |
| 283 | resource->size) - 1, resource->limit); |
| 284 | printk(BIOS_ERR, " %s%s %02lx * [0x%llx - 0x%llx]" |
| 285 | " %s\n", (resource->flags & IORESOURCE_ASSIGNED) |
| 286 | ? "Assigned: " : "", dev_path(dev), |
| 287 | resource->index, resource->base, |
| 288 | resource->base + resource->size - 1, |
| 289 | resource2str(resource)); |
| 290 | } |
| 291 | |
| 292 | printk(BIOS_SPEW, "%s %02lx * [0x%llx - 0x%llx] %s\n", |
| 293 | dev_path(dev), resource->index, resource->base, |
| 294 | resource->size ? resource->base + resource->size - 1 : |
| 295 | resource->base, resource2str(resource)); |
| 296 | } |
| 297 | |
| 298 | /* |
| 299 | * A PCI bridge resource does not need to be a power of two size, but |
| 300 | * it does have a minimum granularity. Round the size up to that |
| 301 | * minimum granularity so we know not to place something else at an |
| 302 | * address positively decoded by the bridge. |
| 303 | */ |
| 304 | |
| 305 | bridge->flags |= IORESOURCE_ASSIGNED; |
| 306 | |
| 307 | printk(BIOS_SPEW, "%s %s: next_base: %llx size: %llx align: %d " |
| 308 | "gran: %d done\n", dev_path(bus->dev), |
| 309 | resource2str(bridge), base, bridge->size, bridge->align, |
| 310 | bridge->gran); |
| 311 | |
| 312 | /* For each child which is a bridge, __allocate_resources. */ |
| 313 | for (dev = bus->children; dev; dev = dev->sibling) { |
| 314 | struct resource *child_bridge; |
| 315 | |
| 316 | if (!dev->link_list) |
| 317 | continue; |
| 318 | |
| 319 | /* Find the resources with matching type flags. */ |
| 320 | for (child_bridge = dev->resource_list; child_bridge; |
| 321 | child_bridge = child_bridge->next) { |
| 322 | struct bus* link; |
| 323 | |
| 324 | if (!(child_bridge->flags & IORESOURCE_BRIDGE) || |
| 325 | (child_bridge->flags & type_mask) != type) |
| 326 | continue; |
| 327 | |
| 328 | /* |
| 329 | * Split prefetchable memory if combined. Many domains |
| 330 | * use the same address space for prefetchable memory |
| 331 | * and non-prefetchable memory. Bridges below them need |
| 332 | * it separated. Add the PREFETCH flag to the type_mask |
| 333 | * and type. |
| 334 | */ |
| 335 | link = dev->link_list; |
| 336 | while (link && link->link_num != |
| 337 | IOINDEX_LINK(child_bridge->index)) |
| 338 | link = link->next; |
| 339 | if (link == NULL) |
| 340 | printk(BIOS_ERR, "link %ld not found on %s\n", |
| 341 | IOINDEX_LINK(child_bridge->index), |
| 342 | dev_path(dev)); |
| 343 | |
| 344 | __allocate_resources(link, child_bridge, |
| 345 | type_mask | IORESOURCE_PREFETCH, |
| 346 | type | (child_bridge->flags & |
| 347 | IORESOURCE_PREFETCH)); |
| 348 | } |
| 349 | } |
| 350 | } |
| 351 | |
| 352 | static int resource_is(struct resource *res, u32 type) |
| 353 | { |
| 354 | return (res->flags & IORESOURCE_TYPE_MASK) == type; |
| 355 | } |
| 356 | |
| 357 | struct constraints { |
| 358 | struct resource io, mem; |
| 359 | }; |
| 360 | |
| 361 | static struct resource *resource_limit(struct constraints *limits, |
| 362 | struct resource *res) |
| 363 | { |
| 364 | struct resource *lim = NULL; |
| 365 | |
| 366 | /* MEM, or I/O - skip any others. */ |
| 367 | if (resource_is(res, IORESOURCE_MEM)) |
| 368 | lim = &limits->mem; |
| 369 | else if (resource_is(res, IORESOURCE_IO)) |
| 370 | lim = &limits->io; |
| 371 | |
| 372 | return lim; |
| 373 | } |
| 374 | |
| 375 | static void constrain_resources(const struct device *dev, |
| 376 | struct constraints* limits) |
| 377 | { |
| 378 | const struct device *child; |
| 379 | struct resource *res; |
| 380 | struct resource *lim; |
| 381 | struct bus *link; |
| 382 | |
| 383 | /* Constrain limits based on the fixed resources of this device. */ |
| 384 | for (res = dev->resource_list; res; res = res->next) { |
| 385 | if (!(res->flags & IORESOURCE_FIXED)) |
| 386 | continue; |
| 387 | if (!res->size) { |
| 388 | /* It makes no sense to have 0-sized, fixed resources.*/ |
| 389 | printk(BIOS_ERR, "skipping %s@%lx fixed resource, " |
| 390 | "size=0!\n", dev_path(dev), res->index); |
| 391 | continue; |
| 392 | } |
| 393 | |
| 394 | lim = resource_limit(limits, res); |
| 395 | if (!lim) |
| 396 | continue; |
| 397 | |
| 398 | /* |
| 399 | * Is it a fixed resource outside the current known region? |
| 400 | * If so, we don't have to consider it - it will be handled |
| 401 | * correctly and doesn't affect current region's limits. |
| 402 | */ |
| 403 | if (((res->base + res->size -1) < lim->base) |
| 404 | || (res->base > lim->limit)) |
| 405 | continue; |
| 406 | |
| 407 | printk(BIOS_SPEW, "%s: %s %02lx base %08llx limit %08llx %s (fixed)\n", |
| 408 | __func__, dev_path(dev), res->index, res->base, |
| 409 | res->base + res->size - 1, resource2str(res)); |
| 410 | |
| 411 | /* |
| 412 | * Choose to be above or below fixed resources. This check is |
| 413 | * signed so that "negative" amounts of space are handled |
| 414 | * correctly. |
| 415 | */ |
| 416 | if ((signed long long)(lim->limit - (res->base + res->size -1)) |
| 417 | > (signed long long)(res->base - lim->base)) |
| 418 | lim->base = res->base + res->size; |
| 419 | else |
| 420 | lim->limit = res->base -1; |
| 421 | } |
| 422 | |
| 423 | /* Descend into every enabled child and look for fixed resources. */ |
| 424 | for (link = dev->link_list; link; link = link->next) { |
| 425 | for (child = link->children; child; child = child->sibling) { |
| 426 | if (child->enabled) |
| 427 | constrain_resources(child, limits); |
| 428 | } |
| 429 | } |
| 430 | } |
| 431 | |
| 432 | static void avoid_fixed_resources(const struct device *dev) |
| 433 | { |
| 434 | struct constraints limits; |
| 435 | struct resource *res; |
| 436 | struct resource *lim; |
| 437 | |
| 438 | printk(BIOS_SPEW, "%s: %s\n", __func__, dev_path(dev)); |
| 439 | |
| 440 | /* Initialize constraints to maximum size. */ |
| 441 | limits.io.base = 0; |
| 442 | limits.io.limit = 0xffffffffffffffffULL; |
| 443 | limits.mem.base = 0; |
| 444 | limits.mem.limit = 0xffffffffffffffffULL; |
| 445 | |
| 446 | /* Constrain the limits to dev's initial resources. */ |
| 447 | for (res = dev->resource_list; res; res = res->next) { |
| 448 | if ((res->flags & IORESOURCE_FIXED)) |
| 449 | continue; |
| 450 | printk(BIOS_SPEW, "%s:@%s %02lx limit %08llx\n", __func__, |
| 451 | dev_path(dev), res->index, res->limit); |
| 452 | |
| 453 | lim = resource_limit(&limits, res); |
| 454 | if (!lim) |
| 455 | continue; |
| 456 | |
| 457 | if (res->base > lim->base) |
| 458 | lim->base = res->base; |
| 459 | if (res->limit < lim->limit) |
| 460 | lim->limit = res->limit; |
| 461 | } |
| 462 | |
| 463 | /* Look through the tree for fixed resources and update the limits. */ |
| 464 | constrain_resources(dev, &limits); |
| 465 | |
| 466 | /* Update dev's resources with new limits. */ |
| 467 | for (res = dev->resource_list; res; res = res->next) { |
| 468 | if ((res->flags & IORESOURCE_FIXED)) |
| 469 | continue; |
| 470 | |
| 471 | lim = resource_limit(&limits, res); |
| 472 | if (!lim) |
| 473 | continue; |
| 474 | |
| 475 | /* Is the resource outside the limits? */ |
| 476 | if (lim->base > res->base) |
| 477 | res->base = lim->base; |
| 478 | if (res->limit > lim->limit) |
| 479 | res->limit = lim->limit; |
| 480 | |
| 481 | /* MEM resources need to start at the highest address manageable. */ |
| 482 | if (res->flags & IORESOURCE_MEM) |
| 483 | res->base = resource_max(res); |
| 484 | |
| 485 | printk(BIOS_SPEW, "%s:@%s %02lx base %08llx limit %08llx\n", |
| 486 | __func__, dev_path(dev), res->index, res->base, res->limit); |
| 487 | } |
| 488 | } |
| 489 | |
| 490 | void allocate_resources(const struct device *root) |
| 491 | { |
| 492 | struct resource *res; |
| 493 | const struct device *child; |
| 494 | |
| 495 | /* Compute resources for all domains. */ |
| 496 | for (child = root->link_list->children; child; child = child->sibling) { |
| 497 | if (!(child->path.type == DEVICE_PATH_DOMAIN)) |
| 498 | continue; |
| 499 | post_log_path(child); |
| 500 | for (res = child->resource_list; res; res = res->next) { |
| 501 | if (res->flags & IORESOURCE_FIXED) |
| 502 | continue; |
| 503 | if (res->flags & IORESOURCE_MEM) { |
| 504 | compute_resources(child->link_list, |
| 505 | res, IORESOURCE_TYPE_MASK, IORESOURCE_MEM); |
| 506 | continue; |
| 507 | } |
| 508 | if (res->flags & IORESOURCE_IO) { |
| 509 | compute_resources(child->link_list, |
| 510 | res, IORESOURCE_TYPE_MASK, IORESOURCE_IO); |
| 511 | continue; |
| 512 | } |
| 513 | } |
| 514 | } |
| 515 | |
| 516 | /* For all domains. */ |
| 517 | for (child = root->link_list->children; child; child=child->sibling) |
| 518 | if (child->path.type == DEVICE_PATH_DOMAIN) |
| 519 | avoid_fixed_resources(child); |
| 520 | |
| 521 | /* Store the computed resource allocations into device registers ... */ |
| 522 | printk(BIOS_INFO, "Setting resources...\n"); |
| 523 | for (child = root->link_list->children; child; child = child->sibling) { |
| 524 | if (!(child->path.type == DEVICE_PATH_DOMAIN)) |
| 525 | continue; |
| 526 | post_log_path(child); |
| 527 | for (res = child->resource_list; res; res = res->next) { |
| 528 | if (res->flags & IORESOURCE_FIXED) |
| 529 | continue; |
| 530 | if (res->flags & IORESOURCE_MEM) { |
| 531 | __allocate_resources(child->link_list, |
| 532 | res, IORESOURCE_TYPE_MASK, IORESOURCE_MEM); |
| 533 | continue; |
| 534 | } |
| 535 | if (res->flags & IORESOURCE_IO) { |
| 536 | __allocate_resources(child->link_list, |
| 537 | res, IORESOURCE_TYPE_MASK, IORESOURCE_IO); |
| 538 | continue; |
| 539 | } |
| 540 | } |
| 541 | } |
| 542 | } |