root/drivers/pci/setup-res.c

DEFINITIONS

1. pci_std_update_resource
2. pci_update_resource
3. pci_claim_resource
4. pci_disable_bridge_window
5. pcibios_retrieve_fw_addr
6. pci_revert_fw_address
7. pcibios_align_resource
8. __pci_assign_resource
9. _pci_assign_resource
10. pci_assign_resource
11. pci_reassign_resource
12. pci_release_resource
13. pci_resize_resource
14. pci_enable_resources

   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, &region, 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         ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
 443         if (ret)
 444                 goto error_resize;
 445 
 446         return 0;
 447 
 448 error_resize:
 449         pci_rebar_set_size(dev, resno, old);
 450         res->end = res->start + pci_rebar_size_to_bytes(old) - 1;
 451         return ret;
 452 }
 453 EXPORT_SYMBOL(pci_resize_resource);
 454 
 455 int pci_enable_resources(struct pci_dev *dev, int mask)
 456 {
 457         u16 cmd, old_cmd;
 458         int i;
 459         struct resource *r;
 460 
 461         pci_read_config_word(dev, PCI_COMMAND, &cmd);
 462         old_cmd = cmd;
 463 
 464         for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 465                 if (!(mask & (1 << i)))
 466                         continue;
 467 
 468                 r = &dev->resource[i];
 469 
 470                 if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
 471                         continue;
 472                 if ((i == PCI_ROM_RESOURCE) &&
 473                                 (!(r->flags & IORESOURCE_ROM_ENABLE)))
 474                         continue;
 475 
 476                 if (r->flags & IORESOURCE_UNSET) {
 477                         pci_err(dev, "can't enable device: BAR %d %pR not assigned\n",
 478                                 i, r);
 479                         return -EINVAL;
 480                 }
 481 
 482                 if (!r->parent) {
 483                         pci_err(dev, "can't enable device: BAR %d %pR not claimed\n",
 484                                 i, r);
 485                         return -EINVAL;
 486                 }
 487 
 488                 if (r->flags & IORESOURCE_IO)
 489                         cmd |= PCI_COMMAND_IO;
 490                 if (r->flags & IORESOURCE_MEM)
 491                         cmd |= PCI_COMMAND_MEMORY;
 492         }
 493 
 494         if (cmd != old_cmd) {
 495                 pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
 496                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 497         }
 498         return 0;
 499 }