drivers/pci/setup-res.c

   1 /*
   2  *      drivers/pci/setup-res.c
   3  *
   4  * Extruded from code written by
   5  *      Dave Rusling (david.rusling@reo.mts.dec.com)
   6  *      David Mosberger (davidm@cs.arizona.edu)
   7  *      David Miller (davem@redhat.com)
   8  *
   9  * Support routines for initializing a PCI subsystem.
  10  */
  11
  12 /* fixed for multiple pci buses, 1999 Andrea Arcangeli <andrea@suse.de> */
  13
  14 /*
  15  * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
  16  *           Resource sorting
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/export.h>
  21 #include <linux/pci.h>
  22 #include <linux/errno.h>
  23 #include <linux/ioport.h>
  24 #include <linux/cache.h>
  25 #include <linux/slab.h>
  26 #include "pci.h"
  27
  28 static void pci_std_update_resource(struct pci_dev *dev, int resno)
  29 {
  30         struct pci_bus_region region;
  31         bool disable;
  32         u16 cmd;
  33         u32 new, check, mask;
  34         int reg;
  35         struct resource *res = dev->resource + resno;
  36
  37         /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
  38         if (dev->is_virtfn)
  39                 return;
  40
  41         /*
  42          * Ignore resources for unimplemented BARs and unused resource slots
  43          * for 64 bit BARs.
  44          */
  45         if (!res->flags)
  46                 return;
  47
  48         if (res->flags & IORESOURCE_UNSET)
  49                 return;
  50
  51         /*
  52          * Ignore non-moveable resources.  This might be legacy resources for
  53          * which no functional BAR register exists or another important
  54          * system resource we shouldn't move around.
  55          */
  56         if (res->flags & IORESOURCE_PCI_FIXED)
  57                 return;
  58
  59         pcibios_resource_to_bus(dev->bus, &region, res);
  60         new = region.start;
  61
  62         if (res->flags & IORESOURCE_IO) {
  63                 mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
  64                 new |= res->flags & ~PCI_BASE_ADDRESS_IO_MASK;
  65         } else if (resno == PCI_ROM_RESOURCE) {
  66                 mask = PCI_ROM_ADDRESS_MASK;
  67         } else {
  68                 mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
  69                 new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
  70         }
  71
  72         if (resno < PCI_ROM_RESOURCE) {
  73                 reg = PCI_BASE_ADDRESS_0 + 4 * resno;
  74         } else if (resno == PCI_ROM_RESOURCE) {
  75
  76                 /*
  77                  * Apparently some Matrox devices have ROM BARs that read
  78                  * as zero when disabled, so don't update ROM BARs unless
  79                  * they're enabled.  See https://lkml.org/lkml/2005/8/30/138.
  80                  */
  81                 if (!(res->flags & IORESOURCE_ROM_ENABLE))
  82                         return;
  83
  84                 reg = dev->rom_base_reg;
  85                 new |= PCI_ROM_ADDRESS_ENABLE;
  86         } else
  87                 return;
  88
  89         /*
  90          * We can't update a 64-bit BAR atomically, so when possible,
  91          * disable decoding so that a half-updated BAR won't conflict
  92          * with another device.
  93          */
  94         disable = (res->flags & IORESOURCE_MEM_64) && !dev->mmio_always_on;
  95         if (disable) {
  96                 pci_read_config_word(dev, PCI_COMMAND, &cmd);
  97                 pci_write_config_word(dev, PCI_COMMAND,
  98                                       cmd & ~PCI_COMMAND_MEMORY);
  99         }
 100
 101         pci_write_config_dword(dev, reg, new);
 102         pci_read_config_dword(dev, reg, &check);
 103
 104         if ((new ^ check) & mask) {
 105                 dev_err(&dev->dev, "BAR %d: error updating (%#08x != %#08x)\n",
 106                         resno, new, check);
 107         }
 108
 109         if (res->flags & IORESOURCE_MEM_64) {
 110                 new = region.start >> 16 >> 16;
 111                 pci_write_config_dword(dev, reg + 4, new);
 112                 pci_read_config_dword(dev, reg + 4, &check);
 113                 if (check != new) {
 114                         dev_err(&dev->dev, "BAR %d: error updating (high %#08x != %#08x)\n",
 115                                 resno, new, check);
 116                 }
 117         }
 118
 119         if (disable)
 120                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 121 }
 122
 123 void pci_update_resource(struct pci_dev *dev, int resno)
 124 {
 125         if (resno <= PCI_ROM_RESOURCE)
 126                 pci_std_update_resource(dev, resno);
 127 #ifdef CONFIG_PCI_IOV
 128         else if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
 129                 pci_iov_update_resource(dev, resno);
 130 #endif
 131 }
 132
 133 int pci_claim_resource(struct pci_dev *dev, int resource)
 134 {
 135         struct resource *res = &dev->resource[resource];
 136         struct resource *root, *conflict;
 137
 138         if (res->flags & IORESOURCE_UNSET) {
 139                 dev_info(&dev->dev, "can't claim BAR %d %pR: no address assigned\n",
 140                          resource, res);
 141                 return -EINVAL;
 142         }
 143
 144         /*
 145          * If we have a shadow copy in RAM, the PCI device doesn't respond
 146          * to the shadow range, so we don't need to claim it, and upstream
 147          * bridges don't need to route the range to the device.
 148          */
 149         if (res->flags & IORESOURCE_ROM_SHADOW)
 150                 return 0;
 151
 152         root = pci_find_parent_resource(dev, res);
 153         if (!root) {
 154                 dev_info(&dev->dev, "can't claim BAR %d %pR: no compatible bridge window\n",
 155                          resource, res);
 156                 res->flags |= IORESOURCE_UNSET;
 157                 return -EINVAL;
 158         }
 159
 160         conflict = request_resource_conflict(root, res);
 161         if (conflict) {
 162                 dev_info(&dev->dev, "can't claim BAR %d %pR: address conflict with %s %pR\n",
 163                          resource, res, conflict->name, conflict);
 164                 res->flags |= IORESOURCE_UNSET;
 165                 return -EBUSY;
 166         }
 167
 168         return 0;
 169 }
 170 EXPORT_SYMBOL(pci_claim_resource);
 171
 172 void pci_disable_bridge_window(struct pci_dev *dev)
 173 {
 174         dev_info(&dev->dev, "disabling bridge mem windows\n");
 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                 if (res->flags & IORESOURCE_IO)
 218                         root = &ioport_resource;
 219                 else
 220                         root = &iomem_resource;
 221         }
 222
 223         dev_info(&dev->dev, "BAR %d: trying firmware assignment %pR\n",
 224                  resno, res);
 225         conflict = request_resource_conflict(root, res);
 226         if (conflict) {
 227                 dev_info(&dev->dev, "BAR %d: %pR conflicts with %s %pR\n",
 228                          resno, res, conflict->name, conflict);
 229                 res->start = start;
 230                 res->end = end;
 231                 res->flags |= IORESOURCE_UNSET;
 232                 return -EBUSY;
 233         }
 234         return 0;
 235 }
 236
 237 static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
 238                 int resno, resource_size_t size, resource_size_t align)
 239 {
 240         struct resource *res = dev->resource + resno;
 241         resource_size_t min;
 242         int ret;
 243
 244         min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
 245
 246         /*
 247          * First, try exact prefetching match.  Even if a 64-bit
 248          * prefetchable bridge window is below 4GB, we can't put a 32-bit
 249          * prefetchable resource in it because pbus_size_mem() assumes a
 250          * 64-bit window will contain no 32-bit resources.  If we assign
 251          * things differently than they were sized, not everything will fit.
 252          */
 253         ret = pci_bus_alloc_resource(bus, res, size, align, min,
 254                                      IORESOURCE_PREFETCH | IORESOURCE_MEM_64,
 255                                      pcibios_align_resource, dev);
 256         if (ret == 0)
 257                 return 0;
 258
 259         /*
 260          * If the prefetchable window is only 32 bits wide, we can put
 261          * 64-bit prefetchable resources in it.
 262          */
 263         if ((res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) ==
 264              (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) {
 265                 ret = pci_bus_alloc_resource(bus, res, size, align, min,
 266                                              IORESOURCE_PREFETCH,
 267                                              pcibios_align_resource, dev);
 268                 if (ret == 0)
 269                         return 0;
 270         }
 271
 272         /*
 273          * If we didn't find a better match, we can put any memory resource
 274          * in a non-prefetchable window.  If this resource is 32 bits and
 275          * non-prefetchable, the first call already tried the only possibility
 276          * so we don't need to try again.
 277          */
 278         if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64))
 279                 ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
 280                                              pcibios_align_resource, dev);
 281
 282         return ret;
 283 }
 284
 285 static int _pci_assign_resource(struct pci_dev *dev, int resno,
 286                                 resource_size_t size, resource_size_t min_align)
 287 {
 288         struct pci_bus *bus;
 289         int ret;
 290
 291         bus = dev->bus;
 292         while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
 293                 if (!bus->parent || !bus->self->transparent)
 294                         break;
 295                 bus = bus->parent;
 296         }
 297
 298         return ret;
 299 }
 300
 301 int pci_assign_resource(struct pci_dev *dev, int resno)
 302 {
 303         struct resource *res = dev->resource + resno;
 304         resource_size_t align, size;
 305         int ret;
 306
 307         if (res->flags & IORESOURCE_PCI_FIXED)
 308                 return 0;
 309
 310         res->flags |= IORESOURCE_UNSET;
 311         align = pci_resource_alignment(dev, res);
 312         if (!align) {
 313                 dev_info(&dev->dev, "BAR %d: can't assign %pR (bogus alignment)\n",
 314                          resno, res);
 315                 return -EINVAL;
 316         }
 317
 318         size = resource_size(res);
 319         ret = _pci_assign_resource(dev, resno, size, align);
 320
 321         /*
 322          * If we failed to assign anything, let's try the address
 323          * where firmware left it.  That at least has a chance of
 324          * working, which is better than just leaving it disabled.
 325          */
 326         if (ret < 0) {
 327                 dev_info(&dev->dev, "BAR %d: no space for %pR\n", resno, res);
 328                 ret = pci_revert_fw_address(res, dev, resno, size);
 329         }
 330
 331         if (ret < 0) {
 332                 dev_info(&dev->dev, "BAR %d: failed to assign %pR\n", resno,
 333                          res);
 334                 return ret;
 335         }
 336
 337         res->flags &= ~IORESOURCE_UNSET;
 338         res->flags &= ~IORESOURCE_STARTALIGN;
 339         dev_info(&dev->dev, "BAR %d: assigned %pR\n", resno, res);
 340         if (resno < PCI_BRIDGE_RESOURCES)
 341                 pci_update_resource(dev, resno);
 342
 343         return 0;
 344 }
 345 EXPORT_SYMBOL(pci_assign_resource);
 346
 347 int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsize,
 348                         resource_size_t min_align)
 349 {
 350         struct resource *res = dev->resource + resno;
 351         unsigned long flags;
 352         resource_size_t new_size;
 353         int ret;
 354
 355         if (res->flags & IORESOURCE_PCI_FIXED)
 356                 return 0;
 357
 358         flags = res->flags;
 359         res->flags |= IORESOURCE_UNSET;
 360         if (!res->parent) {
 361                 dev_info(&dev->dev, "BAR %d: can't reassign an unassigned resource %pR\n",
 362                          resno, res);
 363                 return -EINVAL;
 364         }
 365
 366         /* already aligned with min_align */
 367         new_size = resource_size(res) + addsize;
 368         ret = _pci_assign_resource(dev, resno, new_size, min_align);
 369         if (ret) {
 370                 res->flags = flags;
 371                 dev_info(&dev->dev, "BAR %d: %pR (failed to expand by %#llx)\n",
 372                          resno, res, (unsigned long long) addsize);
 373                 return ret;
 374         }
 375
 376         res->flags &= ~IORESOURCE_UNSET;
 377         res->flags &= ~IORESOURCE_STARTALIGN;
 378         dev_info(&dev->dev, "BAR %d: reassigned %pR (expanded by %#llx)\n",
 379                  resno, res, (unsigned long long) addsize);
 380         if (resno < PCI_BRIDGE_RESOURCES)
 381                 pci_update_resource(dev, resno);
 382
 383         return 0;
 384 }
 385
 386 int pci_enable_resources(struct pci_dev *dev, int mask)
 387 {
 388         u16 cmd, old_cmd;
 389         int i;
 390         struct resource *r;
 391
 392         pci_read_config_word(dev, PCI_COMMAND, &cmd);
 393         old_cmd = cmd;
 394
 395         for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 396                 if (!(mask & (1 << i)))
 397                         continue;
 398
 399                 r = &dev->resource[i];
 400
 401                 if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
 402                         continue;
 403                 if ((i == PCI_ROM_RESOURCE) &&
 404                                 (!(r->flags & IORESOURCE_ROM_ENABLE)))
 405                         continue;
 406
 407                 if (r->flags & IORESOURCE_UNSET) {
 408                         dev_err(&dev->dev, "can't enable device: BAR %d %pR not assigned\n",
 409                                 i, r);
 410                         return -EINVAL;
 411                 }
 412
 413                 if (!r->parent) {
 414                         dev_err(&dev->dev, "can't enable device: BAR %d %pR not claimed\n",
 415                                 i, r);
 416                         return -EINVAL;
 417                 }
 418
 419                 if (r->flags & IORESOURCE_IO)
 420                         cmd |= PCI_COMMAND_IO;
 421                 if (r->flags & IORESOURCE_MEM)
 422                         cmd |= PCI_COMMAND_MEMORY;
 423         }
 424
 425         if (cmd != old_cmd) {
 426                 dev_info(&dev->dev, "enabling device (%04x -> %04x)\n",
 427                          old_cmd, cmd);
 428                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 429         }
 430         return 0;
 431 }