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/init.h>
  20 #include <linux/kernel.h>
  21 #include <linux/export.h>
  22 #include <linux/pci.h>
  23 #include <linux/errno.h>
  24 #include <linux/ioport.h>
  25 #include <linux/cache.h>
  26 #include <linux/slab.h>
  27 #include "pci.h"
  28
  29
  30 void pci_update_resource(struct pci_dev *dev, int resno)
  31 {
  32         struct pci_bus_region region;
  33         bool disable;
  34         u16 cmd;
  35         u32 new, check, mask;
  36         int reg;
  37         enum pci_bar_type type;
  38         struct resource *res = dev->resource + resno;
  39
  40         /*
  41          * Ignore resources for unimplemented BARs and unused resource slots
  42          * for 64 bit BARs.
  43          */
  44         if (!res->flags)
  45                 return;
  46
  47         /*
  48          * Ignore non-moveable resources.  This might be legacy resources for
  49          * which no functional BAR register exists or another important
  50          * system resource we shouldn't move around.
  51          */
  52         if (res->flags & IORESOURCE_PCI_FIXED)
  53                 return;
  54
  55         pcibios_resource_to_bus(dev->bus, &region, res);
  56
  57         new = region.start | (res->flags & PCI_REGION_FLAG_MASK);
  58         if (res->flags & IORESOURCE_IO)
  59                 mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
  60         else
  61                 mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
  62
  63         reg = pci_resource_bar(dev, resno, &type);
  64         if (!reg)
  65                 return;
  66         if (type != pci_bar_unknown) {
  67                 if (!(res->flags & IORESOURCE_ROM_ENABLE))
  68                         return;
  69                 new |= PCI_ROM_ADDRESS_ENABLE;
  70         }
  71
  72         /*
  73          * We can't update a 64-bit BAR atomically, so when possible,
  74          * disable decoding so that a half-updated BAR won't conflict
  75          * with another device.
  76          */
  77         disable = (res->flags & IORESOURCE_MEM_64) && !dev->mmio_always_on;
  78         if (disable) {
  79                 pci_read_config_word(dev, PCI_COMMAND, &cmd);
  80                 pci_write_config_word(dev, PCI_COMMAND,
  81                                       cmd & ~PCI_COMMAND_MEMORY);
  82         }
  83
  84         pci_write_config_dword(dev, reg, new);
  85         pci_read_config_dword(dev, reg, &check);
  86
  87         if ((new ^ check) & mask) {
  88                 dev_err(&dev->dev, "BAR %d: error updating (%#08x != %#08x)\n",
  89                         resno, new, check);
  90         }
  91
  92         if (res->flags & IORESOURCE_MEM_64) {
  93                 new = region.start >> 16 >> 16;
  94                 pci_write_config_dword(dev, reg + 4, new);
  95                 pci_read_config_dword(dev, reg + 4, &check);
  96                 if (check != new) {
  97                         dev_err(&dev->dev, "BAR %d: error updating "
  98                                "(high %#08x != %#08x)\n", resno, new, check);
  99                 }
 100         }
 101
 102         if (disable)
 103                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 104
 105         res->flags &= ~IORESOURCE_UNSET;
 106         dev_dbg(&dev->dev, "BAR %d: set to %pR (PCI address [%#llx-%#llx])\n",
 107                 resno, res, (unsigned long long)region.start,
 108                 (unsigned long long)region.end);
 109 }
 110
 111 int pci_claim_resource(struct pci_dev *dev, int resource)
 112 {
 113         struct resource *res = &dev->resource[resource];
 114         struct resource *root, *conflict;
 115
 116         root = pci_find_parent_resource(dev, res);
 117         if (!root) {
 118                 dev_info(&dev->dev, "no compatible bridge window for %pR\n",
 119                          res);
 120                 return -EINVAL;
 121         }
 122
 123         conflict = request_resource_conflict(root, res);
 124         if (conflict) {
 125                 dev_info(&dev->dev,
 126                          "address space collision: %pR conflicts with %s %pR\n",
 127                          res, conflict->name, conflict);
 128                 return -EBUSY;
 129         }
 130
 131         return 0;
 132 }
 133 EXPORT_SYMBOL(pci_claim_resource);
 134
 135 void pci_disable_bridge_window(struct pci_dev *dev)
 136 {
 137         dev_info(&dev->dev, "disabling bridge mem windows\n");
 138
 139         /* MMIO Base/Limit */
 140         pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0);
 141
 142         /* Prefetchable MMIO Base/Limit */
 143         pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
 144         pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0);
 145         pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff);
 146 }
 147
 148 /*
 149  * Generic function that returns a value indicating that the device's
 150  * original BIOS BAR address was not saved and so is not available for
 151  * reinstatement.
 152  *
 153  * Can be over-ridden by architecture specific code that implements
 154  * reinstatement functionality rather than leaving it disabled when
 155  * normal allocation attempts fail.
 156  */
 157 resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx)
 158 {
 159         return 0;
 160 }
 161
 162 static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 163                 int resno, resource_size_t size)
 164 {
 165         struct resource *root, *conflict;
 166         resource_size_t fw_addr, start, end;
 167         int ret = 0;
 168
 169         fw_addr = pcibios_retrieve_fw_addr(dev, resno);
 170         if (!fw_addr)
 171                 return 1;
 172
 173         start = res->start;
 174         end = res->end;
 175         res->start = fw_addr;
 176         res->end = res->start + size - 1;
 177
 178         root = pci_find_parent_resource(dev, res);
 179         if (!root) {
 180                 if (res->flags & IORESOURCE_IO)
 181                         root = &ioport_resource;
 182                 else
 183                         root = &iomem_resource;
 184         }
 185
 186         dev_info(&dev->dev, "BAR %d: trying firmware assignment %pR\n",
 187                  resno, res);
 188         conflict = request_resource_conflict(root, res);
 189         if (conflict) {
 190                 dev_info(&dev->dev,
 191                          "BAR %d: %pR conflicts with %s %pR\n", resno,
 192                          res, conflict->name, conflict);
 193                 res->start = start;
 194                 res->end = end;
 195                 ret = 1;
 196         }
 197         return ret;
 198 }
 199
 200 static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
 201                 int resno, resource_size_t size, resource_size_t align)
 202 {
 203         struct resource *res = dev->resource + resno;
 204         resource_size_t min;
 205         int ret;
 206
 207         min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
 208
 209         /* First, try exact prefetching match.. */
 210         ret = pci_bus_alloc_resource(bus, res, size, align, min,
 211                                      IORESOURCE_PREFETCH,
 212                                      pcibios_align_resource, dev);
 213
 214         if (ret < 0 && (res->flags & IORESOURCE_PREFETCH)) {
 215                 /*
 216                  * That failed.
 217                  *
 218                  * But a prefetching area can handle a non-prefetching
 219                  * window (it will just not perform as well).
 220                  */
 221                 ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
 222                                              pcibios_align_resource, dev);
 223         }
 224         return ret;
 225 }
 226
 227 static int _pci_assign_resource(struct pci_dev *dev, int resno,
 228                                 resource_size_t size, resource_size_t min_align)
 229 {
 230         struct resource *res = dev->resource + resno;
 231         struct pci_bus *bus;
 232         int ret;
 233         char *type;
 234
 235         bus = dev->bus;
 236         while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
 237                 if (!bus->parent || !bus->self->transparent)
 238                         break;
 239                 bus = bus->parent;
 240         }
 241
 242         if (ret) {
 243                 if (res->flags & IORESOURCE_MEM)
 244                         if (res->flags & IORESOURCE_PREFETCH)
 245                                 type = "mem pref";
 246                         else
 247                                 type = "mem";
 248                 else if (res->flags & IORESOURCE_IO)
 249                         type = "io";
 250                 else
 251                         type = "unknown";
 252                 dev_info(&dev->dev,
 253                          "BAR %d: can't assign %s (size %#llx)\n",
 254                          resno, type, (unsigned long long) resource_size(res));
 255         }
 256
 257         return ret;
 258 }
 259
 260 int pci_assign_resource(struct pci_dev *dev, int resno)
 261 {
 262         struct resource *res = dev->resource + resno;
 263         resource_size_t align, size;
 264         int ret;
 265
 266         align = pci_resource_alignment(dev, res);
 267         if (!align) {
 268                 dev_info(&dev->dev, "BAR %d: can't assign %pR "
 269                          "(bogus alignment)\n", resno, res);
 270                 return -EINVAL;
 271         }
 272
 273         size = resource_size(res);
 274         ret = _pci_assign_resource(dev, resno, size, align);
 275
 276         /*
 277          * If we failed to assign anything, let's try the address
 278          * where firmware left it.  That at least has a chance of
 279          * working, which is better than just leaving it disabled.
 280          */
 281         if (ret < 0)
 282                 ret = pci_revert_fw_address(res, dev, resno, size);
 283
 284         if (!ret) {
 285                 res->flags &= ~IORESOURCE_STARTALIGN;
 286                 dev_info(&dev->dev, "BAR %d: assigned %pR\n", resno, res);
 287                 if (resno < PCI_BRIDGE_RESOURCES)
 288                         pci_update_resource(dev, resno);
 289         }
 290         return ret;
 291 }
 292
 293 int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsize,
 294                         resource_size_t min_align)
 295 {
 296         struct resource *res = dev->resource + resno;
 297         resource_size_t new_size;
 298         int ret;
 299
 300         if (!res->parent) {
 301                 dev_info(&dev->dev, "BAR %d: can't reassign an unassigned resource %pR "
 302                          "\n", resno, res);
 303                 return -EINVAL;
 304         }
 305
 306         /* already aligned with min_align */
 307         new_size = resource_size(res) + addsize;
 308         ret = _pci_assign_resource(dev, resno, new_size, min_align);
 309         if (!ret) {
 310                 res->flags &= ~IORESOURCE_STARTALIGN;
 311                 dev_info(&dev->dev, "BAR %d: reassigned %pR\n", resno, res);
 312                 if (resno < PCI_BRIDGE_RESOURCES)
 313                         pci_update_resource(dev, resno);
 314         }
 315         return ret;
 316 }
 317
 318 int pci_enable_resources(struct pci_dev *dev, int mask)
 319 {
 320         u16 cmd, old_cmd;
 321         int i;
 322         struct resource *r;
 323
 324         pci_read_config_word(dev, PCI_COMMAND, &cmd);
 325         old_cmd = cmd;
 326
 327         for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 328                 if (!(mask & (1 << i)))
 329                         continue;
 330
 331                 r = &dev->resource[i];
 332
 333                 if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
 334                         continue;
 335                 if ((i == PCI_ROM_RESOURCE) &&
 336                                 (!(r->flags & IORESOURCE_ROM_ENABLE)))
 337                         continue;
 338
 339                 if (!r->parent) {
 340                         dev_err(&dev->dev, "device not available "
 341                                 "(can't reserve %pR)\n", r);
 342                         return -EINVAL;
 343                 }
 344
 345                 if (r->flags & IORESOURCE_IO)
 346                         cmd |= PCI_COMMAND_IO;
 347                 if (r->flags & IORESOURCE_MEM)
 348                         cmd |= PCI_COMMAND_MEMORY;
 349         }
 350
 351         if (cmd != old_cmd) {
 352                 dev_info(&dev->dev, "enabling device (%04x -> %04x)\n",
 353                          old_cmd, cmd);
 354                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 355         }
 356         return 0;
 357 }