drivers/pci/bus.c

   1 /*
   2  *      drivers/pci/bus.c
   3  *
   4  * From setup-res.c, by:
   5  *      Dave Rusling (david.rusling@reo.mts.dec.com)
   6  *      David Mosberger (davidm@cs.arizona.edu)
   7  *      David Miller (davem@redhat.com)
   8  *      Ivan Kokshaysky (ink@jurassic.park.msu.ru)
   9  */
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/pci.h>
  13 #include <linux/errno.h>
  14 #include <linux/ioport.h>
  15 #include <linux/proc_fs.h>
  16 #include <linux/slab.h>
  17
  18 #include "pci.h"
  19
  20 void pci_add_resource_offset(struct list_head *resources, struct resource *res,
  21                              resource_size_t offset)
  22 {
  23         struct resource_entry *entry;
  24
  25         entry = resource_list_create_entry(res, 0);
  26         if (!entry) {
  27                 printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
  28                 return;
  29         }
  30
  31         entry->offset = offset;
  32         resource_list_add_tail(entry, resources);
  33 }
  34 EXPORT_SYMBOL(pci_add_resource_offset);
  35
  36 void pci_add_resource(struct list_head *resources, struct resource *res)
  37 {
  38         pci_add_resource_offset(resources, res, 0);
  39 }
  40 EXPORT_SYMBOL(pci_add_resource);
  41
  42 void pci_free_resource_list(struct list_head *resources)
  43 {
  44         resource_list_free(resources);
  45 }
  46 EXPORT_SYMBOL(pci_free_resource_list);
  47
  48 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
  49                           unsigned int flags)
  50 {
  51         struct pci_bus_resource *bus_res;
  52
  53         bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
  54         if (!bus_res) {
  55                 dev_err(&bus->dev, "can't add %pR resource\n", res);
  56                 return;
  57         }
  58
  59         bus_res->res = res;
  60         bus_res->flags = flags;
  61         list_add_tail(&bus_res->list, &bus->resources);
  62 }
  63
  64 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
  65 {
  66         struct pci_bus_resource *bus_res;
  67
  68         if (n < PCI_BRIDGE_RESOURCE_NUM)
  69                 return bus->resource[n];
  70
  71         n -= PCI_BRIDGE_RESOURCE_NUM;
  72         list_for_each_entry(bus_res, &bus->resources, list) {
  73                 if (n-- == 0)
  74                         return bus_res->res;
  75         }
  76         return NULL;
  77 }
  78 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  79
  80 void pci_bus_remove_resources(struct pci_bus *bus)
  81 {
  82         int i;
  83         struct pci_bus_resource *bus_res, *tmp;
  84
  85         for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
  86                 bus->resource[i] = NULL;
  87
  88         list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
  89                 list_del(&bus_res->list);
  90                 kfree(bus_res);
  91         }
  92 }
  93
  94 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
  95 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
  96 static struct pci_bus_region pci_64_bit = {0,
  97                                 (pci_bus_addr_t) 0xffffffffffffffffULL};
  98 static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
  99                                 (pci_bus_addr_t) 0xffffffffffffffffULL};
 100 #endif
 101
 102 /*
 103  * @res contains CPU addresses.  Clip it so the corresponding bus addresses
 104  * on @bus are entirely within @region.  This is used to control the bus
 105  * addresses of resources we allocate, e.g., we may need a resource that
 106  * can be mapped by a 32-bit BAR.
 107  */
 108 static void pci_clip_resource_to_region(struct pci_bus *bus,
 109                                         struct resource *res,
 110                                         struct pci_bus_region *region)
 111 {
 112         struct pci_bus_region r;
 113
 114         pcibios_resource_to_bus(bus, &r, res);
 115         if (r.start < region->start)
 116                 r.start = region->start;
 117         if (r.end > region->end)
 118                 r.end = region->end;
 119
 120         if (r.end < r.start)
 121                 res->end = res->start - 1;
 122         else
 123                 pcibios_bus_to_resource(bus, res, &r);
 124 }
 125
 126 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 127                 resource_size_t size, resource_size_t align,
 128                 resource_size_t min, unsigned long type_mask,
 129                 resource_size_t (*alignf)(void *,
 130                                           const struct resource *,
 131                                           resource_size_t,
 132                                           resource_size_t),
 133                 void *alignf_data,
 134                 struct pci_bus_region *region)
 135 {
 136         int i, ret;
 137         struct resource *r, avail;
 138         resource_size_t max;
 139
 140         type_mask |= IORESOURCE_TYPE_BITS;
 141
 142         pci_bus_for_each_resource(bus, r, i) {
 143                 resource_size_t min_used = min;
 144
 145                 if (!r)
 146                         continue;
 147
 148                 /* type_mask must match */
 149                 if ((res->flags ^ r->flags) & type_mask)
 150                         continue;
 151
 152                 /* We cannot allocate a non-prefetching resource
 153                    from a pre-fetching area */
 154                 if ((r->flags & IORESOURCE_PREFETCH) &&
 155                     !(res->flags & IORESOURCE_PREFETCH))
 156                         continue;
 157
 158                 avail = *r;
 159                 pci_clip_resource_to_region(bus, &avail, region);
 160
 161                 /*
 162                  * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
 163                  * protect badly documented motherboard resources, but if
 164                  * this is an already-configured bridge window, its start
 165                  * overrides "min".
 166                  */
 167                 if (avail.start)
 168                         min_used = avail.start;
 169
 170                 max = avail.end;
 171
 172                 /* Ok, try it out.. */
 173                 ret = allocate_resource(r, res, size, min_used, max,
 174                                         align, alignf, alignf_data);
 175                 if (ret == 0)
 176                         return 0;
 177         }
 178         return -ENOMEM;
 179 }
 180
 181 /**
 182  * pci_bus_alloc_resource - allocate a resource from a parent bus
 183  * @bus: PCI bus
 184  * @res: resource to allocate
 185  * @size: size of resource to allocate
 186  * @align: alignment of resource to allocate
 187  * @min: minimum /proc/iomem address to allocate
 188  * @type_mask: IORESOURCE_* type flags
 189  * @alignf: resource alignment function
 190  * @alignf_data: data argument for resource alignment function
 191  *
 192  * Given the PCI bus a device resides on, the size, minimum address,
 193  * alignment and type, try to find an acceptable resource allocation
 194  * for a specific device resource.
 195  */
 196 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 197                 resource_size_t size, resource_size_t align,
 198                 resource_size_t min, unsigned long type_mask,
 199                 resource_size_t (*alignf)(void *,
 200                                           const struct resource *,
 201                                           resource_size_t,
 202                                           resource_size_t),
 203                 void *alignf_data)
 204 {
 205 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 206         int rc;
 207
 208         if (res->flags & IORESOURCE_MEM_64) {
 209                 rc = pci_bus_alloc_from_region(bus, res, size, align, min,
 210                                                type_mask, alignf, alignf_data,
 211                                                &pci_high);
 212                 if (rc == 0)
 213                         return 0;
 214
 215                 return pci_bus_alloc_from_region(bus, res, size, align, min,
 216                                                  type_mask, alignf, alignf_data,
 217                                                  &pci_64_bit);
 218         }
 219 #endif
 220
 221         return pci_bus_alloc_from_region(bus, res, size, align, min,
 222                                          type_mask, alignf, alignf_data,
 223                                          &pci_32_bit);
 224 }
 225 EXPORT_SYMBOL(pci_bus_alloc_resource);
 226
 227 /*
 228  * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
 229  * resource fits inside a window of an upstream bridge, do nothing.  If it
 230  * overlaps an upstream window but extends outside it, clip the resource so
 231  * it fits completely inside.
 232  */
 233 bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
 234 {
 235         struct pci_bus *bus = dev->bus;
 236         struct resource *res = &dev->resource[idx];
 237         struct resource orig_res = *res;
 238         struct resource *r;
 239         int i;
 240
 241         pci_bus_for_each_resource(bus, r, i) {
 242                 resource_size_t start, end;
 243
 244                 if (!r)
 245                         continue;
 246
 247                 if (resource_type(res) != resource_type(r))
 248                         continue;
 249
 250                 start = max(r->start, res->start);
 251                 end = min(r->end, res->end);
 252
 253                 if (start > end)
 254                         continue;       /* no overlap */
 255
 256                 if (res->start == start && res->end == end)
 257                         return false;   /* no change */
 258
 259                 res->start = start;
 260                 res->end = end;
 261                 res->flags &= ~IORESOURCE_UNSET;
 262                 orig_res.flags &= ~IORESOURCE_UNSET;
 263                 dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n",
 264                                  &orig_res, res);
 265
 266                 return true;
 267         }
 268
 269         return false;
 270 }
 271
 272 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 273
 274 void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
 275
 276 /**
 277  * pci_bus_add_device - start driver for a single device
 278  * @dev: device to add
 279  *
 280  * This adds add sysfs entries and start device drivers
 281  */
 282 void pci_bus_add_device(struct pci_dev *dev)
 283 {
 284         int retval;
 285
 286         /*
 287          * Can not put in pci_device_add yet because resources
 288          * are not assigned yet for some devices.
 289          */
 290         pcibios_bus_add_device(dev);
 291         pci_fixup_device(pci_fixup_final, dev);
 292         pci_create_sysfs_dev_files(dev);
 293         pci_proc_attach_device(dev);
 294
 295         dev->match_driver = true;
 296         retval = device_attach(&dev->dev);
 297         if (retval < 0 && retval != -EPROBE_DEFER) {
 298                 dev_warn(&dev->dev, "device attach failed (%d)\n", retval);
 299                 pci_proc_detach_device(dev);
 300                 pci_remove_sysfs_dev_files(dev);
 301                 return;
 302         }
 303
 304         dev->is_added = 1;
 305 }
 306 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 307
 308 /**
 309  * pci_bus_add_devices - start driver for PCI devices
 310  * @bus: bus to check for new devices
 311  *
 312  * Start driver for PCI devices and add some sysfs entries.
 313  */
 314 void pci_bus_add_devices(const struct pci_bus *bus)
 315 {
 316         struct pci_dev *dev;
 317         struct pci_bus *child;
 318
 319         list_for_each_entry(dev, &bus->devices, bus_list) {
 320                 /* Skip already-added devices */
 321                 if (dev->is_added)
 322                         continue;
 323                 pci_bus_add_device(dev);
 324         }
 325
 326         list_for_each_entry(dev, &bus->devices, bus_list) {
 327                 /* Skip if device attach failed */
 328                 if (!dev->is_added)
 329                         continue;
 330                 child = dev->subordinate;
 331                 if (child)
 332                         pci_bus_add_devices(child);
 333         }
 334 }
 335 EXPORT_SYMBOL(pci_bus_add_devices);
 336
 337 /** pci_walk_bus - walk devices on/under bus, calling callback.
 338  *  @top      bus whose devices should be walked
 339  *  @cb       callback to be called for each device found
 340  *  @userdata arbitrary pointer to be passed to callback.
 341  *
 342  *  Walk the given bus, including any bridged devices
 343  *  on buses under this bus.  Call the provided callback
 344  *  on each device found.
 345  *
 346  *  We check the return of @cb each time. If it returns anything
 347  *  other than 0, we break out.
 348  *
 349  */
 350 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 351                   void *userdata)
 352 {
 353         struct pci_dev *dev;
 354         struct pci_bus *bus;
 355         struct list_head *next;
 356         int retval;
 357
 358         bus = top;
 359         down_read(&pci_bus_sem);
 360         next = top->devices.next;
 361         for (;;) {
 362                 if (next == &bus->devices) {
 363                         /* end of this bus, go up or finish */
 364                         if (bus == top)
 365                                 break;
 366                         next = bus->self->bus_list.next;
 367                         bus = bus->self->bus;
 368                         continue;
 369                 }
 370                 dev = list_entry(next, struct pci_dev, bus_list);
 371                 if (dev->subordinate) {
 372                         /* this is a pci-pci bridge, do its devices next */
 373                         next = dev->subordinate->devices.next;
 374                         bus = dev->subordinate;
 375                 } else
 376                         next = dev->bus_list.next;
 377
 378                 retval = cb(dev, userdata);
 379                 if (retval)
 380                         break;
 381         }
 382         up_read(&pci_bus_sem);
 383 }
 384 EXPORT_SYMBOL_GPL(pci_walk_bus);
 385
 386 struct pci_bus *pci_bus_get(struct pci_bus *bus)
 387 {
 388         if (bus)
 389                 get_device(&bus->dev);
 390         return bus;
 391 }
 392 EXPORT_SYMBOL(pci_bus_get);
 393
 394 void pci_bus_put(struct pci_bus *bus)
 395 {
 396         if (bus)
 397                 put_device(&bus->dev);
 398 }
 399 EXPORT_SYMBOL(pci_bus_put);
 400