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                 if (!r)
 144                         continue;
 145
 146                 /* type_mask must match */
 147                 if ((res->flags ^ r->flags) & type_mask)
 148                         continue;
 149
 150                 /* We cannot allocate a non-prefetching resource
 151                    from a pre-fetching area */
 152                 if ((r->flags & IORESOURCE_PREFETCH) &&
 153                     !(res->flags & IORESOURCE_PREFETCH))
 154                         continue;
 155
 156                 avail = *r;
 157                 pci_clip_resource_to_region(bus, &avail, region);
 158
 159                 /*
 160                  * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
 161                  * protect badly documented motherboard resources, but if
 162                  * this is an already-configured bridge window, its start
 163                  * overrides "min".
 164                  */
 165                 if (avail.start)
 166                         min = avail.start;
 167
 168                 max = avail.end;
 169
 170                 /* Ok, try it out.. */
 171                 ret = allocate_resource(r, res, size, min, max,
 172                                         align, alignf, alignf_data);
 173                 if (ret == 0)
 174                         return 0;
 175         }
 176         return -ENOMEM;
 177 }
 178
 179 /**
 180  * pci_bus_alloc_resource - allocate a resource from a parent bus
 181  * @bus: PCI bus
 182  * @res: resource to allocate
 183  * @size: size of resource to allocate
 184  * @align: alignment of resource to allocate
 185  * @min: minimum /proc/iomem address to allocate
 186  * @type_mask: IORESOURCE_* type flags
 187  * @alignf: resource alignment function
 188  * @alignf_data: data argument for resource alignment function
 189  *
 190  * Given the PCI bus a device resides on, the size, minimum address,
 191  * alignment and type, try to find an acceptable resource allocation
 192  * for a specific device resource.
 193  */
 194 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 195                 resource_size_t size, resource_size_t align,
 196                 resource_size_t min, unsigned long type_mask,
 197                 resource_size_t (*alignf)(void *,
 198                                           const struct resource *,
 199                                           resource_size_t,
 200                                           resource_size_t),
 201                 void *alignf_data)
 202 {
 203 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 204         int rc;
 205
 206         if (res->flags & IORESOURCE_MEM_64) {
 207                 rc = pci_bus_alloc_from_region(bus, res, size, align, min,
 208                                                type_mask, alignf, alignf_data,
 209                                                &pci_high);
 210                 if (rc == 0)
 211                         return 0;
 212
 213                 return pci_bus_alloc_from_region(bus, res, size, align, min,
 214                                                  type_mask, alignf, alignf_data,
 215                                                  &pci_64_bit);
 216         }
 217 #endif
 218
 219         return pci_bus_alloc_from_region(bus, res, size, align, min,
 220                                          type_mask, alignf, alignf_data,
 221                                          &pci_32_bit);
 222 }
 223 EXPORT_SYMBOL(pci_bus_alloc_resource);
 224
 225 /*
 226  * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
 227  * resource fits inside a window of an upstream bridge, do nothing.  If it
 228  * overlaps an upstream window but extends outside it, clip the resource so
 229  * it fits completely inside.
 230  */
 231 bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
 232 {
 233         struct pci_bus *bus = dev->bus;
 234         struct resource *res = &dev->resource[idx];
 235         struct resource orig_res = *res;
 236         struct resource *r;
 237         int i;
 238
 239         pci_bus_for_each_resource(bus, r, i) {
 240                 resource_size_t start, end;
 241
 242                 if (!r)
 243                         continue;
 244
 245                 if (resource_type(res) != resource_type(r))
 246                         continue;
 247
 248                 start = max(r->start, res->start);
 249                 end = min(r->end, res->end);
 250
 251                 if (start > end)
 252                         continue;       /* no overlap */
 253
 254                 if (res->start == start && res->end == end)
 255                         return false;   /* no change */
 256
 257                 res->start = start;
 258                 res->end = end;
 259                 res->flags &= ~IORESOURCE_UNSET;
 260                 orig_res.flags &= ~IORESOURCE_UNSET;
 261                 dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n",
 262                                  &orig_res, res);
 263
 264                 return true;
 265         }
 266
 267         return false;
 268 }
 269
 270 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 271
 272 /**
 273  * pci_bus_add_device - start driver for a single device
 274  * @dev: device to add
 275  *
 276  * This adds add sysfs entries and start device drivers
 277  */
 278 void pci_bus_add_device(struct pci_dev *dev)
 279 {
 280         int retval;
 281
 282         /*
 283          * Can not put in pci_device_add yet because resources
 284          * are not assigned yet for some devices.
 285          */
 286         pci_fixup_device(pci_fixup_final, dev);
 287         pci_create_sysfs_dev_files(dev);
 288         pci_proc_attach_device(dev);
 289
 290         dev->match_driver = true;
 291         retval = device_attach(&dev->dev);
 292         WARN_ON(retval < 0);
 293
 294         dev->is_added = 1;
 295 }
 296 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 297
 298 /**
 299  * pci_bus_add_devices - start driver for PCI devices
 300  * @bus: bus to check for new devices
 301  *
 302  * Start driver for PCI devices and add some sysfs entries.
 303  */
 304 void pci_bus_add_devices(const struct pci_bus *bus)
 305 {
 306         struct pci_dev *dev;
 307         struct pci_bus *child;
 308
 309         list_for_each_entry(dev, &bus->devices, bus_list) {
 310                 /* Skip already-added devices */
 311                 if (dev->is_added)
 312                         continue;
 313                 pci_bus_add_device(dev);
 314         }
 315
 316         list_for_each_entry(dev, &bus->devices, bus_list) {
 317                 BUG_ON(!dev->is_added);
 318                 child = dev->subordinate;
 319                 if (child)
 320                         pci_bus_add_devices(child);
 321         }
 322 }
 323 EXPORT_SYMBOL(pci_bus_add_devices);
 324
 325 /** pci_walk_bus - walk devices on/under bus, calling callback.
 326  *  @top      bus whose devices should be walked
 327  *  @cb       callback to be called for each device found
 328  *  @userdata arbitrary pointer to be passed to callback.
 329  *
 330  *  Walk the given bus, including any bridged devices
 331  *  on buses under this bus.  Call the provided callback
 332  *  on each device found.
 333  *
 334  *  We check the return of @cb each time. If it returns anything
 335  *  other than 0, we break out.
 336  *
 337  */
 338 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 339                   void *userdata)
 340 {
 341         struct pci_dev *dev;
 342         struct pci_bus *bus;
 343         struct list_head *next;
 344         int retval;
 345
 346         bus = top;
 347         down_read(&pci_bus_sem);
 348         next = top->devices.next;
 349         for (;;) {
 350                 if (next == &bus->devices) {
 351                         /* end of this bus, go up or finish */
 352                         if (bus == top)
 353                                 break;
 354                         next = bus->self->bus_list.next;
 355                         bus = bus->self->bus;
 356                         continue;
 357                 }
 358                 dev = list_entry(next, struct pci_dev, bus_list);
 359                 if (dev->subordinate) {
 360                         /* this is a pci-pci bridge, do its devices next */
 361                         next = dev->subordinate->devices.next;
 362                         bus = dev->subordinate;
 363                 } else
 364                         next = dev->bus_list.next;
 365
 366                 retval = cb(dev, userdata);
 367                 if (retval)
 368                         break;
 369         }
 370         up_read(&pci_bus_sem);
 371 }
 372 EXPORT_SYMBOL_GPL(pci_walk_bus);
 373
 374 struct pci_bus *pci_bus_get(struct pci_bus *bus)
 375 {
 376         if (bus)
 377                 get_device(&bus->dev);
 378         return bus;
 379 }
 380 EXPORT_SYMBOL(pci_bus_get);
 381
 382 void pci_bus_put(struct pci_bus *bus)
 383 {
 384         if (bus)
 385                 put_device(&bus->dev);
 386 }
 387 EXPORT_SYMBOL(pci_bus_put);
 388