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 pci_host_bridge_window *window;
  24
  25         window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL);
  26         if (!window) {
  27                 printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
  28                 return;
  29         }
  30
  31         window->res = res;
  32         window->offset = offset;
  33         list_add_tail(&window->list, resources);
  34 }
  35 EXPORT_SYMBOL(pci_add_resource_offset);
  36
  37 void pci_add_resource(struct list_head *resources, struct resource *res)
  38 {
  39         pci_add_resource_offset(resources, res, 0);
  40 }
  41 EXPORT_SYMBOL(pci_add_resource);
  42
  43 void pci_free_resource_list(struct list_head *resources)
  44 {
  45         struct pci_host_bridge_window *window, *tmp;
  46
  47         list_for_each_entry_safe(window, tmp, resources, list) {
  48                 list_del(&window->list);
  49                 kfree(window);
  50         }
  51 }
  52 EXPORT_SYMBOL(pci_free_resource_list);
  53
  54 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
  55                           unsigned int flags)
  56 {
  57         struct pci_bus_resource *bus_res;
  58
  59         bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
  60         if (!bus_res) {
  61                 dev_err(&bus->dev, "can't add %pR resource\n", res);
  62                 return;
  63         }
  64
  65         bus_res->res = res;
  66         bus_res->flags = flags;
  67         list_add_tail(&bus_res->list, &bus->resources);
  68 }
  69
  70 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
  71 {
  72         struct pci_bus_resource *bus_res;
  73
  74         if (n < PCI_BRIDGE_RESOURCE_NUM)
  75                 return bus->resource[n];
  76
  77         n -= PCI_BRIDGE_RESOURCE_NUM;
  78         list_for_each_entry(bus_res, &bus->resources, list) {
  79                 if (n-- == 0)
  80                         return bus_res->res;
  81         }
  82         return NULL;
  83 }
  84 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  85
  86 void pci_bus_remove_resources(struct pci_bus *bus)
  87 {
  88         int i;
  89         struct pci_bus_resource *bus_res, *tmp;
  90
  91         for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
  92                 bus->resource[i] = NULL;
  93
  94         list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
  95                 list_del(&bus_res->list);
  96                 kfree(bus_res);
  97         }
  98 }
  99
 100 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
 101 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 102 static struct pci_bus_region pci_64_bit = {0,
 103                                 (dma_addr_t) 0xffffffffffffffffULL};
 104 static struct pci_bus_region pci_high = {(dma_addr_t) 0x100000000ULL,
 105                                 (dma_addr_t) 0xffffffffffffffffULL};
 106 #endif
 107
 108 /*
 109  * @res contains CPU addresses.  Clip it so the corresponding bus addresses
 110  * on @bus are entirely within @region.  This is used to control the bus
 111  * addresses of resources we allocate, e.g., we may need a resource that
 112  * can be mapped by a 32-bit BAR.
 113  */
 114 static void pci_clip_resource_to_region(struct pci_bus *bus,
 115                                         struct resource *res,
 116                                         struct pci_bus_region *region)
 117 {
 118         struct pci_bus_region r;
 119
 120         pcibios_resource_to_bus(bus, &r, res);
 121         if (r.start < region->start)
 122                 r.start = region->start;
 123         if (r.end > region->end)
 124                 r.end = region->end;
 125
 126         if (r.end < r.start)
 127                 res->end = res->start - 1;
 128         else
 129                 pcibios_bus_to_resource(bus, res, &r);
 130 }
 131
 132 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 133                 resource_size_t size, resource_size_t align,
 134                 resource_size_t min, unsigned long type_mask,
 135                 resource_size_t (*alignf)(void *,
 136                                           const struct resource *,
 137                                           resource_size_t,
 138                                           resource_size_t),
 139                 void *alignf_data,
 140                 struct pci_bus_region *region)
 141 {
 142         int i, ret;
 143         struct resource *r, avail;
 144         resource_size_t max;
 145
 146         type_mask |= IORESOURCE_TYPE_BITS;
 147
 148         pci_bus_for_each_resource(bus, r, i) {
 149                 resource_size_t min_used = min;
 150
 151                 if (!r)
 152                         continue;
 153
 154                 /* type_mask must match */
 155                 if ((res->flags ^ r->flags) & type_mask)
 156                         continue;
 157
 158                 /* We cannot allocate a non-prefetching resource
 159                    from a pre-fetching area */
 160                 if ((r->flags & IORESOURCE_PREFETCH) &&
 161                     !(res->flags & IORESOURCE_PREFETCH))
 162                         continue;
 163
 164                 avail = *r;
 165                 pci_clip_resource_to_region(bus, &avail, region);
 166
 167                 /*
 168                  * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
 169                  * protect badly documented motherboard resources, but if
 170                  * this is an already-configured bridge window, its start
 171                  * overrides "min".
 172                  */
 173                 if (avail.start)
 174                         min_used = avail.start;
 175
 176                 max = avail.end;
 177
 178                 /* Ok, try it out.. */
 179                 ret = allocate_resource(r, res, size, min_used, max,
 180                                         align, alignf, alignf_data);
 181                 if (ret == 0)
 182                         return 0;
 183         }
 184         return -ENOMEM;
 185 }
 186
 187 /**
 188  * pci_bus_alloc_resource - allocate a resource from a parent bus
 189  * @bus: PCI bus
 190  * @res: resource to allocate
 191  * @size: size of resource to allocate
 192  * @align: alignment of resource to allocate
 193  * @min: minimum /proc/iomem address to allocate
 194  * @type_mask: IORESOURCE_* type flags
 195  * @alignf: resource alignment function
 196  * @alignf_data: data argument for resource alignment function
 197  *
 198  * Given the PCI bus a device resides on, the size, minimum address,
 199  * alignment and type, try to find an acceptable resource allocation
 200  * for a specific device resource.
 201  */
 202 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 203                 resource_size_t size, resource_size_t align,
 204                 resource_size_t min, unsigned long type_mask,
 205                 resource_size_t (*alignf)(void *,
 206                                           const struct resource *,
 207                                           resource_size_t,
 208                                           resource_size_t),
 209                 void *alignf_data)
 210 {
 211 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 212         int rc;
 213
 214         if (res->flags & IORESOURCE_MEM_64) {
 215                 rc = pci_bus_alloc_from_region(bus, res, size, align, min,
 216                                                type_mask, alignf, alignf_data,
 217                                                &pci_high);
 218                 if (rc == 0)
 219                         return 0;
 220
 221                 return pci_bus_alloc_from_region(bus, res, size, align, min,
 222                                                  type_mask, alignf, alignf_data,
 223                                                  &pci_64_bit);
 224         }
 225 #endif
 226
 227         return pci_bus_alloc_from_region(bus, res, size, align, min,
 228                                          type_mask, alignf, alignf_data,
 229                                          &pci_32_bit);
 230 }
 231 EXPORT_SYMBOL(pci_bus_alloc_resource);
 232
 233 /*
 234  * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
 235  * resource fits inside a window of an upstream bridge, do nothing.  If it
 236  * overlaps an upstream window but extends outside it, clip the resource so
 237  * it fits completely inside.
 238  */
 239 bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
 240 {
 241         struct pci_bus *bus = dev->bus;
 242         struct resource *res = &dev->resource[idx];
 243         struct resource orig_res = *res;
 244         struct resource *r;
 245         int i;
 246
 247         pci_bus_for_each_resource(bus, r, i) {
 248                 resource_size_t start, end;
 249
 250                 if (!r)
 251                         continue;
 252
 253                 if (resource_type(res) != resource_type(r))
 254                         continue;
 255
 256                 start = max(r->start, res->start);
 257                 end = min(r->end, res->end);
 258
 259                 if (start > end)
 260                         continue;       /* no overlap */
 261
 262                 if (res->start == start && res->end == end)
 263                         return false;   /* no change */
 264
 265                 res->start = start;
 266                 res->end = end;
 267                 dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n",
 268                                  &orig_res, res);
 269
 270                 return true;
 271         }
 272
 273         return false;
 274 }
 275
 276 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 277
 278 /**
 279  * pci_bus_add_device - start driver for a single device
 280  * @dev: device to add
 281  *
 282  * This adds add sysfs entries and start device drivers
 283  */
 284 void pci_bus_add_device(struct pci_dev *dev)
 285 {
 286         int retval;
 287
 288         /*
 289          * Can not put in pci_device_add yet because resources
 290          * are not assigned yet for some devices.
 291          */
 292         pci_fixup_device(pci_fixup_final, dev);
 293         pci_create_sysfs_dev_files(dev);
 294         pci_proc_attach_device(dev);
 295
 296         dev->match_driver = true;
 297         retval = device_attach(&dev->dev);
 298         WARN_ON(retval < 0);
 299
 300         dev->is_added = 1;
 301 }
 302 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 303
 304 /**
 305  * pci_bus_add_devices - start driver for PCI devices
 306  * @bus: bus to check for new devices
 307  *
 308  * Start driver for PCI devices and add some sysfs entries.
 309  */
 310 void pci_bus_add_devices(const struct pci_bus *bus)
 311 {
 312         struct pci_dev *dev;
 313         struct pci_bus *child;
 314
 315         list_for_each_entry(dev, &bus->devices, bus_list) {
 316                 /* Skip already-added devices */
 317                 if (dev->is_added)
 318                         continue;
 319                 pci_bus_add_device(dev);
 320         }
 321
 322         list_for_each_entry(dev, &bus->devices, bus_list) {
 323                 BUG_ON(!dev->is_added);
 324                 child = dev->subordinate;
 325                 if (child)
 326                         pci_bus_add_devices(child);
 327         }
 328 }
 329 EXPORT_SYMBOL(pci_bus_add_devices);
 330
 331 /** pci_walk_bus - walk devices on/under bus, calling callback.
 332  *  @top      bus whose devices should be walked
 333  *  @cb       callback to be called for each device found
 334  *  @userdata arbitrary pointer to be passed to callback.
 335  *
 336  *  Walk the given bus, including any bridged devices
 337  *  on buses under this bus.  Call the provided callback
 338  *  on each device found.
 339  *
 340  *  We check the return of @cb each time. If it returns anything
 341  *  other than 0, we break out.
 342  *
 343  */
 344 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 345                   void *userdata)
 346 {
 347         struct pci_dev *dev;
 348         struct pci_bus *bus;
 349         struct list_head *next;
 350         int retval;
 351
 352         bus = top;
 353         down_read(&pci_bus_sem);
 354         next = top->devices.next;
 355         for (;;) {
 356                 if (next == &bus->devices) {
 357                         /* end of this bus, go up or finish */
 358                         if (bus == top)
 359                                 break;
 360                         next = bus->self->bus_list.next;
 361                         bus = bus->self->bus;
 362                         continue;
 363                 }
 364                 dev = list_entry(next, struct pci_dev, bus_list);
 365                 if (dev->subordinate) {
 366                         /* this is a pci-pci bridge, do its devices next */
 367                         next = dev->subordinate->devices.next;
 368                         bus = dev->subordinate;
 369                 } else
 370                         next = dev->bus_list.next;
 371
 372                 retval = cb(dev, userdata);
 373                 if (retval)
 374                         break;
 375         }
 376         up_read(&pci_bus_sem);
 377 }
 378 EXPORT_SYMBOL_GPL(pci_walk_bus);
 379
 380 struct pci_bus *pci_bus_get(struct pci_bus *bus)
 381 {
 382         if (bus)
 383                 get_device(&bus->dev);
 384         return bus;
 385 }
 386 EXPORT_SYMBOL(pci_bus_get);
 387
 388 void pci_bus_put(struct pci_bus *bus)
 389 {
 390         if (bus)
 391                 put_device(&bus->dev);
 392 }
 393 EXPORT_SYMBOL(pci_bus_put);
 394