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 int devm_request_pci_bus_resources(struct device *dev,
  95                                    struct list_head *resources)
  96 {
  97         struct resource_entry *win;
  98         struct resource *parent, *res;
  99         int err;
 100
 101         resource_list_for_each_entry(win, resources) {
 102                 res = win->res;
 103                 switch (resource_type(res)) {
 104                 case IORESOURCE_IO:
 105                         parent = &ioport_resource;
 106                         break;
 107                 case IORESOURCE_MEM:
 108                         parent = &iomem_resource;
 109                         break;
 110                 default:
 111                         continue;
 112                 }
 113
 114                 err = devm_request_resource(dev, parent, res);
 115                 if (err)
 116                         return err;
 117         }
 118
 119         return 0;
 120 }
 121 EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources);
 122
 123 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
 124 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 125 static struct pci_bus_region pci_64_bit = {0,
 126                                 (pci_bus_addr_t) 0xffffffffffffffffULL};
 127 static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
 128                                 (pci_bus_addr_t) 0xffffffffffffffffULL};
 129 #endif
 130
 131 /*
 132  * @res contains CPU addresses.  Clip it so the corresponding bus addresses
 133  * on @bus are entirely within @region.  This is used to control the bus
 134  * addresses of resources we allocate, e.g., we may need a resource that
 135  * can be mapped by a 32-bit BAR.
 136  */
 137 static void pci_clip_resource_to_region(struct pci_bus *bus,
 138                                         struct resource *res,
 139                                         struct pci_bus_region *region)
 140 {
 141         struct pci_bus_region r;
 142
 143         pcibios_resource_to_bus(bus, &r, res);
 144         if (r.start < region->start)
 145                 r.start = region->start;
 146         if (r.end > region->end)
 147                 r.end = region->end;
 148
 149         if (r.end < r.start)
 150                 res->end = res->start - 1;
 151         else
 152                 pcibios_bus_to_resource(bus, res, &r);
 153 }
 154
 155 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 156                 resource_size_t size, resource_size_t align,
 157                 resource_size_t min, unsigned long type_mask,
 158                 resource_size_t (*alignf)(void *,
 159                                           const struct resource *,
 160                                           resource_size_t,
 161                                           resource_size_t),
 162                 void *alignf_data,
 163                 struct pci_bus_region *region)
 164 {
 165         int i, ret;
 166         struct resource *r, avail;
 167         resource_size_t max;
 168
 169         type_mask |= IORESOURCE_TYPE_BITS;
 170
 171         pci_bus_for_each_resource(bus, r, i) {
 172                 resource_size_t min_used = min;
 173
 174                 if (!r)
 175                         continue;
 176
 177                 /* type_mask must match */
 178                 if ((res->flags ^ r->flags) & type_mask)
 179                         continue;
 180
 181                 /* We cannot allocate a non-prefetching resource
 182                    from a pre-fetching area */
 183                 if ((r->flags & IORESOURCE_PREFETCH) &&
 184                     !(res->flags & IORESOURCE_PREFETCH))
 185                         continue;
 186
 187                 avail = *r;
 188                 pci_clip_resource_to_region(bus, &avail, region);
 189
 190                 /*
 191                  * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
 192                  * protect badly documented motherboard resources, but if
 193                  * this is an already-configured bridge window, its start
 194                  * overrides "min".
 195                  */
 196                 if (avail.start)
 197                         min_used = avail.start;
 198
 199                 max = avail.end;
 200
 201                 /* Ok, try it out.. */
 202                 ret = allocate_resource(r, res, size, min_used, max,
 203                                         align, alignf, alignf_data);
 204                 if (ret == 0)
 205                         return 0;
 206         }
 207         return -ENOMEM;
 208 }
 209
 210 /**
 211  * pci_bus_alloc_resource - allocate a resource from a parent bus
 212  * @bus: PCI bus
 213  * @res: resource to allocate
 214  * @size: size of resource to allocate
 215  * @align: alignment of resource to allocate
 216  * @min: minimum /proc/iomem address to allocate
 217  * @type_mask: IORESOURCE_* type flags
 218  * @alignf: resource alignment function
 219  * @alignf_data: data argument for resource alignment function
 220  *
 221  * Given the PCI bus a device resides on, the size, minimum address,
 222  * alignment and type, try to find an acceptable resource allocation
 223  * for a specific device resource.
 224  */
 225 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 226                 resource_size_t size, resource_size_t align,
 227                 resource_size_t min, unsigned long type_mask,
 228                 resource_size_t (*alignf)(void *,
 229                                           const struct resource *,
 230                                           resource_size_t,
 231                                           resource_size_t),
 232                 void *alignf_data)
 233 {
 234 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 235         int rc;
 236
 237         if (res->flags & IORESOURCE_MEM_64) {
 238                 rc = pci_bus_alloc_from_region(bus, res, size, align, min,
 239                                                type_mask, alignf, alignf_data,
 240                                                &pci_high);
 241                 if (rc == 0)
 242                         return 0;
 243
 244                 return pci_bus_alloc_from_region(bus, res, size, align, min,
 245                                                  type_mask, alignf, alignf_data,
 246                                                  &pci_64_bit);
 247         }
 248 #endif
 249
 250         return pci_bus_alloc_from_region(bus, res, size, align, min,
 251                                          type_mask, alignf, alignf_data,
 252                                          &pci_32_bit);
 253 }
 254 EXPORT_SYMBOL(pci_bus_alloc_resource);
 255
 256 /*
 257  * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
 258  * resource fits inside a window of an upstream bridge, do nothing.  If it
 259  * overlaps an upstream window but extends outside it, clip the resource so
 260  * it fits completely inside.
 261  */
 262 bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
 263 {
 264         struct pci_bus *bus = dev->bus;
 265         struct resource *res = &dev->resource[idx];
 266         struct resource orig_res = *res;
 267         struct resource *r;
 268         int i;
 269
 270         pci_bus_for_each_resource(bus, r, i) {
 271                 resource_size_t start, end;
 272
 273                 if (!r)
 274                         continue;
 275
 276                 if (resource_type(res) != resource_type(r))
 277                         continue;
 278
 279                 start = max(r->start, res->start);
 280                 end = min(r->end, res->end);
 281
 282                 if (start > end)
 283                         continue;       /* no overlap */
 284
 285                 if (res->start == start && res->end == end)
 286                         return false;   /* no change */
 287
 288                 res->start = start;
 289                 res->end = end;
 290                 res->flags &= ~IORESOURCE_UNSET;
 291                 orig_res.flags &= ~IORESOURCE_UNSET;
 292                 dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n",
 293                                  &orig_res, res);
 294
 295                 return true;
 296         }
 297
 298         return false;
 299 }
 300
 301 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 302
 303 void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
 304
 305 /**
 306  * pci_bus_add_device - start driver for a single device
 307  * @dev: device to add
 308  *
 309  * This adds add sysfs entries and start device drivers
 310  */
 311 void pci_bus_add_device(struct pci_dev *dev)
 312 {
 313         int retval;
 314
 315         /*
 316          * Can not put in pci_device_add yet because resources
 317          * are not assigned yet for some devices.
 318          */
 319         pcibios_bus_add_device(dev);
 320         pci_fixup_device(pci_fixup_final, dev);
 321         pci_create_sysfs_dev_files(dev);
 322         pci_proc_attach_device(dev);
 323         pci_bridge_d3_update(dev);
 324
 325         dev->match_driver = true;
 326         retval = device_attach(&dev->dev);
 327         if (retval < 0 && retval != -EPROBE_DEFER) {
 328                 dev_warn(&dev->dev, "device attach failed (%d)\n", retval);
 329                 pci_proc_detach_device(dev);
 330                 pci_remove_sysfs_dev_files(dev);
 331                 return;
 332         }
 333
 334         dev->is_added = 1;
 335 }
 336 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 337
 338 /**
 339  * pci_bus_add_devices - start driver for PCI devices
 340  * @bus: bus to check for new devices
 341  *
 342  * Start driver for PCI devices and add some sysfs entries.
 343  */
 344 void pci_bus_add_devices(const struct pci_bus *bus)
 345 {
 346         struct pci_dev *dev;
 347         struct pci_bus *child;
 348
 349         list_for_each_entry(dev, &bus->devices, bus_list) {
 350                 /* Skip already-added devices */
 351                 if (dev->is_added)
 352                         continue;
 353                 pci_bus_add_device(dev);
 354         }
 355
 356         list_for_each_entry(dev, &bus->devices, bus_list) {
 357                 /* Skip if device attach failed */
 358                 if (!dev->is_added)
 359                         continue;
 360                 child = dev->subordinate;
 361                 if (child)
 362                         pci_bus_add_devices(child);
 363         }
 364 }
 365 EXPORT_SYMBOL(pci_bus_add_devices);
 366
 367 /** pci_walk_bus - walk devices on/under bus, calling callback.
 368  *  @top      bus whose devices should be walked
 369  *  @cb       callback to be called for each device found
 370  *  @userdata arbitrary pointer to be passed to callback.
 371  *
 372  *  Walk the given bus, including any bridged devices
 373  *  on buses under this bus.  Call the provided callback
 374  *  on each device found.
 375  *
 376  *  We check the return of @cb each time. If it returns anything
 377  *  other than 0, we break out.
 378  *
 379  */
 380 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 381                   void *userdata)
 382 {
 383         struct pci_dev *dev;
 384         struct pci_bus *bus;
 385         struct list_head *next;
 386         int retval;
 387
 388         bus = top;
 389         down_read(&pci_bus_sem);
 390         next = top->devices.next;
 391         for (;;) {
 392                 if (next == &bus->devices) {
 393                         /* end of this bus, go up or finish */
 394                         if (bus == top)
 395                                 break;
 396                         next = bus->self->bus_list.next;
 397                         bus = bus->self->bus;
 398                         continue;
 399                 }
 400                 dev = list_entry(next, struct pci_dev, bus_list);
 401                 if (dev->subordinate) {
 402                         /* this is a pci-pci bridge, do its devices next */
 403                         next = dev->subordinate->devices.next;
 404                         bus = dev->subordinate;
 405                 } else
 406                         next = dev->bus_list.next;
 407
 408                 retval = cb(dev, userdata);
 409                 if (retval)
 410                         break;
 411         }
 412         up_read(&pci_bus_sem);
 413 }
 414 EXPORT_SYMBOL_GPL(pci_walk_bus);
 415
 416 struct pci_bus *pci_bus_get(struct pci_bus *bus)
 417 {
 418         if (bus)
 419                 get_device(&bus->dev);
 420         return bus;
 421 }
 422 EXPORT_SYMBOL(pci_bus_get);
 423
 424 void pci_bus_put(struct pci_bus *bus)
 425 {
 426         if (bus)
 427                 put_device(&bus->dev);
 428 }
 429 EXPORT_SYMBOL(pci_bus_put);