drivers/pci/bus.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *      drivers/pci/bus.c
   4  *
   5  * From setup-res.c, by:
   6  *      Dave Rusling (david.rusling@reo.mts.dec.com)
   7  *      David Mosberger (davidm@cs.arizona.edu)
   8  *      David Miller (davem@redhat.com)
   9  *      Ivan Kokshaysky (ink@jurassic.park.msu.ru)
  10  */
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/pci.h>
  14 #include <linux/errno.h>
  15 #include <linux/ioport.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/slab.h>
  18
  19 #include "pci.h"
  20
  21 void pci_add_resource_offset(struct list_head *resources, struct resource *res,
  22                              resource_size_t offset)
  23 {
  24         struct resource_entry *entry;
  25
  26         entry = resource_list_create_entry(res, 0);
  27         if (!entry) {
  28                 printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
  29                 return;
  30         }
  31
  32         entry->offset = offset;
  33         resource_list_add_tail(entry, 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         resource_list_free(resources);
  46 }
  47 EXPORT_SYMBOL(pci_free_resource_list);
  48
  49 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
  50                           unsigned int flags)
  51 {
  52         struct pci_bus_resource *bus_res;
  53
  54         bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
  55         if (!bus_res) {
  56                 dev_err(&bus->dev, "can't add %pR resource\n", res);
  57                 return;
  58         }
  59
  60         bus_res->res = res;
  61         bus_res->flags = flags;
  62         list_add_tail(&bus_res->list, &bus->resources);
  63 }
  64
  65 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
  66 {
  67         struct pci_bus_resource *bus_res;
  68
  69         if (n < PCI_BRIDGE_RESOURCE_NUM)
  70                 return bus->resource[n];
  71
  72         n -= PCI_BRIDGE_RESOURCE_NUM;
  73         list_for_each_entry(bus_res, &bus->resources, list) {
  74                 if (n-- == 0)
  75                         return bus_res->res;
  76         }
  77         return NULL;
  78 }
  79 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  80
  81 void pci_bus_remove_resources(struct pci_bus *bus)
  82 {
  83         int i;
  84         struct pci_bus_resource *bus_res, *tmp;
  85
  86         for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
  87                 bus->resource[i] = NULL;
  88
  89         list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
  90                 list_del(&bus_res->list);
  91                 kfree(bus_res);
  92         }
  93 }
  94
  95 int devm_request_pci_bus_resources(struct device *dev,
  96                                    struct list_head *resources)
  97 {
  98         struct resource_entry *win;
  99         struct resource *parent, *res;
 100         int err;
 101
 102         resource_list_for_each_entry(win, resources) {
 103                 res = win->res;
 104                 switch (resource_type(res)) {
 105                 case IORESOURCE_IO:
 106                         parent = &ioport_resource;
 107                         break;
 108                 case IORESOURCE_MEM:
 109                         parent = &iomem_resource;
 110                         break;
 111                 default:
 112                         continue;
 113                 }
 114
 115                 err = devm_request_resource(dev, parent, res);
 116                 if (err)
 117                         return err;
 118         }
 119
 120         return 0;
 121 }
 122 EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources);
 123
 124 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
 125 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 126 static struct pci_bus_region pci_64_bit = {0,
 127                                 (pci_bus_addr_t) 0xffffffffffffffffULL};
 128 static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
 129                                 (pci_bus_addr_t) 0xffffffffffffffffULL};
 130 #endif
 131
 132 /*
 133  * @res contains CPU addresses.  Clip it so the corresponding bus addresses
 134  * on @bus are entirely within @region.  This is used to control the bus
 135  * addresses of resources we allocate, e.g., we may need a resource that
 136  * can be mapped by a 32-bit BAR.
 137  */
 138 static void pci_clip_resource_to_region(struct pci_bus *bus,
 139                                         struct resource *res,
 140                                         struct pci_bus_region *region)
 141 {
 142         struct pci_bus_region r;
 143
 144         pcibios_resource_to_bus(bus, &r, res);
 145         if (r.start < region->start)
 146                 r.start = region->start;
 147         if (r.end > region->end)
 148                 r.end = region->end;
 149
 150         if (r.end < r.start)
 151                 res->end = res->start - 1;
 152         else
 153                 pcibios_bus_to_resource(bus, res, &r);
 154 }
 155
 156 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 157                 resource_size_t size, resource_size_t align,
 158                 resource_size_t min, unsigned long type_mask,
 159                 resource_size_t (*alignf)(void *,
 160                                           const struct resource *,
 161                                           resource_size_t,
 162                                           resource_size_t),
 163                 void *alignf_data,
 164                 struct pci_bus_region *region)
 165 {
 166         int i, ret;
 167         struct resource *r, avail;
 168         resource_size_t max;
 169
 170         type_mask |= IORESOURCE_TYPE_BITS;
 171
 172         pci_bus_for_each_resource(bus, r, i) {
 173                 resource_size_t min_used = min;
 174
 175                 if (!r)
 176                         continue;
 177
 178                 /* type_mask must match */
 179                 if ((res->flags ^ r->flags) & type_mask)
 180                         continue;
 181
 182                 /* We cannot allocate a non-prefetching resource
 183                    from a pre-fetching area */
 184                 if ((r->flags & IORESOURCE_PREFETCH) &&
 185                     !(res->flags & IORESOURCE_PREFETCH))
 186                         continue;
 187
 188                 avail = *r;
 189                 pci_clip_resource_to_region(bus, &avail, region);
 190
 191                 /*
 192                  * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
 193                  * protect badly documented motherboard resources, but if
 194                  * this is an already-configured bridge window, its start
 195                  * overrides "min".
 196                  */
 197                 if (avail.start)
 198                         min_used = avail.start;
 199
 200                 max = avail.end;
 201
 202                 /* Ok, try it out.. */
 203                 ret = allocate_resource(r, res, size, min_used, max,
 204                                         align, alignf, alignf_data);
 205                 if (ret == 0)
 206                         return 0;
 207         }
 208         return -ENOMEM;
 209 }
 210
 211 /**
 212  * pci_bus_alloc_resource - allocate a resource from a parent bus
 213  * @bus: PCI bus
 214  * @res: resource to allocate
 215  * @size: size of resource to allocate
 216  * @align: alignment of resource to allocate
 217  * @min: minimum /proc/iomem address to allocate
 218  * @type_mask: IORESOURCE_* type flags
 219  * @alignf: resource alignment function
 220  * @alignf_data: data argument for resource alignment function
 221  *
 222  * Given the PCI bus a device resides on, the size, minimum address,
 223  * alignment and type, try to find an acceptable resource allocation
 224  * for a specific device resource.
 225  */
 226 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 227                 resource_size_t size, resource_size_t align,
 228                 resource_size_t min, unsigned long type_mask,
 229                 resource_size_t (*alignf)(void *,
 230                                           const struct resource *,
 231                                           resource_size_t,
 232                                           resource_size_t),
 233                 void *alignf_data)
 234 {
 235 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 236         int rc;
 237
 238         if (res->flags & IORESOURCE_MEM_64) {
 239                 rc = pci_bus_alloc_from_region(bus, res, size, align, min,
 240                                                type_mask, alignf, alignf_data,
 241                                                &pci_high);
 242                 if (rc == 0)
 243                         return 0;
 244
 245                 return pci_bus_alloc_from_region(bus, res, size, align, min,
 246                                                  type_mask, alignf, alignf_data,
 247                                                  &pci_64_bit);
 248         }
 249 #endif
 250
 251         return pci_bus_alloc_from_region(bus, res, size, align, min,
 252                                          type_mask, alignf, alignf_data,
 253                                          &pci_32_bit);
 254 }
 255 EXPORT_SYMBOL(pci_bus_alloc_resource);
 256
 257 /*
 258  * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
 259  * resource fits inside a window of an upstream bridge, do nothing.  If it
 260  * overlaps an upstream window but extends outside it, clip the resource so
 261  * it fits completely inside.
 262  */
 263 bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
 264 {
 265         struct pci_bus *bus = dev->bus;
 266         struct resource *res = &dev->resource[idx];
 267         struct resource orig_res = *res;
 268         struct resource *r;
 269         int i;
 270
 271         pci_bus_for_each_resource(bus, r, i) {
 272                 resource_size_t start, end;
 273
 274                 if (!r)
 275                         continue;
 276
 277                 if (resource_type(res) != resource_type(r))
 278                         continue;
 279
 280                 start = max(r->start, res->start);
 281                 end = min(r->end, res->end);
 282
 283                 if (start > end)
 284                         continue;       /* no overlap */
 285
 286                 if (res->start == start && res->end == end)
 287                         return false;   /* no change */
 288
 289                 res->start = start;
 290                 res->end = end;
 291                 res->flags &= ~IORESOURCE_UNSET;
 292                 orig_res.flags &= ~IORESOURCE_UNSET;
 293                 pci_printk(KERN_DEBUG, dev, "%pR clipped to %pR\n",
 294                                  &orig_res, res);
 295
 296                 return true;
 297         }
 298
 299         return false;
 300 }
 301
 302 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 303
 304 void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
 305
 306 /**
 307  * pci_bus_add_device - start driver for a single device
 308  * @dev: device to add
 309  *
 310  * This adds add sysfs entries and start device drivers
 311  */
 312 void pci_bus_add_device(struct pci_dev *dev)
 313 {
 314         int retval;
 315
 316         /*
 317          * Can not put in pci_device_add yet because resources
 318          * are not assigned yet for some devices.
 319          */
 320         pcibios_bus_add_device(dev);
 321         pci_fixup_device(pci_fixup_final, dev);
 322         pci_create_sysfs_dev_files(dev);
 323         pci_proc_attach_device(dev);
 324         pci_bridge_d3_update(dev);
 325
 326         dev->match_driver = true;
 327         retval = device_attach(&dev->dev);
 328         if (retval < 0 && retval != -EPROBE_DEFER) {
 329                 pci_warn(dev, "device attach failed (%d)\n", retval);
 330                 pci_proc_detach_device(dev);
 331                 pci_remove_sysfs_dev_files(dev);
 332                 return;
 333         }
 334
 335         dev->is_added = 1;
 336 }
 337 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 338
 339 /**
 340  * pci_bus_add_devices - start driver for PCI devices
 341  * @bus: bus to check for new devices
 342  *
 343  * Start driver for PCI devices and add some sysfs entries.
 344  */
 345 void pci_bus_add_devices(const struct pci_bus *bus)
 346 {
 347         struct pci_dev *dev;
 348         struct pci_bus *child;
 349
 350         list_for_each_entry(dev, &bus->devices, bus_list) {
 351                 /* Skip already-added devices */
 352                 if (dev->is_added)
 353                         continue;
 354                 pci_bus_add_device(dev);
 355         }
 356
 357         list_for_each_entry(dev, &bus->devices, bus_list) {
 358                 /* Skip if device attach failed */
 359                 if (!dev->is_added)
 360                         continue;
 361                 child = dev->subordinate;
 362                 if (child)
 363                         pci_bus_add_devices(child);
 364         }
 365 }
 366 EXPORT_SYMBOL(pci_bus_add_devices);
 367
 368 /** pci_walk_bus - walk devices on/under bus, calling callback.
 369  *  @top      bus whose devices should be walked
 370  *  @cb       callback to be called for each device found
 371  *  @userdata arbitrary pointer to be passed to callback.
 372  *
 373  *  Walk the given bus, including any bridged devices
 374  *  on buses under this bus.  Call the provided callback
 375  *  on each device found.
 376  *
 377  *  We check the return of @cb each time. If it returns anything
 378  *  other than 0, we break out.
 379  *
 380  */
 381 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 382                   void *userdata)
 383 {
 384         struct pci_dev *dev;
 385         struct pci_bus *bus;
 386         struct list_head *next;
 387         int retval;
 388
 389         bus = top;
 390         down_read(&pci_bus_sem);
 391         next = top->devices.next;
 392         for (;;) {
 393                 if (next == &bus->devices) {
 394                         /* end of this bus, go up or finish */
 395                         if (bus == top)
 396                                 break;
 397                         next = bus->self->bus_list.next;
 398                         bus = bus->self->bus;
 399                         continue;
 400                 }
 401                 dev = list_entry(next, struct pci_dev, bus_list);
 402                 if (dev->subordinate) {
 403                         /* this is a pci-pci bridge, do its devices next */
 404                         next = dev->subordinate->devices.next;
 405                         bus = dev->subordinate;
 406                 } else
 407                         next = dev->bus_list.next;
 408
 409                 retval = cb(dev, userdata);
 410                 if (retval)
 411                         break;
 412         }
 413         up_read(&pci_bus_sem);
 414 }
 415 EXPORT_SYMBOL_GPL(pci_walk_bus);
 416
 417 struct pci_bus *pci_bus_get(struct pci_bus *bus)
 418 {
 419         if (bus)
 420                 get_device(&bus->dev);
 421         return bus;
 422 }
 423 EXPORT_SYMBOL(pci_bus_get);
 424
 425 void pci_bus_put(struct pci_bus *bus)
 426 {
 427         if (bus)
 428                 put_device(&bus->dev);
 429 }
 430 EXPORT_SYMBOL(pci_bus_put);