drivers/pci/bus.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * From setup-res.c, by:
   4  *      Dave Rusling (david.rusling@reo.mts.dec.com)
   5  *      David Mosberger (davidm@cs.arizona.edu)
   6  *      David Miller (davem@redhat.com)
   7  *      Ivan Kokshaysky (ink@jurassic.park.msu.ru)
   8  */
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/pci.h>
  12 #include <linux/errno.h>
  13 #include <linux/ioport.h>
  14 #include <linux/proc_fs.h>
  15 #include <linux/slab.h>
  16
  17 #include "pci.h"
  18
  19 void pci_add_resource_offset(struct list_head *resources, struct resource *res,
  20                              resource_size_t offset)
  21 {
  22         struct resource_entry *entry;
  23
  24         entry = resource_list_create_entry(res, 0);
  25         if (!entry) {
  26                 pr_err("PCI: can't add host bridge window %pR\n", res);
  27                 return;
  28         }
  29
  30         entry->offset = offset;
  31         resource_list_add_tail(entry, resources);
  32 }
  33 EXPORT_SYMBOL(pci_add_resource_offset);
  34
  35 void pci_add_resource(struct list_head *resources, struct resource *res)
  36 {
  37         pci_add_resource_offset(resources, res, 0);
  38 }
  39 EXPORT_SYMBOL(pci_add_resource);
  40
  41 void pci_free_resource_list(struct list_head *resources)
  42 {
  43         resource_list_free(resources);
  44 }
  45 EXPORT_SYMBOL(pci_free_resource_list);
  46
  47 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
  48                           unsigned int flags)
  49 {
  50         struct pci_bus_resource *bus_res;
  51
  52         bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
  53         if (!bus_res) {
  54                 dev_err(&bus->dev, "can't add %pR resource\n", res);
  55                 return;
  56         }
  57
  58         bus_res->res = res;
  59         bus_res->flags = flags;
  60         list_add_tail(&bus_res->list, &bus->resources);
  61 }
  62
  63 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
  64 {
  65         struct pci_bus_resource *bus_res;
  66
  67         if (n < PCI_BRIDGE_RESOURCE_NUM)
  68                 return bus->resource[n];
  69
  70         n -= PCI_BRIDGE_RESOURCE_NUM;
  71         list_for_each_entry(bus_res, &bus->resources, list) {
  72                 if (n-- == 0)
  73                         return bus_res->res;
  74         }
  75         return NULL;
  76 }
  77 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  78
  79 void pci_bus_remove_resources(struct pci_bus *bus)
  80 {
  81         int i;
  82         struct pci_bus_resource *bus_res, *tmp;
  83
  84         for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
  85                 bus->resource[i] = NULL;
  86
  87         list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
  88                 list_del(&bus_res->list);
  89                 kfree(bus_res);
  90         }
  91 }
  92
  93 int devm_request_pci_bus_resources(struct device *dev,
  94                                    struct list_head *resources)
  95 {
  96         struct resource_entry *win;
  97         struct resource *parent, *res;
  98         int err;
  99
 100         resource_list_for_each_entry(win, resources) {
 101                 res = win->res;
 102                 switch (resource_type(res)) {
 103                 case IORESOURCE_IO:
 104                         parent = &ioport_resource;
 105                         break;
 106                 case IORESOURCE_MEM:
 107                         parent = &iomem_resource;
 108                         break;
 109                 default:
 110                         continue;
 111                 }
 112
 113                 err = devm_request_resource(dev, parent, res);
 114                 if (err)
 115                         return err;
 116         }
 117
 118         return 0;
 119 }
 120 EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources);
 121
 122 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
 123 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 124 static struct pci_bus_region pci_64_bit = {0,
 125                                 (pci_bus_addr_t) 0xffffffffffffffffULL};
 126 static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
 127                                 (pci_bus_addr_t) 0xffffffffffffffffULL};
 128 #endif
 129
 130 /*
 131  * @res contains CPU addresses.  Clip it so the corresponding bus addresses
 132  * on @bus are entirely within @region.  This is used to control the bus
 133  * addresses of resources we allocate, e.g., we may need a resource that
 134  * can be mapped by a 32-bit BAR.
 135  */
 136 static void pci_clip_resource_to_region(struct pci_bus *bus,
 137                                         struct resource *res,
 138                                         struct pci_bus_region *region)
 139 {
 140         struct pci_bus_region r;
 141
 142         pcibios_resource_to_bus(bus, &r, res);
 143         if (r.start < region->start)
 144                 r.start = region->start;
 145         if (r.end > region->end)
 146                 r.end = region->end;
 147
 148         if (r.end < r.start)
 149                 res->end = res->start - 1;
 150         else
 151                 pcibios_bus_to_resource(bus, res, &r);
 152 }
 153
 154 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 155                 resource_size_t size, resource_size_t align,
 156                 resource_size_t min, unsigned long type_mask,
 157                 resource_size_t (*alignf)(void *,
 158                                           const struct resource *,
 159                                           resource_size_t,
 160                                           resource_size_t),
 161                 void *alignf_data,
 162                 struct pci_bus_region *region)
 163 {
 164         int i, ret;
 165         struct resource *r, avail;
 166         resource_size_t max;
 167
 168         type_mask |= IORESOURCE_TYPE_BITS;
 169
 170         pci_bus_for_each_resource(bus, r, i) {
 171                 resource_size_t min_used = min;
 172
 173                 if (!r)
 174                         continue;
 175
 176                 /* type_mask must match */
 177                 if ((res->flags ^ r->flags) & type_mask)
 178                         continue;
 179
 180                 /* We cannot allocate a non-prefetching resource
 181                    from a pre-fetching area */
 182                 if ((r->flags & IORESOURCE_PREFETCH) &&
 183                     !(res->flags & IORESOURCE_PREFETCH))
 184                         continue;
 185
 186                 avail = *r;
 187                 pci_clip_resource_to_region(bus, &avail, region);
 188
 189                 /*
 190                  * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
 191                  * protect badly documented motherboard resources, but if
 192                  * this is an already-configured bridge window, its start
 193                  * overrides "min".
 194                  */
 195                 if (avail.start)
 196                         min_used = avail.start;
 197
 198                 max = avail.end;
 199
 200                 /* Ok, try it out.. */
 201                 ret = allocate_resource(r, res, size, min_used, max,
 202                                         align, alignf, alignf_data);
 203                 if (ret == 0)
 204                         return 0;
 205         }
 206         return -ENOMEM;
 207 }
 208
 209 /**
 210  * pci_bus_alloc_resource - allocate a resource from a parent bus
 211  * @bus: PCI bus
 212  * @res: resource to allocate
 213  * @size: size of resource to allocate
 214  * @align: alignment of resource to allocate
 215  * @min: minimum /proc/iomem address to allocate
 216  * @type_mask: IORESOURCE_* type flags
 217  * @alignf: resource alignment function
 218  * @alignf_data: data argument for resource alignment function
 219  *
 220  * Given the PCI bus a device resides on, the size, minimum address,
 221  * alignment and type, try to find an acceptable resource allocation
 222  * for a specific device resource.
 223  */
 224 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 225                 resource_size_t size, resource_size_t align,
 226                 resource_size_t min, unsigned long type_mask,
 227                 resource_size_t (*alignf)(void *,
 228                                           const struct resource *,
 229                                           resource_size_t,
 230                                           resource_size_t),
 231                 void *alignf_data)
 232 {
 233 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 234         int rc;
 235
 236         if (res->flags & IORESOURCE_MEM_64) {
 237                 rc = pci_bus_alloc_from_region(bus, res, size, align, min,
 238                                                type_mask, alignf, alignf_data,
 239                                                &pci_high);
 240                 if (rc == 0)
 241                         return 0;
 242
 243                 return pci_bus_alloc_from_region(bus, res, size, align, min,
 244                                                  type_mask, alignf, alignf_data,
 245                                                  &pci_64_bit);
 246         }
 247 #endif
 248
 249         return pci_bus_alloc_from_region(bus, res, size, align, min,
 250                                          type_mask, alignf, alignf_data,
 251                                          &pci_32_bit);
 252 }
 253 EXPORT_SYMBOL(pci_bus_alloc_resource);
 254
 255 /*
 256  * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
 257  * resource fits inside a window of an upstream bridge, do nothing.  If it
 258  * overlaps an upstream window but extends outside it, clip the resource so
 259  * it fits completely inside.
 260  */
 261 bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
 262 {
 263         struct pci_bus *bus = dev->bus;
 264         struct resource *res = &dev->resource[idx];
 265         struct resource orig_res = *res;
 266         struct resource *r;
 267         int i;
 268
 269         pci_bus_for_each_resource(bus, r, i) {
 270                 resource_size_t start, end;
 271
 272                 if (!r)
 273                         continue;
 274
 275                 if (resource_type(res) != resource_type(r))
 276                         continue;
 277
 278                 start = max(r->start, res->start);
 279                 end = min(r->end, res->end);
 280
 281                 if (start > end)
 282                         continue;       /* no overlap */
 283
 284                 if (res->start == start && res->end == end)
 285                         return false;   /* no change */
 286
 287                 res->start = start;
 288                 res->end = end;
 289                 res->flags &= ~IORESOURCE_UNSET;
 290                 orig_res.flags &= ~IORESOURCE_UNSET;
 291                 pci_info(dev, "%pR clipped to %pR\n", &orig_res, res);
 292
 293                 return true;
 294         }
 295
 296         return false;
 297 }
 298
 299 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 300
 301 void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
 302
 303 /**
 304  * pci_bus_add_device - start driver for a single device
 305  * @dev: device to add
 306  *
 307  * This adds add sysfs entries and start device drivers
 308  */
 309 void pci_bus_add_device(struct pci_dev *dev)
 310 {
 311         int retval;
 312
 313         /*
 314          * Can not put in pci_device_add yet because resources
 315          * are not assigned yet for some devices.
 316          */
 317         pcibios_bus_add_device(dev);
 318         pci_fixup_device(pci_fixup_final, dev);
 319         pci_create_sysfs_dev_files(dev);
 320         pci_proc_attach_device(dev);
 321         pci_bridge_d3_update(dev);
 322
 323         dev->match_driver = true;
 324         retval = device_attach(&dev->dev);
 325         if (retval < 0 && retval != -EPROBE_DEFER)
 326                 pci_warn(dev, "device attach failed (%d)\n", retval);
 327
 328         pci_dev_assign_added(dev, true);
 329 }
 330 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 331
 332 /**
 333  * pci_bus_add_devices - start driver for PCI devices
 334  * @bus: bus to check for new devices
 335  *
 336  * Start driver for PCI devices and add some sysfs entries.
 337  */
 338 void pci_bus_add_devices(const struct pci_bus *bus)
 339 {
 340         struct pci_dev *dev;
 341         struct pci_bus *child;
 342
 343         list_for_each_entry(dev, &bus->devices, bus_list) {
 344                 /* Skip already-added devices */
 345                 if (pci_dev_is_added(dev))
 346                         continue;
 347                 pci_bus_add_device(dev);
 348         }
 349
 350         list_for_each_entry(dev, &bus->devices, bus_list) {
 351                 /* Skip if device attach failed */
 352                 if (!pci_dev_is_added(dev))
 353                         continue;
 354                 child = dev->subordinate;
 355                 if (child)
 356                         pci_bus_add_devices(child);
 357         }
 358 }
 359 EXPORT_SYMBOL(pci_bus_add_devices);
 360
 361 /** pci_walk_bus - walk devices on/under bus, calling callback.
 362  *  @top      bus whose devices should be walked
 363  *  @cb       callback to be called for each device found
 364  *  @userdata arbitrary pointer to be passed to callback.
 365  *
 366  *  Walk the given bus, including any bridged devices
 367  *  on buses under this bus.  Call the provided callback
 368  *  on each device found.
 369  *
 370  *  We check the return of @cb each time. If it returns anything
 371  *  other than 0, we break out.
 372  *
 373  */
 374 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 375                   void *userdata)
 376 {
 377         struct pci_dev *dev;
 378         struct pci_bus *bus;
 379         struct list_head *next;
 380         int retval;
 381
 382         bus = top;
 383         down_read(&pci_bus_sem);
 384         next = top->devices.next;
 385         for (;;) {
 386                 if (next == &bus->devices) {
 387                         /* end of this bus, go up or finish */
 388                         if (bus == top)
 389                                 break;
 390                         next = bus->self->bus_list.next;
 391                         bus = bus->self->bus;
 392                         continue;
 393                 }
 394                 dev = list_entry(next, struct pci_dev, bus_list);
 395                 if (dev->subordinate) {
 396                         /* this is a pci-pci bridge, do its devices next */
 397                         next = dev->subordinate->devices.next;
 398                         bus = dev->subordinate;
 399                 } else
 400                         next = dev->bus_list.next;
 401
 402                 retval = cb(dev, userdata);
 403                 if (retval)
 404                         break;
 405         }
 406         up_read(&pci_bus_sem);
 407 }
 408 EXPORT_SYMBOL_GPL(pci_walk_bus);
 409
 410 struct pci_bus *pci_bus_get(struct pci_bus *bus)
 411 {
 412         if (bus)
 413                 get_device(&bus->dev);
 414         return bus;
 415 }
 416
 417 void pci_bus_put(struct pci_bus *bus)
 418 {
 419         if (bus)
 420                 put_device(&bus->dev);
 421 }