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