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 /**
 102  * pci_bus_alloc_resource - allocate a resource from a parent bus
 103  * @bus: PCI bus
 104  * @res: resource to allocate
 105  * @size: size of resource to allocate
 106  * @align: alignment of resource to allocate
 107  * @min: minimum /proc/iomem address to allocate
 108  * @type_mask: IORESOURCE_* type flags
 109  * @alignf: resource alignment function
 110  * @alignf_data: data argument for resource alignment function
 111  *
 112  * Given the PCI bus a device resides on, the size, minimum address,
 113  * alignment and type, try to find an acceptable resource allocation
 114  * for a specific device resource.
 115  */
 116 int
 117 pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 118                 resource_size_t size, resource_size_t align,
 119                 resource_size_t min, unsigned int type_mask,
 120                 resource_size_t (*alignf)(void *,
 121                                           const struct resource *,
 122                                           resource_size_t,
 123                                           resource_size_t),
 124                 void *alignf_data)
 125 {
 126         int i, ret = -ENOMEM;
 127         struct resource *r;
 128         resource_size_t max = -1;
 129
 130         type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
 131
 132         /* don't allocate too high if the pref mem doesn't support 64bit*/
 133         if (!(res->flags & IORESOURCE_MEM_64))
 134                 max = PCIBIOS_MAX_MEM_32;
 135
 136         pci_bus_for_each_resource(bus, r, i) {
 137                 if (!r)
 138                         continue;
 139
 140                 /* type_mask must match */
 141                 if ((res->flags ^ r->flags) & type_mask)
 142                         continue;
 143
 144                 /* We cannot allocate a non-prefetching resource
 145                    from a pre-fetching area */
 146                 if ((r->flags & IORESOURCE_PREFETCH) &&
 147                     !(res->flags & IORESOURCE_PREFETCH))
 148                         continue;
 149
 150                 /* Ok, try it out.. */
 151                 ret = allocate_resource(r, res, size,
 152                                         r->start ? : min,
 153                                         max, align,
 154                                         alignf, alignf_data);
 155                 if (ret == 0)
 156                         break;
 157         }
 158         return ret;
 159 }
 160
 161 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 162
 163 /**
 164  * pci_bus_add_device - add a single device
 165  * @dev: device to add
 166  *
 167  * This adds a single pci device to the global
 168  * device list and adds sysfs and procfs entries
 169  */
 170 int pci_bus_add_device(struct pci_dev *dev)
 171 {
 172         int retval;
 173
 174         pci_fixup_device(pci_fixup_final, dev);
 175
 176         retval = pcibios_add_device(dev);
 177         if (retval)
 178                 return retval;
 179
 180         dev->match_driver = false;
 181         retval = device_add(&dev->dev);
 182         if (retval)
 183                 return retval;
 184
 185         dev->match_driver = true;
 186         retval = device_attach(&dev->dev);
 187         WARN_ON(retval < 0);
 188
 189         dev->is_added = 1;
 190         pci_proc_attach_device(dev);
 191         pci_create_sysfs_dev_files(dev);
 192         return 0;
 193 }
 194
 195 /**
 196  * pci_bus_add_child - add a child bus
 197  * @bus: bus to add
 198  *
 199  * This adds sysfs entries for a single bus
 200  */
 201 int pci_bus_add_child(struct pci_bus *bus)
 202 {
 203         int retval;
 204
 205         if (bus->bridge)
 206                 bus->dev.parent = bus->bridge;
 207
 208         retval = device_register(&bus->dev);
 209         if (retval)
 210                 return retval;
 211
 212         bus->is_added = 1;
 213
 214         /* Create legacy_io and legacy_mem files for this bus */
 215         pci_create_legacy_files(bus);
 216
 217         return retval;
 218 }
 219
 220 /**
 221  * pci_bus_add_devices - insert newly discovered PCI devices
 222  * @bus: bus to check for new devices
 223  *
 224  * Add newly discovered PCI devices (which are on the bus->devices
 225  * list) to the global PCI device list, add the sysfs and procfs
 226  * entries.  Where a bridge is found, add the discovered bus to
 227  * the parents list of child buses, and recurse (breadth-first
 228  * to be compatible with 2.4)
 229  *
 230  * Call hotplug for each new devices.
 231  */
 232 void pci_bus_add_devices(const struct pci_bus *bus)
 233 {
 234         struct pci_dev *dev;
 235         struct pci_bus *child;
 236         int retval;
 237
 238         list_for_each_entry(dev, &bus->devices, bus_list) {
 239                 /* Skip already-added devices */
 240                 if (dev->is_added)
 241                         continue;
 242                 retval = pci_bus_add_device(dev);
 243                 if (retval)
 244                         dev_err(&dev->dev, "Error adding device, continuing\n");
 245         }
 246
 247         list_for_each_entry(dev, &bus->devices, bus_list) {
 248                 BUG_ON(!dev->is_added);
 249
 250                 child = dev->subordinate;
 251                 /*
 252                  * If there is an unattached subordinate bus, attach
 253                  * it and then scan for unattached PCI devices.
 254                  */
 255                 if (!child)
 256                         continue;
 257                 if (list_empty(&child->node)) {
 258                         down_write(&pci_bus_sem);
 259                         list_add_tail(&child->node, &dev->bus->children);
 260                         up_write(&pci_bus_sem);
 261                 }
 262                 pci_bus_add_devices(child);
 263
 264                 /*
 265                  * register the bus with sysfs as the parent is now
 266                  * properly registered.
 267                  */
 268                 if (child->is_added)
 269                         continue;
 270                 retval = pci_bus_add_child(child);
 271                 if (retval)
 272                         dev_err(&dev->dev, "Error adding bus, continuing\n");
 273         }
 274 }
 275
 276 void pci_enable_bridges(struct pci_bus *bus)
 277 {
 278         struct pci_dev *dev;
 279         int retval;
 280
 281         list_for_each_entry(dev, &bus->devices, bus_list) {
 282                 if (dev->subordinate) {
 283                         if (!pci_is_enabled(dev)) {
 284                                 retval = pci_enable_device(dev);
 285                                 if (retval)
 286                                         dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
 287                                 pci_set_master(dev);
 288                         }
 289                         pci_enable_bridges(dev->subordinate);
 290                 }
 291         }
 292 }
 293
 294 /** pci_walk_bus - walk devices on/under bus, calling callback.
 295  *  @top      bus whose devices should be walked
 296  *  @cb       callback to be called for each device found
 297  *  @userdata arbitrary pointer to be passed to callback.
 298  *
 299  *  Walk the given bus, including any bridged devices
 300  *  on buses under this bus.  Call the provided callback
 301  *  on each device found.
 302  *
 303  *  We check the return of @cb each time. If it returns anything
 304  *  other than 0, we break out.
 305  *
 306  */
 307 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 308                   void *userdata)
 309 {
 310         struct pci_dev *dev;
 311         struct pci_bus *bus;
 312         struct list_head *next;
 313         int retval;
 314
 315         bus = top;
 316         down_read(&pci_bus_sem);
 317         next = top->devices.next;
 318         for (;;) {
 319                 if (next == &bus->devices) {
 320                         /* end of this bus, go up or finish */
 321                         if (bus == top)
 322                                 break;
 323                         next = bus->self->bus_list.next;
 324                         bus = bus->self->bus;
 325                         continue;
 326                 }
 327                 dev = list_entry(next, struct pci_dev, bus_list);
 328                 if (dev->subordinate) {
 329                         /* this is a pci-pci bridge, do its devices next */
 330                         next = dev->subordinate->devices.next;
 331                         bus = dev->subordinate;
 332                 } else
 333                         next = dev->bus_list.next;
 334
 335                 retval = cb(dev, userdata);
 336                 if (retval)
 337                         break;
 338         }
 339         up_read(&pci_bus_sem);
 340 }
 341 EXPORT_SYMBOL_GPL(pci_walk_bus);
 342
 343 EXPORT_SYMBOL(pci_bus_alloc_resource);
 344 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 345 EXPORT_SYMBOL(pci_bus_add_devices);
 346 EXPORT_SYMBOL(pci_enable_bridges);