linux/drivers/pci/bus.c
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   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
  21void 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}
  36EXPORT_SYMBOL(pci_add_resource_offset);
  37
  38void pci_add_resource(struct list_head *resources, struct resource *res)
  39{
  40        pci_add_resource_offset(resources, res, 0);
  41}
  42EXPORT_SYMBOL(pci_add_resource);
  43
  44void 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}
  53EXPORT_SYMBOL(pci_free_resource_list);
  54
  55void 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
  71struct 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}
  85EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  86
  87void 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 */
 116int
 117pci_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/**
 162 * pci_bus_add_device - add a single device
 163 * @dev: device to add
 164 *
 165 * This adds a single pci device to the global
 166 * device list and adds sysfs and procfs entries
 167 */
 168int pci_bus_add_device(struct pci_dev *dev)
 169{
 170        int retval;
 171
 172        pci_fixup_device(pci_fixup_final, dev);
 173        retval = device_add(&dev->dev);
 174        if (retval)
 175                return retval;
 176
 177        dev->is_added = 1;
 178        pci_proc_attach_device(dev);
 179        pci_create_sysfs_dev_files(dev);
 180        return 0;
 181}
 182
 183/**
 184 * pci_bus_add_child - add a child bus
 185 * @bus: bus to add
 186 *
 187 * This adds sysfs entries for a single bus
 188 */
 189int pci_bus_add_child(struct pci_bus *bus)
 190{
 191        int retval;
 192
 193        if (bus->bridge)
 194                bus->dev.parent = bus->bridge;
 195
 196        retval = device_register(&bus->dev);
 197        if (retval)
 198                return retval;
 199
 200        bus->is_added = 1;
 201
 202        /* Create legacy_io and legacy_mem files for this bus */
 203        pci_create_legacy_files(bus);
 204
 205        return retval;
 206}
 207
 208/**
 209 * pci_bus_add_devices - insert newly discovered PCI devices
 210 * @bus: bus to check for new devices
 211 *
 212 * Add newly discovered PCI devices (which are on the bus->devices
 213 * list) to the global PCI device list, add the sysfs and procfs
 214 * entries.  Where a bridge is found, add the discovered bus to
 215 * the parents list of child buses, and recurse (breadth-first
 216 * to be compatible with 2.4)
 217 *
 218 * Call hotplug for each new devices.
 219 */
 220void pci_bus_add_devices(const struct pci_bus *bus)
 221{
 222        struct pci_dev *dev;
 223        struct pci_bus *child;
 224        int retval;
 225
 226        list_for_each_entry(dev, &bus->devices, bus_list) {
 227                /* Skip already-added devices */
 228                if (dev->is_added)
 229                        continue;
 230                retval = pci_bus_add_device(dev);
 231                if (retval)
 232                        dev_err(&dev->dev, "Error adding device, continuing\n");
 233        }
 234
 235        list_for_each_entry(dev, &bus->devices, bus_list) {
 236                BUG_ON(!dev->is_added);
 237
 238                child = dev->subordinate;
 239                /*
 240                 * If there is an unattached subordinate bus, attach
 241                 * it and then scan for unattached PCI devices.
 242                 */
 243                if (!child)
 244                        continue;
 245                if (list_empty(&child->node)) {
 246                        down_write(&pci_bus_sem);
 247                        list_add_tail(&child->node, &dev->bus->children);
 248                        up_write(&pci_bus_sem);
 249                }
 250                pci_bus_add_devices(child);
 251
 252                /*
 253                 * register the bus with sysfs as the parent is now
 254                 * properly registered.
 255                 */
 256                if (child->is_added)
 257                        continue;
 258                retval = pci_bus_add_child(child);
 259                if (retval)
 260                        dev_err(&dev->dev, "Error adding bus, continuing\n");
 261        }
 262}
 263
 264void pci_enable_bridges(struct pci_bus *bus)
 265{
 266        struct pci_dev *dev;
 267        int retval;
 268
 269        list_for_each_entry(dev, &bus->devices, bus_list) {
 270                if (dev->subordinate) {
 271                        if (!pci_is_enabled(dev)) {
 272                                retval = pci_enable_device(dev);
 273                                if (retval)
 274                                        dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
 275                                pci_set_master(dev);
 276                        }
 277                        pci_enable_bridges(dev->subordinate);
 278                }
 279        }
 280}
 281
 282/** pci_walk_bus - walk devices on/under bus, calling callback.
 283 *  @top      bus whose devices should be walked
 284 *  @cb       callback to be called for each device found
 285 *  @userdata arbitrary pointer to be passed to callback.
 286 *
 287 *  Walk the given bus, including any bridged devices
 288 *  on buses under this bus.  Call the provided callback
 289 *  on each device found.
 290 *
 291 *  We check the return of @cb each time. If it returns anything
 292 *  other than 0, we break out.
 293 *
 294 */
 295void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 296                  void *userdata)
 297{
 298        struct pci_dev *dev;
 299        struct pci_bus *bus;
 300        struct list_head *next;
 301        int retval;
 302
 303        bus = top;
 304        down_read(&pci_bus_sem);
 305        next = top->devices.next;
 306        for (;;) {
 307                if (next == &bus->devices) {
 308                        /* end of this bus, go up or finish */
 309                        if (bus == top)
 310                                break;
 311                        next = bus->self->bus_list.next;
 312                        bus = bus->self->bus;
 313                        continue;
 314                }
 315                dev = list_entry(next, struct pci_dev, bus_list);
 316                if (dev->subordinate) {
 317                        /* this is a pci-pci bridge, do its devices next */
 318                        next = dev->subordinate->devices.next;
 319                        bus = dev->subordinate;
 320                } else
 321                        next = dev->bus_list.next;
 322
 323                retval = cb(dev, userdata);
 324                if (retval)
 325                        break;
 326        }
 327        up_read(&pci_bus_sem);
 328}
 329EXPORT_SYMBOL_GPL(pci_walk_bus);
 330
 331EXPORT_SYMBOL(pci_bus_alloc_resource);
 332EXPORT_SYMBOL_GPL(pci_bus_add_device);
 333EXPORT_SYMBOL(pci_bus_add_devices);
 334EXPORT_SYMBOL(pci_enable_bridges);
 335
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