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(struct list_head *resources, struct resource *res)
  22{
  23        struct pci_bus_resource *bus_res;
  24
  25        bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
  26        if (!bus_res) {
  27                printk(KERN_ERR "PCI: can't add bus resource %pR\n", res);
  28                return;
  29        }
  30
  31        bus_res->res = res;
  32        list_add_tail(&bus_res->list, resources);
  33}
  34EXPORT_SYMBOL(pci_add_resource);
  35
  36void pci_free_resource_list(struct list_head *resources)
  37{
  38        struct pci_bus_resource *bus_res, *tmp;
  39
  40        list_for_each_entry_safe(bus_res, tmp, resources, list) {
  41                list_del(&bus_res->list);
  42                kfree(bus_res);
  43        }
  44}
  45EXPORT_SYMBOL(pci_free_resource_list);
  46
  47void 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
  63struct 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}
  77EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  78
  79void pci_bus_remove_resources(struct pci_bus *bus)
  80{
  81        int i;
  82
  83        for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
  84                bus->resource[i] = NULL;
  85
  86        pci_free_resource_list(&bus->resources);
  87}
  88
  89/**
  90 * pci_bus_alloc_resource - allocate a resource from a parent bus
  91 * @bus: PCI bus
  92 * @res: resource to allocate
  93 * @size: size of resource to allocate
  94 * @align: alignment of resource to allocate
  95 * @min: minimum /proc/iomem address to allocate
  96 * @type_mask: IORESOURCE_* type flags
  97 * @alignf: resource alignment function
  98 * @alignf_data: data argument for resource alignment function
  99 *
 100 * Given the PCI bus a device resides on, the size, minimum address,
 101 * alignment and type, try to find an acceptable resource allocation
 102 * for a specific device resource.
 103 */
 104int
 105pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 106                resource_size_t size, resource_size_t align,
 107                resource_size_t min, unsigned int type_mask,
 108                resource_size_t (*alignf)(void *,
 109                                          const struct resource *,
 110                                          resource_size_t,
 111                                          resource_size_t),
 112                void *alignf_data)
 113{
 114        int i, ret = -ENOMEM;
 115        struct resource *r;
 116        resource_size_t max = -1;
 117
 118        type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
 119
 120        /* don't allocate too high if the pref mem doesn't support 64bit*/
 121        if (!(res->flags & IORESOURCE_MEM_64))
 122                max = PCIBIOS_MAX_MEM_32;
 123
 124        pci_bus_for_each_resource(bus, r, i) {
 125                if (!r)
 126                        continue;
 127
 128                /* type_mask must match */
 129                if ((res->flags ^ r->flags) & type_mask)
 130                        continue;
 131
 132                /* We cannot allocate a non-prefetching resource
 133                   from a pre-fetching area */
 134                if ((r->flags & IORESOURCE_PREFETCH) &&
 135                    !(res->flags & IORESOURCE_PREFETCH))
 136                        continue;
 137
 138                /* Ok, try it out.. */
 139                ret = allocate_resource(r, res, size,
 140                                        r->start ? : min,
 141                                        max, align,
 142                                        alignf, alignf_data);
 143                if (ret == 0)
 144                        break;
 145        }
 146        return ret;
 147}
 148
 149/**
 150 * pci_bus_add_device - add a single device
 151 * @dev: device to add
 152 *
 153 * This adds a single pci device to the global
 154 * device list and adds sysfs and procfs entries
 155 */
 156int pci_bus_add_device(struct pci_dev *dev)
 157{
 158        int retval;
 159        retval = device_add(&dev->dev);
 160        if (retval)
 161                return retval;
 162
 163        dev->is_added = 1;
 164        pci_proc_attach_device(dev);
 165        pci_create_sysfs_dev_files(dev);
 166        return 0;
 167}
 168
 169/**
 170 * pci_bus_add_child - add a child bus
 171 * @bus: bus to add
 172 *
 173 * This adds sysfs entries for a single bus
 174 */
 175int pci_bus_add_child(struct pci_bus *bus)
 176{
 177        int retval;
 178
 179        if (bus->bridge)
 180                bus->dev.parent = bus->bridge;
 181
 182        retval = device_register(&bus->dev);
 183        if (retval)
 184                return retval;
 185
 186        bus->is_added = 1;
 187
 188        /* Create legacy_io and legacy_mem files for this bus */
 189        pci_create_legacy_files(bus);
 190
 191        return retval;
 192}
 193
 194/**
 195 * pci_bus_add_devices - insert newly discovered PCI devices
 196 * @bus: bus to check for new devices
 197 *
 198 * Add newly discovered PCI devices (which are on the bus->devices
 199 * list) to the global PCI device list, add the sysfs and procfs
 200 * entries.  Where a bridge is found, add the discovered bus to
 201 * the parents list of child buses, and recurse (breadth-first
 202 * to be compatible with 2.4)
 203 *
 204 * Call hotplug for each new devices.
 205 */
 206void pci_bus_add_devices(const struct pci_bus *bus)
 207{
 208        struct pci_dev *dev;
 209        struct pci_bus *child;
 210        int retval;
 211
 212        list_for_each_entry(dev, &bus->devices, bus_list) {
 213                /* Skip already-added devices */
 214                if (dev->is_added)
 215                        continue;
 216                retval = pci_bus_add_device(dev);
 217                if (retval)
 218                        dev_err(&dev->dev, "Error adding device, continuing\n");
 219        }
 220
 221        list_for_each_entry(dev, &bus->devices, bus_list) {
 222                BUG_ON(!dev->is_added);
 223
 224                child = dev->subordinate;
 225                /*
 226                 * If there is an unattached subordinate bus, attach
 227                 * it and then scan for unattached PCI devices.
 228                 */
 229                if (!child)
 230                        continue;
 231                if (list_empty(&child->node)) {
 232                        down_write(&pci_bus_sem);
 233                        list_add_tail(&child->node, &dev->bus->children);
 234                        up_write(&pci_bus_sem);
 235                }
 236                pci_bus_add_devices(child);
 237
 238                /*
 239                 * register the bus with sysfs as the parent is now
 240                 * properly registered.
 241                 */
 242                if (child->is_added)
 243                        continue;
 244                retval = pci_bus_add_child(child);
 245                if (retval)
 246                        dev_err(&dev->dev, "Error adding bus, continuing\n");
 247        }
 248}
 249
 250void pci_enable_bridges(struct pci_bus *bus)
 251{
 252        struct pci_dev *dev;
 253        int retval;
 254
 255        list_for_each_entry(dev, &bus->devices, bus_list) {
 256                if (dev->subordinate) {
 257                        if (!pci_is_enabled(dev)) {
 258                                retval = pci_enable_device(dev);
 259                                if (retval)
 260                                        dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
 261                                pci_set_master(dev);
 262                        }
 263                        pci_enable_bridges(dev->subordinate);
 264                }
 265        }
 266}
 267
 268/** pci_walk_bus - walk devices on/under bus, calling callback.
 269 *  @top      bus whose devices should be walked
 270 *  @cb       callback to be called for each device found
 271 *  @userdata arbitrary pointer to be passed to callback.
 272 *
 273 *  Walk the given bus, including any bridged devices
 274 *  on buses under this bus.  Call the provided callback
 275 *  on each device found.
 276 *
 277 *  We check the return of @cb each time. If it returns anything
 278 *  other than 0, we break out.
 279 *
 280 */
 281void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 282                  void *userdata)
 283{
 284        struct pci_dev *dev;
 285        struct pci_bus *bus;
 286        struct list_head *next;
 287        int retval;
 288
 289        bus = top;
 290        down_read(&pci_bus_sem);
 291        next = top->devices.next;
 292        for (;;) {
 293                if (next == &bus->devices) {
 294                        /* end of this bus, go up or finish */
 295                        if (bus == top)
 296                                break;
 297                        next = bus->self->bus_list.next;
 298                        bus = bus->self->bus;
 299                        continue;
 300                }
 301                dev = list_entry(next, struct pci_dev, bus_list);
 302                if (dev->subordinate) {
 303                        /* this is a pci-pci bridge, do its devices next */
 304                        next = dev->subordinate->devices.next;
 305                        bus = dev->subordinate;
 306                } else
 307                        next = dev->bus_list.next;
 308
 309                /* Run device routines with the device locked */
 310                device_lock(&dev->dev);
 311                retval = cb(dev, userdata);
 312                device_unlock(&dev->dev);
 313                if (retval)
 314                        break;
 315        }
 316        up_read(&pci_bus_sem);
 317}
 318EXPORT_SYMBOL_GPL(pci_walk_bus);
 319
 320EXPORT_SYMBOL(pci_bus_alloc_resource);
 321EXPORT_SYMBOL_GPL(pci_bus_add_device);
 322EXPORT_SYMBOL(pci_bus_add_devices);
 323EXPORT_SYMBOL(pci_enable_bridges);
 324