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_bus_add_resource(struct pci_bus *bus, struct resource *res,
  22                          unsigned int flags)
  23{
  24        struct pci_bus_resource *bus_res;
  25
  26        bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
  27        if (!bus_res) {
  28                dev_err(&bus->dev, "can't add %pR resource\n", res);
  29                return;
  30        }
  31
  32        bus_res->res = res;
  33        bus_res->flags = flags;
  34        list_add_tail(&bus_res->list, &bus->resources);
  35}
  36
  37struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
  38{
  39        struct pci_bus_resource *bus_res;
  40
  41        if (n < PCI_BRIDGE_RESOURCE_NUM)
  42                return bus->resource[n];
  43
  44        n -= PCI_BRIDGE_RESOURCE_NUM;
  45        list_for_each_entry(bus_res, &bus->resources, list) {
  46                if (n-- == 0)
  47                        return bus_res->res;
  48        }
  49        return NULL;
  50}
  51EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  52
  53void pci_bus_remove_resources(struct pci_bus *bus)
  54{
  55        struct pci_bus_resource *bus_res, *tmp;
  56        int i;
  57
  58        for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
  59                bus->resource[i] = NULL;
  60
  61        list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
  62                list_del(&bus_res->list);
  63                kfree(bus_res);
  64        }
  65}
  66
  67/**
  68 * pci_bus_alloc_resource - allocate a resource from a parent bus
  69 * @bus: PCI bus
  70 * @res: resource to allocate
  71 * @size: size of resource to allocate
  72 * @align: alignment of resource to allocate
  73 * @min: minimum /proc/iomem address to allocate
  74 * @type_mask: IORESOURCE_* type flags
  75 * @alignf: resource alignment function
  76 * @alignf_data: data argument for resource alignment function
  77 *
  78 * Given the PCI bus a device resides on, the size, minimum address,
  79 * alignment and type, try to find an acceptable resource allocation
  80 * for a specific device resource.
  81 */
  82int
  83pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
  84                resource_size_t size, resource_size_t align,
  85                resource_size_t min, unsigned int type_mask,
  86                resource_size_t (*alignf)(void *,
  87                                          const struct resource *,
  88                                          resource_size_t,
  89                                          resource_size_t),
  90                void *alignf_data)
  91{
  92        int i, ret = -ENOMEM;
  93        struct resource *r;
  94        resource_size_t max = -1;
  95
  96        type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
  97
  98        /* don't allocate too high if the pref mem doesn't support 64bit*/
  99        if (!(res->flags & IORESOURCE_MEM_64))
 100                max = PCIBIOS_MAX_MEM_32;
 101
 102        pci_bus_for_each_resource(bus, r, i) {
 103                if (!r)
 104                        continue;
 105
 106                /* type_mask must match */
 107                if ((res->flags ^ r->flags) & type_mask)
 108                        continue;
 109
 110                /* We cannot allocate a non-prefetching resource
 111                   from a pre-fetching area */
 112                if ((r->flags & IORESOURCE_PREFETCH) &&
 113                    !(res->flags & IORESOURCE_PREFETCH))
 114                        continue;
 115
 116                /* Ok, try it out.. */
 117                ret = allocate_resource(r, res, size,
 118                                        r->start ? : min,
 119                                        max, align,
 120                                        alignf, alignf_data);
 121                if (ret == 0)
 122                        break;
 123        }
 124        return ret;
 125}
 126
 127/**
 128 * pci_bus_add_device - add a single device
 129 * @dev: device to add
 130 *
 131 * This adds a single pci device to the global
 132 * device list and adds sysfs and procfs entries
 133 */
 134int pci_bus_add_device(struct pci_dev *dev)
 135{
 136        int retval;
 137        retval = device_add(&dev->dev);
 138        if (retval)
 139                return retval;
 140
 141        dev->is_added = 1;
 142        pci_proc_attach_device(dev);
 143        pci_create_sysfs_dev_files(dev);
 144        return 0;
 145}
 146
 147/**
 148 * pci_bus_add_child - add a child bus
 149 * @bus: bus to add
 150 *
 151 * This adds sysfs entries for a single bus
 152 */
 153int pci_bus_add_child(struct pci_bus *bus)
 154{
 155        int retval;
 156
 157        if (bus->bridge)
 158                bus->dev.parent = bus->bridge;
 159
 160        retval = device_register(&bus->dev);
 161        if (retval)
 162                return retval;
 163
 164        bus->is_added = 1;
 165
 166        retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity);
 167        if (retval)
 168                return retval;
 169
 170        retval = device_create_file(&bus->dev, &dev_attr_cpulistaffinity);
 171
 172        /* Create legacy_io and legacy_mem files for this bus */
 173        pci_create_legacy_files(bus);
 174
 175        return retval;
 176}
 177
 178/**
 179 * pci_bus_add_devices - insert newly discovered PCI devices
 180 * @bus: bus to check for new devices
 181 *
 182 * Add newly discovered PCI devices (which are on the bus->devices
 183 * list) to the global PCI device list, add the sysfs and procfs
 184 * entries.  Where a bridge is found, add the discovered bus to
 185 * the parents list of child buses, and recurse (breadth-first
 186 * to be compatible with 2.4)
 187 *
 188 * Call hotplug for each new devices.
 189 */
 190void pci_bus_add_devices(const struct pci_bus *bus)
 191{
 192        struct pci_dev *dev;
 193        struct pci_bus *child;
 194        int retval;
 195
 196        list_for_each_entry(dev, &bus->devices, bus_list) {
 197                /* Skip already-added devices */
 198                if (dev->is_added)
 199                        continue;
 200                retval = pci_bus_add_device(dev);
 201                if (retval)
 202                        dev_err(&dev->dev, "Error adding device, continuing\n");
 203        }
 204
 205        list_for_each_entry(dev, &bus->devices, bus_list) {
 206                BUG_ON(!dev->is_added);
 207
 208                child = dev->subordinate;
 209                /*
 210                 * If there is an unattached subordinate bus, attach
 211                 * it and then scan for unattached PCI devices.
 212                 */
 213                if (!child)
 214                        continue;
 215                if (list_empty(&child->node)) {
 216                        down_write(&pci_bus_sem);
 217                        list_add_tail(&child->node, &dev->bus->children);
 218                        up_write(&pci_bus_sem);
 219                }
 220                pci_bus_add_devices(child);
 221
 222                /*
 223                 * register the bus with sysfs as the parent is now
 224                 * properly registered.
 225                 */
 226                if (child->is_added)
 227                        continue;
 228                retval = pci_bus_add_child(child);
 229                if (retval)
 230                        dev_err(&dev->dev, "Error adding bus, continuing\n");
 231        }
 232}
 233
 234void pci_enable_bridges(struct pci_bus *bus)
 235{
 236        struct pci_dev *dev;
 237        int retval;
 238
 239        list_for_each_entry(dev, &bus->devices, bus_list) {
 240                if (dev->subordinate) {
 241                        if (!pci_is_enabled(dev)) {
 242                                retval = pci_enable_device(dev);
 243                                if (retval)
 244                                        dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
 245                                pci_set_master(dev);
 246                        }
 247                        pci_enable_bridges(dev->subordinate);
 248                }
 249        }
 250}
 251
 252/** pci_walk_bus - walk devices on/under bus, calling callback.
 253 *  @top      bus whose devices should be walked
 254 *  @cb       callback to be called for each device found
 255 *  @userdata arbitrary pointer to be passed to callback.
 256 *
 257 *  Walk the given bus, including any bridged devices
 258 *  on buses under this bus.  Call the provided callback
 259 *  on each device found.
 260 *
 261 *  We check the return of @cb each time. If it returns anything
 262 *  other than 0, we break out.
 263 *
 264 */
 265void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 266                  void *userdata)
 267{
 268        struct pci_dev *dev;
 269        struct pci_bus *bus;
 270        struct list_head *next;
 271        int retval;
 272
 273        bus = top;
 274        down_read(&pci_bus_sem);
 275        next = top->devices.next;
 276        for (;;) {
 277                if (next == &bus->devices) {
 278                        /* end of this bus, go up or finish */
 279                        if (bus == top)
 280                                break;
 281                        next = bus->self->bus_list.next;
 282                        bus = bus->self->bus;
 283                        continue;
 284                }
 285                dev = list_entry(next, struct pci_dev, bus_list);
 286                if (dev->subordinate) {
 287                        /* this is a pci-pci bridge, do its devices next */
 288                        next = dev->subordinate->devices.next;
 289                        bus = dev->subordinate;
 290                } else
 291                        next = dev->bus_list.next;
 292
 293                /* Run device routines with the device locked */
 294                device_lock(&dev->dev);
 295                retval = cb(dev, userdata);
 296                device_unlock(&dev->dev);
 297                if (retval)
 298                        break;
 299        }
 300        up_read(&pci_bus_sem);
 301}
 302EXPORT_SYMBOL_GPL(pci_walk_bus);
 303
 304EXPORT_SYMBOL(pci_bus_alloc_resource);
 305EXPORT_SYMBOL_GPL(pci_bus_add_device);
 306EXPORT_SYMBOL(pci_bus_add_devices);
 307EXPORT_SYMBOL(pci_enable_bridges);
 308
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