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
  91        for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
  92                bus->resource[i] = NULL;
  93
  94        pci_free_resource_list(&bus->resources);
  95}
  96
  97/**
  98 * pci_bus_alloc_resource - allocate a resource from a parent bus
  99 * @bus: PCI bus
 100 * @res: resource to allocate
 101 * @size: size of resource to allocate
 102 * @align: alignment of resource to allocate
 103 * @min: minimum /proc/iomem address to allocate
 104 * @type_mask: IORESOURCE_* type flags
 105 * @alignf: resource alignment function
 106 * @alignf_data: data argument for resource alignment function
 107 *
 108 * Given the PCI bus a device resides on, the size, minimum address,
 109 * alignment and type, try to find an acceptable resource allocation
 110 * for a specific device resource.
 111 */
 112int
 113pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 114                resource_size_t size, resource_size_t align,
 115                resource_size_t min, unsigned int type_mask,
 116                resource_size_t (*alignf)(void *,
 117                                          const struct resource *,
 118                                          resource_size_t,
 119                                          resource_size_t),
 120                void *alignf_data)
 121{
 122        int i, ret = -ENOMEM;
 123        struct resource *r;
 124        resource_size_t max = -1;
 125
 126        type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
 127
 128        /* don't allocate too high if the pref mem doesn't support 64bit*/
 129        if (!(res->flags & IORESOURCE_MEM_64))
 130                max = PCIBIOS_MAX_MEM_32;
 131
 132        pci_bus_for_each_resource(bus, r, i) {
 133                if (!r)
 134                        continue;
 135
 136                /* type_mask must match */
 137                if ((res->flags ^ r->flags) & type_mask)
 138                        continue;
 139
 140                /* We cannot allocate a non-prefetching resource
 141                   from a pre-fetching area */
 142                if ((r->flags & IORESOURCE_PREFETCH) &&
 143                    !(res->flags & IORESOURCE_PREFETCH))
 144                        continue;
 145
 146                /* Ok, try it out.. */
 147                ret = allocate_resource(r, res, size,
 148                                        r->start ? : min,
 149                                        max, align,
 150                                        alignf, alignf_data);
 151                if (ret == 0)
 152                        break;
 153        }
 154        return ret;
 155}
 156
 157/**
 158 * pci_bus_add_device - add a single device
 159 * @dev: device to add
 160 *
 161 * This adds a single pci device to the global
 162 * device list and adds sysfs and procfs entries
 163 */
 164int pci_bus_add_device(struct pci_dev *dev)
 165{
 166        int retval;
 167
 168        pci_fixup_device(pci_fixup_final, dev);
 169        retval = device_add(&dev->dev);
 170        if (retval)
 171                return retval;
 172
 173        dev->is_added = 1;
 174        pci_proc_attach_device(dev);
 175        pci_create_sysfs_dev_files(dev);
 176        return 0;
 177}
 178
 179/**
 180 * pci_bus_add_child - add a child bus
 181 * @bus: bus to add
 182 *
 183 * This adds sysfs entries for a single bus
 184 */
 185int pci_bus_add_child(struct pci_bus *bus)
 186{
 187        int retval;
 188
 189        if (bus->bridge)
 190                bus->dev.parent = bus->bridge;
 191
 192        retval = device_register(&bus->dev);
 193        if (retval)
 194                return retval;
 195
 196        bus->is_added = 1;
 197
 198        /* Create legacy_io and legacy_mem files for this bus */
 199        pci_create_legacy_files(bus);
 200
 201        return retval;
 202}
 203
 204/**
 205 * pci_bus_add_devices - insert newly discovered PCI devices
 206 * @bus: bus to check for new devices
 207 *
 208 * Add newly discovered PCI devices (which are on the bus->devices
 209 * list) to the global PCI device list, add the sysfs and procfs
 210 * entries.  Where a bridge is found, add the discovered bus to
 211 * the parents list of child buses, and recurse (breadth-first
 212 * to be compatible with 2.4)
 213 *
 214 * Call hotplug for each new devices.
 215 */
 216void pci_bus_add_devices(const struct pci_bus *bus)
 217{
 218        struct pci_dev *dev;
 219        struct pci_bus *child;
 220        int retval;
 221
 222        list_for_each_entry(dev, &bus->devices, bus_list) {
 223                /* Skip already-added devices */
 224                if (dev->is_added)
 225                        continue;
 226                retval = pci_bus_add_device(dev);
 227                if (retval)
 228                        dev_err(&dev->dev, "Error adding device, continuing\n");
 229        }
 230
 231        list_for_each_entry(dev, &bus->devices, bus_list) {
 232                BUG_ON(!dev->is_added);
 233
 234                child = dev->subordinate;
 235                /*
 236                 * If there is an unattached subordinate bus, attach
 237                 * it and then scan for unattached PCI devices.
 238                 */
 239                if (!child)
 240                        continue;
 241                if (list_empty(&child->node)) {
 242                        down_write(&pci_bus_sem);
 243                        list_add_tail(&child->node, &dev->bus->children);
 244                        up_write(&pci_bus_sem);
 245                }
 246                pci_bus_add_devices(child);
 247
 248                /*
 249                 * register the bus with sysfs as the parent is now
 250                 * properly registered.
 251                 */
 252                if (child->is_added)
 253                        continue;
 254                retval = pci_bus_add_child(child);
 255                if (retval)
 256                        dev_err(&dev->dev, "Error adding bus, continuing\n");
 257        }
 258}
 259
 260void pci_enable_bridges(struct pci_bus *bus)
 261{
 262        struct pci_dev *dev;
 263        int retval;
 264
 265        list_for_each_entry(dev, &bus->devices, bus_list) {
 266                if (dev->subordinate) {
 267                        if (!pci_is_enabled(dev)) {
 268                                retval = pci_enable_device(dev);
 269                                if (retval)
 270                                        dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
 271                                pci_set_master(dev);
 272                        }
 273                        pci_enable_bridges(dev->subordinate);
 274                }
 275        }
 276}
 277
 278/** pci_walk_bus - walk devices on/under bus, calling callback.
 279 *  @top      bus whose devices should be walked
 280 *  @cb       callback to be called for each device found
 281 *  @userdata arbitrary pointer to be passed to callback.
 282 *
 283 *  Walk the given bus, including any bridged devices
 284 *  on buses under this bus.  Call the provided callback
 285 *  on each device found.
 286 *
 287 *  We check the return of @cb each time. If it returns anything
 288 *  other than 0, we break out.
 289 *
 290 */
 291void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 292                  void *userdata)
 293{
 294        struct pci_dev *dev;
 295        struct pci_bus *bus;
 296        struct list_head *next;
 297        int retval;
 298
 299        bus = top;
 300        down_read(&pci_bus_sem);
 301        next = top->devices.next;
 302        for (;;) {
 303                if (next == &bus->devices) {
 304                        /* end of this bus, go up or finish */
 305                        if (bus == top)
 306                                break;
 307                        next = bus->self->bus_list.next;
 308                        bus = bus->self->bus;
 309                        continue;
 310                }
 311                dev = list_entry(next, struct pci_dev, bus_list);
 312                if (dev->subordinate) {
 313                        /* this is a pci-pci bridge, do its devices next */
 314                        next = dev->subordinate->devices.next;
 315                        bus = dev->subordinate;
 316                } else
 317                        next = dev->bus_list.next;
 318
 319                /* Run device routines with the device locked */
 320                device_lock(&dev->dev);
 321                retval = cb(dev, userdata);
 322                device_unlock(&dev->dev);
 323                if (retval)
 324                        break;
 325        }
 326        up_read(&pci_bus_sem);
 327}
 328EXPORT_SYMBOL_GPL(pci_walk_bus);
 329
 330EXPORT_SYMBOL(pci_bus_alloc_resource);
 331EXPORT_SYMBOL_GPL(pci_bus_add_device);
 332EXPORT_SYMBOL(pci_bus_add_devices);
 333EXPORT_SYMBOL(pci_enable_bridges);
 334
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