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_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
  37 struct 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 }
  51 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  52
  53 void 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  */
  82 int
  83 pci_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  */
 134 int 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  */
 153 int 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         /* Create legacy_io and legacy_mem files for this bus */
 167         pci_create_legacy_files(bus);
 168
 169         return retval;
 170 }
 171
 172 /**
 173  * pci_bus_add_devices - insert newly discovered PCI devices
 174  * @bus: bus to check for new devices
 175  *
 176  * Add newly discovered PCI devices (which are on the bus->devices
 177  * list) to the global PCI device list, add the sysfs and procfs
 178  * entries.  Where a bridge is found, add the discovered bus to
 179  * the parents list of child buses, and recurse (breadth-first
 180  * to be compatible with 2.4)
 181  *
 182  * Call hotplug for each new devices.
 183  */
 184 void pci_bus_add_devices(const struct pci_bus *bus)
 185 {
 186         struct pci_dev *dev;
 187         struct pci_bus *child;
 188         int retval;
 189
 190         list_for_each_entry(dev, &bus->devices, bus_list) {
 191                 /* Skip already-added devices */
 192                 if (dev->is_added)
 193                         continue;
 194                 retval = pci_bus_add_device(dev);
 195                 if (retval)
 196                         dev_err(&dev->dev, "Error adding device, continuing\n");
 197         }
 198
 199         list_for_each_entry(dev, &bus->devices, bus_list) {
 200                 BUG_ON(!dev->is_added);
 201
 202                 child = dev->subordinate;
 203                 /*
 204                  * If there is an unattached subordinate bus, attach
 205                  * it and then scan for unattached PCI devices.
 206                  */
 207                 if (!child)
 208                         continue;
 209                 if (list_empty(&child->node)) {
 210                         down_write(&pci_bus_sem);
 211                         list_add_tail(&child->node, &dev->bus->children);
 212                         up_write(&pci_bus_sem);
 213                 }
 214                 pci_bus_add_devices(child);
 215
 216                 /*
 217                  * register the bus with sysfs as the parent is now
 218                  * properly registered.
 219                  */
 220                 if (child->is_added)
 221                         continue;
 222                 retval = pci_bus_add_child(child);
 223                 if (retval)
 224                         dev_err(&dev->dev, "Error adding bus, continuing\n");
 225         }
 226 }
 227
 228 void pci_enable_bridges(struct pci_bus *bus)
 229 {
 230         struct pci_dev *dev;
 231         int retval;
 232
 233         list_for_each_entry(dev, &bus->devices, bus_list) {
 234                 if (dev->subordinate) {
 235                         if (!pci_is_enabled(dev)) {
 236                                 retval = pci_enable_device(dev);
 237                                 if (retval)
 238                                         dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
 239                                 pci_set_master(dev);
 240                         }
 241                         pci_enable_bridges(dev->subordinate);
 242                 }
 243         }
 244 }
 245
 246 /** pci_walk_bus - walk devices on/under bus, calling callback.
 247  *  @top      bus whose devices should be walked
 248  *  @cb       callback to be called for each device found
 249  *  @userdata arbitrary pointer to be passed to callback.
 250  *
 251  *  Walk the given bus, including any bridged devices
 252  *  on buses under this bus.  Call the provided callback
 253  *  on each device found.
 254  *
 255  *  We check the return of @cb each time. If it returns anything
 256  *  other than 0, we break out.
 257  *
 258  */
 259 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 260                   void *userdata)
 261 {
 262         struct pci_dev *dev;
 263         struct pci_bus *bus;
 264         struct list_head *next;
 265         int retval;
 266
 267         bus = top;
 268         down_read(&pci_bus_sem);
 269         next = top->devices.next;
 270         for (;;) {
 271                 if (next == &bus->devices) {
 272                         /* end of this bus, go up or finish */
 273                         if (bus == top)
 274                                 break;
 275                         next = bus->self->bus_list.next;
 276                         bus = bus->self->bus;
 277                         continue;
 278                 }
 279                 dev = list_entry(next, struct pci_dev, bus_list);
 280                 if (dev->subordinate) {
 281                         /* this is a pci-pci bridge, do its devices next */
 282                         next = dev->subordinate->devices.next;
 283                         bus = dev->subordinate;
 284                 } else
 285                         next = dev->bus_list.next;
 286
 287                 /* Run device routines with the device locked */
 288                 device_lock(&dev->dev);
 289                 retval = cb(dev, userdata);
 290                 device_unlock(&dev->dev);
 291                 if (retval)
 292                         break;
 293         }
 294         up_read(&pci_bus_sem);
 295 }
 296 EXPORT_SYMBOL_GPL(pci_walk_bus);
 297
 298 EXPORT_SYMBOL(pci_bus_alloc_resource);
 299 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 300 EXPORT_SYMBOL(pci_bus_add_devices);
 301 EXPORT_SYMBOL(pci_enable_bridges);