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_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 }
  34 EXPORT_SYMBOL(pci_add_resource);
  35
  36 void 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 }
  45 EXPORT_SYMBOL(pci_free_resource_list);
  46
  47 void 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
  63 struct 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 }
  77 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  78
  79 void 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  */
 104 int
 105 pci_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  */
 156 int 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  */
 175 int 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  */
 206 void 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
 250 void 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  */
 281 void 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 }
 318 EXPORT_SYMBOL_GPL(pci_walk_bus);
 319
 320 EXPORT_SYMBOL(pci_bus_alloc_resource);
 321 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 322 EXPORT_SYMBOL(pci_bus_add_devices);
 323 EXPORT_SYMBOL(pci_enable_bridges);