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_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 }
  36 EXPORT_SYMBOL(pci_add_resource_offset);
  37
  38 void pci_add_resource(struct list_head *resources, struct resource *res)
  39 {
  40         pci_add_resource_offset(resources, res, 0);
  41 }
  42 EXPORT_SYMBOL(pci_add_resource);
  43
  44 void 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 }
  53 EXPORT_SYMBOL(pci_free_resource_list);
  54
  55 void 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
  71 struct 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 }
  85 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  86
  87 void 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  */
 112 int
 113 pci_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  */
 164 int pci_bus_add_device(struct pci_dev *dev)
 165 {
 166         int retval;
 167         retval = device_add(&dev->dev);
 168         if (retval)
 169                 return retval;
 170
 171         dev->is_added = 1;
 172         pci_proc_attach_device(dev);
 173         pci_create_sysfs_dev_files(dev);
 174         return 0;
 175 }
 176
 177 /**
 178  * pci_bus_add_child - add a child bus
 179  * @bus: bus to add
 180  *
 181  * This adds sysfs entries for a single bus
 182  */
 183 int pci_bus_add_child(struct pci_bus *bus)
 184 {
 185         int retval;
 186
 187         if (bus->bridge)
 188                 bus->dev.parent = bus->bridge;
 189
 190         retval = device_register(&bus->dev);
 191         if (retval)
 192                 return retval;
 193
 194         bus->is_added = 1;
 195
 196         /* Create legacy_io and legacy_mem files for this bus */
 197         pci_create_legacy_files(bus);
 198
 199         return retval;
 200 }
 201
 202 /**
 203  * pci_bus_add_devices - insert newly discovered PCI devices
 204  * @bus: bus to check for new devices
 205  *
 206  * Add newly discovered PCI devices (which are on the bus->devices
 207  * list) to the global PCI device list, add the sysfs and procfs
 208  * entries.  Where a bridge is found, add the discovered bus to
 209  * the parents list of child buses, and recurse (breadth-first
 210  * to be compatible with 2.4)
 211  *
 212  * Call hotplug for each new devices.
 213  */
 214 void pci_bus_add_devices(const struct pci_bus *bus)
 215 {
 216         struct pci_dev *dev;
 217         struct pci_bus *child;
 218         int retval;
 219
 220         list_for_each_entry(dev, &bus->devices, bus_list) {
 221                 /* Skip already-added devices */
 222                 if (dev->is_added)
 223                         continue;
 224                 retval = pci_bus_add_device(dev);
 225                 if (retval)
 226                         dev_err(&dev->dev, "Error adding device, continuing\n");
 227         }
 228
 229         list_for_each_entry(dev, &bus->devices, bus_list) {
 230                 BUG_ON(!dev->is_added);
 231
 232                 child = dev->subordinate;
 233                 /*
 234                  * If there is an unattached subordinate bus, attach
 235                  * it and then scan for unattached PCI devices.
 236                  */
 237                 if (!child)
 238                         continue;
 239                 if (list_empty(&child->node)) {
 240                         down_write(&pci_bus_sem);
 241                         list_add_tail(&child->node, &dev->bus->children);
 242                         up_write(&pci_bus_sem);
 243                 }
 244                 pci_bus_add_devices(child);
 245
 246                 /*
 247                  * register the bus with sysfs as the parent is now
 248                  * properly registered.
 249                  */
 250                 if (child->is_added)
 251                         continue;
 252                 retval = pci_bus_add_child(child);
 253                 if (retval)
 254                         dev_err(&dev->dev, "Error adding bus, continuing\n");
 255         }
 256 }
 257
 258 void pci_enable_bridges(struct pci_bus *bus)
 259 {
 260         struct pci_dev *dev;
 261         int retval;
 262
 263         list_for_each_entry(dev, &bus->devices, bus_list) {
 264                 if (dev->subordinate) {
 265                         if (!pci_is_enabled(dev)) {
 266                                 retval = pci_enable_device(dev);
 267                                 if (retval)
 268                                         dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
 269                                 pci_set_master(dev);
 270                         }
 271                         pci_enable_bridges(dev->subordinate);
 272                 }
 273         }
 274 }
 275
 276 /** pci_walk_bus - walk devices on/under bus, calling callback.
 277  *  @top      bus whose devices should be walked
 278  *  @cb       callback to be called for each device found
 279  *  @userdata arbitrary pointer to be passed to callback.
 280  *
 281  *  Walk the given bus, including any bridged devices
 282  *  on buses under this bus.  Call the provided callback
 283  *  on each device found.
 284  *
 285  *  We check the return of @cb each time. If it returns anything
 286  *  other than 0, we break out.
 287  *
 288  */
 289 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 290                   void *userdata)
 291 {
 292         struct pci_dev *dev;
 293         struct pci_bus *bus;
 294         struct list_head *next;
 295         int retval;
 296
 297         bus = top;
 298         down_read(&pci_bus_sem);
 299         next = top->devices.next;
 300         for (;;) {
 301                 if (next == &bus->devices) {
 302                         /* end of this bus, go up or finish */
 303                         if (bus == top)
 304                                 break;
 305                         next = bus->self->bus_list.next;
 306                         bus = bus->self->bus;
 307                         continue;
 308                 }
 309                 dev = list_entry(next, struct pci_dev, bus_list);
 310                 if (dev->subordinate) {
 311                         /* this is a pci-pci bridge, do its devices next */
 312                         next = dev->subordinate->devices.next;
 313                         bus = dev->subordinate;
 314                 } else
 315                         next = dev->bus_list.next;
 316
 317                 /* Run device routines with the device locked */
 318                 device_lock(&dev->dev);
 319                 retval = cb(dev, userdata);
 320                 device_unlock(&dev->dev);
 321                 if (retval)
 322                         break;
 323         }
 324         up_read(&pci_bus_sem);
 325 }
 326 EXPORT_SYMBOL_GPL(pci_walk_bus);
 327
 328 EXPORT_SYMBOL(pci_bus_alloc_resource);
 329 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 330 EXPORT_SYMBOL(pci_bus_add_devices);
 331 EXPORT_SYMBOL(pci_enable_bridges);