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
  18 #include "pci.h"
  19
  20 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
  21                           unsigned int flags)
  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                 dev_err(&bus->dev, "can't add %pR resource\n", res);
  28                 return;
  29         }
  30
  31         bus_res->res = res;
  32         bus_res->flags = flags;
  33         list_add_tail(&bus_res->list, &bus->resources);
  34 }
  35
  36 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
  37 {
  38         struct pci_bus_resource *bus_res;
  39
  40         if (n < PCI_BRIDGE_RESOURCE_NUM)
  41                 return bus->resource[n];
  42
  43         n -= PCI_BRIDGE_RESOURCE_NUM;
  44         list_for_each_entry(bus_res, &bus->resources, list) {
  45                 if (n-- == 0)
  46                         return bus_res->res;
  47         }
  48         return NULL;
  49 }
  50 EXPORT_SYMBOL_GPL(pci_bus_resource_n);
  51
  52 void pci_bus_remove_resources(struct pci_bus *bus)
  53 {
  54         struct pci_bus_resource *bus_res, *tmp;
  55         int i;
  56
  57         for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
  58                 bus->resource[i] = 0;
  59
  60         list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
  61                 list_del(&bus_res->list);
  62                 kfree(bus_res);
  63         }
  64 }
  65
  66 /**
  67  * pci_bus_alloc_resource - allocate a resource from a parent bus
  68  * @bus: PCI bus
  69  * @res: resource to allocate
  70  * @size: size of resource to allocate
  71  * @align: alignment of resource to allocate
  72  * @min: minimum /proc/iomem address to allocate
  73  * @type_mask: IORESOURCE_* type flags
  74  * @alignf: resource alignment function
  75  * @alignf_data: data argument for resource alignment function
  76  *
  77  * Given the PCI bus a device resides on, the size, minimum address,
  78  * alignment and type, try to find an acceptable resource allocation
  79  * for a specific device resource.
  80  */
  81 int
  82 pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
  83                 resource_size_t size, resource_size_t align,
  84                 resource_size_t min, unsigned int type_mask,
  85                 resource_size_t (*alignf)(void *,
  86                                           const struct resource *,
  87                                           resource_size_t,
  88                                           resource_size_t),
  89                 void *alignf_data)
  90 {
  91         int i, ret = -ENOMEM;
  92         struct resource *r;
  93         resource_size_t max = -1;
  94
  95         type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
  96
  97         /* don't allocate too high if the pref mem doesn't support 64bit*/
  98         if (!(res->flags & IORESOURCE_MEM_64))
  99                 max = PCIBIOS_MAX_MEM_32;
 100
 101         pci_bus_for_each_resource(bus, r, i) {
 102                 if (!r)
 103                         continue;
 104
 105                 /* type_mask must match */
 106                 if ((res->flags ^ r->flags) & type_mask)
 107                         continue;
 108
 109                 /* We cannot allocate a non-prefetching resource
 110                    from a pre-fetching area */
 111                 if ((r->flags & IORESOURCE_PREFETCH) &&
 112                     !(res->flags & IORESOURCE_PREFETCH))
 113                         continue;
 114
 115                 /* Ok, try it out.. */
 116                 ret = allocate_resource(r, res, size,
 117                                         r->start ? : min,
 118                                         max, align,
 119                                         alignf, alignf_data);
 120                 if (ret == 0)
 121                         break;
 122         }
 123         return ret;
 124 }
 125
 126 /**
 127  * pci_bus_add_device - add a single device
 128  * @dev: device to add
 129  *
 130  * This adds a single pci device to the global
 131  * device list and adds sysfs and procfs entries
 132  */
 133 int pci_bus_add_device(struct pci_dev *dev)
 134 {
 135         int retval;
 136         retval = device_add(&dev->dev);
 137         if (retval)
 138                 return retval;
 139
 140         dev->is_added = 1;
 141         pci_proc_attach_device(dev);
 142         pci_create_sysfs_dev_files(dev);
 143         return 0;
 144 }
 145
 146 /**
 147  * pci_bus_add_child - add a child bus
 148  * @bus: bus to add
 149  *
 150  * This adds sysfs entries for a single bus
 151  */
 152 int pci_bus_add_child(struct pci_bus *bus)
 153 {
 154         int retval;
 155
 156         if (bus->bridge)
 157                 bus->dev.parent = bus->bridge;
 158
 159         retval = device_register(&bus->dev);
 160         if (retval)
 161                 return retval;
 162
 163         bus->is_added = 1;
 164
 165         retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity);
 166         if (retval)
 167                 return retval;
 168
 169         retval = device_create_file(&bus->dev, &dev_attr_cpulistaffinity);
 170
 171         /* Create legacy_io and legacy_mem files for this bus */
 172         pci_create_legacy_files(bus);
 173
 174         return retval;
 175 }
 176
 177 /**
 178  * pci_bus_add_devices - insert newly discovered PCI devices
 179  * @bus: bus to check for new devices
 180  *
 181  * Add newly discovered PCI devices (which are on the bus->devices
 182  * list) to the global PCI device list, add the sysfs and procfs
 183  * entries.  Where a bridge is found, add the discovered bus to
 184  * the parents list of child buses, and recurse (breadth-first
 185  * to be compatible with 2.4)
 186  *
 187  * Call hotplug for each new devices.
 188  */
 189 void pci_bus_add_devices(const struct pci_bus *bus)
 190 {
 191         struct pci_dev *dev;
 192         struct pci_bus *child;
 193         int retval;
 194
 195         list_for_each_entry(dev, &bus->devices, bus_list) {
 196                 /* Skip already-added devices */
 197                 if (dev->is_added)
 198                         continue;
 199                 retval = pci_bus_add_device(dev);
 200                 if (retval)
 201                         dev_err(&dev->dev, "Error adding device, continuing\n");
 202         }
 203
 204         list_for_each_entry(dev, &bus->devices, bus_list) {
 205                 BUG_ON(!dev->is_added);
 206
 207                 child = dev->subordinate;
 208                 /*
 209                  * If there is an unattached subordinate bus, attach
 210                  * it and then scan for unattached PCI devices.
 211                  */
 212                 if (!child)
 213                         continue;
 214                 if (list_empty(&child->node)) {
 215                         down_write(&pci_bus_sem);
 216                         list_add_tail(&child->node, &dev->bus->children);
 217                         up_write(&pci_bus_sem);
 218                 }
 219                 pci_bus_add_devices(child);
 220
 221                 /*
 222                  * register the bus with sysfs as the parent is now
 223                  * properly registered.
 224                  */
 225                 if (child->is_added)
 226                         continue;
 227                 retval = pci_bus_add_child(child);
 228                 if (retval)
 229                         dev_err(&dev->dev, "Error adding bus, continuing\n");
 230         }
 231 }
 232
 233 void pci_enable_bridges(struct pci_bus *bus)
 234 {
 235         struct pci_dev *dev;
 236         int retval;
 237
 238         list_for_each_entry(dev, &bus->devices, bus_list) {
 239                 if (dev->subordinate) {
 240                         if (!pci_is_enabled(dev)) {
 241                                 retval = pci_enable_device(dev);
 242                                 pci_set_master(dev);
 243                         }
 244                         pci_enable_bridges(dev->subordinate);
 245                 }
 246         }
 247 }
 248
 249 /** pci_walk_bus - walk devices on/under bus, calling callback.
 250  *  @top      bus whose devices should be walked
 251  *  @cb       callback to be called for each device found
 252  *  @userdata arbitrary pointer to be passed to callback.
 253  *
 254  *  Walk the given bus, including any bridged devices
 255  *  on buses under this bus.  Call the provided callback
 256  *  on each device found.
 257  *
 258  *  We check the return of @cb each time. If it returns anything
 259  *  other than 0, we break out.
 260  *
 261  */
 262 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 263                   void *userdata)
 264 {
 265         struct pci_dev *dev;
 266         struct pci_bus *bus;
 267         struct list_head *next;
 268         int retval;
 269
 270         bus = top;
 271         down_read(&pci_bus_sem);
 272         next = top->devices.next;
 273         for (;;) {
 274                 if (next == &bus->devices) {
 275                         /* end of this bus, go up or finish */
 276                         if (bus == top)
 277                                 break;
 278                         next = bus->self->bus_list.next;
 279                         bus = bus->self->bus;
 280                         continue;
 281                 }
 282                 dev = list_entry(next, struct pci_dev, bus_list);
 283                 if (dev->subordinate) {
 284                         /* this is a pci-pci bridge, do its devices next */
 285                         next = dev->subordinate->devices.next;
 286                         bus = dev->subordinate;
 287                 } else
 288                         next = dev->bus_list.next;
 289
 290                 /* Run device routines with the device locked */
 291                 down(&dev->dev.sem);
 292                 retval = cb(dev, userdata);
 293                 up(&dev->dev.sem);
 294                 if (retval)
 295                         break;
 296         }
 297         up_read(&pci_bus_sem);
 298 }
 299
 300 EXPORT_SYMBOL(pci_bus_alloc_resource);
 301 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 302 EXPORT_SYMBOL(pci_bus_add_devices);
 303 EXPORT_SYMBOL(pci_enable_bridges);