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