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