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  * 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 void __devinit pci_bus_add_device(struct pci_dev *dev)
  81 {
  82         device_add(&dev->dev);
  83
  84         down_write(&pci_bus_sem);
  85         list_add_tail(&dev->global_list, &pci_devices);
  86         up_write(&pci_bus_sem);
  87
  88         pci_proc_attach_device(dev);
  89         pci_create_sysfs_dev_files(dev);
  90 }
  91
  92 /**
  93  * pci_bus_add_devices - insert newly discovered PCI devices
  94  * @bus: bus to check for new devices
  95  *
  96  * Add newly discovered PCI devices (which are on the bus->devices
  97  * list) to the global PCI device list, add the sysfs and procfs
  98  * entries.  Where a bridge is found, add the discovered bus to
  99  * the parents list of child buses, and recurse (breadth-first
 100  * to be compatible with 2.4)
 101  *
 102  * Call hotplug for each new devices.
 103  */
 104 void __devinit pci_bus_add_devices(struct pci_bus *bus)
 105 {
 106         struct pci_dev *dev;
 107
 108         list_for_each_entry(dev, &bus->devices, bus_list) {
 109                 /*
 110                  * Skip already-present devices (which are on the
 111                  * global device list.)
 112                  */
 113                 if (!list_empty(&dev->global_list))
 114                         continue;
 115                 pci_bus_add_device(dev);
 116         }
 117
 118         list_for_each_entry(dev, &bus->devices, bus_list) {
 119
 120                 BUG_ON(list_empty(&dev->global_list));
 121
 122                 /*
 123                  * If there is an unattached subordinate bus, attach
 124                  * it and then scan for unattached PCI devices.
 125                  */
 126                 if (dev->subordinate) {
 127                        if (list_empty(&dev->subordinate->node)) {
 128                                down_write(&pci_bus_sem);
 129                                list_add_tail(&dev->subordinate->node,
 130                                                &dev->bus->children);
 131                                up_write(&pci_bus_sem);
 132                        }
 133                         pci_bus_add_devices(dev->subordinate);
 134
 135                         sysfs_create_link(&dev->subordinate->class_dev.kobj, &dev->dev.kobj, "bridge");
 136                 }
 137         }
 138 }
 139
 140 void pci_enable_bridges(struct pci_bus *bus)
 141 {
 142         struct pci_dev *dev;
 143         int retval;
 144
 145         list_for_each_entry(dev, &bus->devices, bus_list) {
 146                 if (dev->subordinate) {
 147                         retval = pci_enable_device(dev);
 148                         pci_set_master(dev);
 149                         pci_enable_bridges(dev->subordinate);
 150                 }
 151         }
 152 }
 153
 154 /** pci_walk_bus - walk devices on/under bus, calling callback.
 155  *  @top      bus whose devices should be walked
 156  *  @cb       callback to be called for each device found
 157  *  @userdata arbitrary pointer to be passed to callback.
 158  *
 159  *  Walk the given bus, including any bridged devices
 160  *  on buses under this bus.  Call the provided callback
 161  *  on each device found.
 162  */
 163 void pci_walk_bus(struct pci_bus *top, void (*cb)(struct pci_dev *, void *),
 164                   void *userdata)
 165 {
 166         struct pci_dev *dev;
 167         struct pci_bus *bus;
 168         struct list_head *next;
 169
 170         bus = top;
 171         down_read(&pci_bus_sem);
 172         next = top->devices.next;
 173         for (;;) {
 174                 if (next == &bus->devices) {
 175                         /* end of this bus, go up or finish */
 176                         if (bus == top)
 177                                 break;
 178                         next = bus->self->bus_list.next;
 179                         bus = bus->self->bus;
 180                         continue;
 181                 }
 182                 dev = list_entry(next, struct pci_dev, bus_list);
 183                 if (dev->subordinate) {
 184                         /* this is a pci-pci bridge, do its devices next */
 185                         next = dev->subordinate->devices.next;
 186                         bus = dev->subordinate;
 187                 } else
 188                         next = dev->bus_list.next;
 189
 190                 /* Run device routines with the device locked */
 191                 down(&dev->dev.sem);
 192                 cb(dev, userdata);
 193                 up(&dev->dev.sem);
 194         }
 195         up_read(&pci_bus_sem);
 196 }
 197 EXPORT_SYMBOL_GPL(pci_walk_bus);
 198
 199 EXPORT_SYMBOL(pci_bus_alloc_resource);
 200 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 201 EXPORT_SYMBOL(pci_bus_add_devices);
 202 EXPORT_SYMBOL(pci_enable_bridges);