xref: /openbmc/linux/drivers/pci/bus.c (revision 1da177e4)
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 	unsigned long size, unsigned long align, unsigned long min,
38 	unsigned int type_mask,
39 	void (*alignf)(void *, struct resource *,
40 			unsigned long, unsigned long),
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, min, -1, align,
64 					alignf, alignf_data);
65 		if (ret == 0)
66 			break;
67 	}
68 	return ret;
69 }
70 
71 /**
72  * add a single device
73  * @dev: device to add
74  *
75  * This adds a single pci device to the global
76  * device list and adds sysfs and procfs entries
77  */
78 void __devinit pci_bus_add_device(struct pci_dev *dev)
79 {
80 	device_add(&dev->dev);
81 
82 	spin_lock(&pci_bus_lock);
83 	list_add_tail(&dev->global_list, &pci_devices);
84 	spin_unlock(&pci_bus_lock);
85 
86 	pci_proc_attach_device(dev);
87 	pci_create_sysfs_dev_files(dev);
88 }
89 
90 /**
91  * pci_bus_add_devices - insert newly discovered PCI devices
92  * @bus: bus to check for new devices
93  *
94  * Add newly discovered PCI devices (which are on the bus->devices
95  * list) to the global PCI device list, add the sysfs and procfs
96  * entries.  Where a bridge is found, add the discovered bus to
97  * the parents list of child buses, and recurse (breadth-first
98  * to be compatible with 2.4)
99  *
100  * Call hotplug for each new devices.
101  */
102 void __devinit pci_bus_add_devices(struct pci_bus *bus)
103 {
104 	struct pci_dev *dev;
105 
106 	list_for_each_entry(dev, &bus->devices, bus_list) {
107 		/*
108 		 * Skip already-present devices (which are on the
109 		 * global device list.)
110 		 */
111 		if (!list_empty(&dev->global_list))
112 			continue;
113 		pci_bus_add_device(dev);
114 	}
115 
116 	list_for_each_entry(dev, &bus->devices, bus_list) {
117 
118 		BUG_ON(list_empty(&dev->global_list));
119 
120 		/*
121 		 * If there is an unattached subordinate bus, attach
122 		 * it and then scan for unattached PCI devices.
123 		 */
124 		if (dev->subordinate && list_empty(&dev->subordinate->node)) {
125 			spin_lock(&pci_bus_lock);
126 			list_add_tail(&dev->subordinate->node, &dev->bus->children);
127 			spin_unlock(&pci_bus_lock);
128 			pci_bus_add_devices(dev->subordinate);
129 
130 			sysfs_create_link(&dev->subordinate->class_dev.kobj, &dev->dev.kobj, "bridge");
131 		}
132 	}
133 }
134 
135 void pci_enable_bridges(struct pci_bus *bus)
136 {
137 	struct pci_dev *dev;
138 
139 	list_for_each_entry(dev, &bus->devices, bus_list) {
140 		if (dev->subordinate) {
141 			pci_enable_device(dev);
142 			pci_set_master(dev);
143 			pci_enable_bridges(dev->subordinate);
144 		}
145 	}
146 }
147 
148 EXPORT_SYMBOL(pci_bus_alloc_resource);
149 EXPORT_SYMBOL_GPL(pci_bus_add_device);
150 EXPORT_SYMBOL(pci_bus_add_devices);
151 EXPORT_SYMBOL(pci_enable_bridges);
152