1 /*
2 * system.c - a driver for reserving pnp system resources
3 *
4 * Some code is based on pnpbios_core.c
5 * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
6 * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
7 * Bjorn Helgaas <bjorn.helgaas@hp.com>
8 */
9
10 #include <linux/pnp.h>
11 #include <linux/device.h>
12 #include <linux/init.h>
13 #include <linux/slab.h>
14 #include <linux/kernel.h>
15 #include <linux/ioport.h>
16
17 static const struct pnp_device_id pnp_dev_table[] = {
18 /* General ID for reserving resources */
19 {"PNP0c02", 0},
20 /* memory controller */
21 {"PNP0c01", 0},
22 {"", 0}
23 };
24
reserve_range(struct pnp_dev * dev,struct resource * r,int port)25 static void reserve_range(struct pnp_dev *dev, struct resource *r, int port)
26 {
27 char *regionid;
28 const char *pnpid = dev_name(&dev->dev);
29 resource_size_t start = r->start, end = r->end;
30 struct resource *res;
31
32 regionid = kmalloc(16, GFP_KERNEL);
33 if (!regionid)
34 return;
35
36 snprintf(regionid, 16, "pnp %s", pnpid);
37 if (port)
38 res = request_region(start, end - start + 1, regionid);
39 else
40 res = request_mem_region(start, end - start + 1, regionid);
41 if (res)
42 res->flags &= ~IORESOURCE_BUSY;
43 else
44 kfree(regionid);
45
46 /*
47 * Failures at this point are usually harmless. pci quirks for
48 * example do reserve stuff they know about too, so we may well
49 * have double reservations.
50 */
51 dev_info(&dev->dev, "%pR %s reserved\n", r,
52 res ? "has been" : "could not be");
53 }
54
reserve_resources_of_dev(struct pnp_dev * dev)55 static void reserve_resources_of_dev(struct pnp_dev *dev)
56 {
57 struct resource *res;
58 int i;
59
60 for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) {
61 if (res->flags & IORESOURCE_DISABLED)
62 continue;
63 if (res->start == 0)
64 continue; /* disabled */
65 if (res->start < 0x100)
66 /*
67 * Below 0x100 is only standard PC hardware
68 * (pics, kbd, timer, dma, ...)
69 * We should not get resource conflicts there,
70 * and the kernel reserves these anyway
71 * (see arch/i386/kernel/setup.c).
72 * So, do nothing
73 */
74 continue;
75 if (res->end < res->start)
76 continue; /* invalid */
77
78 reserve_range(dev, res, 1);
79 }
80
81 for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) {
82 if (res->flags & IORESOURCE_DISABLED)
83 continue;
84
85 reserve_range(dev, res, 0);
86 }
87 }
88
system_pnp_probe(struct pnp_dev * dev,const struct pnp_device_id * dev_id)89 static int system_pnp_probe(struct pnp_dev *dev,
90 const struct pnp_device_id *dev_id)
91 {
92 reserve_resources_of_dev(dev);
93 return 0;
94 }
95
96 static struct pnp_driver system_pnp_driver = {
97 .name = "system",
98 .id_table = pnp_dev_table,
99 .flags = PNP_DRIVER_RES_DO_NOT_CHANGE,
100 .probe = system_pnp_probe,
101 };
102
pnp_system_init(void)103 static int __init pnp_system_init(void)
104 {
105 return pnp_register_driver(&system_pnp_driver);
106 }
107
108 /**
109 * Reserve motherboard resources after PCI claim BARs,
110 * but before PCI assign resources for uninitialized PCI devices
111 */
112 fs_initcall(pnp_system_init);
113