xref: /linux/drivers/pnp/system.c (revision 07d4e9af109221ab731c5aaf832e89776c64b013)
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 
25 static void reserve_range(const char *pnpid, resource_size_t start,
26 			  resource_size_t end, int port)
27 {
28 	struct resource *res;
29 	char *regionid;
30 
31 	regionid = kmalloc(16, GFP_KERNEL);
32 	if (regionid == NULL)
33 		return;
34 	snprintf(regionid, 16, "pnp %s", pnpid);
35 	if (port)
36 		res = request_region(start, end - start + 1, regionid);
37 	else
38 		res = request_mem_region(start, end - start + 1, regionid);
39 	if (res == NULL)
40 		kfree(regionid);
41 	else
42 		res->flags &= ~IORESOURCE_BUSY;
43 	/*
44 	 * Failures at this point are usually harmless. pci quirks for
45 	 * example do reserve stuff they know about too, so we may well
46 	 * have double reservations.
47 	 */
48 	printk(KERN_INFO "pnp: %s: %s range 0x%llx-0x%llx %s reserved\n",
49 	       pnpid, port ? "ioport" : "iomem",
50 	       (unsigned long long)start, (unsigned long long)end,
51 	       NULL != res ? "has been" : "could not be");
52 }
53 
54 static void reserve_resources_of_dev(const struct pnp_dev *dev)
55 {
56 	int i;
57 
58 	for (i = 0; i < PNP_MAX_PORT; i++) {
59 		if (!pnp_port_valid(dev, i))
60 			continue;
61 		if (pnp_port_start(dev, i) == 0)
62 			continue;	/* disabled */
63 		if (pnp_port_start(dev, i) < 0x100)
64 			/*
65 			 * Below 0x100 is only standard PC hardware
66 			 * (pics, kbd, timer, dma, ...)
67 			 * We should not get resource conflicts there,
68 			 * and the kernel reserves these anyway
69 			 * (see arch/i386/kernel/setup.c).
70 			 * So, do nothing
71 			 */
72 			continue;
73 		if (pnp_port_end(dev, i) < pnp_port_start(dev, i))
74 			continue;	/* invalid */
75 
76 		reserve_range(dev->dev.bus_id, pnp_port_start(dev, i),
77 			      pnp_port_end(dev, i), 1);
78 	}
79 
80 	for (i = 0; i < PNP_MAX_MEM; i++) {
81 		if (!pnp_mem_valid(dev, i))
82 			continue;
83 
84 		reserve_range(dev->dev.bus_id, pnp_mem_start(dev, i),
85 			      pnp_mem_end(dev, i), 0);
86 	}
87 }
88 
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 
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