xref: /openbmc/linux/drivers/pnp/system.c (revision 732a675a)
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(struct pnp_dev *dev, resource_size_t start,
26 			  resource_size_t end, int port)
27 {
28 	char *regionid;
29 	const char *pnpid = dev->dev.bus_id;
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, "%s range 0x%llx-0x%llx %s reserved\n",
52 		port ? "ioport" : "iomem",
53 		(unsigned long long) start, (unsigned long long) end,
54 		res ? "has been" : "could not be");
55 }
56 
57 static void reserve_resources_of_dev(struct pnp_dev *dev)
58 {
59 	struct resource *res;
60 	int i;
61 
62 	for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) {
63 		if (res->flags & IORESOURCE_UNSET)
64 			continue;
65 		if (res->start == 0)
66 			continue;	/* disabled */
67 		if (res->start < 0x100)
68 			/*
69 			 * Below 0x100 is only standard PC hardware
70 			 * (pics, kbd, timer, dma, ...)
71 			 * We should not get resource conflicts there,
72 			 * and the kernel reserves these anyway
73 			 * (see arch/i386/kernel/setup.c).
74 			 * So, do nothing
75 			 */
76 			continue;
77 		if (res->end < res->start)
78 			continue;	/* invalid */
79 
80 		reserve_range(dev, res->start, res->end, 1);
81 	}
82 
83 	for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) {
84 		if (res->flags & (IORESOURCE_UNSET | IORESOURCE_DISABLED))
85 			continue;
86 
87 		reserve_range(dev, res->start, res->end, 0);
88 	}
89 }
90 
91 static int system_pnp_probe(struct pnp_dev *dev,
92 			    const struct pnp_device_id *dev_id)
93 {
94 	reserve_resources_of_dev(dev);
95 	return 0;
96 }
97 
98 static struct pnp_driver system_pnp_driver = {
99 	.name     = "system",
100 	.id_table = pnp_dev_table,
101 	.flags    = PNP_DRIVER_RES_DO_NOT_CHANGE,
102 	.probe    = system_pnp_probe,
103 };
104 
105 static int __init pnp_system_init(void)
106 {
107 	return pnp_register_driver(&system_pnp_driver);
108 }
109 
110 /**
111  * Reserve motherboard resources after PCI claim BARs,
112  * but before PCI assign resources for uninitialized PCI devices
113  */
114 fs_initcall(pnp_system_init);
115