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/acpi.h> 11 #include <linux/pnp.h> 12 #include <linux/device.h> 13 #include <linux/init.h> 14 #include <linux/slab.h> 15 #include <linux/kernel.h> 16 #include <linux/ioport.h> 17 18 static const struct pnp_device_id pnp_dev_table[] = { 19 /* General ID for reserving resources */ 20 {"PNP0c02", 0}, 21 /* memory controller */ 22 {"PNP0c01", 0}, 23 {"", 0} 24 }; 25 26 #ifdef CONFIG_ACPI 27 static bool __reserve_range(u64 start, unsigned int length, bool io, char *desc) 28 { 29 u8 space_id = io ? ACPI_ADR_SPACE_SYSTEM_IO : ACPI_ADR_SPACE_SYSTEM_MEMORY; 30 return !acpi_reserve_region(start, length, space_id, IORESOURCE_BUSY, desc); 31 } 32 #else 33 static bool __reserve_range(u64 start, unsigned int length, bool io, char *desc) 34 { 35 struct resource *res; 36 37 res = io ? request_region(start, length, desc) : 38 request_mem_region(start, length, desc); 39 if (res) { 40 res->flags &= ~IORESOURCE_BUSY; 41 return true; 42 } 43 return false; 44 } 45 #endif 46 47 static void reserve_range(struct pnp_dev *dev, struct resource *r, int port) 48 { 49 char *regionid; 50 const char *pnpid = dev_name(&dev->dev); 51 resource_size_t start = r->start, end = r->end; 52 bool reserved; 53 54 regionid = kmalloc(16, GFP_KERNEL); 55 if (!regionid) 56 return; 57 58 snprintf(regionid, 16, "pnp %s", pnpid); 59 reserved = __reserve_range(start, end - start + 1, !!port, regionid); 60 if (!reserved) 61 kfree(regionid); 62 63 /* 64 * Failures at this point are usually harmless. pci quirks for 65 * example do reserve stuff they know about too, so we may well 66 * have double reservations. 67 */ 68 dev_info(&dev->dev, "%pR %s reserved\n", r, 69 reserved ? "has been" : "could not be"); 70 } 71 72 static void reserve_resources_of_dev(struct pnp_dev *dev) 73 { 74 struct resource *res; 75 int i; 76 77 for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) { 78 if (res->flags & IORESOURCE_DISABLED) 79 continue; 80 if (res->start == 0) 81 continue; /* disabled */ 82 if (res->start < 0x100) 83 /* 84 * Below 0x100 is only standard PC hardware 85 * (pics, kbd, timer, dma, ...) 86 * We should not get resource conflicts there, 87 * and the kernel reserves these anyway 88 * (see arch/i386/kernel/setup.c). 89 * So, do nothing 90 */ 91 continue; 92 if (res->end < res->start) 93 continue; /* invalid */ 94 95 reserve_range(dev, res, 1); 96 } 97 98 for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) { 99 if (res->flags & IORESOURCE_DISABLED) 100 continue; 101 102 reserve_range(dev, res, 0); 103 } 104 } 105 106 static int system_pnp_probe(struct pnp_dev *dev, 107 const struct pnp_device_id *dev_id) 108 { 109 reserve_resources_of_dev(dev); 110 return 0; 111 } 112 113 static struct pnp_driver system_pnp_driver = { 114 .name = "system", 115 .id_table = pnp_dev_table, 116 .flags = PNP_DRIVER_RES_DO_NOT_CHANGE, 117 .probe = system_pnp_probe, 118 }; 119 120 static int __init pnp_system_init(void) 121 { 122 return pnp_register_driver(&system_pnp_driver); 123 } 124 125 /** 126 * Reserve motherboard resources after PCI claim BARs, 127 * but before PCI assign resources for uninitialized PCI devices 128 */ 129 fs_initcall(pnp_system_init); 130