kernel/drivers/pnp/system.c

   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);