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/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, 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
  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
  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);