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, 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         int i;
  60
  61         for (i = 0; i < PNP_MAX_PORT; i++) {
  62                 if (!pnp_port_valid(dev, i))
  63                         continue;
  64                 if (pnp_port_start(dev, i) == 0)
  65                         continue;       /* disabled */
  66                 if (pnp_port_start(dev, i) < 0x100)
  67                         /*
  68                          * Below 0x100 is only standard PC hardware
  69                          * (pics, kbd, timer, dma, ...)
  70                          * We should not get resource conflicts there,
  71                          * and the kernel reserves these anyway
  72                          * (see arch/i386/kernel/setup.c).
  73                          * So, do nothing
  74                          */
  75                         continue;
  76                 if (pnp_port_end(dev, i) < pnp_port_start(dev, i))
  77                         continue;       /* invalid */
  78
  79                 reserve_range(dev, pnp_port_start(dev, i),
  80                               pnp_port_end(dev, i), 1);
  81         }
  82
  83         for (i = 0; i < PNP_MAX_MEM; i++) {
  84                 if (!pnp_mem_valid(dev, i))
  85                         continue;
  86
  87                 reserve_range(dev, pnp_mem_start(dev, i),
  88                               pnp_mem_end(dev, i), 0);
  89         }
  90 }
  91
  92 static int system_pnp_probe(struct pnp_dev *dev,
  93                             const struct pnp_device_id *dev_id)
  94 {
  95         reserve_resources_of_dev(dev);
  96         return 0;
  97 }
  98
  99 static struct pnp_driver system_pnp_driver = {
 100         .name     = "system",
 101         .id_table = pnp_dev_table,
 102         .flags    = PNP_DRIVER_RES_DO_NOT_CHANGE,
 103         .probe    = system_pnp_probe,
 104 };
 105
 106 static int __init pnp_system_init(void)
 107 {
 108         return pnp_register_driver(&system_pnp_driver);
 109 }
 110
 111 /**
 112  * Reserve motherboard resources after PCI claim BARs,
 113  * but before PCI assign resources for uninitialized PCI devices
 114  */
 115 fs_initcall(pnp_system_init);